Basics of Kniting by Vasant Kothari

www.vasantkothari.com

A
Series of Articles
On
Basics of Knitting
By
Vasant Kothari

INDEX
1. Basics of Knitting - Introduction
2. Basic Terminologies
3. Knitting Machine Needles
4. Basic Elements of Knitting
5. Knit, Tuck & Miss Stitch
6. Weft Knitting
7. Knitting Loop Structure & Notations
8. Single Jersey & Rib Fabric
9. Purl & Interlock Fabric
10. Straight Bar Knitting Machine
11. Flat Knitting Machine
12. Circular Knitting Machine
13. Warp Knitting
14. Warp Knitted Fabrics
15. Warp Knitting Machine
16. Tricot Machine
17. Raschel Machine
18. Compound Needle Machine
19. Yarn Requirements for Knitting
20. Knitting Fabric Quality Parameters
21. Defects in knitted fabrics
22. Testing of Knitted Fabrics
23. Production Calculations
24. Costing Of Knitted Fabrics
25. Processing of Knitted Fabric
26. Relaxation of Knitted Fabric
27. Development Process of Knitted Fabric
28. Sourcing of Knitted Fabric
29. Garment Manufacturing of Knitted Fabrics
30. Seamless Knitting

20/KNITTING VIEWS/JANUARY-FEBRUARY 2010
Knitting is the second most frequently used method of fabric
construction. The term “Knitting” describes the technique of
constructing textile structures by forming a continuous length of yarn into
columns of vertically intermeshed loops.
Knitted fabrics have been gaining popularity during the past two decades,
thanks to the increased versatility of techniques and adaptability of the
many new manmade fibres. Knitted fabrics are now widely used in the
applications where woven fabrics formerly predominated. Today, the usage
of knitted fabrics ranges from hosiery, underwear, sweaters, slacks, to rugs
and other home furnishings.
Why knits are popular?
Knitted fabrics are popular today because:
• It is usually soft and drapes well
• It molds and moves easily with body movement
• It has good stretch ability
• It resists wrinkles
• Most importantly, knits relate well to contemporary life-styles
History
From the beginning the art of knitting was an occupation for women.
Traditional hand knitting, using knitting needles or pins, has been
practiced for thousands of years. The earliest example of true knitting is
a pair of knitting socks found in Egypt, dating back to 1100 A.D -just over
9 centuries ago! Socks and stockings were knitted because they had to
be shaped to the foot or leg. By the 16th century knitting had advanced
into a craft, the first real evidence of a production knitting machine was
the stocking frame, invented by the Reverend William Lee in 1589. The
invention laid the foundation for the development of knitting technology.
Lee’s invention enabled the knitting of loops at 10 times the speed of
traditional hand pin knitting.
Basics ofBasics ofBasics ofBasics ofBasics of
KNITTINGKNITTINGKNITTINGKNITTINGKNITTING - An introduction- An introduction- An introduction- An introduction- An introduction
VASANT R KOTHARI - has done
Master’s in Textiles Technology
from DKTE’s Textile and
Engineering Institute, Ichalkaranji
(Shivaji University, Kolhapur),
Maharashtra. He has also done
Diploma in Export management
(Apparel Export) from the Indian
Institute of Export Management,
and Garment Export and
Merchandising Management from
NIFT, Bangalore. Presently, he’s
working as an Assistant Professor
in Department of Fashion
Technology, NIFT, Bangalore.
(This is his first input from the
series of articles that will be
published in upcoming issues of
knitting Views)

KNITTING VIEWS/JANUARY-FEBRUARY 2010/21
Weaving Knitting
Convertingyarnintofabricby Convertingyarnintofabricby
interlacementofwarpandweft interlopingusingknittingelements
Thecapitalinvestmentishigh Capitalinvestmentisusuallylower
Noteasyascomparedwithknitting Settingupamachineiseasyandfaster
Lessproductivity Highproductivity
Designmodificationisdifficult Stylesanddesignscanbechanged
easilyandfaster
Wovenfabric Knittedfabric
Lessextensibility Highextensibility
Highelasticrecovery Incompleteelasticrecovery
Lesscreaseresistance Highcreaseresistance
Generallyfabricisthin Fabricisthicker
(Forthesameyarncount) (Forthesameyarncount)
Easytotear Difficulttotear
Requiresironing Ironingnotrequired
Highpleatsharpness Lesspleatsharpness
Lesspermeabilitytoair Morepermeabilitytoair
Strongerfabrics Lessstrongerfabrics
Morerigidascompared Feelofthefabricissofter
Nosuchproblems Anysmalldefectoccurringinthefabric
can leadtofurtherdamageinthecloth
becauseitcannotbemendedeasily
Testedbyloadingorextending Testedbymulti-directionalfabric
fabricsinwarp/weft burstingstrengthtest
Difference between knitting and weaving
The major difference between knitted and woven structures lies
in the way the yarns are interconnected geometrically. In weaving,
two sets of parallel yarns are interconnected by interlacing them
at right angles. Different woven structures are produced by
varying this basic principle.
In knitting, the yarns are initially formed into loops, and then
these loops are interconnected in a variety of ways in order to
produce a textile structure. Based on this principle, a textile fabric
is produced by using only one set of yarns.
As a result of this interlooping of yarns, the structure of a weft or
a warp knitted fabric is more open when compared to the structure
of a woven fabric. Because of this interloping of yarns, a knitted
fabric could be stretched more than a woven fabric, even when
only a small force is applied. Once this force is eased the fabric
slowly returns to its original dimensions. In fact, weft and warp
knitted fabrics have higher elongation values than woven fabrics
due to their structure, and their elastic behaviour generally exceeds
the elastic properties of the yarns used to knit the fabric.

Comparedwithwarpknitting,weftknittingisamoreversatilemethod
of fabric production in terms of both the range of fabric structures
that can be produced and the yarn types that can be utilised. Weft
knitting is the simplest method of converting a yarn into a fabric.
Inwarpknitting,eachwarpthreadisfedmoreorlessinlinewiththe
direction in which the fabric is produced, and each needle in the
knitting width must be fed with at least one thread at each course.
Compared to weaving and weft knitting it is the fastest method of
converting yarn into fabric, though modern developments in weft
knitting machines mean that there is now very little difference in
terms of production between the two forms of knitting
Weft knitting Warp knitting
Course-wiseyarnfeeding Walewiseyarnfeeding
Yarnpathhorizontal Yarnpatheitherverticalordiagonal
Theloopsareformedacross Theloopsareformedvertically thewidth
offabric downthelengthoffabric
Needlesknitsequentially Needlesknitconcurrently
Possibletoknitwithoneyarn Needwarpyarnsheet
Coneorcheeseyarnsupply Onelongbeamoranumberofsmall
warpbeamsyarnsupply
Usuallystaplefibreyarns Onlyfilamentyarnscanbe
canbeworked successfullyworked
Normallylatchneedlesareused Latch,beardorcompoundneedlesareused
Lessversatility Moreversatility
Changingdesignaffectthespeed Changingdesigndoesnotaffectthespeed
Relativelynotconsistentand Consistentanduniformqualityproduct
uniformqualityproduct
Loopsarenotuniform Loopsareuniform
Stretchinbothdirection Stretchinwidthwisedirection
Dimensionallylessstable Dimensionallymorestable
Weftknittingmachinesare Warpknittingmachinesaremoreexpensive
lessexpensive
Runningcostsisless Runningcostsishigh
Softeryarnisrequired(lesstwist) Strongeryarnisrequired(moretwist)
Shortproductionruns Formassscaleproduction
Smallfloorspacerequirements Needmorespace
E.g.CircularKnittingmachine E.g.TricotandRaschelmachine
Due to the structure and good elastic behaviour of knitted fabrics,
knitted garments are comfortable to wear. The air trapped in the
loops of a knitted garment insulates the human body against cold.
At the same time the relatively loose and open structure aids in
the perspiration process of the human body, especially when the
knitted fabric is made of yarns spun from natural fibres. Due to the
interlooping of yarns, the knitted fabrics also have better crease
recoveringpropertiescomparedtofabricswovenfromsimilaryarns.
Classification of knitted fabrics
The knitting industry is divided into two distinct sectors, weft
knitting and warp knitting.
Weft knitting
In weft knitting, the loops are formed across the width of the
fabric, and each weft thread is fed more or less at a right angle to
the direction in which
the fabric is produced. It
is possible to knit with
only one thread or cone
of yarn, though
production demands
have resulted in circular
weft knitting machines
being manufactured with
up to 192 threads.
Warp knitting
Warp Knitting is a method of producing a fabric by using needles
similar to those used in weft knitting, but with the knitted loops
made from each warp
thread being formed
down the length of the
fabric; the loops are
formed vertically down
the length of the fabric
from one thread as
opposed to across the
width of the fabric, as in
case of weft knitting.

22/KNITTING VIEWS/MARCH-APRIL 2010
Machine knitting
Knitted structures are progressively built-up from row
after row of intermeshed loops. The newly-fed yarn
is converted into a new loop in each needle hook.
VASANT R KOTHARI - has done Master’s in
Textiles Technology from DKTE’s Textile and
Engineering Institute, Ichalkaranji (Shivaji
University, Kolhapur), Maharashtra. He has also
done Diploma in Export Management (Apparel
Export) from the Indian Institute of Export
Management, and Garment Export and
Merchandising Management from NIFT,
Bangalore. Presently, he’s working as an Assistant
Professor in Department of Fashion Technology,
NIFT, Bangalore. (This is his second input from the
series of articles in knitting Views)
The needle then draws the new loop head first through
the old (fabric) loop, which it has retained from the
previous knitting cycle.
Theneedles,atthesametime,release,(cast-offorknock-
over) the old loops so that they hang suspended by
their heads from the feet of the new loops whose heads
are still held in the hooks of the needles.
Basic terminologies
for fabric knitting

