# Dosing Disc Thickness Calculation for Capsule Filling Machine

To control the quality and weight of capsules, you need a sound understanding of every aspect of a capsule filling machine dosing disc. All these revolve around calculating a proper thickness of the dosing disc.

Image showing a fully assembled tamping pin capsule filling machine dosing disc

Two types of capsule filling machine dosing discs

Normally, the dosing disc thickness calculation of capsule filling machines is a cumbersome process that is done during the manufacturing process. In most cases, a capsule filler will come with different types of dosing discs depending on the type or size of capsule you intend to fill.

Now, this brings us to an integral aspect you need to consider when calculating the thickness of capsule filling machine dosing discs.

## How Size of Capsules Affect Size of Dosing Disc Thickness

The modern capsule filling machines can fill a wide range of capsule sizes. This makes them suitable for a wide range of applications.

It is for this reason that the manufacturer will specify the specific capsule sizes you can use with a given dosing disc thickness.

The table above shows the maximum dosing disk thickness for different capsule sizes

Remember, the dosing disc thickness will also affect other vital components and specifications of a capsule filling machine.

## How Dosing Disc Thickness Affect Other Part Specifications of Capsule Fillers

The thickness of a capsule filling machine dosing disc influence the size of other components such as height of filling rod retainer. Furthermore, a change in the height of the filling rod will affect both the density and volume of the powder.

Below is a table showing various parameters for a dosing disc thickness of about 18mm:

 Station 1 2 3 4 5 Depth into dosing disk 9 5 3 2 0.5

Clearly, you can see that the correct specifications of the dosing disc dimensions will affect the efficiency and accuracy of the capsule fill weights. Therefore, you’ll perform a wide range of tests based on a number of parameters such as:

• Type of motion – the disc is normally subjected to a rotary indexing motion.
• How the powder moves from the hopper to the disc
• The magnitude of centrifugal force that carries the powder to outer edges of the disc
• Magnitude of the compression force

In the modern capsule filling setups in pharmaceutical industries, there are different test mechanisms that simulate the operation of capsule filler machines. With this, it’s easy to tell the dosing disc thickness a capsule filling process requires.

## How Product Formulations Affect Dosing Disc Thickness

For different product formulations, you’ll need multiple dosing discs with different thickness.

But, why is this so?

A light, fluffy and a bulk heavy density product will require capsule filler dosing discs with different thickness. Therefore, you need to understand the key properties of the fill material.

## Conclusion

In short, the dosing disc thickness of a capsule filling machine will determine the accuracy, precision, reliability and predictable performance of the machine. Normally, the capsule filling machine manufacturer will provide a guideline on this.

Remember, all the necessary calculations are done during the manufacturing process.