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Pharmaceutical Technology TRENDS IN MANUFACTURING 2022 eBOOK 13 long due to ineffective cleaning and drying proce- dures (Figure 3). Another common problem found during the as- sessment step is granule wear, including abrasion, impregnation, and pitting. If the granule being com- pressed is particularly hard and abrasive, the tooling will wear faster (Figure 4). Regular assessment will give an indication of when the abrasion starts and when repair may be required. It is recommended to always check tooling when it is removed from the press and at regular intervals when not in use. Assessment should be performed using digital equipment that delivers high magnifi- cation, additional lighting, and the benefit of image sharing for further evaluation. Restoring order through repair Repair is advantageous for many reasons, it will recondition the surface finish of uncoated tool- ing, rectify minor damage, preserve tablet image and definition, prevent breakages, and keep tablet problems to a minimum. Any repairs should be completed following assessment. Tooling that has suffered light surface wear, cor- rosion, and minor damage can be repaired back to a useable condition. This should only take place when absolutely necessary and never on coated punches as a result of the abrasive nature of repair; repairing coated punches increases the risk of compromising the functional performance of the coating (Figure 5). A motorized chuck along with a double ended polishing motors, used in conjunction with abra- sive remedial polishing accessories is an effective method of repairing. It is vital, however, that the repair is accurately and extensively completed by skilled technicians to ensure that the tooling toler- ance limits are not altered out of specification. Check critical dimensions Measuring and controlling tooling dimensions can give a good indication of when tooling needs to be replaced. Measurement is fundamental in the pro- duction of tablets and the fourth step in the mainte- nance process. Measurement is important to dimensional con- trols and ensures the critical tool dimensions are always met. This includes the working length on the punch (from the bottom of the cup to the head Figure 2. Ultrasonic is the most effective cleaning method to ensure tooling is clean and free from contaminant. Figure 3. One of the key contributors for corrosion that we see, is incorrect or poor maintenance procedures.