Softening finishes are important textile after treatments that can make fabrics softer through the use of chemical softeners. Softening finishes work by orienting softener molecules on fiber surfaces and penetrating fibers to plasticize the polymer chains, reducing brittleness. This creates properties like softness, fullness, smoothness, flexibility, drape and pliability. The three main types of softeners are cationic, anionic and non-ionic softeners, which work through different molecular interactions with fibers. Silicone softeners also provide unique softness and properties. While softeners improve handle, some can reduce durability, cause discoloration or affect dye properties.

1. Softening finishes
Softening finishes are among the most important of
textile chemical after treatments.

2. INTRODUCTION
• With chemical softeners, textiles can achieve an
agreeable,
 soft hand
 (supple, pliant, sleek and fluffy),
 some smoothness,
 more flexibility
 and better drape and pliability.
• To achieve the desired quality of fabric handle or
softness
• Chemicals used to impart the desired softness in fabric
is termed as SOFTNERS

3. INTRODUCTION
• The hand of a fabric is a subjective sensation felt by
the skin when a textile fabric is touched with
– the finger tips and gently compressed.
• The perceived softness of a textile is the
combination of several measurable physical
phenomena such as
1. elasticity,
2. compressibility
3. and smoothness.
• During preparation, textiles can become embrittled
because
– natural oils and waxes or fibre preparations are removed.

4. INTRODUCTION
• Finishing with softeners can overcome this
deficiency and even improve on the original
suppleness. Other properties improved by softeners
include
1. the feeling of added fullness,
2. antistatic properties
3. and sewability.
• Disadvantages sometimes seen with chemical
softeners include
– Reduced crockfastness,
– yellowing of white goods,
– changes in hue of dyed goods
– and fabric structure slippage.

5. Mechanisms of the softening
effect

6. Mechanisms of the softening effect
• Softeners provide their main effects Basic Mechanism
» on the surface of the fibres. •Softeners provide their main
effects on the surface of the
• Small softener molecules, in addition, fibres.
penetrate the fibre
and provide an internal plasticisation of the
fibre forming polymer •Softeners orient themselves
by reducing of the glass transition temperature toward the fibre creating a
new surface consisting of
Tg.
molecular chains that provide
• The physical arrangement of the usual the characteristic softening
and lubricity.
softener molecules on the fibre surface is
important and shown in Fig .
– It depends on the ionic nature of the softener
molecule
•Small softener molecules
– and the relative hydrophobicity of the fibre penetrate the fibre and
surface. provide plasticisation of fibre
forming polymer

7. Most softeners consist of molecules with both a
hydrophobic and a hydrophilic part

8. Cationic softeners
Mechanisms of the softening effect
• orient themselves with their
positively charged ends
toward
– the partially negatively charged
fibre (zeta potential),
– creating a new surface of
hydrophobic
• carbon chains that provide
the characteristic excellent
softening and lubricity seen
– with cationic softeners.

9. Anionic softeners
Mechanisms of the softening effect
• orient themselves with their
negatively charged ends
– repelled away from the
negatively charged fibre
surface.
• This leads to higher
hydrophilicity,
– but less softening than with
cationic softners

10. non-ionic softeners
• The orientation of non-
ionic softeners depends
on the
– nature of the fibre
surface,
• with the hydrophilic
portion of the softener
being attracted to
– Hydrophilic surfaces
• and the hydrophobic
portion being attracted
to
– hydrophobic surfaces.

11. Desirable Properties of Softners
1. Compatible with other chemicals
2. Easy to handle
3. Good exhaustion properties
4. Stable to high temperature
5. No effect on shade or fastness
6. Non toxic, biodegradable, non corrosive

12. Product types and their
chemistry
Most softeners consist of molecules with both a
hydrophobic
and a hydrophilic part.
Therefore, they can be classified as
surfactants (surface active agents)
and are to be found concentrated at the fibre
surfaces.

13. Product types and their chemistry
• Most softeners have a low water solubility. Therefore softening
products are usually sold as
– oil in water emulsions containing 20–30 % solids.
• The softener molecules typically contain a long
– Alkyl group,
– sometimes branched, of more than 16 and up to 22 carbon
atoms,
– but most have 18 corresponding to the stearyl residue.
• Exceptions to this molecular structure are the special categories of
 silicones,
 paraffins
 and polyethylene softeners.
• About one-third of the softeners used in the textile industry are
– Silicone based.

14. Types of Softeners
Depending on charge on parent molecule.

15. Cationic softeners
• typical cationic softener structures, for example,
• N,N-distearyl- N,N-dimethyl ammonium chloride (DSDMAC).
• Cationic softeners have the best softness and are reasonably durable to laundering.
• They can be applied by
– exhaustion to all fibres
– from a high liquor to goods ratio bath
– and they provide a hydrophobic surface
– and poor rewetting properties, because their hydrophobic groups are
oriented away from the fibre surface.
• They are usually not compatible
– with anionic products (precipitation of insoluble adducts).
• Cationic softeners attract soil, may cause
– yellowing upon exposure to high temperatures
– and may adversely affect the lightfastness of direct and reactive dyes.
• Inherent ecological disadvantages of many conventional (unmodified) quaternary
ammonium compounds (quaternaries) are fish toxicity and poor biodegradability.

