In Part I we saw the consequences of using low-cost (likely off-spec) raw materials or consumables – the expenditure of many resources and man-hours to track down contamination sources. Unfortunately, this scenario plays out all too often when sub-standard wipers are substituted (to “save money”) for a previously specified branded product that had been performing without incident or issue. Wipers play a unique role in the cleanroom. Of all the consumables used in the cleanroom, only the wipers are in close proximity or in actual contact with the manufactured product.
In the semiconductor industry, wipers are employed for cleaning the equipment used to process silicon wafers incorporating highly complex, submicron electronic circuitry. The wafers are in contact with surfaces that were cleaned with wipers and any contamination introduced by the wipers onto those surfaces can be transferred to the wafer, compromising the individual chips on the wafer. The cost impact can be in the hundreds of thousands of dollars.
In the medical device industry, wipers are used to wipe down the finished product prior to the terminal sterilization process. In this case, wipers are in actual contact with the product, and unless the wipers are of the highest quality, contamination (in the form of bioburden, particles, fibers, residues, etc.) can be transferred to the device and that contamination can be implanted in the patient. Not good.
You’ll end up paying many times the price difference.
If you’re using the highest quality wipers -the equivalent of gold - don’t substitute low- cost, sub-standard wipers - the equivalent of brass, which can be made to look like gold. You’ll end up paying many times the price difference.
Suppliers may suggest to their customers that they consider using private- label wipers as a cost-saving benefit. Experienced cleanroom supervisors and quality and process engineers are justifiably leery of such suggestions because of the possibility of unknown contaminants in the wiper – contaminants that could endanger the viability or yield of their products (see Part 1). Less knowledgeable individuals may be attracted to the cost-saving temptation, thinking all wipers are just white squares of fabric. These individuals and the suppliers of private-label wipers may be totally unaware of the immense amount of technology incorporated into branded wipers. Technology such as:
• Fabric selection, knitting and finishing for optimum abrasion resistance
• Edge sealing to minimize particles and fibers
• Laundering to optimize absorbency and minimize contaminants
• Testing to the strictest quality standards on every manufactured lot based on industry standards
• Lot to lot consistency
The quality of your consumables is incorporated into the quality of your products.
Strange as it sounds, branded, high-quality cleanroom wipers are often the least-expensive approach to guaranteeing product integrity and yield. Individuals who have tried private-label wipers have learned to their dismay that there is no truth to the phrase “a wiper is a wiper is a wiper”.