TABLET COMPRESSION MACHINE
History of Tablet Compression Machine :-:
History of Tablet Compression Machine :- In 1952–1954 Higuchi and his
group have instrumented upper and lower compression, ejection, and
punch displacement on an eccentric tablet press , and Pioneered the
modern study of compaction process. In 1966 , a U.S. patent was
granted to Knoechel and coworkers for force measurement on a tablet
press. In mid-1980s , custom-made press monitoring systems were
described and the first commercial instrumentation packages became
available, including both the systems for product development and press
Tablet compression machine or tablet presses are designed with the
following basic components. Hopper for holding and feeding granulation
to be compressed. Dies that define the size and shape of tablet Punches
for compressing the granulation within the dies. Cam tracks for guiding
the movement of the punches A feeding mechanism for moving
granulation from the hopper into dies .
Instrumentation :- The tablet press comprises of following parts.
Punches Dies Auxiliary equipments
Punch and its parts :-:
Punch and its parts :- TIP BARREL NECK HEAD
Punch :- These are two types. Upper punch and lower punch . Neck of
the upper punch is smaller than the lower punch These are made by
steel , in order to withstand with the force existed by rollers. Both upper
& lower punches are same in length except in “B” tooling. For large dose
preparation D tooling is preferable.
Standard Deep Flat Flat faced bevel edge
Selection of punch depends on two factors. Force applied Shape
required For heavy forces shallow or standard cups are preferable.
Compression force is highly correlated with a variety of tablet properties.
As compression increases, so does tablet hardness and weight (at
constant thickness and true density), along with a force required to eject
a tablet . Many variables affect the force of compression: press settings,
press speed, punch length variation, punch wear, and damage,
formulation and excipient properties.
Steel Hardness and Selection:-:
Steel Hardness and Selection :- Several types of tool steel are normally
used in the fabrication of compression tooling. The proper selection
becomes critical to a successful overall operation. The steel
characteristics to be looked for in descending order of importance.
Toughness to withstand the cyclic compaction forces Wear resistance
Comparison Standered Type S 5 : shock resistance silicone steel. good
ductility and toughness. If 3 3% Nickel is added to S 5 which has greater
ductility but less resistant to abrasion than the S 5
premium Types: D2 & D3 High carbon & chrome alloys. Greater
resistance. But less ductility which result in breakage. Used for light
compaction forces .
Steel selection :-:
Steel selection :- Shape of the punch cup. Compressing force. Material
nature. Ex : abrasive, corrosive(stainless steel)
DIES :- These are holded by die table. These are in different sizes ,
made by steel. Selection of die depends upon the dose we wanted.
Diameter of a tablet depends upon the die we select. These are
available in different diameter. Die is fixed by the die screw. For large
size tablets D tooling dies are preferable.
TOOLING ( in inches) :-:
TOOLING ( in inches) :- Tooling type& punch parameters BB B D Barrel
length 5.25 5.25/3.56 5.25 Barrel diameter 0.75 0.75 1 Head diameter 1
Coating of Dies and Punches:
Coating of Dies and Punches Why coating is required? To protect from
Sticky material, Corrosive material, Abrasive material. Different type of
coating : Titanium Nitride Coating Electroless Nickel Plating (ENI)
Chromium Nitride Coating ( CrN ) Chromium Carbon Nitride ( CrCN )
Coating Diamond Coating of Diamond like Carbon (DLC) Cr- CrN -Cr
Multilayer Coating ( Nano Coating)
Auxiliary parts Tablet dedusters . Hopper. Compression analyzers.
Signal conditioning systems. Strain gages.
Working of tablet press :-:
Working of tablet press :- Irrespective of the tablet press types ( single
station or rotary) the following steps are majorly involved. Filling. Weight
adjusting. Compression. Ejection.
Production rate depends on Number of stations. Number of
compressions per cycle. Speed of the turret s.
Manufacturer Number of stations available Min Max Tablet per
minute(TPM) Min Max Colton 12 90 480 1600 Whilhelm Fette,Gmbh ,
HumburgW . Koln 20 55 300/900 3300/8250 Killian & Co ., Gmbh Koln,
W.Germany 14 67 140/383 1083/10,000 Mnesty machine
ltd.Liverpool,England . 16 69 600/1500 3330/10,000 Stroke merril 33 65
1200/3300 3500/10,000 Hatta Iron works,Horry Engineering Co. Osaka,
Japan 28 71 420/1420 1920/7100
Differences between single & rotary tablet presses :-:
Differences between single & rotary tablet presses :- Single punch
Consist of one station. production rate low. Tpm is aproximatly 100.
Lower punch do nt move wile compression.
Rotary punch More stations. Production rate is high. Tpm is 10,000.
Both punches move. ex: colton
Quality Control :-:
Quality Control :- Punches: Overall length Working length Cup depth
Tips – round and capsule Tip and Barrel concentricity Head, Head flat
and Neck Barrel Dies: Height and outside diameter Die bore diameter
using expandable, small bore gauges Die bore major and minor axis
using Vernier caliper and expandable, small bore gauges Die Bore
concentricity Squareness Visual Inspection Dimensional Inspection
Maintenance of Dies and Punches:
Maintenance of Dies and Punches Why is it required ? To improve the
lifespan of toolings . How are they Maintained ? Fitting instructions
usually as per the manual given. Warm soap water and a soft brush are
suitable for thorough cleaning Not to be touched by bare fingers
Thoroughly coated with an acid-free oil in order to prevent corrosion.
Tooling should be regularly checked. Polishing – By hand “Drag
Finishing” machine Storage cabinets for tooling – Clashing Dusting