KNITTING VIEWS/MARCH-APRIL 2010/23
A cohesive knitted loop structure is thus
produced by a combination of the
intermeshed needle loops and yarn that
passes from needle loop to needle loop.
The knitted loop structure may not always
be noticeable because of the effect of
structural fineness, fabric distortion,
additional pattern threads or the masking
effect of finishing processes.
Knitted loops are arranged in rows,
roughly equivalent to the weft and warp
of woven structures. These are termed
‘courses’ and ‘wales’ respectively.
Wales
Wales are columns of loops across the
length of the fabrics; they are measured in
units of (Wales/cm). Wales generally
produced by the same needle knitting at
successive (not necessarily all) knitting
cycles. A wale commences as soon as an
empty needle starts to knit.
The numbers of wales determine the width
of fabric.
Loop length
Looplength,measuredinmillimetres,isthe
length of yarn in one knitted loop. It is one
of the most important factors controlling
the properties of knitted fabrics. Generally,
the larger the loop length, the more open
and lighter the fabric.
Courses
Courses are rows of loops across the
width of fabrics; they are measured in units
of (Courses/cm). Courses are produced by
adjacent needles during the same knitting
cycle. The number of courses determines
the length of fabric.
Stitch density
Stitch density refers to the total number
of loops in a measured area of fabric. It is
measured in units per square per
centimetre/inch. The figure is obtained by
counting the number of courses or pattern
rows in one inch (or centimetres) and the
number of wales in one inch (or
centimetres), then multiplying the number
of courses by the number of wales.
Stitch density gives a more accurate
measurement than does a linear
measurementofonlycoursesoronlywales.
Tension acting in one direction might
produce a low reading for the courses and
a high reading for the wales; when they are
multiplied together this effect is cancelled
out. Stitch density is directly related to the
“loop length,” which is the length of yarn
contained in one complete knitted loop.
Loop length will affect the following
parametres:
• Stitch density/fabric density
• Tightness factor
• Fabric weight
• Fabric cost
• Dimensional stability
• Physical performance; pilling, burst
strength
As loop length decreases, stitch density,
tightness factor, fabric weight, fabric cost,
dimensional stability increases and vice
versa. There is a definite correlation
between the yarn count and loop length
of a fabric and this can be defined as the
“cover factor.” The cover factor hence
determines the handle, drape and
performance of the fabric. Just as the yarn
type dictates the optimum loop length, this
in turn dictates the gauge or knitting
machine required to knit the yarn.
Gauge
In knitting, the word gauge, technical
abbreviation GG, refers to "Knitting
machines" fineness and is the number of
needles in a measured space on the knitting
machine. Higher-gauge fabrics (those with
more stitches) are made with finer needles;
lower -gauge fabrics are made with coarser
or larger needles.
"Gauge,” is also termed as “cut” and
“tension.” This “unit of measure” is equal
to the number of needles contained in the

“gauge” (size) and it is simply countable
on the bed of needles of each knitting
machines, flat or circular.
To describe the stitch density of a single
or double knit fabric, the fabric may be
designated as an 18-, 20-, 22-, or 24-cut
fabric. Higher the cut, closer the stitches;
lower the cut, coarser the fabric.
Varying types of knitting machines
measure gauge over different distances
on the machine. For example, circular knit
hosiery measures the number of needles
in 1.0 inch, full-fashioned knitting in 1.5
inches, and Rachel knits in 2.0 inches.
Because of these differences, it is best to
keep in mind the generalised principle that
the higher the gauge, the closer the
stitches.
The size of the needle and the spacing of
the needles on knitting machines
determine the number and size of the knit
stitches and their closeness. Each wale is
formed on one needle. The number of
needles is equal to the number of wales.
The closeness of the stitches determines
whether a knit fabric will be lightweight
and open, or heavier and denser. The term
gauge is also used to describe the
closeness of knit stitches.
If we move clockwise from Ato D in the
pictures above, we find that the knitted
structures are progressively decreasing
in gauge and in fineness. Gauge is very
important as everyone knits a little
differently; some people knit loosely,
while some knit very tight. When the
same yarn and the same sized needles
are given to two different knitters, there
is a good chance that they will come up
with a different gauge. The gauge of a
knitted fabric depends on the pattern of
stitches in fabric, kind of yarn, size of
knitting needles, and tension of the
individual knitter.
• The coarser the yarn, coarser will be
the gauge and the fewer stitches per
inch
• The finer the yarn, finer will be the
gauge and the more stitches per inch
• The larger (thicker) the needle,
coarser will be the gauge and the
bigger the stitches
• The smaller (thinner) the needle,
finer will be the gauge and the
smaller the stitches
• The bigger the stitches, coarser will
be the gauge and the fewer stitches
per inch
• The smaller the stitches, finer will be
the gauge and the more stitches per
inch
In the next session, we would be
discussing about various kinds of
knitting needles
4GG
5GG
6GG

38/KNITTING VIEWS/MAY-JUNE 2010
VASANT R KOTHARI - has done Master’s
in Textiles Technology from DKTE’s Textile
and Engineering Institute, Ichalkaranji
(Shivaji University, Kolhapur), Maharashtra.
He has also done Diploma in Export
Management (Apparel Export) from the
Indian Institute of Export Management, and
Garment Export and Merchandising
Management from NIFT, Bangalore.
Presently, he’s working as an Assistant
Professor in Department of Fashion
Technology, NIFT, Bangalore. (This is his
third input from the series of articles in
knitting Views)
The fundamental elements in construction of
knitted fabrics are the knitting needles as
they are the main elements for intermeshing of
loops. The quality of the knitted fabric is largely
dependent on the effectiveness and accuracy
of the loop, which in turn largely depends on
the needle.
Small variations in the needle manufacture can lead
to irregular fabric. The surface of needles should be
highly polished allowing the yarn and the loop to
slide free. The needle must have high strength and
toughness to give durability. A typical needle must
performseveralmillionknittingactionswithoutfault.
Types of knitting needles: There are three types of
needles. These are:-
1. Bearded needle 2. Latch needle
3. Compound needle
Heart of KnittingHeart of KnittingHeart of KnittingHeart of KnittingHeart of KnittingHeart of KnittingHeart of KnittingHeart of KnittingHeart of KnittingHeart of Knitting
Knitting Needles MachinesKnitting Needles Machines

KNITTING VIEWS/MAY-JUNE 2010/39
The Latch needle is primarily used in weft
knitting, and the other two are used for
warp knitting. A coarse (large and thick)
needle usually knits with a coarse yarn
(large hook), whereas a fine (small and
thin) needle usually knits with fine yarn
(small hook).
Bearded needle
The bearded needle was used by William
Lee in his stocking frame to enable a
single needle to undertake the tasks
achieved by hand knitters with two
needles. This needle is the simplest and
cheapest to produce, but it does require
an additional element to close the beard
during knitting. In the case of warp
knitting it is a presser bar. The majority
of modern high speed warp knitting
machines now use compound needles
rather than bearded needle.
The needle consists of five main parts.
1.Shaft or stem – used with the jack
sinkers to form new loops
2.Head – the point at which the stem is
bent to form the beard, it helps to draw
the new loop through the old loop
3.Beard – the needle continues from the
head to be turned back on itself to form
the beard. The beard is used to trap
new loops while old loops are pushed
over the top
4.Grooveoreye–asmallgrooveisworked
into the stem of the needle to allow the
beard to fit flush with the stem and
ensure the old course is pushed over
the beard
5.Shank – bent for individual location in
the machine or cast with others in a
metal ‘lead’. The shank is used to attach
the needle to the frame
Bearded needle characteristics
1. The knitting section occupies a
considerable amount of space, thus
limiting productivity
2. The needles can set vertically or
horizontally
3. The needle has the disadvantage of
requiring a pressing edge to close the
bearded hook
4. The presser may be in the form of a bar,
blade, verge or wheel
5. Finer in Cross Section, therefore, more
needles in unit space. Hence Finer
Gauge (60 needles/per inch) can be
achieved
6. High wear and tear and can break easily
7. Strain on the yarn is less
8. No possibility of fluff or lint
accumulation on the needle
9. Most of the warp knitting machines use
beard needles
Fig 3.1
Bearded
needle in the
open and
closed
positions
Fig 3.2
Latch needle
Head
Beard
Eye
Stem
Shank
Hook
Latch-Blade
Latch Spoor
Stem
Butt
Tail

Latch needle
Matthew Townsend, a Leicester hosier,
patented the latch needle in 1849, and
compared to the bearded needle, which
evolved some 260 years earlier, it has the
advantage of being self acting, though it
is slightly more expensive to produce.
The needle consists of seven main parts:
1.Stem – Used to hold the course of old
loops
2.Hook – The hook is used to catch a
thread and form loops
3.Rivet – The rivet, which may be plain or
threaded, holds the latch in place and
allows it to pivot
4.Latch – The latch combines the task
performed by the presser bar and the
beard of the bearded needle
5.Latch spoon – The latch spoon is an
extension of the blade, and bridges the
gap between the hook and the stem
covering the hook when closed
6.Butt – The butt enables the movement
of the needle to be controlled by a cam
mechanism. A track raises and lowers
the needle
7.Tail – Used to provide support to the
needle
Latch needle characteristics:
1. Most widely used in weft knitting
2. More expensive than the bearded
needle, because of the assembly of the
needle and latch
3. It is self-acting or loop-controlled, and
is sometimes termed the ‘automatic’
needle
4. It can work at any angle
5. Needle Depth determines the loop
length
6. Variation of the height of reciprocating
action produces knit, tuck or miss
stitch
7. It is ideally suited for use with
computer-controlled electronic
selection devices
8. It makes a longer stroke in the cycle of
knitting
9. The Latch needle takes a longer time
to knit a loop and hence the knitting
machine is generally found slower
10. Latch needles are thick and rigid
11. Needle deflection is difficult
12. It imposes a certain strain on the yarn
13. There is also a possibility of fluff or lint
accumulation on the latch due to
rubbing action of the yarn on the needle
Compound needle
Compound needles were designed in the
mid of 19th Century. It consists of two
separately controlled parts; these are-the
open hook and the sliding closing element
(tongue, latch, piston, and plunger). The
two parts rise and fall as a single unit but
at the top of the rise, the hook moves faster
to open the hooks and at the start of the
fall the hook descends faster to close the
hook. It is easier to drive the hooks and
tongues collectively to form two separate
bars as in warp knitting; than to move each
hook and tongue individually as in weft
knitting.
Two types of compound needle have been
employed in warp knitting machines:
1. The open stem “Pusher type” or slide
needle has a closing wire or tongue that
slides externally along a groove on the
edge of the flat hook member
2. The tubular pipe needle has its tongue
sliding inside the tube of the open hook
Compound needle characteristics:
1. The compound needle is expensive
2. It offers a much shorter, smoother and
simpler knitting action in comparison to
other needles
3. Both members of Compound Needle
have a straight moment, thus the
knitting speed can be increased
4. There is no strain on the yarn
Fig 3.3 Hook
Fig 3.4
Latch spoon
Fig 3.5
Latch
movement
Fig. 3.6 Compound
needle (Pusher type)
Fig. 3.7
Compound
needle
(Tubular
pipe)

Fig 3.9
Fig 3.8
Commonpoints
The three needles considered above, while
differing in design, have the following
points in common.
1.Hook – to take & hold newly fed yarn
2.Closing mechanism – to allow the held
loop to leave the needle
3.Stem
4.Control Butt – for individual or
collective movement
Loop formation process
During yarn feeding, the hook is opened
to release the retained old loop and to
receive the new loop which is then
enclosed in the hook (As shown in Fig.
3.8). The new loop is then drawn by the
hook through the old loop which slides
on the outside of the bridge of the enclosed
hook (As shown in Fig. 3.9). All needles
must therefore have some method of
closing the knitting needle hook to retain
the new loop and exclude the old loop (As
shown in Fig. 3.10).
Fig 3.10
Fig 3.11 Needles at 90º on cylinder (Vertical)
and dial (Horizontal)
Fig 3.12 Needles at rectangular or flat bed
Needle orientation
Needlesintheknittingmachineareusually
orientedeithervertically,horizontally,orat
45º. Needles are held in the position by
needle beds - pieces of metal into which
slots or grooves have been cut. The beds
can be rectangular or circular.
Fig 3.13 Needles at 45º on V Bed Knitting Machine
In the next session, we would be discussing about the elements of knitting.
Comparisonofneedles
Bearded needle Latch needle
Required another element to close the hook Self acting needle
Less expensive More expensive
Beard needles are thin and flexible Latch needles are thick and rigid
Usually mounted on finer gauge Usually mounted on coarser gauge
It wears and breaks easily Strong in nature
No strain on yarn Imposes certain strain on yarn
It makes a shorter stroke in the knitting cycle It makes a longer stroke in the knitting cycle
Stitches are tight and minimum loop robbing Stitches are loose
No fly and fluff generation Due to rubbing, fly and fluff generation is high
Time required to knit the loop is less Takes longer time to knit the loop
The speed of the machine is high The speed of the machine is less
Latchneedle Compoundneedle
Self acting needle Consist of two separately-controlled parts
Less expensive Very expensive
Preferred for Weft Knitting Preferred for Warp Knitting
Vibration is more Short, smooth, simple harmonic movement,
so there is less vibration
Yarns are under stress No stress on yarn
The vertical clearing height is very good The vertical clearing height is not so good
Latch needles produces the long & The needle can knit tight, uniform stitches that
narrow loops tend to be rounder
Latch needles are relatively thick Because of its slim construction and short hook
fine warp knitted are possible
Speed is relatively less Can work at high speed

