Hand lay-up molding

Basically, the hand lay-up molding process was used, with 98wt% of the structure via... 

Chem. Descrip. Silicone-free polymeric sol n. with 84%. It. aromatic naphtha (CAS 64742-95-6), 6%. 1-methoxy-2-propanol acetate Uses Defoamer, air release agent for unsat. polyester laminating, spray-up, hand lay-up molding, gel coats, soiv.-free epoxy flooring systems, coatings... 

Compression molds and tooling are more expensive than hand lay-up molds. 

Uses Castings used for aircraft glazing, electrical components, decorative applications. Resins used for premix and prepreg molding materials, matched metal molding and hand lay-up molding. ... 

Halbmaske half-reaction (electrode potentials) Teilreaktion hammer mill Hammennuhle hand lay-up molding/ contact molding/ impression molding Handauflegeverfahren hand mill Handmiihle hand mold Handwerkzeug,... 

Lutrol OP2000 defoamer, hand cleaners Cetoleth-30 Chemal 2EH-2 Chemal 2EH-5 Chemal BN-5 Chemal CSA-10 Chemal OA-23/70 PEG-S butyl ether defoamer, hand lay-up molding BYK -A500 BYK -A501... 

The hand lay-up or spray-up process, used universally for the production of laminar composites incorporating glass fiber reinforcement, is most efficient for the manufacture of large parts, such as boats, bathtubs, tanks, architectural shapes, and recreational accessories. Resins intended for spray-up processes are usually modified with thixotropic additives, such as fumed siHca (1%), to reduce the risk of drainage when appHed over large vertical mold surfaces. Molds are also made from ERP for short-mn products usually surfaced with a tooling gel coat to provide consistent surface quaHty and appearance. 

Gel coats are pigmented polyester coatings appHed to the mold surface and are an integral part of the finished laminate. Gel coats are used widely on hand lay-up and spray-up parts to enhance surface aesthetics and coloration as weU as to provide an abrasion-resistant waterproof surface that protects the underlying glass-reinforced stmcture. 

Hand Lay-Up and Spray-Up. In hand lay-up, fiber reinforcements in mat or woven form are placed on the mold surface and then saturated with a Hquid polymer, typicaHy a polyester resin, that has been chemically activated to polymerize (cure) without the addition of heat. Multiple pHes of reinforcement and multiple cure steps aHow very heavy waH thicknesses to be achieved. 

For spas, shower stalls, bath tubs, etc, a gel coat containing no fiber reinforcement is appHed first to the mold. It forms a smooth, strong, impervious, durable chemical, weather, and wear-resistant surface. The bulk of the resin, which may be reinforced with glass fiber, is appHed by hand lay-up or by spray gun. The article is then cured at or near ambient conditions. 

Ease of cure, easy removal of parts from mold surfaces, and wide availabiHty have made polyesters the first choice for many fiber-reinforced composite molders. Sheet mol ding compound, filament winding, hand lay-up, spray up, and pultmsion are all weU adapted to the use of polyesters. Choosing the best polyester resin and processing technique is often a challenge. The polyester must be a type that is weU adapted to the processing method and must have the final mechanical properties requked by the part appHcation. Table 1 Hsts the deskable properties for a number of fiber-reinforced composite fabrication methods. 

Class C applies to hand lay-up, vacuum bag, and other methods using molds made of RP/C material. It applies to parts that would be covered by Class B when they are not molded with a high degree of care. 

Resin Transfer Molding Spray-up Hand Lay-up Mat-Preform Compound... 

Compression molding Filament winding Hand lay-up Mat molding Pressure bag molding Continuous pultrusion Injection molding Spray-up... 

Foam vs. Sheet Molding Foam vs. Hand Lay-up Foam vs. Injection... 

Thus, the fiber is impregnated in the partially cured resin. Depending upon the assembly the fiber is usually unidirectional, but they can also be made bidirectional or some other combination. The process of fitting the prepreg into, generally onto, the mold is called layup. Generally a number of layers of prepreg are used. The lay-up may be done by hand, called hand lay-up, or done automatically, or by a combination of automatic and hand layup. As expected, hand lay-up is more costly but is essential where one-of-a-kind products are produced. 

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