Sheet molding

Sheet molding uses three groups of fillers for different purposes metal oxides for curing, fibers for reinforcement, particulate fillers for variety of other purposes such as improvements in mechanical properties, chemical resistance and surface appearance. The technology is very well documented. [Pg.772]

Fillers are used in these products to improve mechanical properties or impart flammability resistance. Fillers are frequently silane-treated to further improve mechanical properties. Fillers must have a low moisture (below 0.1%), a low absorption of resin, and are expected to impart thixotropic properties. There are special cases. For example, if peroxyketals are used as initiators, basic fillers have to be used because acidic fillers interfere with cure times and the shelf-life of the composition. Shape and particle size distribution must be considered in filler selection to impart the desired rheological properties. Calcium carbonate is the most popular filler but aluminum trihydrate, anhydrous calcium sulfate, and silica are also frequently used. Barite is well suited to this application, especially if acid [Pg.772]

Glass fiber is used for reinforcement. The glass fiber must be properly surface sized to give the best mechanical performance and fire resistance. Good fiber wetting and low moisture content are also required. [Pg.773]

Many defects in molded sheet can be related to fillers. Blistering may be caused by moisture but also by insufficient wetting of fibers and entrapped air pockets. Inconsistent cure and thickening is caused by the presence of moisture. Improper fiber orientation may initiate Ifacture cracks. Flow marks, streaks, warpage, and protruding fibers are also caused by improper fiber orientation. [Pg.773]

Properties Glass-filled Mineral-filled Sheet Molding Sheet... [Pg.1030]

HDPE, high density polyethylene PP, polypropylene EVA, ethylene—vinyl alcohol SMC, sheet-molding compound ERP, fiber-reinforced plastic LDPE, low density polyethylene PE, polyethylene BMC, bulk mol ding compound TPE, thermoplastic elastomer. [Pg.369]

Composites. The history of phenoHc resin composites goes back to the early development of phenoHc materials, when wood flour, minerals, and colorants were combined with phenoHc resins to produce mol ding compounds. In later appHcations, resin varnishes were developed for kraft paper and textile fabrics to make decorative and industrial laminates. Although phenoHcs have been well characterized in glass-reinforced composites, new developments continue in this area, such as new systems for Hquid-injection molding (LIM) and sheet-molding compounds (SMC). More compHcated composite systems are based on aramid and graphite fibers. [Pg.307]

PhenoHc sheet-molding compound is seeing increased use in interior and exterior appHcations in mass transit. The trains in service on the English Channel tunnel have several panels made from phenoHc SMC which had to meet the strict European safety standards for fire and smoke generation. [Pg.307]

Sanitary ware, including tubs, showers, combined units, basins, and toilet tank, may be made of thermoformed ABS or acryHc sheet, molded glass-fiber-reinforced polyester, or cast acryHc resins. The glass-polyester type dominates the tub/shower market. It is possible to install the units as a two-component system, assembled in place. Gel coats may be of thermoformed decorative acryHc skins. To reduce the smoke generated by fire, methyl... [Pg.336]

Cellulose esters, especially acetate propionate and acetate butyrate mixed esters, have found limited use in a wide variety of specialty appHcations such as in nonfogging optical sheeting (171), low profile additives to improve the surface characteristics of sheet-molding (SMC) compounds and hulk-molding (BMC) compounds (172,173), and controlled dmg release via encapsulation (174). [Pg.261]

SMC = sheet molding compound BMC = bulk molding compound. [Pg.18]

Values measured with 2 mm thickness sheet molded by iujection molding machine set at cylinder temperature 150°C, mold temperature 20°C. [Pg.532]

Two-component urethane adhesives are used to bond sheet molding compound (SMC) panels for automotive OEM and aftermarket applications. Two-part urethanes are used as laminating adhesives in the RV industry. [Pg.795]

Sheet molding compound (SMC) consists of randomly oriented chopped fibers in a matrix of resin and filler. SMC is produced in the continuous manner shown in Figure 1-16. Note that the polyethylene film protects the roller system from getting gummed up with the resin-filler paste. The rug-like rolls of SMC are then used in compression molding machines to create large parts such as the sides of cars and trucks. [Pg.22]

Methyl methacrylate ch3 j J Plexiglas, Lucite Paint, sheets, moldings... [Pg.242]

There are many ways in which foams can be processed and used as slabs, blocks, boards, sheets, molded shapes, sprayed coatings, extruded profiles, foamed in place in existing cavities, in which the liquid material is poured and allowed to foam, and as structural foams (Chapter 6, STRUCTURAL FOAM). Conventional equipment such as extruders, injection, or compression machines is used. However specially designed machines are available to just produce foamed products. [Pg.496]

Design Parameter Resin-Transfer Molding Spray-up Hand Lay-up Mat/Preform Sheet Molding Compound... [Pg.525]

Foam vs. Sheet Molding Foam vs. Hand Lay-up Foam vs. Injection... [Pg.562]

Shear modulus, polyamide, 138 Sheet molding compounds (SMCs), 30 Shoe sole products, 205 Shore hardness gauge, 243 Side-chain liquid crystalline polymers, 49 Side reactions, in transition metal coupling, 477... [Pg.600]

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