24/KNITTING VIEWS/JULY-AUGUST 2010
Master’s in Textiles Technology
from DKTE’s Textile and
Engineering Institute, Ichalkaranji
(Shivaji University, Kolhapur),
Maharashtra. He has also done
Diploma in Export Management
(Apparel Export) from the Indian
Institute of Export Management,
and Garment Export and
Merchandising Management
from NIFT, Bangalore. Presently,
he’s working as an Assistant
Professor in Department of
Fashion Technology, NIFT,
Bangalore. (This is his fourth input
from the series of articles in
knitting Views)
Basic elements
of knitting
The basic elements of knitting machines are knitting needles, sinkers, jack,
cams and yarn feeding. Knitting needles are the main elements of any
knitting machines which have already been discussed in the previous article.
The sinker
The sinker is the second primary knitting element. It is a thin metal plate
with an individual or a collective action operating approximately at right
angles from the hook side of the needle bed, between adjacent needles.

KNITTING VIEWS/JULY-AUGUST 2010/25
The main parts of sinkers are as follows:
1 – Butt 2 – Butt breadth 3 – Height of shank
4 – Buldge 5 – Neb 6 – Length of neb 7 – Throat angle
8 – Sinker platform height 9 – Breadth of lower shank
10 – Clearance 11 – Throat
Fig 4.1 Position of
sinker and needle
Fig 4.2 Main components of sinker
Sinkers may perform one or more of the following functions;
dependent upon the machine’s knitting action and consequent
sinker shape and movement:
• Loop formation • Holding-down • Knocking-over
The main function of the sinker is to assist the needles in the loop
formation by sinking or knitting newly laid yarns into loop as its
forward edge or catch (C) advances between the two adjacent
needles. This is only for bearded needle, whereas on latch needle
weftknittingmachinesandwarpknittingmachines,loopformation
is not a function of the sinkers.
The second and more common function of sinkers on modern
machines is to hold down the old loops at a lower level on the
needle stems than the new loops that are being formed, and to
prevent the old loops from being lifted as the needles rise to
clear them from their hooks. The protruding nib or nose of sinker
(N) is positioned over the sinker loop of the old loop (O),
preventing it from rising with the needle.
The third function of the sinker – as a knock-over surface – is
illustrated in Fig.4.4 where its upper surface or belly (B) supports
the old loop (O) as the new loop (NL) is drawn through it.
Fig 4.3 Action of the loop-
forming sinker
The jack
The jack is a secondary weft knitting element, which may be
used to provide versatility of latch needle selection and
movement. It is placed below and in the same trick as the needle
and has its own operating butt and cam system.
The cam
Knitting cams are solid steel plates and with the assembly of
different cam plates a track for a butt can be arranged. Each
needle movement can be obtained by means of cams acting on
the needle butt. The fig 4.5 shows the simplest cam design.
Fig 4.4 Action of the knock-
over sinker
Cams are devices, which convert the rotary machine drive into a
suitable reciprocating action for the needles and other elements.
The upward movement of the needle is obtained by the rising
cam or clearing cam. The rising cam places the needle at a certain
level as it approaches the yarn area. Cams controlling the
downward movement of the needles are called stitch cam. The
stitch cam draws the needle down below the knitting level,
thereby drawing a loop formed by the fed yarn through the loop
already on the needle. The lowest point to which the needle is
Fig 4.5 Knitting cam design

drawn by the stitch cam is called the “cast-off” position. They
are screwed to the cylindrical cam ring and are adjustable in
vertical direction. If the stitch cam is raised, then shorter loop is
drawn below the sinker level and a tighter fabric will result. With
lowering the cam, a reverse result is obtained.
Guard cam keeps the needle butts in their raceway. Running cam
or up-through cam keep the needle butts at a low level until they
meet the next rising cam.
The needle cam race consists of
1 Clearing cam 2 Stitch cam 3 Up-throw cam, which are
vertically adjustable together for alteration of stitch length
4 and 6 Guard cam 5 Return cam
The three sections of the sinker cam race are
7 Race cam 8 Sinker withdrawing cam 9 Sinker-return cam,
which is adjustable in accordance with the stitch length
Cam systems generate both the needle and the sinker
displacements for sinker machines and cylinder and dial
displacements for double jersey machines. Fig 4.7 shows both
the sinker cam track above and the needle cam track below. The
needle track shows the typical three stage needle displacement
of (1/4) the raising or clearing cam, (2/3) the lowering or stitch
cam and (5/6) the guard cam that returns the needle to its entry
position for the next cam system. The sinker track shows the
engaged position (section 7) when the needle is clearing. The
sinker disengages in sections 8 and 9 so that knock-over can
take place and re-engages into section 7. The displacement
diagrams of the needles and sinkers are also shown.
Fig 4.6 Cams and Latch needle moment
Fig 4.7 Needle and Sinker cam system
Yarn feeding
Basically two types of yarn feeding are there
• Moving the needles past the stationary yarn feed
• Most circular weft knitting machines have revolving needle
cylinders and stationary cams, feeders and yarn packages.
In this case, the fabric tube must revolve with the needles,
as must the fabric rollers and take-up mechanism
• Moving the yarn past the stationary needle bed
• As when the yarn moves past the needles, the fabric will be
stationary because the loops hang from the needles. This
arrangement exists on all warp knitting machines, and on
weft knitting machines with straight beds and circular
machines with stationary cylinders and dial
Fig 4.8 Modern four
track cylinder cam block
(Inthenextissue,wewouldbediscussingabout
the Knitted loop structure and notations.)

22/KNITTING VIEWS/SEPTEMBER-OCTOBER 2010
There are three principle stitches utilised in knit fabrics: Knit,
tuck and miss stitch. These three stitches, or combinations
of them appearing in the same fabric, form the basis of all knitted
fabrics.
Formation of loop structures
The weft knitted structures described so far have been totally
composed of knitted loops, which are produced whenever the
needle clears the old loop, receives the new yarn and knock
over the old loop from the previous knitting cycle. Fig. 6.1 shows
the three possible positions of the needle at the time of feeding
the yarn. They are referred to as knit, tuck and miss positions.
These different stitches are produced by controlling the height
of the needles and the individual selection of needles enable
knit, tuck or miss stitches to be formed.
For different stitch requirements, swing cams or auxiliary cams
are placed between the rising cams and the stitch cams to change
the path of the needle butts to form a raceway and the needle
butts travel in this restricted path accordingly to form knit, tuck
and miss stitch.
Master’s in Textiles Technology from
DKTE’s Textile and Engineering Institute,
Ichalkaranji (Shivaji University, Kolhapur),
Maharashtra. He has also done Diploma
in Export Management (Apparel Export)
from the Indian Institute of Export
Management, and Garment Export and
Merchandising Management from NIFT,
Bangalore. Presently, he’s working as an
Assistant Professor in Department of
Fashion Technology, NIFT, Bangalore.
(This is his fifth input from the series of
articles in Knitting Views)

KNITTING VIEWS/SEPTEMBER-OCTOBER 2010/23
Knit stitch
The knit stitch is the basic stitch. It is also called the plain stitch.
Knit stitch is formed when the needle carries out a complete
stroke, reaching the maximum height on the looping plane.
The tuck loop will always lie at the back of the held loop. The
numbers of consecutive tucks on any one needle is limited by the
amount of yarn that the needle hook can hold, with the maximum
usually being between four to five loops. Fig 6.5 shows the
technical face of the tuck stitch along with the knitting notations.
Fig 6.1 Three needle positions for the production of three stitch types.
Fig 6.2 Cam setting for different stitches
Tuck stitch
A tuck stitch is formed when a knitting needle holds its old loop
and then receives a new yarn. Two loops then collect in the
needle hook. The previously formed knitted loop is called the
held loop and the loop which joins it is a tuck loop.
Fig 6.3 Face and back of knit stitch
Fig 6.4 Tuck stitch produced on a latch needle machine
Fig 6.5 Technical face of tuck stitch fabric with stitch notations

The resultant stitch is elongated. Tuck stitches appear on the
back of a fabric and may be recognised as an invertedV, sometime
elongated for two or more courses, depending on how many
times the stitched was tucked. Fig 6.6 shows a single tuck viewed
from technical face and back of the fabric.
Fig 6.7 shows a single tuck viewed from the technical back and,
in addition, how this structure is represented using conventional
stitch notations.
Tuck stitches tends to reduce the length of the fabric and increase
its width (Wales are pushed apart), resulting in the fabric being
thicker (yarn from the tuck stitch lies on top of the preceding
stitch) with less extension in the width.
The tuck stitch is used in knitted fabric to create design effects
in colour, raised surface texture, or a hole or eyelet effect.
Miss stitch
A miss stitch is created when one or more knitting needles are
deactivated and do not move into position to accept the yarn.
The yarn merely passes by and no stitch is formed.
The float will lie freely on the reverse side of the held loop, which
is the technical back, and in the case of rib and interlock
structures it will be inside the fabric. Fig 6.10 illustrates that the
float will extend from the base of one knitted or tucked loop to
the next.
Fig 6.6 Tuck stitch
Fig 6.7 Tucking over four adjacent plain needles
Fig 6.8 Tuck stitch (Face and Back)
Fig 6.9 Float stitch produced on a latch needle machine
Fig 6.10 Technical face of float stitch
Miss stitch is also known as float stitch or welt stitch. Fig 6.11
shows the face and the back of the miss stitch.
Fig 6.12 shows a four needle float viewed from the technical
back, together with the conventional stitch notation used to
represent this structure.
The introduction of miss stitches results in the fabric becoming
narrower in width, since the wales are pulled closer together and
theheldloop‘robs’yarnfromadjacentloops.Thistendstoimprove
fabric stability. The miss stitch also has a tendency to increase

fabric weight, and reduce both stretch, and width. Amiss stitch is
used to create colour and figure designs in knitted fabric since it
permits the selective positioning of yarns in a fabric.
Fig 6.11 Miss stitch
6.12 Floating across four adjacent plain needles
Fig 6.14 Successive tucks and floats
(In the next edition, we would be
discussing about Weft Knitting.)
Fig 6.13 Miss stitch (Front and back)
Knit, tuck and miss stitches can be used in any of the four fabric
types – single jersey, rib, purl or interlock – to produce a wide
range of structural effects. Fig 6.14 shows the combination of all
three stitches.

