A tablet press is a mechanical device that compresses powder into tablets of uniform size and weight. A tablet press can be used to manufacture tablets of a wide variety of materials, including pharmaceuticals, nutraceuticals, cleaning products, industrial pellets and cosmetics. To form a tablet, the granulated powder material must be metered into a cavity formed by two punches and a die, and then the punches must be pressed together with great force to fuse the material together.
2. Contents
Introduction
Parts of Punch
Parts of Dies
Standards in Tooling
Types of Tooling
Multi-tip Tooling
Procurement of Punches
Inspection of Tooling
Lubrication and Polishing
Destruction of Tooling
Conclusion
3. What is compression?
Compression is a process by which powders or granules are compressed, with the help of a
compression machine, to form a tablet.
Shape, size and hardness of a tablets depend upon the die and punches used.
What are tablets?
Tablets are oral solid unit dosage form of medicament or medicaments with suitable
excipients, prepared either by molding or by compression.
What is tooling?
Compression tooling or tablet tooling is a set which includes a lower punch which fits into a
die from the bottom and an upper punch, having a head of the same shape and dimensions,
which enters the die cavity from the top after tablet material fills the die cavity.
Introduction
4. 1.HEAD: which guides the punch through the cam track of the
machine during rotation
2.HEAD FLAT (DWELL FLAT): area of the head that receives
the compression force from roller (in upper punches) and
determines the weight and ejection height (in lower punches).
3.OUTSIDE HEAD ANGLE: gets in touch with the roller prior
to head flat, while compression.
4.INSIDE HEAD ANGLE: which pulls down the lower punches
after ejection and lifts the upper punches after compression.
5.NECK: The relieved area between the head and barrel, which
provides clearance for the cams.
Parts of punch
5. 6. BARREL: This area guides the punch (while going up and down) with reference to
turrets guides.
7. TIP: This determines size, shape and profile of the tablet.
8. TIP FACE: This area of punch is where the tablet is formed. Good surface finish is
required here to make quality tablets.
9. KEY ANGLE: the relationship of the punch key to the tablet shape. The keys position
is influenced by the tablet shape, take off angle, and turret rotation.
6. 1. DIE OUTER DIAMETER: The outside diameter of the
die, which is compatible with the die pockets in the press.
2. DIE HEIGHT: The overall height of the die.
3. DIE BORE: The cavity where the tablet is made. The
cavity’s shape and size determine the same form of tablet.
4. CHAMFER: Entry angle of the die bore.
5. TAPER DIES: These are the dies with tapered bore on one
or both sides. They are used for easy ejection of tablets.
6. DIE GROOVE: The groove around the periphery of the
die, which allows the die to be fixed in the press.
Parts of dies
7. Standards in Tooling
TSM: Tableting Specification Manual ( used in U.S)
EU: Euronorm ( used outside the U.S)
Specification TSM EU
Inside head angle for “B” 37⁰ 30⁰
Punch head configuration Angled head Domed head
Overall length 133.35 mm 133.60 mm
8. Types of Tooling
The tooling vary in punch barrel diameter, die outer diameter and die height.
Type of
Tooling
Punch
length
(mm)
Barrel
diameter
(mm)
Die
diameter
(mm)
Height of
dies (mm)
Max. Tab.
Size (mm)
Round/
Capsule
B 133.60 19 30.15 22.22 16/19
D 133.60 25.4 38.1 23.82 25/25
BB 133.60 19 24.0 22.22 13/14
DB 133.60 25.4 30.15 23.22 19/19
9. Multi-tip tooling
Advantages-
• Significantly increase tablet production: Number of
tablets per turret rotation multiplied by number of tips
• Reduce press run time per output, reduction in press
setup time per output of tablets
• Cut operating costs as fewer tools required for a given
output, less maintenance required per batch of tablets
10. • For the procurement of punch set, an approved drawing of the same, from the production
department is sent to the supplier.
• The drawing contains critical information like:
Type of tooling
Punch length
Number of set
Upper and lower punch embossing
Cup depth
Land
MOC
• The punch set is then cleaned using 70% IPA and then inspected for any damage or
defect.