16. Cationic softeners
• Quaternary ammonium compounds are easily
removed from waste water by
 adsorption
 and by precipitation with anionic compounds.
• Quaternaries with ester groups, for example
 tri-ethanol amine esters, are biodegradable,
through the hydrolysis of the ester group
• The example of an ester quaternary in Fig. 3.2 is
 synthesised from tri-ethanol-amine,
• esterified with a double molar amount of
 stearic acid
 and then quaternarised with di-methyl-sulfate.

18. Cationic Softeners
1. Advantages 1. Dis-Advantages
2. Incompatible with anionic
2. Soft, lofty, silky handle to auxiliaries including FBA's
most fabrics at low levels of
add-on 3. Free amine causes yellowing
3. Substantive to most fibres and may change dye shade or
affect light fastness
4. Good lubricant properties
and often have positive 4. May react with residual chlorine
effect on wet fastness from bleach baths
5. Improve tear
strength, abrasion 5. Adversely affect soil removal
resistance and sewability proporties,
6. Improve antistatic properties 6. Can cause tendering of sulphur
( especially on synthetics) dyed fabrics

19. Anionic softeners
• Anionic softeners are heat stable
– at normal textile processing temperatures
• And compatible with other components
of
– dye and bleach baths.
• They can easily be
• washed off
• and provide strong antistatic effects
• and good rewetting properties
• because their anionic groups are
oriented outward and are surrounded by
a thick hydration layer

20. Sulfonates are, in contrast to sulfates, resistent to hydrolysis
They are often used for special applications, such as
 medical textiles,
or in combination with
 anionic fluorescent brightening agents(FBA).
Disadvantages
• Inferior in softness performance to
Advantages cationics, generally and sensitive to water
• Compatible with FBA's hardness and electrolytes in the finish bath
• Have good rewetting properties
• Usually higher concentrations required and
• Do not tender Sulphur-dyed goods even then cationic impart softer feel
• Used extensively on mechanically • Limited durability to laundering and dry
finished fabrics mechanically finished e.g. cleaning
• Not exhaust from bath (except onto wool and
brushed, sheared , sanforised nylon) and must be padded

21. Non-ionic softeners based on paraffin and
polyethylene
• Polyethylene (Fig. 3.5) can be modified by air
oxidation in the melt at high pressure to add
– hydrophilic character (mainly carboxylic acid groups).
• Emulsification in the presence of alkali will provide
– higher quality, more stable products.

22. Perform well as lubricants
Non-ionic Softeners
Advantages •Most have good non-
yellowing properties and
• They show high lubricity (reduced usually do not cause shade
surface friction) change
• that is not durable to dry cleaning,
• they are stable to extreme pH •Compatible with cationic
conditions and heat
and anionic products
• at normal textile processing
conditions, including FBA's and do not
• and are reasonably priced tender sulphur-dyed goods
• and compatible with most textile
chemicals. •Easily removed if
reprocessing is necessary
Disadvantages
•Handle generally poorest out of anionic, cationic and non- ionic
•Usually have negative effect on wet fastness properties of dyes
•Cannot easily be applied by exhaust

23. Ethoxylated non-ionic softeners
• These polyglycol ethers are synthesised by the
addition of ethylene oxide to
 fatty alcohols,
 carboxylic acids,
 esters,
 amides or amines (Fig. 3.5).
• They are surfactants and often used as antistatic
agents and as components of fibre spin finishes.
Their main characteristics are
 relatively high substantivity
 and hydrophilicity, nonyellowing
 and sometimes a low softening effect and lubricity,
 and a potential for foaming during processing.

24. Silicone softeners
Non-ionic and cationic examples of silicone
softeners are shown in Fig
They provide
very high softness,
special unique hand,
high lubricity,
 good sewability,
elastic resilience, crease recovery, abrasion
resistance and tear strength.
They show
good temperature stability
and durability, with a high degree of permanence
for those products that form crosslinked films
and a range of properties from hydrophobic to
hydrophilic

25. Silicone softeners
• Depending on their method of synthesis, silicone
softeners can contain variable amounts of
– volatile siloxane oligomers
• Together with volatile emulsifiers these oligomers
can cause
– pollution problems in the waste air from tenter frames
• In textile finishing, silicones are also used as
1. water repellents,
2. elastomeric finishes,
3. coatings
4. and as defoamers.

