The laundering of ChemStat garments must be done correctly to retain the durability, longevity, and smooth looks designed into the ChemStat fabrics. If the concluding recommendations are heeded, ChemStat users can expect many years of satisfaction from their garments.
Cleanroom garments require frequent laundering to prevent a buildup of particulates and sebaceous oils from the skin. Sebaceous oils in particular can adversely affect the static-dissipative properties of cleanroom fabrics.
NASA and EOS/ESD specify 2 to 4 initial pre-launderings prior to initial use of any static-dissipative cleanroom garment to ensure removal of embedded oils and fatty acids imparted to the fabric and garment during manufacture.
For cleanrooms with very low Class ratings, daily changes and launderings are recommended. ChemStat fabrics have been designed for a very high frequency of launderings without any lessening of performance under normal cleanroom and cleanroom laundry conditions.
The polyester fibers in ChemStat fabrics are subject to more rapid degradation in alkaline environments than in acidic environments. Therefore, the wash water should be neutralized as closely as possible to a pH value of 7.0 (or slightly less for tolerance). This is especially important in the final rinse prior to drying; elevated drying temperature accelerates fiber damage, when pH increases to less tolerable levels as the moisture evaporates.
In addition to affecting pH in the drying process, the moisture content can contribute to hard wrinkling if the temperature is allowed to rise above 130°F (55°C).
The temperature and pH of the water should be monitored and recorded continuously to prevent premature fabric wear and abnormally high particle counts. To ensure low particle counts, the laundering of ChemStat 909A Plus, ChemStat 959 Plus, and ChemStat 969 Plus may also neccesitate more thorough rinsing cycles than with conventional fabrics, due to their higher particle filtration efficiency.
Do not use chlorine bleach. Chlorine bleach will not enhance the brightness of color and will attach the polyester fibers, reducing fabric strength noticeably.