This document summarizes the working of tablet punching machines. It discusses how tablets are formed through the combined pressing action of upper and lower punches in a die. It describes the different types of punches and dies used to form tablets of various shapes. The document also explains the basic parts and working principles of single punch and rotary tablet pressing machines, including the filling, compression, and ejection stages of the tablet formation process. Common problems like capping, lamination, chipping, cracking, sticking, picking and double impressions that can occur during tablet compression are also summarized along with their causes and remedies.

1. WORKING OF TABLET
PUNCHING MACHINE
Presented by-
Chetan Singh Bisht

2. Introduction
 The tablet press is a high-speed mechanical
device. It compresses the ingredients into the
required tablet shape with extreme precision. It
can make the tablet in many shapes, although
they are usually round or oval. Also, it can press
the name of the manufacturer or the product into
the top of the tablet .
 Tablet punching machines work on the principle of
compression.
 A tablet is formed by the combined pressing
action of two punches and a die.

3. Punches & Dies
Tooling Station :- The upper
punch ,the lower punch and
the die which accommodate
one station in a tablet press.
Tooling Set :- A complete set
of punches and dies to
accommodate all stations in a
tablet press.

5. Standards
 Internationally there are two recognized standards
for tablet compression tooling the TSM standard
and the EU standard.
 TSM is acronym for the ‘TABLET
SPECIFICATION MANUAL’ and is recognized in
the America and is considered exclusive in the
United States.
 The EU tooling standard is internationally
recognized and is more widely used than TSM
standard.EU which is the acronym for
‘EUROSTNADARD’ is considered the European
standard for interchangeable B and D type
compression tools

7. B and D tooling
 Tablet compression machines are made in
keeping in view the type of dies and punches will
be used on them , The dies and punches and
their setup on compression machine is called
tooling , it is classified as B and D mainly .
The B tooling dies and punch can be further
have specifications as BB and D tooling can also
be dies and punches can be utilsed on B tooling
machine which is called as DB
Mainly there are two standards, a D and B .

8. Difference between B and D
tooling

9. Different Shapes of Dies and
Punches
 Round shape punch die set
 Oval shape punch die set
 Capsule shape punch die set
 Geometric shape punch die set
 Irregular shape punch die set
 Core rod tooling punch die set

10. Round shape Punch Die Set
Used by pharmaceutical
and veterinary industry.
Can manufacture following
type of tablets:
 Shallow Concave
Ball Shape
 Deep Concave Flat
Faced
 Concave with Edges
Flat with Bevel
Edges
 Normal Concave

11. Oval Shape Punch Die Set
Applicable to pharmaceutical
and ayurvedic industries.
Can manufacture following
types of tablets:
 Flat Faced Flat with
bevel edges
 Concave/Deep/Deep
Concave with bevel
edges.

12. Capsule shape punch die set
Applicable to
pharmaceutical and
ayurvedic industries.
Can manufacture
following types of tablets:
 Concave with Edges
 Deep Concave Flat
Faced
 Normal concave Flat
with Bevel Edges.

13. Geometric Shape Punch Die Set
Applicable to
pharmaceutical,
confectionery, chemical,
industrial powder
metallurgy industries.Can
manufacture following
types of tablet:
 Triangular
 Benzene
 Rhombus
 Rectangular Square

14. Irregular Shape Punch Die Set
Are applicable to
confectionery
industries.
Available with different
size, concavity, and flat
in plain or engraved
break line.

15. Parts Of A Tablet Press
Tablet presses are designed with following basic
components:
1. Hopper for holding and feeding granulation
2. Dies that define the size and shape of the tablet.
3.Punches for compressing the granulation within
the dies.
4.Cam tracks for guiding the movement of the
punches.
5. A feeding mechanism for moving granulation from
hopper
into the dies.

17. Auxiliary Equipments
1.Granulation Feeding Device:
In many cases, speed of die table is such that the time of
die under feed frame is too short to allow adequate or
consistent gravity filling of die with granules, resulting in
weight variation and content uniformity. These also seen
with poorly flowing granules. To avoid these problems,
mechanized feeder can employ to force granules into die
cavity.
2..Tablet weight monitoring devices:-
High rate of tablet output with modern press requires
continuous tablet weight monitoring with electronic
monitoring devices

18. 3. Tablet Deduster : -
In almost all cases, tablets coming out of a tablet
machine bear excess powder on its surface and are
run through the tablet deduster to remove that
excess powder.
4. Fette machine
Fette machine is device that chills the compression
components to allow the compression of low melting
point substance such as waxes and thereby making
it possible to compress product with low meting
points.

19. Types Of Tablet Punching
Machines:
Single punch tablet press Multi-station rotary press

20. Single Punch Tablet Press
 Single punch tablet press is also called as a
eccentric press or single station press
 It is most simplest machine for tablet
manufacturing
 Single station tablet press employs a single
tooling station that is a die and a pair of upper
and lower punches
 This tablet press is available as both manually
operated and power driven

21. In this single punch
tablet press, the
compaction force on
the fill material is
exerted by only the
upper punch while
the lower punch is
immovable such as
action equivalent to
hammering motion

23. It is also called multi
station tablet press.
Multi station presses
are termed rotary
because the head of
the machine that
holds the upper
punches, dies and
lower punches in
place rotates.
Rotary Tablet Press

24. Steps associated with Single punch & Rotatory
punch machine

25. Working Principle of Compression
Machine:
1. Filling and Dosing of the Dies
The material to be pressed reaches the rotary or
gravityfeeder
from the material supply. The fill cam below the feeder
pulls
the lower punches down by a fixed amount and the dies
are
filled with material. The quantity of the material filled in is
larger than the actual amount required i.e. excess dosing
is
done.
Thereafter, the dosing unit lifts the lower punches until
only

26. 2. Compression of the Tablets
After that, the upper cam course lowers the
upper punch until the upper punches are
inserted into the dies. The lower punches are
guide to the pre-compression cam.
When the punches pass the pre-compression
cam, they are inserted a little more into the
dies and the material is pre-compressed and
the slugs are formed. Thereafter, in the main
compression roller,
the tablets reach their final height and hardness.

