Tools for tablet pressing are covered with various coatings for the purpose of increasing the surface hardness grade, obtaining higher abrasion resistance and lowering the friction coefficient and the propensity of tools to seizure as well as achieving higher corrosion resistance and anti-adhesive properties.
One of the major methods of surface protection is comprised by galvanic chrome plating, which is perfect for a number of standard applications. The coating is applied with the use of the electrolytic method in sulphate bath, which allows for obtaining a 5-micron thick coating.
Apart from this we offer the application of coatings in the plasma PVD process, including:
GALVANIC CHROME PLATING
A layer of hard chromium applied on a galvanic basis increases abrasion resistance and prevents the pressed powder from adhesion to the surface of the pressing punch. Moreover, it comprises a good anticorrosive cover.
This is a vapor metal deposit process. Compared to the galvanic coating, the benefits of PVD coating are as follows:
- better edge stability
- contour preservation
- wear protection
CRN CHROMIUM NITRIDE
The properties of CRN coating prevail over the properties of commonly used galvanic chrome plating, allowing for:
- decreasing susceptibility to adhesion
- an exceptionally homogenous structure and low density of pores
- a very good price-quality ratio.
TIN OR TIAIN (TITANIUM NITRIDE OR ALUMINIUM NITRIDE)
With regard to their susceptibility to adhesion, they are comparable with CrN. Other advantages:
- High tear and wear protection.
- A smooth layer of low roughness.
- Very high hardness.
DLC (DIAMOND LIKE CARBON)
Carbon-diamond shaped coating. A very resistant layer to abrasion. Gives long-lasting protection against adhesion. It is mainly used with products such as effervescent tablets and other difficult products.