20/KNITTING VIEWS/NOVEMBER-DECEMBER 2010
DKTE’s Textile and Engineering
Institute, Ichalkaranji (Shivaji
University, Kolhapur), Maharashtra.
Management (Apparel Export) from
the Indian Institute of Export
Management, and Garment Export
and Merchandising Management
from NIFT, Bangalore. Presently, he’s
working as an Assistant Professor in
Department of Fashion Technology,
NIFT, Bangalore. (This is one of the
inputs from the series of his articles)
Knitted fabrics provide comfortable
wear to almost any style of garment.
Most knits contour to the body's
silhouette without restricting movement
because of its open structure. This makes
knit fabrics ideal for innerwear, bodywear
and sportswear garments. While many
variations of knit fabrics exist such that
used for hosiery, there are two basic types
of knit fabrics—weft knits and warp
knits—and it’s the direction in which the
yarns making up the fabric are looped that
determines which type of knit the fabric
is. From these two types of knit fabrics
come various subtypes that consumers
encounter in fabric stores and read within
garment descriptions.
Weft knitting is the simplest method of
converting a yarn into fabrics. Weft
knitting is a method of forming a fabric in
which the loops are made in horizontal way
from a single yarn and intermeshing of
loops take place in a circular or flat form
on a crosswise basis. In this method each
weft thread is fed, more or less, at right
angles to direction in which fabric is
formed. Each course in a weft knit builds
upon the previous knitted course. Most
of the weft knitting is of tubular form. It is
possible to knit with only one thread or
cone of yarn, though production demands
have resulted in circular weft knitting
machines being manufactured with upto
192 threads (feeders).
Common weft knits
In woven fabric structures, three weaves,
are called basic weaves, viz., plain, twill
andsatin.Inasimilarway,inaweftknitting
structure, the following four structures are
considered as basic weft knit structure.
• Plain jersey fabric • Rib fabric
• Purl fabric • Interlock fabric
Plain jersey fabrics, also known as single
jersey, have an identifiable right/face and
wrong /back side. Other types are known
Basics of knitting - Weft knitting
as double jersey, just as the name implies,
uses two sets of yarns on opposed needles
resulting in a heavier fabric that looks the
sameoneitherside.Doubleknitfabricshave
little stretch; retain their shape and works
best for tailored garments. Each of these
fabric types is unique in appearance and
function.
Plain jersey fabric
Plain jersey fabric is the simplest weft
knitted structure that is possible to
produce with one set of needle. It is very
economical to produce. It is having definite
face and back and is most easily
recognised. Face is having all knit stitches
with smooth texture, while back is having
purl stitches with textured and mottled
appearance. These fabrics are produced
on flat as well as circular machines.
Characteristics of jersey knits
• Stretch crosswise and lengthwise
• Stretches more in the crosswise

KNITTING VIEWS/NOVEMBER-DECEMBER 2010/21
• Tend to run or ladder if stitch breaks
• Fabric less stable and curls when cut
• Special finishes counteract curling and
improve stability
• Highest machine productivity
End-uses of jersey knits
• Sheets • Sweaters • Terry robes
• T-shirts • Men’s underwear
• Dresses • Hosiery and pantyhose
• Fully fashion garments
Jersey knit variations
• Fleece • Intarsia • Jacquard knits
• Knitted terry • Knitted velour • Lisle
• Plaited knits • Silver-pile knits
End-uses of rib knits
• Collars and cuffs • Necklines • Bottom
edges of sweaters • Double knits
jackets •Knit hats • Men’s hosiery
End uses for purl knits
• Infant and children’s wear
• Sweaters • Scarves
• Fancy garment parts
Interlock fabric
Interlock structure consists of two 1 x 1
rib fabrics knitted one after the other by
means of two separate yarns, which knits
alternately on the face and back of the
fabric and are interlocked together.
Interlock is a reversible fabric, which has
similar smooth appearance on each side.
Interlock is produce on a cylinder and dial
circular weft knitting machine, with
alternate long and short needles opposite
to each other on cylinder and dial.
Characteristics of interlock knits
• Reversible • It does not curl
• Firmer fabric • Less extensible as
compared to other jersey fabrics
• Heavier and thicker as compare to rib
• It unroves from the course knitted the
last • Costlier fabric • Better insulator
Fig: Rib fabric
Fig: Plain jersey fabric
Rib fabric
Rib fabric is a double jersey knitted fabric
with vertical rows (wales) of loops meshed
in the opposite direction to each other.
Simplest rib fabric is 1 x 1 rib having
alternate wales knitted to the front and
back. The ribs tend to close up to create a
double faced fabric, which has the same
appearance on both sides. Rib knits
fabrics are produced with the knitting
machines having two sets of needle,
normally positioned at rights angle to each
other.
Characteristics of rib knits
• Also called as double jerseys fabric
• Its reversible fabric • More elastic than
jersey knits • More thicker than jersey
knits • More stretch crosswise than
lengthwise • Edges do not curl • Very
stable • Running and laddering still a
problem • More expensive to produce
• Next highest machine productivity
Purl fabric
Purl fabric has loop knitted to the front
and back on alternate courses, in contrast
to a rib fabric, which is knitted to the front
and back on alternate wales.Asimple purl
fabric looks like somewhat like the back of
jersey knit on the both side of the fabric.
The simples purl fabric is known as 1 x 1
fabrics. Purl fabrics are made on knitting
machinescalledpurlknitmachinesorlinks-
or-links machines.
Characteristics of purl knits
• Slowest of the knitting machines
• Both side similar appearance
• More expensive
• Good stretch in all direction
• Stretches out of shape easily
• Crosswise stretch less than a jersey knit
• Thicker than jersey knits
• Does not curl
• Can be unroved from either end
Fig: Purl fabric
Fig: Interlock fabric
End-uses for interlock knits
• Outwear fabric • Dress wear
• Skirt • Blouses • T-shirts
Variables in weft knitted fabric
A great deal of variety may be created by
manipulating the following:
• Fibre content • Yarn type and twist
• Fabric count • Colouration • Finishes
and • Variations of tuck, knit and miss
stitches
(In the next issue, we would be discussing
about Plain jersey and rib fabrics.)

VASANT R KOTHARI
has done Master’s in Textiles
Technology from DKTE’s
Textile and Engineering
University, Kolhapur),
Maharashtra. He has also
done Diploma in Export
Management (Apparel Export)
from the Indian Institute of
Export Management, and
Garment Export and
Merchandising Management
from NIFT, Bangalore.
Presently, he’s working as an
Assistant Professor in
Department of Fashion
Technology, NIFT, Bangalore.
(This is his seventh input from
the series of articles in
Knitting Views)
The needle loop
The upper part of the loop produced by
the needle drawing the yarn is called the
needle loop. It is the basic unit of a knitted
structure. Each stitch or knitted loop
consists of a top arc (head), two legs and
two bottom half-arcs (feet).
At the base of each leg is a foot, which
meshes through the head of the loop
formed at the previous knitting cycle,
usually by that needle. The yarn passes
from the foot of one loop into the foot and
leg of the next loop formed by it.
The sinker loop
The lower part of the knitted loop is
technically referred as sinker loop. It is the
piece of yarn that joins one weft-knitted
needle loop to the next. On bearded needle
weft knitting machines, loop-forming
sinkers form the sinker loops in
succession between the needles – hence
the origin of the term sinker loop. On latch
needle weft knitting machines, however,
the sinker loops are automatically formed
as the needles, in succession, draw their
new loops.
Fig 5.1: Components of needle loop

Fig 5.2: Intermeshing points of a needle loop
Fig 5.3: Needle loop and sinker loop
Face loop
During loop formation, when the new loop
emerges through the old loop from back
to the face (or front) side, it is called as
face loop or weft knit loop.
Back loop
If the new loop passes from the face side
to the back side of old loop, it is called as
back loop or weft purl loop.
The knitted stitch
The knitted stitch is the basic unit of
intermeshing which usually consists of
three or more intermeshed needle loops.
The centre loop has been drawn through
Fig 5.4: Face loop and back loop
the head of the lower previously-formed
loop and is, in turn, intermeshed through
its head by the loop above it.
The repeat unit of a stitch is the minimum
repeat of intermeshed loops that can be
placed adjoining other repeat units in
order to build up an unbroken sequence
in width and depth
For a stitch, depending on the position of
the legs at the binding points, a technical
back and a technical front side is defined.
Fig 5.5: The knitted stitch
Fig 5.6
Technical face
The side of knitted fabric that consists all
of face or knit loops, is called as technical
faceofthefabric.Itisthefrontsideoffabric.
Technical back
Thesideofknittedfabrichavingfullofback
or purl loops, is called as the technical back
of the fabric. It is the back side of the fabric.
Fig 5.7: Face side of plain knitted fabric
Fig 5.8: Back side of plain knitted fabric
Face
Back
Knitting notations
A knitting notation is a simple, easily-
understood, symbolic representation of
Fig 5.9: Technical face and back of single
jersey fabric
Needle Loop
Sinker Loop
Face Loop Back Loop
The technical back of a stitch The technical front of a stitch

a knitting repeat sequence and its resultant
fabric structure that eliminates the need
for time-consuming and possibly
confusing sketches and written
descriptions.
Graph paper
This method is developed by the Leicester
School of Textiles for weft knitting only.
In this method each square represents a
needle or stitch. An ‘X’ symbol is placed
in a square where a face stitch occurs and
an ‘O’ where there is a reverse stitch
Basically two methods are recognised for
knitting notations:
1. Point paper 2. Graph paper
Point paper
Eachpointrepresentsaneedleinplainview
from above and, after the thread path has
beendrawn,italsorepresentsitsstitch.Each
horizontal row of points thus represents
adjacent needles during the same knitting
cycleandthecourseproducedbythem.The
lowest row of points represents the starting
course in knitting.
Fig 5.10
Fig 5.11
Fig 5.12: Point paper notations of various
knitting designs
Fig 5.12: Graph paper notations of various
knitting designs
New Loop
Face loop
stitch and
notation
Old loop
Old loop
New Loop
Reverse
loop stitch
and
notation

