Clean rooms

Cleaning formulations Cleaning products Cleaning solvents Cleanness Clean rooms... 

Higher or lower quaUty at more or less cost will meet the needs of some consumers. Acetone is often produced under contract to meet customer specifications which are different from those of ASTM D329. Some specialty grades are analy2ed reagent, isotopicaHy labeled, clean room, Hquid chromatography, spectroscopic, ACS reagent (48), semiconductor (low metals), and Federal Specification 0-A-51G. 

Polyesters are also used in continuous filament spunbonded nonwovens (see Nonwoven fabrics). Reemay spunbonded fabric is composed of continuous filament PET with a polyester copolymer binder. These spunbonded fabrics are available in a wide range of thicknesses and basis weights and can be used for electrical insulation, coated fabric substrates, disposable apparel for clean rooms, hospitals, and geotextiles (qv). 

Other appHcations of firefly hioluminescence include measurement of the activity of bacteria in secondary sewage treatment activated sludge (296,297), detection of bacteria in clean rooms and operating rooms, measurement of bacteria in bottled foods, beverages (298), and pharmaceuticals (299), determination of the antimicrobial activity of potential dmgs (300), determination of the viabiHty of seeds (301), and measuring marine biomass concentrations as a function of ocean depth or geographical location (302). 

Nonwoven wipe categories include products for babies and adults, the food service and electronics industries, medical and clean room appHcations, industrial cleaning, computer diskettes, and household products such as dusters, tea towels, shoe cleaning cloths, towelettes, and hand towels. Nonwoven fabrics are used to filter air, water, petroleum (qv), food, and beverages. Nonwovens loaded with abrasives, cleansers, or finishes can be found in a variety of products used by many industries and in many homes to scour or poHsh. Also, a majority of garments designed to protect industrial workers and consumers from hazardous environments are made from nonwoven fabrics. 

Electrical Hazards. Because carbon fibers are conductive, the airborne filaments can create serious problems shorting out electrical equipment. The best option is to locate sensitive equipment in clean rooms outside of areas where carbon fiber is being processed. If this is not possible, electrical cabinets must be effectively sealed to prevent contact with carbon fibers. A filtered air-positive purge provides additional protection for sensitive equipment. 

Many of the fabrication processes for iategrated circuits are similar or coaceptuaHy related to those used ia the manufacture of ptinted wiring boards. However, because of the extremely fine device features, fabrication must be carried out ia clean rooms having strictly controlled environments. Particulate and chemical contamination are minimized, and temperature, humidity, and even vibration are carefully controlled. 

Eor health care facilities see NEPA 99. Clean rooms require superior static control measures where flammable liquids are handled. Smoke may be... 

Clean air lock After exiting the shower, the worker proceeds through a clean air lock area toward the clean room. This area has been used for hanging up respirators after cleaning to air dry. From the clean air lock the worker proceeds into the clean room. 

Clean room The clean room is an area where showered workers dry off, dress up in their street clothes, and exit the decontamination area. The clean room should have a clean locker for every worker. The... 

The order used to clean these areas may be intuitive, but for clarity s sake we should keep in mind the following principle. Cleanup should be performed in the cleanest areas first. For the five-stage decontamination area mentioned, cleaning should start in the clean room. In fact, cleaning should start in the cleanest area of the clean room, and then address each area in order of cleanliness. The last area to be cleaned will be the dirty room. If workers will be performing cleanup activities, they should be properly trained and qualified. If an outside service is utilized, those workers should also be trained and qualified [4]. 

The process itself often sets requirements on the ventilation parameters, and it also affects the ventilation—for example, by secondary flows coming from moving wires or trucks. A very special case is clean rooms, where the high purity requirements set strict target conditions for ventilation. 

The arrangement shown in Fig. 9.28 is used in industrial halls or auditoriums. Clean rooms have complex systems using laminar flow to ensure that the room IS fully ventilated. 

Figure 9.29 shows a typical arrangement of a laminar-flow clean room. The flow may be vertical through a perforated ceiling and floor. 

The following example illustrates some of these features. In a clean room with automated transporting and processing facilities, there are two quality classes of air. The space close to the small items under processing and the treating facilities should be exposed only to air of class A quality (very low contaminant level) and the rest of the room air is class B quality (normal standard). Figures 11.2 and 11.3 (see color insert) represent two out of a large number of parameter studies. 

Airlock A two- or three-door enclosure providing access to a clean room that reduces the air leakage of external pol luted air into the clean room. 

Bioclean classes The various standards of contaminant control to which clean rooms are held. 

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