LFT-G® Polyamide 66 Long Carbon Fiber Filled Compounds Injection molding pellets

What is LFT Materials?

LFT long fiber reinforced thermoplastic engineering materials,compared to ordinary short fiber reinforced thermoplastic materials (fiber length is less than 1-2 mm), the LFT process produces thermoplastic engineering material's fibers in lengths of 5-25 mm. The long fibers are impregnated with the resin through a special mold system to obtain long strips that are fully impregnated with the resin ,and then cut to the length as required. The most used base resin is PP, by PA6, PA66, PPA,PA12,MXD6,PBT, PET,TPU,PPS, LCP,PEEK, etc. Conventional fibers include glass fiber, carbon fiber,special fibers include basalt fiber and quartz fiber, etc. Depending on the end use, the finished products can be used for injection molding,extrusion, molding, etc., or directly used for plastic instead of steel and thermoset products.

Long carbon fiber reinforced composites can solve your problems when other methods of reinforced plastics do not provide the performance you need or if you want to replace metal with plastic. Long carbon fiber reinforced composites can cost-effectively reduce the cost of goods and effectively improve the mechanical properties of engineering polymer. Long fibers can be uniformly distributed inside the product to form a network skeleton, thus improving the mechanical properties of the material product.

What is Polyamide 66 Long Carbon Fiber Reinforcement?

Nylon 6,6, also written as nylon 6-6, nylon 66, or nylon 6/6, is a more crystalline version of nylon 6.  It is also referred to as polyamide 66 or PA 66.  It has improved mechanical properties due to its more ordered molecular structure.  Nylon 66 for machining has improved temperature resistance and lower rates of water absorption when compared to standard nylon 6. The advantages of nylon 6,6 are that the yield strength is higher than nylon 6 and nylon 610.  It has high strength, toughness, rigidity, and low coefficient of friction in a wide temperature range.  In addition, it is oil resistant and resistant to chemical reagents and solvents. However, PA66 has strong hygroscopicity and poor dimensional stability, which limits its application.  In order to obtain nylon 66 engineering material with higher strength, it should be modified by carbon fiber reinforcement.

The mechanical properties of long carbon fiber reinforced nylon 66 (LCFR-PA66) are obviously better than those of short carbon fiber reinforced nylon 66 (SCFR-PA66), and the molding processing performance is also better.  It can be molded by various molding methods such as injection molding and compression molding, and complex components can also be formed. Therefore, long carbon fiber reinforced nylon 66 can be widely used in building materials, aerospace, electronic devices, furniture and other fields, especially in the automotive industry application market.

The production process of long carbon fiber reinforced nylon 66 is different from that of short carbon fiber reinforced nylon 66. The short carbon fiber reinforced nylon 66 particle is chopped under the friction and shearing of screw and barrel, and the short carbon fiber reinforced nylon 66 particle is obtained with the length of carbon fiber monofilament about 0.5mm.  The length of some carbon fiber monofilament in the final product is lower than the critical length of reinforcement, and the carbon fiber is easy to be extracted from the nylon 66 matrix when the product is stressed.  The strength of carbon  fiber is not fully utilized, and the mechanical properties of the product are not high.

Long carbon fiber reinforced nylon 66 has better reinforcement effect and dimensional stability, and the rigidity, tensile, bending, impact resistance and fatigue resistance of the manufactured products are better, and the service life is longer.

Q & A

Q: Does long glass fiber and long carbon fiber injection have special requirements for injection molding machines and molds?
A: There are certainly requirements. especially from the product design structure, as well as the injection molding machine screw nozzle and mold structure injection molding process must consider the requirements of long fiber.

Q. The product is easy to brittle, so changing to use long fiber reinforced thermoplastic materials can solve this problem?
A: The overall mechanical properties must be improved. The characteristics of long glass fiber and long carbon fiber are the advantages in mechanical properties. It has 1-3 times higher (toughness) than short fiber , and the tensile strength(strength and rigidity) is increased by 0.5-1 times. 

Q. How to choose the reinforcement method and length of the material when using long fiber reinforced thermoplastic material?
A: The selection of materials depend on the requirements of the products. It is necessary to assess how much the content is enhanced and how much length is more appropriate, which are depending on the performance requirements of the products.