VASANT R KOTHARI has done Master’s in Textiles Technology from DKTE’s Textile and Engineering Institute,
Ichalkaranji (Shivaji University, Kolhapur), Maharashtra. He has also done Diploma in Export Management
(Apparel Export) from the Indian Institute of Export Management, and Garment Export and Merchandising
Management from NIFT, Bangalore. Presently, he’s working as an Assistant Professor in Department of Fashion
Technology, NIFT, Bangalore. (This is his eighth input from the series of articles in Knitting Views).
Single jersey fabric
If a weft knitted fabric has one side
consisting only of face stitches, and the
opposite side consisting of back stitches,
then it is described as a plain knitted fabric.
It is also frequently referred to as a single
jersey fabric (single fabric).
Technical face of single jersey fabric is
smooth, with the side limbs of the needle
loops having the appearance of columns
of V’s in the wales. These are useful as
basic units of design when knitting with
different coloured yarns. On the technical
back, the heads of the needle loops and
the bases of the sinker loops form
columns of interlocking semi-circles,
whose appearance is sometimes
emphasised by knitting alternate courses
in different coloured yarns.
Plain is the simplest and most economical
weft knitted structure to produce and has
the maximum covering power. It normally
has a potential recovery of 40 per cent in
width after stretching.
Fig 8.1: The technical face of plain jersey
Fig 8.2: The technical back of plain jersey
Fig 8.3: Face & back side of plain jersey fabric
Back side of
the fabric..
Fig 8.4: Face side
of the fabric
Cross
section

Production of single-jersey
fabric
Single jersey fabrics are produced on flat
as well as circular machines, having one
set of needles in one needle bed and are
called jersey machines, plain-knit
machines, or single knit machines. Most
of the single-jersey fabrics are produced
on circular machines whose latch needle
cylinder and sinker ring revolve through
the stationary knitting cam systems that,
together with their yarn feeders, are
situated at regular intervals around the
circumference of the cylinder. The yarn is
supplied from cones, placed either on an
integral overhead bobbin stand or on a
free-standing creel, through tensioners,
stops motions and guide eyes down to
the yarn feeder guides. The fabric, in
tubular form, is drawn downwards from
inside the needle cylinder by tension rollers
and is wound onto the fabric-batching
roller of the winding-down frame.
The knitting action
Figure 8.6 – 8.10 shows the knitting
action of a latch needle and holding-
down sinker during the production of a
course of plain fabric.
Tucking in the hook orrest position: The
sinker is in forward position, holding down
the old loop (fabric) whilst the needle rises
from the rest position.
Fig 8.5: Knitting notation of single jersey fabric
Clearing: The sinker is still forward as the
needle has been raised to its highest
positionclearingtheoldloopfromitslatch.
Fig 8.6: Tucking in the hook or rest position
Yarn feeding: The sinker is partially move
back allowing the feeder to present its yarn
to the descending needle hook and also
freeing the old loop so that it can slide up
the needle stem and under the open latch
spoon.
Fig 8.7 Clearing
Knock-over: Thesinkerisfullywithdrawn
whilst the old loop has closed the latch to
trap the new yarn; needle descends to
knock over its old loop on the sinker belly.
Fig 8.8: Yarn feeding
Holding-down: Thesinkermovesforward
to hold down the new loop in its throat
whilst the needle rises under the influence
of the up throw came to the rest position
where the head of the open hook just
protrudes above the sinker belly.
All needles in one bed can pull loops in
only one direction as shown in fig 8.11.
As a consequence, jersey-knit materials
Fig 8.9: Knock over
are unbalanced and have a tendency to
curl at the edges. This condition can
frequently be corrected in fabric finishing.
If not corrected, this problem can be quite
troublesome in cutting and sewing
operations. Jersey-knit fabrics stretch
more in the width directions.
Fig 8.10: Holding down
A wide variety of knitted fabrics are made
with the jersey-knit construction, ranging
from sheer, lightweight hosiery to thick,
bulky sweaters. Most full-fashioned
sweaters are fundamentally jersey-knit
fabric types. Additional fabrics that use
jersey-knit construction are men's
underwear, T-shirts, pantyhose, knit terry,
knit velour, and many more. One
shortcoming of jersey-knit fabrics is that if
one yarn breaks, it causes an unravelling
of adjoining stitches in the wale, called a
run. Lightweight filament-yarn jerseys are
especially susceptible to runs due partially
totheverysmoothsurfaceoffilament yarn.
Rib fabric
Rib has a vertical cord appearance
because the face loop wales tend to move
over and in front of the reverse loop wales.
One vertical row of wale is meshed in the
Fig 8.11: Single jersey circular knit fabric
on machine

opposite direction to the other vertical row
of wales. Face row or loops tends to close
up in one plane and so also the back row
of loops in the other plain. Thus stitches
of rib fabrics lie in two planes and hence
the rib structure is also known as double
jersey structure.
1 x 1 rib has the appearance of the technical
face of plain fabric on both sides until
stretched to reveal the reverse loop wales
in between.
Relaxed 1 x 1 rib is theoretically twice the
thickness and half the width of an
equivalent plain fabric, but it has twice as
much width-wise recoverable stretch. In
practice, 1 x 1 rib normally relaxes by
approximately 30 per cent compared with
its knitting width.
Fig 8.12: Technical face and back of rib fabric
Production of rib fabric
Rib-knit fabrics are produced with knitting
machines that are somewhat different from
those used for jersey knits. Because rib
knits have stitches drawn to both sides of
the fabric, the machines used to make
them, called rib-knit machines, require two
sets of needles usually positioned at right
angles to each other; each set of needles
Fig 8.13: Rib fabric structure
Fig 8.15: Knitting notation of rib fabric
Fig 8.14: Top view of rib fabric
Fig 8.14: Front view of
rib fabric
Fig 8.14:
Cross section
view of rib
fabric
Fig 8.14: Back view of
rib fabric
is capable of producing stitches. The fabric
is formed between the two needle-holding
beds. The machinery required to produce
rib-knitfabricissubstantiallymorecomplex
and operates at slower speeds than
knitting machines used for jersey fabrics.
Rib knits are produced on flat (V-Bed) as
well as circular machines.
The knitting action of the circular rib
machine
Theknittingactionofacircularribmachine
is shown in Fig. 8.18 – 8.21:
Clearing: In clearing position, the
cylinder and dial needles move out to clear
the plain and rib loops formed in the
previous cycle
Fig 8.16: Two sets of needle on rib
knitting machine
Fig 8.17: Graphic representation of two sets
of needle on rib knitting machine
Yarnfeeding:Theneedlesstarttheirreturn
moment and are withdrawn into their tricks
so that the old loops are covered by the
open latches and the new yarn is fed into
the open hooks.
Fig 8.18: Clearing
Fig 8.19: Yarn feeding

Knocking-over: The needles are
withdrawn into their tricks so that the old
loops are knocked over and the new loops
are drawn through them.
If cylinder needle is knocking over before
dial needle, then it is known as delayed
timing, which is very popular in
production of rib fabric as it produces
tighter fabric due to robbing back (this is
where some yarn is taken from the
previously knitted stitch to make the
current stitch). If both, cylinder and dial
needle knock over together, to produce
loops of equal size, it is known as
synchronised timing.
Fig 8.20: Knocking over
Fig 8.21: Knock over
1 x 1 rib is balanced by alternate wales of
face loops on each side; it therefore lies
flat without curl when cut. It is a more
expensive fabric to produce than plain and
is a heavier structure; the rib machine also
requires finer yarn than a similar gauge
plainmachine.Likeallweft-knittedfabrics,
it can be unroved from the end-knitted last
by drawing the free loop heads through
to the back of each stitch. It can be
distinguished from plain by the fact that
Fig 8.22: Delayed timing
Fig 8.23: Synchronised timing
the loops of certain wales are withdrawn
in one direction and the others in the
opposite direction, whereas the loops of
plain are always withdrawn in the same
direction, from the technical face to the
technical back.
Rib cannot be unroved from the end
knitted first because the sinker loops are
securely anchored by the cross-meshing
between face and reverse loop wales.
This characteristic, together with its
elasticity, makes rib particularly suitable
for the extremities of articles such as
undergarments, tops of socks, cuffs of
sleeves, knit hats, rib borders of
garments, and stolling and strapping for
cardigans. Rib structures are elastic, form-
fitting, and etain warmth better than plain
structures
(In the next article, we would be discussing
about purl and interlock fabrics.)
(The Author can be contacted at
www.vasantkothari.com)

Ichalkaranji (Shivaji University, Kolhapur), Maharashtra. He has also done Diploma in Export Management (Apparel
Export) from the Indian Institute of Export Management, and Garment Export and Merchandising Management
from NIFT, Bangalore. Presently, he’s working as an Assistant Professor in Department of Fashion Technology,
NIFT, Bangalore. (This is his ninth input from the series of articles in Knitting Views).
Purl fabric
The Purl fabrics are also known as link-
linkfabrics.Purlwasoriginallyspelt‘pearl’
and was so named because of its similar
appearance to pearl droplets. In purl, the
loops of one course are intermeshed in
one direction and the loops of the next
course intermeshed in opposite direction,
i.e. the alternate courses having face and
back loops. It means each wale contains
both knit stitches and purl stitches. This
differs from the rib fabric, in which the
wales contain either knit or purl stitches.
A simple purl fabric looks somewhat like
the back of a jersey knit on both sides of
the fabric. The simplest purl fabric is
Fig 9.1: The technical face of purl fabric
Fig 9.2: 1 x 1 purl fabric
Fig 9.3: Face and back side of
plain jersey fabric
known as 1 x 1 purl, in which one course
has all knit stitches and the next course
has all purl stitches. The cycle repeats on
the third course.A2 x 2 purl knit fabric is
made with two courses of knit stitches
followed by two courses of purl stitches.
Fig 9.5: Knitting notation of purl fabric
Fig 9.4: Face side of the fabric
Cross
section
Back side of the
fabric

