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What is the main molding method of epoxy glass fiber board

What is the main molding method of epoxy glass fiber board

1. Hand lay-up-wet layup

Apply a release agent and a layer of medium-active liquid thermosetting resin with a viscosity of 0.3-0.4PaS to the surface of the mold in turn (after the gel coat is coagulated) and a layer of fiber reinforced materials. The fiber reinforced materials have surface felt and non-twisted coarse There are several kinds of gauze (checkered cloth). Use a hand-held roller or brush to impregnate the fiber reinforced material with resin, drive out air bubbles, and compact the base layer. The layup operation is repeated many times until the design thickness of the product is reached. The resin is cured at room temperature due to polymerization reaction. Can be heated to accelerate curing. At present, hand lay-up is the main form in my country, which accounts for about 80% of resin-based composite materials.

2. Resin injection and resin transfer RTM molding

RTM is a closed-mold low-pressure molding method. Place the fiber-reinforced material between the upper and lower molds; close the mold and clamp the mold; inject the resin under pressure; open the mold after the resin is cured, and remove the product. Before the resin gelation process starts, the resin must be filled into the mold cavity, and the pressure prompts the resin to quickly transfer into the mold and impregnate the fiber material.

3. Molding of sheet SMC (bulk BMC)

Add initiators, fillers, pigments, internal mold release agents, low-shrinkage additives, thickeners, etc. into the resin, and mix them to form a resin paste. The resin paste falls on the lower film of the SMC unit (commonly used polyethylene film or nylon film), and at the same time, it settles on the lower film and chopped into 25~55mm glass fiber strands, and then is covered with a layer of film to become a sheet. Sandwich roll. Store the coil for several days to thicken the material to reach a moldable viscosity. SMC is supplied as a backup in a bundled state. The coil is unrolled, cut, weighed, put in the heated steel mold platinum, pressurized to solidify and mold, and then the finished product is obtained.