In general, tablet tooling damages can be attributed to poor handling, material choice , and problems in designing process or manufacturing stage. Tablet tooling is usually made from hardened and tempered steel. After a series of strict manufacturing process of annealing, normalizing, quenching, tempering, precooking, and hardening, a qualified tooling can be brought forth. Tablet tooling is rotated through a cam track system at high speeds that exert high friction forces. Meanwhile, high cyclic compaction force is also applied to the punch heads via the precompresion and main compression rollers to form what can sometimes be aggressive granules and powders into the final tablet. The dedicate punch tips are extremely vulnerable to accidental damage at various stages of this process. This article aims to analyze ZP9 tablet tooling damages from four aspects by real-life examples to explain how these problems could be avoided.
► Handling Damage
One of the most common damages is caused during handling process, including packing/unpacking the tooling, installing/uninstalling the tools in or out of tablet press machine, tool cleaning or maintenance procedure, and storage or transportation. Such kind of damage occurs on the punch-tip land area in the form of nicks and burrs. As a result, nothing but poor quality tablets could be made, or even further damages to both tooling and tablet making machine. To avoid or lessen the possibility of such kind of tooling damage, a better understanding of the nature of tooling, a careful maintenance and storage, and responsible handling operation are indispensable factors.
► Operating Judgment
Tablet failure or machinery malfunction can be occasionally related to inappropriate operating judgment. It seems that it is just a matter of operator’s observation by naked eyes, but, actually, it is also concerning operating conditions.
Tablet failure largely depends on the nature of punch tip, usually referred to as tip cup or cup where the tablets are formed, and the detail such as embossing or break lines are contained. Repeated compressure to the cup thousands of times per running hour is easily to cause broken tip edge and blending edge. At this moment, tooling condition should be optimized, or fatigue or brittle fracture would be found on the punch tip. The operator is required to have rich experience in observing machine running and punch tips condition, making appropriate decisions if something goes wrong. Keep a regular check on the machine as well as punch and die, and make a timely maintenance and replacement is critical for producing high quality tablets.
► Aggressive Formulations
Aggressive formulation can lead to the tooling damages like abrasion, pitting, corrosion and other similar problems. The ZP tablet tooling is generally fabricated from hardened and tempered steel, but it can be deteriorated quickly due to various granule aggressive formulas. The tool materials should be optimized in accordance with the formulation being compressed. Certain granules are so hard and coarse to scratch the punch tip, leaving some marks. While some formulas contain corrosive elements that react with the tooling material. Adjusting the granule materials or improving the quality of tooling are all effective ways to avoid corrosive issues.
► Die Wear
Die wear, also known as “die ringing” because the wear takes place in the area of the die bore where the tablet is compacted, is usually caused by the wear of long-time operation and the corrosion effect of abrasive granules and powders. The condition of the punch die surface is so important that directly related to the quality of the tablets and pills. Tablet problems like capping, chipping, delamination are some of the problems may possibly occur when die becomes wore. This type of wear can be reduced by using different zones in the die bore where the tablet is compacted or by the selection of a harder, more wear-resistant die material.Loading Likes...