Tablet compression machines are designed with consideration of the types of dies and punches they will use. The dies and punches and their setup on compression machine is called tablet tablet tooling , it is mainly classified as B and D type.
Difference between B and D tooling:
D tooling:
Barrel Diameter is 1 inch
Head Diameter is 1 and ¼ th inches length is 5.25 inches
Dies outer diameter is 0.945.
BB Tolling:
Barrel Diameter is 0.75 inch
Head Diameter is 1 inch length is 5.25 inches
Dies outer diameter is 30.16 mm
B tooling is same as BB with the only difference being that the lower punch is just 3 and 9/16th inches long.
1. Head: This is the end of the punch that guides it along the cam track of the tablet machine during its rotation.
2. Head flat(Dwell Flat): This is the flat surface on the head of the punch that receives the compression force from rollers (for upper punches) and determines the weight and ejection height (for lower punches).
3. Outside head Angle: The area gets in touch with the roller prior to head flat , while
Compression.
4. Inside Head Angle: This is the area, which pulls down the lower punches after ejection and lifts the upper punches after compression.
5. Neck: The relived area between the head and barrel, that provides clearance for the cams.
6. Barrel: This area guides the punch (while going up and down) with reference to turret guides.
7. Stem: The section of the punch opposite the head, starting from the tip and extending to the point where the full diameter of the barrel begins. If a chamfer is present, the barrel typically reaches its full diameter just above the chamfer.
8. Tip: This determines size, shape & profile of the tablet.
9. Tip face: This area of punch is where the tablet is formed. Good surface finish is required here to bet quality tablets.
10. Working Length: This is the distance between the bottom of the cup and the head flat, which determines the weight and thickness of the tablet.
11. Overall length: Distance between top of the cup and the head flat.
12. Key Angle: This indicates the alignment of the punch key in relation to the shape of the tablet. The position of the key is affected by the tablet shape, the take-off angle, and the turret’s rotation direction.
13. Domed Heads: It increases the dwell time, which helps to achieve better tablet hardness.
14. Dwell time: The time that the punches remain under the pressure roller while rotating within the machine.
15. Clearance: Die bore diameter – punch tip diameter = Clearance.
16. Hardness: Typically measured in HRC (Rockwell ‘C’ scale), with the following optimal readings:
Steel Hardness:
OHNS O1 58-59
HCHC D2 59-60
HCHC D3 61-62
1. For punches AISI O1(OHNS).
2. For dies AISI D3(HCHC).
3. Highly abrasive product AISI D2(HCHC) punches.
Die: hardened steel (HCHC) mould to make the shape of a tablet.
Die Terminology:
1. Die. O.D.: 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.
‘B’ Tooling-22.225 mm
‘D’ Tooling-23.820 mm
‘BB’Tooling-22.225 mm
3. Die Bore: The cavity where the tablet is formed. The shape and size of this cavity determine the shape of the tablet.
4. Chamfer: Entry angle of the die bore.
5. Taper dies: dies with tapered bore on one or both sides. They are used for easy ejection of tablets (mainly for double layered tablets.
6. Die Groove: The groove around the periphery of the die, which allows the die to be fixed in the press.
7. Lined (Insert) Dies: Dies fitted with a linear insert made from a much harder, more wear resistant Material such as tungsten carbide and ceramic.
Made of tooling:- OHNS :- Oil harden non sticky stainless steel
HCHC: High chromium High Carbon
Punch standard: – Europe, Japan, TSM