Fig 9.9: Interlock fabric structure
Fig 9.6: Circular and flatbed purl
knitting machine Fig 9.8: Purl needle transfer action
Production of purl fabric
Purl-knit fabrics are made on knitting
machinescalledpurl-knitmachinesorlinks-
and-links machines. The purl knitting
machines are basically of flat and circular
types as shown in fig 9.6. The flat is having
two horizontal beds for needle movement
and central gap for fabric formation. The
circular type has two cylinders, one above
the other and thus referred as super
imposed cylinder machine. As stitches are
sometimes drawn to the front and
sometimes to the back, two sets of needles
arerequiredtoproducethesefabrics.Inpurl
machines,however,ratherthantwodistinct,
separate sets of needles, one set of double-
headed latch needles is used as shown in
fig9.7.Thetwoneedlebedsareinalignment
with each other. The double headed needles
movefromoneneedlebedtotheother,from
side to side of the knitted fabric as it is
produced,alternatelymakingstitchesonone
fabric side and then the other.
The purl-knit machines used to produce
purl knit fabrics are the most versatile
industrial knitting machines. These
machines can produce plain and rib as well
as purl fabrics. By selective programming
of needle motion, fabrics of all three types,
sometimes with unique design effects are
possible. Purl-knit machines are widely
used in the sweater industry.
Although extremely versatile, the purl knit
machines have the lowest rate of
production of all knitting machines.
The knitting action
Fig 9.8 shows the knitting action of a
flatbed purl machine which has tricks in
each of the needle beds. They are in line
with one another to enable the transfer of
purl needle from the control of a slider in
one bed into the control of a slider in the
opposite bed.
Position 1 shows engagement of the head
of the receiving slider with the needle hook
that was originally knitting from the
opposing bed. In position 2, the needle
has been moved to the centre, with both
sliders engaging the needle hook. The
sliders then start to move back, but the
slider in the back bed is pressed down by
a cam, so that front bed slider is freed from
the needle hook and the needle is
transferred to the back bed.
In position 3, the slider in the back bed has
control of the needle and it can be seen that
the yarn is fed to the opposite end of the
needle, when compared to that of position
1.Thenthesliderinthebackbedhasmoved
the needle to knock over position to
complete the formation of the purl stitch.
It should be noted that a purl stitch is made
when a loop is formed by one hook and
then at the next course by the other hook
of the same needle, so that one course is
formed on the front bed and the next
course is formed on the back bed to create
a 1 x 1 purl structure.
Fabric characteristics
To identify a purl-knit fabric, fabric need
to stretch in its length direction. The
appearance of alternating rows of knit
stitches and purl stitches in the course
direction is evidence of a purl knit.
Generally purl-knit fabrics tend to lie flat
and do not curl as do jersey knits. Purl
fabric has same appearance in face and
back. It can unroved from either end.
Lengthwise extension is more as compare
to width wise and hence purl fabric
contract towards the centre in a course
wise direction. Thickness of fabric is two
to three times more as compare to single
jersey fabric.
The fabric is commonly used for children’s
wear and sweaters.
Interlock fabric
Interlock-knit fabrics are a variation of rib
knits made on the interlock machine.
Interlock is an interlocking of two 1 x 1 rib
structures in such a way that the face wale
of fabric “1” is directly in front of the
‘reverse wale’ of the rib fabric “2”.
Interlock has the technical face of plain
fabric on both sides, but its smooth
surface cannot be stretched out to reveal
the reverse meshed loop wales because
the wales on each side are exactly opposite
to each other and are locked together as
shown in Fig. 9.9. Each interlock pattern
row (often termed an ‘interlock course’)
requires two feeder courses, each with a
separate yarn that knits on separate
alternate needles, producing two half-
Fig 9.7: Double headed latch needle
Therefore, the cost per pound of fabric
produced is highest for purl knit fabrics.
Knitting machines for jersey knits have
the highest productivity but the lowest
versatility. Productivity for rib-knit
machines falls between those for jersey
and purl machines.

Production of interlock fabric
Interlock is produced mainly on special
cylinder and dial circular machines and on
some double-system V-bed flat machines.
In interlock machine
• Interlock gating, the needles in two beds
being exactly opposite each other so
that only one of the two can knit at any
feeder
• Both, the cylinder and dial beds should
have two types of needles viz., long and
short needles
• Alternate placement of long and short
needles in both the beds is required
• The long needle of one bed should face
the short needle of the other bed and
vice versa
• Two separate cam systems in each bed,
each controlling half the needles in an
alternate sequence, one cam system
controlling knitting at one feeder, and
the other at the next feeder
• Needles set out alternately, one
controlledfromonecamsystem,thenext
from the other; diagonal and not
opposite needles in each bed knit
together
• Minimum of two yarns are required to
knit one interlock course and hence a
minimum of two feeders supply
• The knitting style is in such a manner
that only long needles of dial and
cylinder will knit with the first feeder
and only short needles of dial and
cylinder will knit with second feeder
Fabric characteristics
To determine whether a fabric is an
interlock or a rib, spread the fabric width
wise, and view the fabric wales carefully
at the top edge of the cloth. If the knit
stitches are one behind the other, the
fabric is interlock. If the wales of knit
stitch alternate, the fabric is rib.
Interlock fabric is a reversible balanced,
smooth, stable structure that lies flat
withoutcurl.Like1x1rib,itwillnotunrove
from the end knitted first, but it is thicker,
heavier and narrower than rib of
equivalent gauge, and requires a finer,
better, more expensive yarn.
It unroves from the course knitted the last.
The fabric becomes costlier due to
thickness and less production. Interlock
is used for outwear fabrics, often using
wool, acrylic and polyester yarns, while
cotton and polyester/cotton blends are
used for the production of underwear
fabrics. Interlock fabrics are also popular
for blouses, dresses, and dressy T-shirts.
Their dimensional stability and the fact
that they do not tend to easily stretch out
of shape contribute to these popular uses.
Interlock fabrics offer a smooth surface
for printing by both screen and heat-
transfer methods
In the next article, we would be discussing
about straight bar knitting machine.
(The Author can be contacted at
www.vasantkothari.com)
Fig 9.17: Interlock cam system
gauge 1 x 1 rib courses whose sinker loops
cross over each other. Thus, odd feeders
will produce alternate wales of loops on
each side and even feeders will produce
the other wales.
Fig 9.16: Graphic representation of two sets
of needle on interlock knitting machine
Fig 9.15: Knitting notation of interlock fabric
Fig 9.12: Front view of interlock fabric
Fig 9.13: Back view of interlock fabric
Fig 9.14: Cross section
view of interlock fabric

Ichalkaranji (Shivaji University, Kolhapur), Maharashtra. He has also done Diploma in Export Management (Apparel
Export) from the Indian Institute of Export Management, and Garment Export and Merchandising Management
from NIFT, Bangalore. Presently, he’s working as an Assistant Professor in Department of Fashion Technology,
NIFT, Bangalore. (This is his tenth input from the series of articles in Knitting Views)
Aknitting machine is a device used to
createknittedfabricsinasemiorfully
automated fashion. There are numerous
types of knitting machines, ranging from
the simple, non-mechanical, to the highly
complex and electronic. All, however,
producesinglejerseyfabricstocomplicated
jacquard knitted fabrics, usually either flat
or tubular, and of varying degrees of
complexity. Pattern stitches can be selected
by hand manipulation of the needles, or
with push-buttons and dials, mechanical
punch cards, or electronic pattern reading
devices and computers. These knitting
machines also ranges from high production
to limited production capacity.
The three main groups of weft knitting
machinery may broadly be classified as
either straight bar frames, flats, or circulars,
according to their frame design and needle
bed arrangement.
From table it can be seen that the simplest
weft knitting machinery has one set of
needles, arranged either in a straight line
(flat bar/straight bar) or around cylinder
(circular). These machines are capable of
producing single jersey fabrics, but not
double jersey fabrics, and can use a
combination of three types of stitch: knit,
miss or tuck.With two needle beds, double
jersey fabrics such as rib and interlock can
be produced on both flat bar machines and
circular machines.
Straight bar frame machines
Straight bar frames is a specific type of
machine having a vertical bar of bearded
needles whose movement is controlled by
circular engineering cams attached to a
revolving cam-shaft in the base of the
machine? The length of the machine is
divided into a number of knitting heads
(‘sections’ or ‘divisions’) and each head
is capable of knitting a separate but
identically-dimensioned fashion-shaped
garment panel.

KNITTING VIEWS/JULY-AUGUST 2011/23
Classification of various groups of weft knitting machine
Knitting action of straight bar
machine
Below figure shows the movement of the
knitting elements to produce one course
of loops in straight bar machine. In thread
laying process, the carrier moves across
the knitting head for laying the yarn on
the noses of the sinkers and dividers and
on the beard side of the needles to form
the new course in the fabric.
The next step is Sinking, in which the
slurcockcontacts the jacks; it is shaped
so that each jack in turn pushes thesinker
forwards to kink a loop around every two
adjacent needles.
The needle bar starts moving away from
the pressing-edge and the sinkers and
dividers withdraw so that the newly-
formed course of loops drops off their
noses onto the knocking-over bits. At the
time of completion of knock-over, the
needle bar descends to its lowest position.
As the heads descend below the belly of
the knocking-over bits, the old course of
loops is collectively knocked-over. The
sinkers and dividers move collectively
forward to hold down the fabric, the needle
bar rises to the thread-laying position. The
catch bar is slightly raised to release the
sinkers for individual movement at the start
of the next course.
In dividing step, the catch bar moves the
dividers forwards, collectively, whilst the
needle bar tips slightly outwards to allow
the double loops to be divided into equal-
sized needle loops around every needle.
The needle bar start descending, placing
the new loops inside the hooks of the
beards. The catch bar is now lowered so
that the sinkers, as well as the dividers,
are collectively controlled by it for the rest
of the knitting cycle. They now start to
withdraw. The needle bar moves towards
the sinker verge, causing the beards to be
pressed. A further downward movement
of the needle bar ‘lands’ the previous
course of loops, resting on the knock-over
bits, onto the closed beards.
Straight bar frames are long and expensive
machines that are highly productive in a
very narrow sphere of garment
manufacture. The knitting width is small
and fashion tends not to encourage full
exploitation of the fashion shaping and
stitch-transfer patterning potential of the
machines.
Straight bar machines are known for their
production of high-quality garments as a
result of the gentle knitting action, low
fabric tension and fashion shaping, which
reduces the waste of expensive yarn during
cutting and is emphasised on the garments
by carefully-positioned fashion marks.
The straight bar frame is the only bearded
needle weft knitting machine that is still
commercially viable, although it now faces
serious competition from electronically-
controlled flat machines
Source: Knitting Technology by David J
Spencer (Third Ed)
(In the next session, we would be
discussing about flat knitting machine.)
Fig 10.7: Knocking over the loops
Fig 10.1: Knitting head of straight bar machine
Fig 10.4: Dividing the loop
Fig 10.5: Pressing
Fig 10.2: Laying the thread
Fig 10.3: Sinking the loops Fig 10.6: Landing the loops

Flat knitting machines, also referred to
as “Flatbeds” or “V-beds,” have two
rib gated, diagonally-approaching
needle beds, set at between 90 and 104
degrees to each other and are positioned
so that the upper ends form an inverted
“V”. The interactions between the yarn
and the knitting elements that create the
fabric occur at the apex of the V and the
fabric moves away downward between
the two beds, drawn down by the take-
down system.
This knitting machine stitch potential
includes needle selection on one or both
beds, racked stitches, needle-out designs,
striping, tubular knitting, changes of
knitting width, and loop transfer. Further,
a wide range of yarn counts may be knitted
for each machine gauge, including a
number of ends of yarn at each knitting
system; the stitch length range is also
wide; and there is the possibility of
changing the machine gauge.
The modern V-bed knitting machine is a
highly engineered, fully automated,
electronically controlled, precision
knitting system. The operation and
supervision of the machines of the simpler
type are also less arduous than for other
weft knitting machines. The number of
garments or panels knitted across the
machine depends upon the knitting width,
yarn carrier arrangement, yarn path and
yarn package accommodation.
(The machine shown in fig. 11.2 is a
member of the Stoll CMS family of
machines. The knitting needles, beds and
other active elements are enclosed within
sliding covers to reduce noise and fibre
contamination and to enhance safety.)
V-bed knitting machine
A solidly built machine frame supports the
two rigid needle beds. Needles slide up
and down the beds in slots known as
“tricks,” cut into rigid needle beds, which
maintain the orientation and spacing of
the needles and support them when they
impact with the CAM system. The tricks
in the opposing beds are arranged so that
the needles can pass between each other
VASANT R KOTHARI has done Master’s in Textiles
TechnologyfromDKTE’sTextileandEngineeringInstitute,
Ichalkaranji(ShivajiUniversity,Kolhapur),Maharashtra.He
has also done Diploma in Export Management (Apparel
Export) from the Indian Institute of Export Management,
and Garment Export and Merchandising Management
fromNIFT,Bangalore.Presently,he’sworkingasanAssistant
Professor in Department of Fashion Technology, NIFT,
Bangalore. (This is his eleventh input from the series of
articles in Knitting Views)
Fig 11.1: Needles in V-bed
Fig 11.2: V-bed machine
The flat knit machines are the most
versatile of the weft knitting machines.

