Today, I want to share with you another critical aspect of a tablet compression machine called tablet press tooling.
Normally, the words “tablet press tooling” refer to two major components:
- Dies
- Punches
These two tools determine the shape, size and nature of the tablet.
In this article, you’re going to learn about all the fundamental aspects of punches and dies.
These will range from the design process, type of materials, special treatments and the recommended standards among other aspects.
What is a Tablet Press Tooling?
In any tablet press machine and as I had explained in one of my previous blogs (Working Principle of Rotary Tablet Press), punches & dies are key elements of tablet compression process.
In the case of rotary tablet press machines, punches and dies are located in the turret section.
From the animation below, it is quite clear that:
- A tablet press has both upper and lower punches
- Lower punches seals the dies from the bottom. They play an integral role in ensuring a precise amount of powder fills the die by adjusting appropriately. Besides, they help during the compression and ejection process.
- Upper punches play a fundamental role in ensuring a precise amount of compression force is exerted on the powder. As a result, they help to form the desired tablet size and shape.
In short, tablet press punches and dies are metallic components designed to determine the size and dimensions of the final tablet.
Considering that they are responsible for the final appearance of the tablet, they must be designed with high precision and accuracy.
Again, the choice of material is critical here since the tablet press tools and dies are exposed to:
- Strong compression forces that may cause tool damage
- Abrasive and corrosive environment that may cause deterioration of the tool
Furthermore, tablet press punch and die treatments are mandatory to ensure the tooling meets the required compression standards.
Even with the complex process of determining an appropriate tablet compression tooling, any punch die system should be durable and guarantee high productivity.
I know the process of choosing a suitable tablet compression punch and die type can be overwhelming.
That’s why SaintyCo team is always here to help.
Types of Tablet Press Punches & Dies
Generally, we have many types of tablet compression machine punches and dies.
The design and shape of any tablet press tooling depend on the nature of the tableting process at hand.
A number of factors such as the classification of tablet press, types of tablet design and production capacity are just a few aspects that determine the types of tablet press punches and dies.
Let’s review some of the most common types of tablet press tooling:
Standard Tablet Press Tooling
Well, these are the simplest forms of punch and die systems of a tablet compression machine.
With these types of tablet compression punch and die systems, you can produce normal shapes of tablets such as round, oval or capsule shaped tablets.
In addition to these, you may produce tablets with additional marks such as dividing lines, letters or logos.
In most cases, these tablet press toolings require simple machining process hence, they are affordable for most start-ups.
Again, to get the best standard types of tablet press machines, you need to contact the tablet compression machine manufacturer.
It is the only way to have a perfect cooperation that will enable you to choose a perfect tablet press tooling.
However, when you use standard punches and dies to produce tablets, there is always a high chance of counterfeits.
This is why you may consider custom designs of tablet press tooling.
Custom Tablet Press Tooling
Customization is an important process when you wish to eliminate the possibility of having counterfeit tablets.
It is for this reason that reputable pharmaceutical companies opt for unusually shaped tablets.
As a result, they go for tablet compression tools with complex designs.
This may include their unique identity or marks.
Such tablet compression punches and dies have a complex design.
As a result, they are also expensive.
At times, these tablet press toolings may require special designs such as:
- Smaller or larger sizes than the ordinary tools
- Punches with revolving heads
- Longer or shorter tips
- Special undercut on the tool tip
Remember, all these will be in an attempt to make the punch and die systems as unique as possible.
Apart from these two, another aspect of tablet press tooling that is of great interest is multiple tools.
Multiple Tip Tablet Press Tooling
These tools are common in high capacity tablet press machines.
Unlike other tools, with these tools, you can produce more than one tablet in every punching station.
Below is a good example of multiple tip tablet press tooling:
Whenever you adopt this king of tooling for any tablet compression machine, some of the key benefits include:
- High productivity; normally, the number of tablets you’ll produce for a single rotation of the turret depends on the number of tool tips.
- Significant cost savings since you’ll have few tools to store and low machine running costs.
So, what do I mean by the second point? I know it may seem ambiguous.
It basically implies that, you will only operate the tablet compression machine within a short time to get thousands of tablets. This will save the machine from possible wear and tear, besides saving on energy costs.
I am sure this is what every pharmaceutical company is looking for?
Like other tablet press tooling, the multiple tip tablet press tooling come in a wide range of shapes and designs.
This will depend on the specific objectives of the pharmaceutical company – whether you need standard or custom designs.
Obviously, you don’t need such kinds of tooling for small scale, clinical trials or R&D tablet compression machines.
In short, the design of a tablet press tooling will depend on your specific production needs.
With all these in mind, now let’s move to another critical aspect of the tablet press tooling:
Suitable Material for Punch & Die Systems of Tablet Press
First, the best material for punch and die systems of any tablet compression machine should adhere to the Current Good Manufacturing Practice (cGMP).
This implies that they meet specific quality standards hence, performance and longevity are predictable.
Second, the type of material you intend to compress into powder should dictate the type of punch and die material.
For instance, compressing abrasive materials require a special tool unlike the soft and non-abrasive materials.