27. 3. Ejection and Exit of the Tablets
After the compression, the upper cam course pulls
the
upper punches into their top position and
simultaneously the ejection device lifts the lower
punches until the tablets are ejected from the dies.
The tablet stripping device strips the tablets off the
lower punches and passes them on to the
discharge chute.

28. The stages in the compression cycle are shown in figure

30. TABLET PROCESSING
PROBLEMS AND ITS REMEDIES
Capping
The upper or lower segment of the tablet separates
horizontally, either partially or completely from the main body
and comes off as a cap, during ejection from the tablet press,
or during subsequent handling.
Reason:
Due to the air–entrapment in a compact during
compression, and subsequent expansion of tablet on
ejection of a tablet from a die.

31. The Causes and Remedies of
Capping related to ‘Machine’
Sr.
No.
CAUSES REMEDIES
1. Poorly finished dies Polish dies properly. Investigate other steels or
other materials.
2. Deep concave punches or beveled-edge
faces of punches.
Use flat punches.
3. Lower punch remains below the face of die
during ejection.
Make proper setting of lower punch during
ejection.
4. Incorrect adjustment of sweep-off blade. Adjust sweep-off blade correctly to facilitate
proper ejection.
5. High turret speed. Reduce speed of turret (Increase dwell time).

32. Lamination
Separation of a tablet into two or more distinct
horizontal layers.
Reason:
Air–entrapment during compression and subsequent
release on ejection.
The condition is exaggerated by higher speed of
turret.

33. The Causes and Remedies of Lamination
related to ‘Machine’
Sr.
No.
CAUSES REMEDIES
1. Rapid relaxation of the peripheral
regions of a tablet, on ejection from a
die.
Use tapered dies, i.e. upper part of the die
bore has an outward taper of 3° to 5°.
2. Rapid decompression Use pre-compression step. Reduce turret
speed and reduce the final compression
pressure.

34. Chipping
Breaking of tablet edges, while the tablet
leaves the press or during subsequent
handling and coating operations.
Reason:
Incorrect machine settings, specially mis-set
ejection take-off.

35. The Causes and Remedies of Chipping
related to ‘Machine’
Sr.
No.
CAUSES REMEDIES
1. Groove of die worn at compression
point.
Polish to open end, reverse or replace the
die.
2. Barreled die (center of the die wider
than ends)
Polish the die to make it cylindrical
3. Edge of punch face turned
inside/inward.
Polish the punch edges
4. Concavity too deep to compress powder
blend.
Reduce concavity of punch faces. Use flat
punches.

36. Cracking
Small, fine cracks observed on the upper and lower
central surface of tablets, or very rarely on the
sidewall are referred to as ‘Cracks’.
Reason:
It is observed as a result of rapid expansion of tablets,
especially when deep concave punches are used.

37. The Causes and Remedies of Cracking
related to ‘Machine’
Sr. No.
CAUSES REMEDIES
1. Tablet expands on ejection due to air entrapment. Use tapered die.
2. Deep concavities cause cracking while
removing tablets
Use special take-off.

38. Sticking
Tablet material adhering to the die wall.
Filming is a slow form of sticking and is largely due to
excess moisture in the granulation.
Reason:
Improperly dried or improperly lubricated granules.

39. The Causes and Remedies of
Sticking related to ‘Machine’
Sr. No.
CAUSES REMEDIES
1. Concavity too deep for granulation. Reduce concavity to optimum.
2. Too little pressure. Increase pressure.
3. Compressing too fast. Reduce speed.

40. Picking
Small amount of material from a tablet is sticking to and
being removed off from the tablet-surface by a punch
face.
The problem is more prevalent on the upper punch faces than
on the lower ones.
 Reason:
 Picking is of particular concern when punch tips have
engraving or embossing letters.
 Granular material is improperly dried.

41. The Causes and Remedies of Picking
related to ‘Machine’
Sr.
No.
CAUSES REMEDIES
1. Rough or scratched punch faces. Polish faces to high luster.
2. Embossing or engraving letters on punch
faces such as B, A, O, R, P, Q, G.
Design lettering as large as possible.
Plate the punch faces with chromium to
produce a smooth and non-adherent face.
3. Bevels or dividing lines too deep. Reduce depths and sharpness.
4. Pressure applied is not enough; too soft
tablets.
Increase pressure to optimum.

42. Double Impression
 Involves only those punches, which have a monogram or other
engraving on them.
 If the upper punch is uncontrolled, it can rotate during the short
travel to the final compression stage and create a double
impression.
 Reason:
 At the moment of compression, the tablet receives the imprint
of the punch.
 The lower punch freely drops and travels uncontrolled for a
short distance before riding up the ejection cam to push the
tablet out of the die
 Now during this free travel, the punch rotates and at this point,
the punch may make a new impression on the bottom of the
tablet, resulting in ‘double impression’.

43. The Causes and Remedies of Double
Impression
Sr.
No.
CAUSE REMEDIES
1. Free rotation of either upper
punch or lower punch during
ejection of a tablet.
-Use keying in tooling, i.e. inset a key alongside of
the punch, so that it fits the punch and prevents
punch rotation.
-Newer presses have anti-turning devices, which
prevent punch rotation.