Application of Glass Fiber Reinforced Composites in Automobiles
  Non-metallic materials used in automobiles include plastics, rubber, self adhesive joint tape, friction materials, woven glass cloth, glass and other materials, involving petrochemical, light industry, textile, building materials and other related materials The industrial sector, so the application of non-metallic materials in automobiles, reflects a country's comprehensive economic and technological strength, and also includes a large number of related industries' technological development and application capabilities.

  The glass fiber reinforced composite materials currently used in automobiles include: reinforcing fibers, mat fiberglass reinforced thermoplastic materials, sheet molding compounds, resin transfer molding materials and hand lay-up FRP products.

  At present, the glass fiber reinforced plastics used in automobiles mainly include: PP fiberglass chopped strands, glass fiber reinforced PA66 or PA6, and a small amount of PBT and PPO materials. Reinforced PP is mainly used to make products such as engine cooling fan blades, upper and lower covers of timing belts, but some products have defects such as poor appearance quality and warpage, so non-functional parts are gradually filled with PP such as talcum powder and other inorganic fillers. alternative.
  Reinforced PA materials have been used in passenger cars and commercial vehicles, and are generally used to make some small functional parts, such as: lock body guards, safety wedges, embedded nuts, accelerator pedals, shift upper and lower guards - Protective cover, opening handle, etc. If the quality of the material selected by the parts manufacturer is unstable, the production process is improperly used or the material is not dried well, the weak part of the product will break.

  Plastic intake manifold is a new technology developed in recent years. Compared with aluminum alloy cast intake manifold, it has the advantages of light weight, smooth inner surface, shock absorption and heat insulation, etc., so it is widely used in foreign automobiles. , All the materials used in it are glass fiber reinforced PA66 or PA6, mainly using the fusion core method or vibration friction welding method. At present, relevant domestic units have carried out research in this area and achieved phased results.
With the requirements of light weight and environmental protection in automobiles, the foreign automobile industry is more and more inclined to use GMT materials to meet the needs of structural parts, mainly because stitched chopped strand mat materials have good toughness, short molding cycle, and production efficiency. It is regarded as one of the materials in the 21st century with a series of advantages such as high cost, low processing cost and no pollution to the environment, and is mainly used in the production of multifunctional brackets for passenger cars, instrument panel brackets, seat frames, engine guards, battery brackets Etc., the Audi A6 and A4 cars currently produced by FAW-Volkswagen have adopted stitch mat fiberglass materials, but they have not achieved localized production.

  In order to improve the quality of the whole vehicle to catch up with the international advanced level and achieve the purpose of weight reduction, shock absorption and noise reduction, relevant domestic units have carried out research on the production of GMT materials and product molding processes during the 8th and 9th five-year period, and have mass production. The capacity of GMT material, the production line with an annual output of 3000 tons roving mat material has been built in Jiangyin, Jiangsu, and domestic automobile manufacturers have also adopted GMT material in the design of some models, and have started batch trial production.
Sheet molding compound (SMC) is mainly composed of SMC roving, unsaturated resin, low shrinkage additives, fillers and various auxiliaries. It is an important glass fiber reinforced thermosetting plastic. The advantages of mass production and A-grade surface are widely used in automobiles. At present, there has been new progress in the application of foreign SMC materials in automobiles. Now, the largest application of SMC in automobiles is body panels, accounting for 70% of the amount of SMC, and structural parts and transmission parts are the fastest growing. In the next five years, the amount of SMC used in automobiles will continue to increase by 22% to 71%, while the growth rate in other industries will be 13% to 35%.
(1) High-content glass fiber reinforced sheet molding compounds are increasingly used in automotive structural parts, and two Ford models (Ex-plorer and Ranger) last demonstrated its performance on structural parts in 1995. Because of its multiple functions, it is widely considered to be very advantageous in structural design, so it is widely used in automobile dashboards, steering gears, radiator systems and electronic device systems.

(2) Application of low-density SMC materials The specific gravity of low-density SMC is 1.3. In practical applications and tests, it is 30% lighter than standard SMC, and the specific gravity of standard SMC is 1.9. Using this low-density SMC can reduce weight by approximately 45% compared to comparable parts made of steel.

(3) Other applications The application of SMC in automobiles, in addition to the above-mentioned new uses, is also used to produce other parts, such as: cab doors, inflatable roofs, bumper frames, cargo doors, sun visors, A And D pillars, body panels, roof drains, carport side rails, truck boxes, etc. Among them, the large amount is used for the outer panel of the body.