PROCUREMENT OF PUNCHES
11. Inspectionof Tooling
Overall height and working length:
• The height of punches is measured with the help of dial gauge.
• The dial gauge is set at zero position with the help of master
punch.
• The punches are kept inside the punch holder over the metal
pad of the gauge and checked for any deviation from the zero
position.
• When head angle is kept at the upright position, the measured
height is called overall height. While, when tip is kept at the
upright position, the height measured is working length.
• For multi-tip tooling, a marking is given near a tip which is
considered as tip no. 1, and then remaining tips are measured
in anticlockwise direction.
• The overall height should be within 133.60 ± 0.08 mm.
12. Tip diameter of punches:
• Tip diameter is checked with the help of a Vernier caliper.
• The readings should be within ± 0.1 mm if the standard dimension.
• The tolerance limit for tip diameter is ± 0.02 mm.
Barrel diameter of punches:
• Body diameter is checked with the help of a Vernier caliper.
• The tolerance limit for barrel diameter is ± 0.02 mm.
Difference in concentricity of punches:
• Concentricity of a punch is checked with the help of V block pad by placing the
punch horizontally on it.
• Dial gauge is set at zero position over the punch body. The punch is rotated in
clockwise direction and checked for any deviation from the zero position.
• The deflection should be within ± 0.05 mm of the standard dimension.
13. Punch head angle:
• “Go-No Go” punch head tester is used for checking punch head.
• Punch head is passed through “go” side of punch head tester and it should pass easily.
• Punch head is passed through “no go” side of punch head tester and it should not pass
through it.
Embossing of punches:
• Embossing of punches is checked using magnifying lens or embossing checking kit.
Height of dies:
• Height of dies is measured using Vernier caliper.
• The tolerance limit for height of dies in -0.03mm.
Outer diameter of dies:
• Outer diameter of dies is measured using Vernier calipers.
• The tolerance limit for outer diameter of dies is -0.02mm.
14. Frequency of Inspection:
• When a new punch set is received.
• After completion of 100 million tablets ± 5 million tablets. For tablets having batch size of
more than 10 million tablets, inspection is done after completion of 10 batches.
• For multi-tip tooling, inspection frequency depends on number of tips in a single punch.
e.g. if tips in multi-tip tooling is 5, then inspection is performed after completion of 500
million ± 25 million tablets (100 million tablets ± 5 million tablets * 5)
• If a tip in multi-tip tooling gets damaged, then the tip is replaced and inspection of the
punch is performed.
• Whenever required, or due to variation in tablet physical parameters.
15. LUBRICATIONANDPOLISHING
Lubrication:
Lubrication of tooling is important for smooth and efficient running of tablet compression
machine. Lubrication reduces wear during use and oil coating during storage prevents rust.
• Punch sets are lubricated using food grade oil (light liquid paraffin/ OKS 370)
Polishing:
Polishing of punch set is important to increase its shelf life. Polishing is performed:
When there is blackening or roughness on punch tip
When there is continuous sticking on punch tip
Before every usage and as and when required
• Polishing is carried out using polishing machine which contains walnut shells and food
grade paste.
16. DESTRUCTIONOF TOOLING
• Punch set gets damaged during handling or cleaning.
• Multi-tip punch set gets damaged during handling and cleaning.
• The punch set should be destroyed if any major wear and tear is found in them.
• After completion of 500 million tablets.
• During inspection, if any abnormality is found.
• If punches, tip, dies, etc gets damaged during operation, it should be addressed through
deviation.
The punches are defaced before discard to prevent misuse of the same.
17. Conclusion
• Tooling are an integral part of compression machine. The size, shape and
strength of tablets depend upon the type of tooling used.
• Selection of appropriate design for meeting specific tablet compression
applications is critical.
• Inspection of punches at regular interval helps in identification of any
damage present in the punch set.
• Proper maintenance of tooling is important to prevent any wear and tear of
punch set and improve the shelf life of the tools.