So, what am I trying to say here?
You need to understand the entire tablet compression process.
Through this you’ll choose an appropriate material for the tablet press tooling.
This should go hand in hand with your ability to understand the specific properties of various materials.
In most cases, die are made from stainless steel that has superior wear resistance. Some of the most common materials include:
- High carbon steel
- Tungsten carbide
- High chrome steel
Generally, a good material should combine extremely high wear resistance and compressive strength.
Such materials reduce any possibility of die ringing.
Die wear is a common problem in the pharmaceutical industry and it may result in a range of annoying phenomenon such as:
- Tablet capping
- Delamination
- Tablet ejection force
Obviously, all these will affect the efficiency of the tablet compression process.
It is important that you opt for tablet press tooling material that meets the highest quality standards for efficiency and durability.
Remember, there are many different grades of material you can use for your punches and dies.
Also, at times, these materials may react with certain ingredients resulting in possible contamination of the final product.
In such situations, you’ll require punched and dies with special treatment.
Tablet pressing tools are polished by automatic drag finishing machines to achieve mirror polishing.
Treating & Coating Tablet Press Tooling
We treat punches and dies to increase the service life span and product yield. The kind of treatment will depend on the specific task at hand.
These treatments will reduce possible problems such as sticking and picking.
Frankly, there are hundreds of treatments and coating in the market today.
Clearly, that may be beyond the scope of this article.
Still, I will discuss some of the most common punch and die treatments in the market.
These may include:
1. Diamond Coating
The idea here is to introduce properties of diamond to a punch and die system. Such tools are suitable for effervescent tablets.
Diamond coated tools are generally abrasive resistant and durable.
They don’t stick and their hardness is nearly 6 times more than the ordinary tablet presses.
2. Galvanic Chrome Treatment
This tablet press tooling is suitable for most standard tablet press applications.
In most cases, the coating is about 5 microns.
The coating is one of the most popular types of treatment in most pharmaceutical industries.
Another technique that is almost similar to the galvanic chrome treatment is the physical vapor deposition (PVD).
Well, this procedure protects the tooling system of a tablet compression machine from wear and ensures better stability.
3. Chrome Nitride Coating
The final surface of the tablet press tooling is better than the galvanic treatment.
It has a high quality to price ratio with enhanced wear protection.
4. Aluminum – Titanium Nitride or Titanium Nitride Coating
This treatment is known for its smooth finish and higher surface hardness.
Therefore, it is a perfect choice for most pharmaceutical tablet compression applications.
Apart from these, tablet compression tooling may be heat treated to enhance their performance.
Heat treatment is an essential process in the tablet press tool design.
By adopting a suitable treatment, you’ll be guaranteed of excellent overall equipment efficiency (OEE).
Again, even as you go through all these processes, following the stipulated standards in the industry is still very critical.
This is why this subject may not be complete without an overview of the tablet press tooling standards.
EU and TSM Specifications of Tablet Press Punches & Dies
Whenever you’re planning to invest in new tablet press tooling, there will be two standard designs to consider.
These include:
- Tablet Specification Manual (TSM); this is the American standard
- Euro Standard (EU); it is a popular standard in the European Market
So, depending on the specific geographical area you intend to venture into, the two options available are the TSM and EU specifications for a tablet press tooling system.
Generally, the configurations of these tools are almost the same except for their dimensions.
TSM vs. EU Tablet Press Standards
Broadly, the TSM standards are mainly used in the U.S.A. and they were established by the American Pharmacist Association (APhA).
On the other hand, the EU standards are widely used standards outside the United States.
The main differences between these two tablet press tool designs are:
- Punch length in EU standard is 0.010 inches longer than TSM standards
- In both tool types “B” and “D” the head thickness is larger in the TSM tooling system than in EU specifications
- TSM punch heads have an angled top profile while in EU standard, it has a domed profile
- Comparing the “B” type tooling; in TSM, the inside head angle for punches is 37° while in EU specifications it is 30°
Well, this brings us to the last segment of this article.
From above, you can classify the existing tablet press tooling systems as:
- B
- D
- BB
- DB
You can learn more about this in my article on: What is a Pharmaceutical Tablet Press Machine (An Ultimate Guide for Beginners & Professionals)
In that article, I have two tables:
Dimensions of tablet press tooling as you can see below:
And, a comparison between the two standards:
This information is handy whenever you’re buying a new tablet press machine.
Conclusion
As you can see, a tablet press tooling plays a fundamental role in tableting process.
Therefore, choosing an appropriate design that meets your specific tablet compression applications is critical.
Furthermore, the design, treatment and standardization of tablet press tool types are fundamental in ensuring maximum and efficient productivity.
For inquiries or questions on tablet press punches and dies, feel free to contact our technical team.
Further Reading:
- Tablet Manufacturing Process – by Asadulla Mulla
- Tablet Press Machine – Source: Wikipedia
- Difference Between B and D Tooling – Source: Tablet Dosage Form
- Working of a Tablet Press Machine – By Chetan Singh Bisht
- Multiple Station Tablet Rotary Press – By Saraswathi.B