At first glance, it is almost impossible to detect microscopic signs of abrasive wear and corrosion that may reduce the effectiveness of pharmaceutical Tablet compression tools. The high performance tools used by pharmaceutical companies in the manufacture of capsules and Tablet PCs requires surfaces very polished, free from scratch in order to maintain the contact surface necessary to compress powders formulate and develop a consistent, quality product. Unfortunately, the industry standard for tools steels such as series D, series s and stainless steel 440 C (408) is prone to corrosion and abrasive wear. As surfaces of work of punches and dies rough wear and corrosion, produces a number of physical phenomena that Act to reduce Tableting productivity and increase manufacturing costs.
Increase of mechanical interlock-
When microscopic scratches and wells are developed on surfaces of tools, pharmaceutical powders can get caught in these imperfections in the surface. As additional Tablets are compressed, powders adhere to particles trapped in the surface and begin to build-up on the surface. Unfortunately, due to the fact that these imperfections are nearly invisible to the human eye, the effects of these scratches and wells are noticeable not unless it is too late. Finally, duellists and collecting appear and production must be stopped to remove and clean punches. The losses for the manufacturer quickly mounted each second that production is disconnected.
By the same token, if corrode surfaces of tools of Tablet PCs and building layers of oxide on the surface of punch, dust will start to stick to rough oxide layers. Cleaning with detergents or solvents, the adherent dust will be removed but will not restore the original goal of the surfaces of tools. Tools in this condition requires regular buffing and polishing to smooth scratches and wells and eliminate corrosion products to restore surfaces to working conditions. Once again, production must be halted to remove and Polish the machine tools.
Greater friction between dust and Punch / Die surfaces -
If due to scratching or corrosion, rough surfaces will increase the forces of friction as a powder flow through the faces punched during compression. Because the pharmaceutical production Tablet PC is an extremely accurate process, minor imperfections in the process at any level will result in a growing number of additional problems on the line. Manufacturers use default levels of materials that have been found to achieve the highest levels of efficiency. After a minor surface abrasions begin to appear in tools, lubricants and glidants default levels no longer effective. Superior compression forces may be required and increase the work of ejection.
Reduction of the life of Tablet compression tools-
Constant restoration of punch faces worn and corroded by buffing and polishing has a significantly negative impact on the life of the tool. Composite cleaners contain Abrasives that actually remove thin layers of metal surface to Polish out scratches and pits. Repeated buffing can reduce the size of critical drilling in the area of land at the tip of punch, degrading thus the adjustment between the punch and die. Constant buffing also produces a rapid degradation of the proportions of aspect of highlighted features in shock. Both cases drastically reduces the life of the drill.
Rather than continue the cycle of abrasive wear, restoration and subsequent degradation, pharmaceutical manufacturers have additional options for the maintenance of the surface integrity of high performance tools. There are a number of different performance coatings available, each with different advantages and disadvantages. Some coatings of metal precision, as the application by the IBED process of coating, they are able to protect and improve the Tablet compression tools surfaces and apply to low temperature, thereby eliminating the possibility of dimensional distortion of tools. The result is longer-lasting and more efficient for pharmaceutical Tablet compression tools.
Dr. Deutchman is currently President and Director of research and development at Beamalloy Technologies, LLC where he is directly involved with the research, development and application of the patented Beamalloy IBED process of lining. He is the author of numerous articles published in a variety of scientific and trade journals, holds numerous patents and lectures widely on surface engineering.