Fig 11.7: CAM plate and knitting carriage
The yarn supply is situated above the
machine and the yarn is fed to the needles
via yarn feeders that culminates in a tube
or bore to precisely position the yarn. The
feeder is fixed to a feeder block that slides
along a feeder rail located above the needle
bed. Modern machines typically have four
feeder rails with 4/6 knitting feeders/rail.
The feeder precedes the needle
movement across the bed in such a way
that the yarn is placed across the open
latch of the needle during the clearing
displacement so that when the needle
retracts and the latch closes the yarn is
trapped in the hook.
On the most basic V-bed machines a roller
traction system pulls the fabric down
between the needle beds to provide the
take-down tension necessary to maintain
the position of the old loop against the
verge of the needle bed during the clearing
displacement.
The modern flat knit machine also has its
own on-board control and programming
computer and the LCD monitor display
built into the sliding machine covers.
Normally, in a production environment
these machines can be networked and
knitting programmes can be downloaded
from the CAD/programming stations
directly to the machine's computer.
Equally, production statistics can be
collected centrally.
Knitting action of flat knitting
machine
Fig 11.3: Line diagram of V-bed knitting machine
Fig 11.6: Carriage movement and its
influence on knitting needle
Fig 11.4: Rib gaiting
Fig 11.5: Needles in tricks
The front edge of the needle bed also acts
as a knock-over support by helping to
maintain the position of the fabric during
knock-over.
The needle then tracks through the CAM
system as shown by the blue line in the
following diagram
1 The rest position: The tops of the heads
of the needles are level with the edge of
the knock-over bits.
2 Clearing: The needle butts are lifted as
to raise the needles to ‘tucking in the
hook’ height.
3 Yarn feeding: The yarn is fed as the
needles descend under the control of
guard cam. The required loop length is
drawn by each needle as it descends
the stitch CAM.
4 Knocking-over:Toproducesynchronised
knocking-over of both needle beds
simultaneously, the stitch CAM in the
front system is set lower than the
auxiliary stitch CAM, so that the latter
is rendered ineffective.
5 Delayed timing: If, however, delayed
timing of the knock-over is employed,
knock-over in the front bed will occur
after knock-over in the back bed.
Delayed timing is only normally used
ongauges finer than 8 NPI and cannot
be used for broad ribs
during loop formation. This arrangement
of the beds is called rib gaiting.
The two CAM systems are contained
within the carriage. The carriage or “CAM
box” traverses across the needle beds and
selects needles to be knitted as it
reciprocates side to side. The carriage
effectively raises and lowers the needles
on both beds simultaneously as it passes
over them, depending on the desired
pattern. Needle bed lengths can vary from
1.0 m to 2.2 m width and each is designed
for a specific task or purpose.
Fig 11.8: Knitting action of flat knitting machines
(In the next session, we would be discussing
about circular knitting machines.)
Bow
Yarnfeeder
Yarntake-back
spring Yarn guides
Yarn
Carriage
Needlebed
Fabric
take-down roller
Control
unit
Lowering cam
(Stitch cam)
Guiding
cam
High butt
needle
Lowbutt
needle The raising CAM
is in half position
Brushes
Yarn
carrier

The term ‘circular’ covers all those weft
knitting machines whose needle beds
are arranged in circular cylinders and/or
dials, including latch, bearded, or (very
occasionally) compound needle
machinery, knitting a wide range of fabric
structures, garments, hosiery and other
articles in a variety of diametres. Circular
knitting machines are either of body size
or larger, having a single cylinder or double
cylinder, cylinder and dial arrangement, as
is also the case with small diametre
machines for hosiery. The modern circular
knitting machine is a highly engineered,
electronically controlled, precision
knitting system capable of producing high
quality fabric at very high speeds.
The main features of a circular knitting
machine are:
1. The frame or body is circular according
to needle bed shape supports the
majority of the mechanisms of
the machine
VASANTRKOTHARI hasdoneMaster’s inTextilesTechnology
from DKTE’s Textile and Engineering Institute, Ichalkaranji
(ShivajiUniversity,Kolhapur),Maharashtra.Hehasalsodone
Diploma in Export Management (Apparel Export) from the
Indian Institute of Export Management, and Garment Export
and Merchandising Management from NIFT, Bangalore.
Presently, he’s working as an Assistant Professor in
Department of Fashion Technology, NIFT, Bangalore. (This is
his twelfth input from the series of articles inKnitting Views)
2. The yarn supply system or the creel
for holding the yarn packages
3. Yarn tensioning devices
4. Yarn feed control
5. Yarn stop motion
6. Yarn feed carriers or guides
7. The knitting system, which includes
the housing and driving of knitting
elements and needle selection device
8. The fabric take down mechanism
9. Start, stop and inching buttons
10. The automatic lubrication system
In circular knitting machine, the yarn from
the package is unwounded and comes
downward through guides, tensioners,
stop motion, for being supplied to the
needles. The knitted fabric is taken down
inside the cylinder and ultimately rolled
on the cloth roller. Since the needles are
arranged in a circle on a circular knitting
Fig 12.1: Circular knitting machine Fig 12.2: Closet view of tubular fabric

KNITTING VIEWS/NOVEMBER-DECEMBER 2011/25
machine, the fabric is a tubular. It is usually
slit open when used.
Normally, circular knitting also adopts the
same knitting principles as the flat bed
machines. The circular machine starts to
knit when the CAM systems on the
needle beds (cylinder and dial) move
along the surface quite similar to that of
the carriage on a flat bed machine. The
only difference is that the operation is
continuous as CAM system of the circular
machine does not need to stop during
knitting because there is no beginning
or end of a course.
CAM technology
Circular knitting CAM systems only
allow for unidirectional knitting. CAM
systems generate both the needle and
the sinker moment for single jersey
machines and cylinder and dial moment
for double jersey machines. The given
diagram shows both the sinker CAM
track above and the needle CAM track.
The needle track shows the typical three
stage needle displacement of (1&4) the
raising or clearing CAM, (2&3) the
lowering or stitch CAM and (5&6) the
guard CAM that returns the needle to
its entry position for the next CAM
system. The sinker track shows the
engaged position (section 7) when the
needle is clearing. The sinker
disengages in sections 8 and 9 so that
knock-over can take place and re-
engages into section 7. The moment
diagrams of the needles and sinkers are
also shown in between CAMs.
Multi system circular machine
Similar to a flatbed machine, multi-system
circular knitting is also possible. Fig 12.4
is a schematic diagram of a circular
knitting machine having eight systems.
As shown in figure, it is clear that every
CAM system is knitting at the same time
and each of CAM system is having its
own supply of yarn for its own course.
So, when the machine runs, all eight
systems move together and hence eight
courses of fabric are in knitting at the same
time. In other words, at the end of one
revolution of the CAM system, eight
courses of fabric are completed. Similarly,
if there is more CAM systems around the
machine, there will be more fabric courses
being produced in a single revolution of
the machine, for example, say if there are
30 CAM systems, 30 courses of fabric
will be completed in one revolution of the
CAM system.
As compared to a flatbed machine with a
circular machine, the CAM systems of a
circular machine always operate at their
maximum speed. Also, circular machines
always have much more CAM systems
than flat bed machines. A double system
machine with 100-inch needle bed
produces about 45 courses per minute and
a 30-inch, 90-feed circular machine
produces about 2,700 courses per minute.
Further,incircularknittingmachine,needle
action is a result of the relative motion
between the CAM plates and the needle
butt. The same needle action will be
achieved whether the CAM plate is
moving across the needle butt or the
needle butt is moving across the CAM
plate. So basically, there are two types of
circular machines distinguished by the
rotation of the machine.
I. CAM box revolving machine
II. Cylinder revolving machine
If the CAM plates are moving across the
needle butts, the needle bed or the cylinder
will be stationary keeping the needle butts
in place while the CAM box carries the
CAM plates, yarn feeders with their yarn
packages are all rotating around the
machine. This type of machine is called
CAM box revolving machine.
On the other hand, if the needle butts are
moving across the CAM plates, the CAMFig 12.3: CAM system
It may be noted that the number of
systems around the machine is limited
by the circumference of the needle
cylinder. Usually all the space on the
circumference is issued up for placing
CAM systems. The actual number of
CAM systems depends on the cylinder
diametre and the dimensions (width) of
the CAM boxes. For example, a 30-inch
diametre machine may have 72 to 90
CAM systems. Since each CAM system
must have its own yarn supply and hence
a yarn feeder, such machine can be
referred as 30-inch, 90-Feed machine.
From above figure, further, it can be seen
that whether there are eight systems or
80 systems, the space taken up by the
machine will not be changed.
Fig 12.4: Multi system circular machine
Package
for cam
system 1
Cam Box 1
Cylinder

boxes will be stationary keeping the
camplates in place. The needle bed will
then have to move across the CAM boxes
with the needle butts in the needle tricks.
For a circular machine, the needle bed is
cylinder and then it rotates and that will
be the only moving part with the CAM
boxes, yarn feeders and yarn packages all
stationary. This type of machine is called
cylinder revolving machine.
It would be clear that cylinder revolving
machine is simpler in construction and
consumes less power than CAM box
revolving machine since there are less
moving components. As a matter of fact,
most of the circular machines are cylinder
revolving type. Only those machines such
as the garment length machines are CAM
box revolving because of their complexity.
Those are machines with 6-18 feeds
producing complex knitting structures
which cannot be accomplished if the
machine is cylinder revolving.
Circular knitting machine is naturally the
choice for the volume production. Since it
is ideal for volume production, there are
purposely built circular machines. For
example, plain knit fabric is always in
Reference: Weft knitting – Introduction
by Dr TY Lo, Institute of Textiles &
Clothing, Hong Kong
demand and large quantities. Circular with
justone set of needles in the cylinder is
available for plain knit only.All other knit
structures requiring the second set of
needles will be impossible but just
producing plain fabric will be able to keep
it occupied all the time
discussing about warp knitting.)

