Tablet Compression Tooling

Tablet compression tooling is an integral part of a tablet compression machine that defines the tablet’s various physical characteristics. It can make or break the entire tablet batch and establishes its physical properties. 

What is tablet compression tooling?

Tablet compression tooling refers to the set of dies and punches that gives the tablet its physical characteristics such as shape, size, weight and hardness. For example, if the punch head is round, tablets will be round-shaped; if the punch head is square, the tablet’s shape will also be square.

They are fixed in the turret, and their number varies, depending upon the type of tablet compression machine, since different machines can handle different tooling numbers.

Tablet tooling is the machine parts that have a direct impact on tablets. In contrast with other machine parts such as CAM, gears and motors, they only indirectly affect machine performance rather than affecting the tablet properties and characteristics.

Table tooling consists of Upper punch, lower punch and a die.

• The upper Punch is attached to the upper portion of the turret. It is used to exert force on the powder in the die from the upper position. The upper Punch receives pressure from the upper-pressure roll of the table compression machine.

• A lower Punch is attached to the lower part of the turret and exerts force from the lower side. It receives pressure from the lower compression roll of the compression machine. In some machines, the lower Punch does not exert force but instead supports the upper Punch for exerting force on the powder in the die.

• Die is a round-shaped mechanical assembly having a cavity in its middle. The powder is filled in the die through the action of various cams in a tablet compression machine. The upper and lower Punch presses the powder in die against each other.

Since tooling is attached to the turret, each rotates during the machine operation. The powder filling in the die and subsequent compression takes during the rotation. After compression and powder conversion, to tablet automatically ejects the tablet out of the die.

Part of tablet compression tooling?

There are different parts of tablet compression tooling, each having a distinct function. Let’s briefly discuss an essential part of tablet tooling.

Head

The head is the upper portion of tooling, and it rests on a guiding cam of a tablet compression machine. Its basic function is to guide the tooling during the entire turret rotation and prevent the ejection of punch from the cam.

Head Flat

It is the topmost part that is flat in its appearance. Its function is to receive the pressure from the compression roller of the tablet machine to exert force on the powder in the die. This part also defines the dwell time, i.e. how much time a powder in the die receives pressure. A larger head flat increases the dwell time and vice versa. 

Neck

The neck acts as a supporting and connecting part between the head and body. It is also used to hold the punch in the bore of the turret and facilitates easy movement.

Key

The key is a small flat mechanical part attached to the upper punch in a small spacing. It is attached to prevent the upper punch from rotating in its place and remains fixed during the rotation of the tablet. Its primary function is to keep the upper punch aligned with the die and prevent accidents. 

For the lower punch, it is not included, as the lower punch remains in the die, and there is no issue of alignment.

Tip

The tip is the lower portion of the punch and comes in direct contact with powder in the die. It is designed according to the requirements of the physical characteristics of tablets, and it defines the physical, quality and therapeutic effects of a tablet.

Commonly it also includes a company logo or any other identification for engraving on the tablet surface. 

Types of tablet tooling in pharma industry

Tooling types refer to specific tooling having specialized physical dimensions. Each type differs in the size of punches and dies, enabling them to produce a tablet of varying characteristics.

There are four common tooling used in pharmaceutical industry and are

• B – type

• D – type

• BB – type

• DB - type

Each tooling is categorized according to punch diameter, die diameter and punch length.

B-type tooling is used with smaller tablets with a maximum tablet diameter of around 16mm. D-type tooling is used with large-sized tablets with a maximum diameter of up to 25mm. In addition to B & D type tooling, there are also BB and DB tooling.

Below table provides detail of B, D , BB and BD tooling

Importance of tablet tooling in pharmaceutical industry

As discussed above, tablet tooling is an integral part of a tablet compression machine that defines physical characteristics. It also serves additional purposes necessary for security, branding and other applications.

Let’s discuss some of these functions.

Tablet identification

Tablet tooling is used to identify tablets having specific specifications. Because in a pharma organization, the same product has different strengths. Although different packaging designs separate these tablets, markings on a tablet are also used as an additional layer of identification. 

Tablet tooling is used to identify tablets having specific specifications. Because in a pharma organization, the same product has different strengths. Although different packaging designs separate these tablets, markings on a tablet are also used as an additional layer of identification. 

Marketing

Tablet tooling is also used as a mechanism of marketing for tablets. The punches are engraved with specific markings such as logos and alphanumeric characters that represent the tablet manufacturer, which in turn serves as a marketing tool for the pharmaceutical manufacturer. A common practice is to engrave a company logo to the punch tip that identifies the tablet manufacturer.

Some ways tooling is used in marketing include the following

• Engraving of Company logo

• Specific font style 

• Design and placement of the company's logo

Anti-Counterfeiting

Tablet tooling also helps tablet manufacturers implement anti-Counterfeiting measures to protect a tablet from misuse. Because the pharma sector is a typical victim of anti-Counterfeiting that damages the pharma manufacturer's reputation, hurts customer trust and causes a loss in market share.

Anti-Counterfeiting techniques are not visible to the naked eye, nor can an ordinary person recognize them. Instead, it can be only identified by authorized personnel involved in the product development stage.

Some techniques that can be implemented by using tablet tolling for anti-Counterfeiting include

• Changing the thickness of tooling embossing from different places

• Tilting the angle of some letter

• Altering the dimension of the company logo.

Common problems related to tablet tooling

Let’s discuss some common problems related to tablet tooling and how to prevent them.

Handing Issues

The most common problem caused to tablet tooling is due to improper handling. Since heavy tooling increases the risk of tooling damage if not handled properly.  

Commonly, handing issues occur during the unpacking of tooling when they are first delivered to the pharma manufacturer. It also causes problems when installed on the tablet compression machine and during cleaning.

Handing can be improved by adequately training the personnel responsible for the tooling. Training in areas such as the importance of tooling, cost factor, and the impact of damaged tooling on the final product can effectively improve tooling handling during production.

Operating conditions

Tooling is also affected by the operating conditions of tablet compression machines.

For example, if a tablet compression machine is operated at very high speed with higher compression roll pressures or is frequently started and stopped.

It affects the mechanical nature of tooling and degrades delicate parts such as punch tip. Inappropriate operating conditions can also result in cracks, chipping of edges, and can also cause a piece of punch to break away. 

These issues can be prevented by operating the tablet compression machine in line with the guidance of the tablet machine or tooling manufacturer. Avoid operating the tablet machine with maximum operating conditions such as maximum speed and pressure.

Inappropriate cleaning practices

Pharma products comprise chemical compounds that can react with other solid or liquid substances, including metal. 

Pharma products can damage the tablet tooling if they are not adequately cleaned after finishing a batch, before holidays and during the gap in production. The traces that will remain on the tooling will decrease the strength of the tooling, thereby reducing its ability to sustain the force, causing corrosion of the tooling and a change in the physical appearance. 

To avoid the above problems and like these, design a proper cleaning system. Some effective cleaning practices include but are not limited to 

• Avoid sharp and hard objects for cleaning, as these will cause scratches and damage the tooling surface

• It must be performed regularly at the end of the shift or day. 

• Especially check if there are cracks, corrosion or any sign of significant damage. 

• Use polishing devices to improve the surface finish

• Use proper lubrication for the tooling. It will help in smooth compression. 

• After cleaning, thoroughly inspect the tooling for any sign of corrosion, cracks and damaged parts.

About the Author

Muhammad Asim Niazi has a vast experience of about 11 years in a Pharmaceutical company. During his tenure he worked in their different departments and had been part of many initiatives within the company. He now uses his experience and skill to write interested content for audiences at PharmaSources.com.