With the country's reform of motor vehicles, vehicle weight reduction has become a high-frequency word. Especially in various automobile-related forums or conferences, lightweighting has become almost the focus of discussion without exception.
In addition to carbon fiber materials, which materials can be used as a car's 'slimming tool'?
Long fiber reinforced thermoplastic composites
Long fiber-reinforced thermoplastic composites (LFT) are a new class of advanced lightweight materials in the field of fiber-reinforced polymers. With thermoplastic resins as the matrix, long fibers (mainly glass fibers and carbon fibers, 10-25mm) are used as fiber-reinforced materials. Thermoplastic composite material, with light weight, high strength, strong impact heat resistance, corrosion resistance, excellent molding processability, can be designed and repeated recycling, environmental protection and other properties, and has a high cost performance and low density, in the car Lightweight applications show better prospects.
The mechanical properties of the LFT are closely related to the length of the reinforcing fibers. Compared to similar short fibers (with fiber lengths less than about 1 mm), LFT materials have higher strength, impact resistance, energy absorption, etc. than injection molded thermoplastic composites. All aspects have been greatly improved. These characteristics also create conditions for LFT's more demanding application of automotive interior and exterior structural and semi-structural components, becoming one of the main reasons favored by the automotive industry.
Specifically, this material is mainly used for automobile dashboard skeletons, front-end modules (tank brackets), sunroof brackets, battery brackets, door brackets, hoods, shifters, accelerator pedals, etc. Take the instrument panel bracket as an example. It can meet the requirements of high fluidity, high stiffness, low creep, safety, dimensional stability, and light weight.
Glass fiber reinforced material
As one kind of inorganic non-metallic material, glass fiber performs particularly well in terms of insulation, heat resistance, corrosion-resistant mechanical strength, etc., but the disadvantage is brittleness and poor wear resistance. It is a glass ball or waste glass. The raw material is made by high-temperature melting, drawing, winding, weaving, etc. The diameter of its monofilament is several micrometers to 20 micrometers, which is equivalent to 1/20 to /5 of a hair. Each bundle of fiber strands consists of hundreds or even thousands of monofilaments. Glass fibers are commonly used as reinforcing materials in composite materials, electrical insulation materials and thermal insulation materials.
As early as many years ago, brand-name cars took the lead in the use of glass fiber and its composite materials, such as Lincoln Continental used SMC engine hood, bumper, rear trunk lid, glass fiber reinforced PET air-conditioning tubes, exhaust valves, etc. With the requirements for safety, comfort, environmental protection, and light weight of automobiles, the automotive industry both domestically and internationally prefers this material, which is based on its superior characteristics and enables it to replace some automotive semi-structured parts. Steel and aluminum.
It is understood that the LFT reinforcing fibers for automobiles are usually glass fibers. In theory, the proportion of such glass fibers in the products can reach 10% to 80% (referring to the mass ratio). In practice, the proportion of commonly used glass fibers is usually 20%. 40%. As a reinforcing material, glass fiber is usually used to make reinforced plastic or reinforced rubber, and its own characteristics make it more widely used in front-end modules, plastic fuel tanks, underbody guards, spare tire boxes, In many parts such as panoramic sunroof, engine lower plate, etc. The overall weight of the plastics steel lightweight technology used by each main engine plant is selected according to the models, and the outer decoration can bring more than 60kg of lightweight effect.
Natural fiber composites
Common natural fibers include wood fiber, hemp fiber, cotton fiber, bamboo fiber, etc. In many light-weight materials, natural fibers seem to receive less attention than others, but in the past two years, this material has also increasingly Appear in the public's field of vision, in which the proportion of wood fiber is the heaviest.
In the case of Volkswagen XL1, its interior parts, including ventilation ducts, all use wood fiber. Compared with the public Polo, after using wood fiber, the weight has changed from 184 kg to 80 kg. About 57%.
In addition to Volkswagen XL1, BMW, Audi, Mercedes-Benz and many other models also used this material in door panels, trim panels, seat backs, instrument panels, ABC columns, trunk lids and other components.