If you are a current cleanroom garment user, the true test is not by testing your garments, it’s by testing your product.  Most internal quality assurance departments have all the necessary equipment to test the critical components of their product.  A simple pareto analysis of the defects can be very revealing.  As an example, I once worked with a company that made glass for critical applications.  The glass was manufactured in a white room.  Defects that were cause for rejection were:  1) foreign objects embedded in the glass 2) scratches 3) discoloration 4) improper thickness.  When performing a pareto analysis of the rejected product, they learned that the number one reason for the rejection was foreign objects embedded in the glass. 

Display data in Pareto Chart form for easy analysis

A closer look revealed it was mostly fibers and hairs.  Upgrading their garment program from frocks to coveralls and adding bouffants and beard covers dramatically reduced their reject rate.  Once the program was in place for a while, a re-evaluation indicated the number 1 cause for rejects was now discoloration.  Upgrading the cleanroom garment program to full-face hoods certainly would not have any affect on the discoloration, so there was no reason to change the garment program further.If your product reject rate is low due to particulates and fibers, your garment program is working for you!  If you are finding particulates and fibers on or in your product, it’s time to re-evaluate your garment program.  Should you wear a different type of garment?  Perhaps a different fabric is in order?  Maybe your people are not changing garments frequently enough?  Start with the simple changes first and measure the affect on your product.

The garments that are processed in a cleanroom laundry should be tripled packaged in the laundry’s cleanroom environment.  At Tri State, each garment is bagged in a high grade, low particulate plastic bag.  The bag is hermetically sealed to assure no outside air can get in it until the seal is broken.  A number of these individual bags are then placed in a secondary bag.  Then a couple of these bags are placed in a tertiary bag.  The content of the bag is noted, usually with the kind of garment, size and quantity.  Now this final bag is ready to leave the Class 10 (ISO4) environment of the cleanroom laudnry.  It is helpful to the end user if the content is all coveralls, all hoods or all boots.  This way the bag can be stored somewhere outside the end users change area until that item is needed. 

Remember, the outside bag has been in contact with many environments in its travels.  When the person responsible for maintaining the change area and its inventories is ready to bring the garments into the change area, they first remove that outer bag outside the change area environment.  They can then bring the secondary bag into the change area (if you recall the outside of this bag was only exposed to the cleanroom laundry’s Class 10 environment).  Therefore no unnecessary contaminants are brought into the change area and there is no need for the person to wipe down the outside of the bag.  The person then removes the secondary bag, and places the primary garment bags in the bins or lockers.  The garments remain in their primary bags until a person is ready to wear them.

If garments are hung between uses, they should be hung in the change area “downwind” from where the clean garments are stored.  The most likely spot is nearest the outer door.  The cleanest air in the change area should be reserved for the cleanest items stored in the change room, including the packaged garments, wipers, swabs, and other consumable items.

Lot numbers may be printed on labels with other pertinent information

Lot numbers on each package of cleanroom clothing can be extremely beneficial to the end user.  When a garment is taken out of a package and there appears to be a problem with it you know would have effected every garment in the batch process, then having the packages each identified with their lot number makes it real handy to pull only those garments you know are effected.  Also, if the end user asks for a change in garment processing, such as the addition or elimination of a softener, it is easy to tell by the lot number identifications which garments were processed before and after the change.

If a wearer finds a non-conformance, such as the garment is still damp, in disrepair, or stained, they can provide that lot number to the uniform service supplier to assist in the investigation and hasten corrective action.  If the end user suspects that garments may be contributing to high particle counts in their room, providing the lot nmber identification to the supplier will allow them to provide you with the data surrounding the batch processing of those garments.  This might include critical criteria such as wash temperatures and chemicals, what other garments were processed with yours, cleanroom HVAC gauge readings, and garment test results.

Lastly, the lot numbers are extremely helpful in inventory control.  People who are responsibe for setting up the garment packages in a change area should rotate the inventories for first in, first out use.  This would help make certain all inventories receive the same amount of wear and washings over time.  The lot numbers also help to determine how well the inventories are being used.  When inventories are used most efficiently, lot numbers would only be 3-5 weeks old by the time the garment is worn.  If packaged garments in your inventory have lot nmbers that are 20-50 weeks old, you have more garments than you need.  If the lot numbers are only 1-2 weeks old, you don’t have enough and risk shortages.  In either case it’s time to adjust your inventories.