Elastomeric sheets

Data for thermal movement of various bitumens and felts and for composite membranes have been given (1). These describe the development of a thermal shock factor based on strength factors and the linear thermal expansion coefficient. Tensile and flexural fatigue tests on roofing membranes were taken at 21 and 18°C, and performance criteria were recommended. A study of four types of fluid-appHed roofing membranes under cycHc conditions showed that they could not withstand movements of <1.0 mm over joiats. The limitations of present test methods for new roofing materials, such as prefabricated polymeric and elastomeric sheets and Hquid-appHed membranes, have also been described (1). For evaluation, both laboratory and field work are needed. 

Waterproof. Waterproofing barrier systems may be either hot- or cold-appHed. The hot-appHed generaUy involve a bituminous material such as asphalt used in conjunction with a reinforcing fabric such as roofing felt, cotton, or glass cloth. Cold-appHed can be bituminous or elastomeric materials either in Hquid or sheet form, with or without fabric reinforcement. Liquid elastomeric treatments include neoprene, polyurethanes, and blends of these or epoxies with bituminous materials. Among the commonly used precured elastomeric sheet materials are neoprene, polyisobutylene, EPDM mbber, and plasticized PVC. Polyethylene and PVC films and nonwoven plastic or glass fabric coated with bituminous materials also find use (78). Because these... 

The first use for butyl mbber was ia inner tubes, the air-retention characteristics of which contributed significantly to the safety and convenience of tires. Good weathefing, ozone resistance, and oxidative stabiUty have led to appHcations ia mechanical goods and elastomeric sheeting. Automobile tires were manufactured for a brief period from butyl mbber, but poor abrasion resistance restricted this development at the time. 

Chlorosulfonated polyethylene Hypalon DuPont Elastomeric Sheeting... 

One invention consists of a multipurpose cleaner/primer for roofing membranes. These elastomeric sheets are normally powdered with talc to prevent interlayer sticking in the roll. Instead of using separate cleaning solvent followed by a primer application the... 

The elastomeric sheetings made out of butyl and polychloroprene rubbers were first introduced as barriers against water migration. In the early 1960s, EPDM rubbers were commercially available. Considering the superiority of EPDM-based membrane over other elastomers, its application to construction industry as moisture barrier was first introduced in the United States about 30 years ago. 

Poly[0.89(GVGVP),0.11(GNG T)] was y-irradiation cross-linked using a dose of 20 Mrads to form an elastomeric sheet, designated as X -poly[0.89(GVGW), 0.11(GNG T)]. The sheet was cut into 1 cm pieces. One such piece was then... 

Tear resistance is the measure of stress required to continue rupturing an elastomeric sheet, usually after an initiating cut. 

The non-vulcanized or imcured rubber sheets that are self-curing are gradually cured on the roof by heat from the sun. Once they are cured, their behavior is similar to that of cured elastomers. If they are not self-curing, they remain uncured and exhibit properties similar to thermoplastics during their service life. In general, elastomeric sheets have good... 

Hi-Tuff Precision Elastomeric Sheeting, Technical Bulletin, Stevens Molded Products—a Department of J. P. Stevens Co., Inc., Easthampton, Mass. 

The main development of the filter press from the simpler versions just described has been to include an impervious elastomeric sheet in each plate compartment (one for each plate on the feed side of the filter medium, butting up against the corresponding sheet of the next plate). These flexible sheets can be inflated pneumatically so as to press down on the drained cake, once filtration is complete, and so dewater it by compression. This type of filter press is then known as the diaphragm filter press (as shown in Figure 3.72). (Initially this sheet was referred to as a membrane, and the term membrane filter press became quite confusingly well-known. 

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