Preparation method for SMC composite material

Abstract

The invention relates to a preparation method for an SMC composite material. The preparation method comprises the following steps: successively adding 18 to 25 parts of unsaturated resin, 18 to 22 parts of a low-profile shrinking agent, 6 to 9 parts of thermoplastic, 0.4 to 0.6 part of an auxiliary agent, 0.3 to 0.6 part of a curing agent, 2 to 4 parts of an internal release agent, 0.15 to 0.3 part of a polymerization inhibitor, 34 to 38 parts of an inorganic filling material, 6 to 9 parts of PE powder and 0.8 to 1 part of a thickening agent so as to prepare a resin paste; uniformly coating a high-density polyethylene film with the prepared resin paste in a scraping manner, cutting 24 to 26 parts of glass fiber into the glass fiber with a length of 2 to 3 CM, uniformly dispersing the cut glass fiber between upper and lower high-density polyethylene films, and allowing the resin paste and the alkali-free glass fiber to be completely impregnated so as to form a sheet material; thickening the sheet material at 40 to 45 DEG C for 6 to 12 hours so as to obtain an SMC sheet material molded plastic; and placing sheared SMC sheet material molded plastic into a mold, carrying out mold molding at a temperature of 145 to 155 DEG C, maintaining pressure for a period of time, and carrying out processes like mold closing, demolding and trimming so as to obtain a final product. The preparation method provided by the invention prepares an SMC product with low density, good mechanical properties and high gloss surface.

Description

technical field [0001] The invention relates to a method for preparing an SMC composite material, in particular to a method for preparing a lightweight SMC sheet for automobiles. Background technique [0002] SMC is the English abbreviation of Sheet Molding Compound. The middle core material is composed of glass fiber impregnated with resin paste, and the upper and lower sides are covered with polyethylene film. It is a raw material for dry manufacturing polyester FRP products: among them , The resin paste contains various components such as unsaturated polyester resin, low shrinkage additive, internal mold release agent, styrene, thickener, etc., forming a "sandwich structure". In 1953, the United States (Rubber) first invented the chemical thickening of unsaturated polyester resin. In 1960, West Germany Bayer realized the industrial production of SMC. SMC in the world market began to take shape in the late 1960s, and has been growing at an annual rate of 20%-20% since the...

AI Technical Summary

Problems solved by technology

[0003] The use of composite materials in the automotive industry has been relatively popular. Although it can meet the needs in terms of mechanical and weather resistance, there is no major breakthrough in the lightweight of automobiles, and the density of SMC composite materials cannot be reduced.

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