VASANT R KOTHARI has done Master’s in Textiles
Technology from DKTE’s Textile and Engineering
Institute, Ichalkaranji (Shivaji University, Kolhapur),
Maharashtra. He has also done Diploma in Export
Management (Apparel Export) from the Indian
Institute of Export Management, and Garment
Export and Merchandising Management from NIFT,
Bangalore. Presently, he’s working as an Assistant
Professor in Department of Fashion Technology,
NIFT, Bangalore. (This is his thirteenth input from
the series of articles in Knitting Views)

Another interesting segment of the
knitting industry is the warp knitting.
Warp knitting is defined as a loop forming
process in which the yarn is fed into
knitting zone, parallel to the fabric
selvedge. Warp knitted fabrics are a
product of a technology process carried
out on warp knitting machines.
The history of warp knitting is closely
associated with two names, William Lee
and Karl Mayer. In 1589 William Lee
applied for patent of his first machine for
making knitted articles, in that way he laid
the foundations for mechanical
manufacturing and making the technical
base to develop warp knitting technology.
In 1947, the insightful entrepreneur and
mechanic, Karl Mayer showed off first
warp knitting loom. The machine was
compiled two guide bars, and with bearded
needles, attained a speed of 200 rpm. It
marked the starting of technical era in
pioneering leaps in the field of
warp knitting.
fromweft-knitandtheirmachinery.Inwarp
knitting, each needle loops have its own
thread, means there is one warp for one
wale, and it also differs in the way in which
the yarn is fed to the needles. Further, the
source of yarn on a warp-knitting machine
is a warp beam containing a very large
number of parallel yarns, similar to a warp
beamonaloom.Sometimes,morethanone
warp is needed, depending upon the
fabric design.
stitches on the face of the fabric appear
vertically, but at a slight angle; and the
stitches on the back appear horizontally
as floats at a slight angle.
These floats called laps, or under laps, is a
distinguishing identification of warp knits.
Warp knitting may be flat or tubular and
can be produced in many varieties of
patterns. It can yield cloth with a
dimensional stability almost equal to that
of woven fabric. Yet, a modern 28-gauge
machine can produce a cloth 168 inches
wide at a rate of 1,000 courses per minute
that is 4,700,000 stitches per minute.
Warp and weft knitting are similar fabric
manufacturing processes as both utilise
needles to form and intermesh loops. As
the name implies, the loop formation is
warp wise, i.e., vertically upward. Unlike,
weft knitting, most of the warp knitting
machine is open width/flat knitting.
Generally, warp knitting is done by
machine, whereas weft knitting is done by
both hand and machine.
Formation of warp knit fabrics
Warp-knit fabrics and the machinery used
to produce them are substantially different
In weft knitting, a single yarn end may be
fed to all the needles and knitting
progresses around, or across the machine
to produce the weft knitted fabrics for any
number of courses and wales.
In warp knitting, however, each needle is
supplied with a yarn (or yarns) and all the
needles knit at the same time producing a
complete course at once so the total
number of individual yarns is equal to the
total stitches in a row.The needles produce
parallel rows of loops simultaneously that
are interlocked in a zigzag pattern, as
shown in fig 13.5. In this way, the warp
knittedfabricisformedbyknittingthewarp
yarns on the adjacent needles course by
course and intermesh the loops with the
neighbouring yarns to form fabric. The
Advantages of warp knit fabric
Dimensional stability
• In general, warp knitted fabric are more
stable than weft knitted fabric. By
modifying its structure (by weft
insertion), the warp knitted can be as
good as woven fabric
Fabric tightness
• The warp knitted fabrics are thinner than
double knitted fabrics and the loops are
smaller than double knitted fabric
Fabricappearance
• Most regular warp knitted fabrics give
a nice, clean and balanced loop on
surface. Normally the technical face and
back for warp knitted are different
13.4: Warp knit fabric (face)
13.2: Basic weft knit (a) and warp knit
(b) loop
The subsequent
loops formed
from one thread
are placed in the
same course
The subsequent
loops formed from
one thread are
placed in the
subsequent courses
13.3: Weft and warp knitted structure
Fig 13.1: Warp knitted fabric
13.5: Warp knit fabric (back)

VASANT R KOTHARI has done Master’s in Textiles Technology from
DKTE’s Textile and Engineering Institute, Ichalkaranji (Shivaji University,
Kolhapur), Maharashtra. He has also done Diploma in Export
Management (Apparel Export) from the Indian Institute of Export
Management, and Garment Export and Merchandising Management
from NIFT, Bangalore. Presently, he’s working as an Assistant Professor
in Department of Fashion Technology, NIFT, Bangalore. (This is his
fourteenth input from the series of articles in Knitting Views)
Warp knitting is defined as a stitch
forming process in which the yarns
are supplied to the knitting zone parallel
to the selvedge of the fabric, i.e. in the
direction of the wales. In warp knitting,
every knitting needle is supplied with at
least one separate yarn. In order to
connect the stitches to form a fabric, the
yarns are deflected laterally between the
needles. In this manner a knitting needle
often draws the new yarn loop through
the knitted loop formed by another end of
yarn in the previous knitting cycle.
A simple warp knitted loop structure is
shown in fig 14.1 – 14.3. As compared to
weft knitting in warp knitting also, the
vertical line of loops (i.e. wales) and the
horizontal line of loops (i.e. course), the
loop portion (i.e. overlap) and the
diagonal floats of yarns (i.e. underlap) are
seen in fig 14.3.
The warp knitted fabric structure has
dissimilar appearance on the technical face
and technical back side as shown in figure
14.1 and 14.2. Practically all warp-knitted
fabrics can be identified and distinguished
from weft-knitted materials by careful
examination of the face and back of the
fabric, usually with the aid of a pick glass.
The face of the fabric has rather clearly
defined knit stitches generally running
vertically (in the lengthwise direction), but
slightly angled from side to side. At the
back side of the fabric, the diagonal line of
yarns (i.e. underlaps) run right and left
throughout in a zigzag manner. These
Fig 14.3: Overlap and underlap in
warp knitted fabric
Fig 14.2: Warp knit fabric structure (Back)Fig 14.1: Warp knit fabric structure (Face)
Fig 14.4: Formation of warp knitted fabric
underlaps play an important role in
influencing the pattern effects. The length
or extent of these underlap floats and their
direction of running cause a variety of
design possibilities in warp knitting. The
recognition of laps in a knitted fabric is
the most important distinguishing feature
identifying warp knits.

Warp knitted laps
Loops are termed ‘laps’ in warp knitting
because the warp guides lap their yarn
around the needles in order to form the
loop structure. A warp knitted structure is
made up of two parts. The first is the stitch
itself, which is formed by wrapping the
yarn around the needle and drawing it
through the previously knitted loop. This
wrapping of the yarn is called an overlap.
The diagram shows the path taken by the
eyelet of one yarn guide travelling through
the needle line, making a lateral overlap
(shog) and making a return swing. This
movement wraps the yarn around the
needle ready for the knock-over
displacement. The second part of stitch
formation is the length of yarn linking
together the stitches and this is termed the
underlap, which is formed by the lateral
movement of the yarns across the needles.
1)Overlaponly
In overlap, the guide bar only feed yarn to
the same needle all the time. The result is
that each needle knits a chain of stitches.
Example: 1-0/01, known as pillar stitch.A
pillar stitch is not a fabric, but is commonly
used with other lapping movements to
form a fabric.
2)Underlaponly
Underlapalonecannotformintoafabricand
is commonly used with other lapping
movements. If a guide bar only made
underlaps in a multi-guide structure, this
guidebariscalledinlaybarandthewarpare
calledinlayyarn,whichneverformintoloops
but only “tie-in” at the back of the fabric.
3)Overlapwithunderlap
When overlap and underlap are worked
together, two types of fabrics can be
formed. The first one, as shown in fig 14.8-
14.10, when overlap and underlap are
moving in the same direction, an open lap
fabric will be formed. The second one, as
shown in fig 14.11 – 14.13, when overlap
and underlap are moving in opposite
direction, closed lap will be produced.
Fig 14.5 a: Subsequent courses
Fig 14.5 b: Same needle, wale
Fig 14.5 c: Subsequent courses and
subsequent wales
Fig 14.6: Guide
bar movement
Fig 14.7: Overlapping
and underlapping
Fig 14.8: Open lap
Fig 14.9:
Open lap
Fig 14.10: Open lap
Fig 14.11: Closed lap
Point paper diagram: Each point shows
a needle in a course; each row shows a
different course
Basic combination of overlap
and underlaps
All warp knit fabric structures are
composed of both overlap and underlap:
4)Neitheroverlapnorunderlap
This seems to be warp float in the fabric.
The guide bars give no lateral movements
for a few courses in the repeat, laying the
warps straight in the fabric. For a multi
guide bar fabric, it is used to hide colour
warps at the back for a colour pattern.
Fig 14.12:
Closed lap
Fig 14.13: Closed lap
Characteristics of warp
knitted fabrics
• Extremely versatile in pattern effects
with yarn
• Rigid to elastic
• Cannot be raveled
• Good air and water permeability
• Good crease resistance
• Good drapability
• Good dimensional stability
• Good strength
discussing about warp knitting machines)

The history of warp knitting machine is closely associated
with two names – William Lee and Karl Mayer. Unlike weft
knitting machines, most of the warp knitting machines is open
width/ flat type. As the name implies, loop formation is warp
wise i.e. parallel to fabric selvedge. In warp knitting, fabric is
madebyformingloopsfromyarnscomingfromwarpbeam,which
run in the direction of fabric formation. Every needle is fed by
separate yarn for loop formation. In order to connect the loops
into a fabric, the yarns are shifted (shogged) between the needles.
In this manner the needle draws the new loop through the loop
formed by another yarn in the previous knitting cycle. This
unique feature of the loop continuity in upward direction makes
the warp knitting fabrics more special with respect to their
characteristics, production and applications. Warp knitting
machines produce the widest range of fabric types and qualities
of any fabric forming technology.
Though the machine initiation has started very long back, in the
middle of 20th century only the major developments in the
manufacture of warp knitting machines has taken place. The
warp knitting machines have gained their importance due to
advent of manmade fibres such as nylon, polypropylene,
polyester, acrylic, etc. Today, there is a vast range of machine
sizes, types and configurations, ranging from 10 cm-wide crochet
machine to a 5 mtr-wide geotextiles machine are available in the
market. Modern warp knitting machines are engineered to operate
at high knitting speeds (upto 3,000 cycles/min) and these
machines may produce in excess of 5 sq mtr/min. Consequently,
it is difficult to encapsulate such a range within a simple
description. The given figure shows a typical knitting machine
producing fabric for apparel.
The main machine frame is constructed from sturdy cast steel or
welded vertical side frames held together and stabilised by a
large welded steel box section transverse girder. The needle bar
and yarn guides are mounted transversely above box section
girder in middle of the machine and run virtually full width of
machine.Machinewidthsrangefrom1mtrto5or6mtrdepending
on type and end-use of fabric.
The yarn supply may be carried on warp beams situated above
the knitting elements on beam control systems mounted on the
side frames. Alternatively the beams may be mounted on A-
frames behind the machine to permit greater beam capacities, or
machine may be supplied from individual yarn packages mounted
in creels behind machine.
The fabric is taken away downwards and to the front of the
machine to a take-up roller, or it may travel under a walkway for
the operator, to be taken-up on a bulk fabric roller that is remote
from the machine.
Basics of knitting
Warp Knitting Machines
VASANT R KOTHARI has done
DKTE’s Textile and Engineering
University, Kolhapur), Maharashtra.
Management (Apparel Export) from
the Indian Institute of Export
Management, and Garment Export
and Merchandising Management
from NIFT, Bangalore. Presently, he’s
working as an Assistant Professor in
Department of Fashion Technology,
NIFT, Bangalore. (This is his fifteenth
input from the series of articles in
Knitting Views)

Basics of Kniting by Vasant Kothari

Basics of Kniting by Vasant Kothari

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