Materials Science Paves Way to Right First Time Tooling Steel Selection

Wear and degradation of tooling is inevitable in tablet manufacture and will lead to other tablet-making problems, such as adherence of the granules because of the pitted and worn surfaces of the punches and also capping or lamination of the tablets. To overcome this problem, I Holland has studied materials science and uses a continuous component testing programme and the MCP (Metal Conditioning Project).

This project has led to advancement in I Holland’s understanding of steel metallurgy, allowing the company to further improve the properties of the I Holland PharmaGrade steel types for tablet tooling. The correct choice of material will help to reduce the risk of damage to the punches and dies from the effects of abrasion, corrosion and impregnation of hard granules. There are thousands of steel types available, yet only a few meet the complex design and functional requirements necessary for tablet tooling.

The right steel is key to the successful performance of tablet compression tooling. I Holland’s PharmaGrade range of steels have been tested to achieve the following necessary characteristics:

• Strength: ability to withstand an applied stress without failure.

• Fatigue resistance: aggressive and localised structural damage that occurs when a material is subject to cyclic loading.

• Toughness: resistance to chipping, cracking and punch tip breakage.

• Abrasive wear resistance: resistance to abrasive wear of punch tips and die bores.

• Adhesive wear resistance: resistance to adhesive wear, galling and welding.

• Hardness: resistance to impregnation from hard, sharp granules.

• Compressive strength: resistance to die bore ringing and plastic deformation of punch tip edges.

• Corrosion resistance: resistance to oxidising, staining and discolouration.

Chemical composition of the steel is only one part of the overall equation, material selection must also be considered together with good tablet design for strong punch cups and punch tip edges.

After years of extensive research and development, I Holland has a number of steel types in the PharmaGrade range to suit a variety of applications, including the standard HPG-S steel to the HPG-TC a PharmaGrade Tungsten Carbide. Together with the range of PharmaCote treatments and coatings, all tablet manufacturing problems can be dealt with.

I Holland Ltd, +44 115 972 6153, info@iholland.co.uk, www.iholland.co.uk.