Characteristics of LFRT When designing parts with high rigidity and ultra-high toughness, LFRT-long glass fiber reinforced thermoplastic-is definitely the most cost-effective choice. Compared with the commonly used short FRP, the bending modulus and impact strength of long FRP are increased by 2 times and 4 times respectively, and can remain unchanged at -30℃. LFRT can meet the needs of a wide range of end users, and because of its high hardness, light weight, corrosion resistance, low cost and excellent processability, it can adapt to various products with complex structures and is the best choice to replace metals. Compared with other types of reinforced materials, its outstanding performance is mainly manifested in the following aspects: ● The unique non-oriented fiber network structure enables the material to maintain high mechanical properties under high and low temperature conditions and high and low frequency alternating environments; Excellent impact resistance, high modulus, high strength, low warping and thermal expansion coefficient close to metal; Isotropy, low shrinkage, low creep and high dimensional stability; Excellent wear resistance and fatigue resistance; Excellent chemical resistance; Excellent surface finish. Excellent formability: high fluidity, easy demoulding and little damage to screw. As early as 1980s, European and American countries put forward the concept of LFRT (or LFT, LFC, etc.). However, at that time, fiber impregnation technology, injection molding and compression molding technology of long fiber pellets and production equipment were relatively backward, and people made great progress in the research and application of short fiber reinforcement and filling of thermoplastics, which led to the slow progress of LFRT technology. In the mid-1990s, with the rapid development of the automobile industry and the enhancement of people's awareness of environmental protection and energy saving, lightweight automobiles began to become the development trend of new automobiles. This development trend of automobile industry makes people turn their attention to the research and development of LFRT again. Some world-class companies have developed a series of long fiber reinforced thermoplastic materials and corresponding preparation processes and equipment, each with core intellectual property rights. Azdel and Quadrant solved the technical problems of glass fiber mat impregnation and mass production equipment, and produced GMT (glass fiber mat reinforced thermoplastic composite) sheets. Ticona, RTP and Sabic solved the design problem of impregnation and impregnation die for long glass fiber and produced LFRT pellets. At the end of 200 1, GE Plastics acquired LNP Engineering Plastics Company of Kawasaki Steel Co., Ltd., the world's largest manufacturer of engineering thermoplastic blends, thus enhancing the blending business of GE engineering plastics. At the same time, GE and PPG Industrial Company * * * set up Azdel Company to carry out LFRT business; Krauss Maffei and Dieffenbacher solved the technical problems of screw structure and rapid pressing, and made breakthroughs in direct injection molding and direct compression molding of LFRT respectively. In a short period of three years from 200/kloc-0 to 2003, diefenbach sold more than 30 LFRT direct molding production lines, producing bumpers, dashboards and floor guards for Skoda, Polo, Passat, Touran, Golf, Mercedes-Benz A/E, Smart, BMW and Fiat Stilo. Environmental protection, energy saving and automobile lightweight have become the main driving forces for the rapid development of LFRT. In 2002, the output of LFRT reached 60,000 tons/year (in terms of regional distribution, PP accounted for 56%, PA accounted for 32%, and Europe and America accounted for 92%), and maintained a growth rate of about 30%. In 2006, the consumption in Europe alone was close to 654.38+400,000 tons. After rapid development in recent years, the proportion of Asia has also increased significantly. Application field LFRT long glass fiber reinforced thermoplastic LFRT has been successfully applied to the following industries: automobile industry: front-end frame, body door panel module, instrument panel frame, cooling fan and frame, battery bracket, bumper frame, seat frame, hood, pedal, fender, spare tire frame, etc. Household appliances industry: washing machine drum, pulsator, triangular bracket of washing machine, air conditioning guide fan, etc. Used to completely replace short fiber reinforced PA, ABS or metal materials. Electromechanical industry: catheter blades and motor filter covers, blades/coaxial cylinder clutch fittings/high-load, high-lift submersible motors, water pumps/thrust bearings, guide bearings/locomotive guide rails, vacuum pumps, compressor rotors, coil shafts, etc. Communication electronics industry: high-precision connector/igniter assembly, relay base/microwave oven transformer spool, frame/electrical connector, relay, solenoid valve package/scanner assembly, etc. Petrochemical industry: anti-corrosion and wear-resistant parts, platform grids, filters, reactor internals, etc. Others: power tool shell, bicycle skeleton, snowboard, ground motorcycle pedal, civil safety toe cap, safety helmet, water pump shell, impeller, etc.
Long fiber reinforced thermoplastic (LFRT) is one of the fastest growing materials in polymer composite industry. Its advantages of high specific tensile properties and recyclability enable it to replace metals and thermosetting composites in many fields of daily life. In addition to independently selecting reinforcing materials from various fibers and matrix from various thermoplastic polymers in LFRTs, its properties can be changed according to the needs of customers. This material already exists in the depths of the ocean and has been used in space, because they do not respond to temperature changes.
LFRTs has also become an increasingly valuable and popular part of building envelope components, such as windows and doors.