PP as one of the common plastic materials, with excellent overall performance, good chemical stability, good molding performance and relatively low prices; but there PP strength, modulus, low hardness, low temperature impact resistance is poor, forming Shrinkage, easy to aging and other shortcomings.
In general, PP material tensile strength between 20M ~ 30MPa, bending strength between 25M ~ 50MPa, flexural modulus between 800M ~ 1500MPa. Therefore, it is modified so that it can be adapted to the needs of the product. Today, each modified PP has a large number of applications in the field of household appliances and automotive applications.
Long Glass Fiber
GF (glassfiber or fiberglass) is a kind of excellent performance inorganic non-metallic material, the advantage is good insulation, heat resistance, good corrosion resistance, high mechanical strength, but the disadvantage is brittle, poor wear resistance. One of the main uses of glass fiber reinforced materials for composite materials. Long glass generally refers to the length of more than 10mm glass fiber.
Long glass fiber reinforced PP plastic
Long glass fiber reinforced PP plastic refers to the length of 10 to 25mm glass fiber modified PP composite material, after injection molding process to form a glass fiber length greater than 3.1mm three-dimensional structure, the English LongGlassFiberpolypropylene, abbreviated as LGFPP. There is a lot of information at home and abroad will long-fiber reinforced thermoplastics referred to as LFT (Long-fiberreinforcethermoplastic). From the material definition, LGFPP belongs to LFT.
As a vehicle module carrier material, this material can not only effectively improve the rigidity, impact resistance, creep resistance and dimensional stability of the products, but also can make complicated automobile module products.
Long glass fiber reinforced PP particle morphology
Generally 12 mm or 25 mm in length, about 3 mm in diameter columnar particles. About 12mm of the length of the pellet is mainly used for injection molding, and about 25mm length of the pellet is mainly used for compression molding. In this particle, the glass fiber has the same length as the particle, the content of the glass fiber can range from 20% to 70%, and the color of the particle can be matched according to the requirement of the customer.
Why Ford company with long glass fiber reinforced PP, rather than short glass fiber reinforced PP?
In order for the glass fibers to function well in plastics to increase the strength, the length of the glass fibers must be made greater than their critical length Lo. The data show that when the fiber length less than the critical length of the fiber reinforced plastic subjected to a certain load, the fiber will be pulled out, the fiber strength can not be fully utilized. The critical length, Lo, is related to the specific plastic variety, and for a glass-reinforced polypropylene, the Lo is 3.1 mm.
This shows that the failure mode is mainly the fiber is pulled out and can not meet the strength requirements of the module carrier material. Therefore, the development and application of long glass fiber reinforced polypropylene and its injection molding technology, is to be prepared to enhance the length of glass fiber about 10mm of polypropylene raw materials, and through improved injection molding process to ensure that products in the glass fiber length 3.1mm the above.
Advantages of LFT vs. Short Fiber Reinforced Thermoplastic Composites:
• Long fiber length, significantly improve the mechanical properties of products.
• Higher stiffness and specific strength, better impact resistance, especially for automotive applications.
• Improved creep resistance, good dimensional stability and high part forming accuracy.
Excellent fatigue resistance.
• Better stability in hot and humid environments.
• During the forming process, the fibers can move relative to each other in the forming mold, resulting in less fiber damage.
Long glass fiber reinforced PP manufacturing process
Long glass fiber reinforced PP applications
Automotive: Front-end modules, door modules, shift mechanisms, electronic throttle pedals, instrument panel skeletons, cooling fans and frames, battery trays, bumper brackets, underbody fenders, sunroof frames, material. The use of this material in these areas has been greatly promoted in Europe and the current consumption is 20,000 T / Y.
Appliance industry: washing machine drum, washing machine triangle bracket, a brush roller, air conditioning fans, used to replace short glass fiber reinforced PA, APS cargo metal materials.
Communications, electronics, electrical appliances industry: telecommunications electronics industry, high-precision connectors, ignition components, coil axis, relay base, microwave oven transformer coil frame / frame, electrical connectors, solenoid valve package, scanner components.
Other: Electric tool housing, pump or meter housing, impeller, bicycle frame, snowboard, ground locomotive pedals, military / civilian safety helmets, safety shoes Baotou, used to replace short glass fiber reinforced PA, PPO and so on.