Reinforced-plastic pressure-curing

Storage May develop pressure vent bottle periodically Uses Polymerization initiator/catalyst/crosslinking agent for cure of unsaturated polyester resins in gel coats to eliminate or reduce porosity mfg. of acrylic resins hardener for fiberglass-reinforced plastics catalyst in food-contact crosslinked polyesters Regulatory FDA 21 CFR 177.2420... 

The terms reinforced plastics (RP) and composites refer to combinations of plastic materials and reinforcing materials, usually in fiber form (chopped fibers, porous mats, woven fabrics, continuous fibers, etc. see Fig. 7-1). Both thermoset (TS) and thermoplastic (TP) resins are used. When modern RP industry started in 1940, glass-fiber-reinforced unsaturated polyester (TS), low pressure or contact pressure, curing resins were used. Today about 60 percent of the plastics industry uses many different forms of glass fiber-polyester composites. In this chapter the abbreviation RP will be used, and in references to polyester resin it will refer only to TS, as relatively little TP polyester is used in RPs. 

This process is an economical press molding method for manufacturing an intermediate number of parts, such as 200 to 2,000. It uses low-pressure, room-temperature curing resins, and inexpensive molds. Cold press is similar to compression molding except that the resin curing action occurs via its own exothermic heat of reaction (after resins are mixed with catalyst, etc.). Pressures are moderate, usually 20 to 50 psi. Thus molds can be made of relatively inexpensive metals, plaster, or reinforced plastics. The edges need not be trimmed. Ribs, bosses, and other fairly complex shapes are not easily produced. Two good mold surfaces are obtained. 

A closed vessel for conducting either a chemical reaction or other operation (e.g., cooling) under pressure and heat. Autoclaves are widely used for bonding and curing reinforced plastic laminates. 

Autoclave 6-to- klav [F, fr. aut- + L clavis key] (1876) n. A strong pressure vessel with a quick-opening door and means for heating and applying pressure to its contents. Autoclaves are widely used for bonding and curing reinforced-plastic laminates such as polyesters, epoxies, and phenolics. They are closed vessels for conducting a chemical reaction, sterilization or other operation under pressure and heat. 

---