26. Silicone softeners
• the high molecular flexibility of the silicone chain
• is the reason for
– the very low glass transition temperature
– (about –100 °C)
– and for their special softness.
• They postulate that to a great extent the methyl groups of the
OSi(CH3)2-structure
– shield the oxygen atoms from outside contact
• Therefore the surface of fibres finished with
– Poly-di-methyl-siloxane is mostly non-polar and
hydrophobic
• In the case of cellulose, wool, silk and polyamide fibres, there are
strong hydrogen bonds between
• the hydroxyl or amino groups of the fibres
• and the amino groups of the modified silicones (Fig. 3.7, upper figure)..

27. Silicone softeners on polar fibres.
• These bonds act as an anchor for the silicone, which
forms an evenly distributed film on the fibre surface.
• Good water repellency and very soft hand are the result.
• With an optimal content of amino side groups, the
polysiloxane segments between the anchor sites are
long enough to maintain their high flexibility.
• This is the main reason for the softness and the
lubricating effect of amino functional silicones on
polar fibres.

28. Silicone softeners on non-polar fibres.
• In the case of relatively non-polar fibres such as
polyester, the hydrophobic segments of the silicone
chains interact strongly with the hydrophobic fibre
surface (Fig. 3.7, lower figure).
• The positively charged amino side groups of the silicone
chains repel each other and give rise to enhanced
flexibility of the silicone chain loops.
• This again is the reason for the specially soft hand of
amino functional silicones on non-polar fibres.

30. Amino-functional siloxanes are one of the most important product in textile softeners
•Their softening properties are unique and in practice they have been proved
superior to other compounds
•The siloxane backbones are modified by amino residues
• SILICONE SOFTNERS SILICONE SOFTNERS
• •silicon dioxide can be •Silicones are structurally bound with silicon dioxide
considered as basis of the in form of organically modified quartz, and this is
whole modern silicone the reason why they are called polysiloxanes
chemistry •Silicone oils, silicone rubber and silicone resins
• •Silicon is with 25.8% the are the three most important raw material groups of
second most important which more than 2000 high quality products can be
element of the earth's made for many different application
crust after oxygen
• •However in nature silicon
Silicones offer a large number of application
is always in form of
possibilities in the textile because of the varied
compounds, primarily as
nature of product properties
silicon dioxide (sand) and
•Silicones give a variety of finishing effects like
silicates
brilliancy, softness, volume and elasticity. They also
improve the technological demands of sewability,
soil and water repellence

31. The amino siloxane can vary in the nitrogen content and the chain length of the
siloxane
•These modifications influence the handle characteristics, the tendency to yellowing
and the reactivity of the siloxane to the fibre
•The degree of softness normally becomes higher with increasing nitrogen content
The different sizes of particles have an important impact on application technical
properties
•The medium particle size of macro- Softners based on micro-emulsions penetrate into the
interior of the fibre, so that a good core softness is
emulsions is in the range of approx. 100 to achieved
1000 nm •Softners of macro-emulsion formulation when applied
•Of micro-emulsions the average size of accumulate more at the fibre surface, and soft,
particle of emulsified silicone drop is voluminous and smooth handle effects are obtained
smaller than 10 nm this means that the
fluid drops are smaller than the wavelength A semi-micro emulsion has droplets of silicone oil that
of visible light, which can penetrate such are 10 to 100 times smaller than those in conventional
macro-emulsion
an emulsion without becoming defused •When semi-micro emulsion is applied to a textile
substrate. Smaller droplets penetrate in structure easily
•Giving more lubrication between yarns and fibers with
increased suppleness & Drape properties of fabric
•While macro-emulsion does not penetrate so well and
deposits more onto the surface giving a softer surface
feel to the fabric.

32. Silicon SOFTNERS
• Silicone Softeners
Disadvantages
Advantages
•Create water-repellency of some type,
1. • Silky handle on all fibres making them unsuitable when
2. • Water-clear oils - stable to absorbency is required
heat and light
•Cannot easily be removed for redyeing
3. • Improve tear strength,
•Expensive
abrasion resistance, and
excellent for improving sewing
properties
4. • Amino-functional silicones
improve durable press
performance of cotton goods
5. • Non-yellowing at moderate
temperatures

33. Selection of Softener
Yellowing Exhaustibility
•Usually the more cationic, the more the –Normally cationic softeners are
softener yellows recommended
–Non-ionic can be used with cationic
emulsifiers
Fastness Properties –Anionic on wool
•Cationic softeners give better wash
fastness but they may have a negative
effect of light fastness Effect on Seam Slippage
•Non-ionic may have negative effect on wet •Silicones can adversely affect
fastness slippage
•Heat Stability and Smoke Point
•May cause processing problem on
Shade Change
drying
•Non-ionic normally have less tendency to
•Odour
cause shade change.
•Fabric odour may be produced by
•Some cationic and anionic will cause
softener
shade change
•Silicones have tendency to 'bloom' shade