Improvement method of LFT Reinforced thermoplastic material process
LFT stands for Long Fibre Reinforced Thermoplastics and in the automotive composites industry refers to products made by blending and producing reinforcing fibres of more than 10mm in length with thermoplastic polymers that have low density, high specific strength, high specific modulus and high impact resistance. For LFT-G materials for injection moulding, the retention of fibre length is a major control point in the moulding process. Improvements can generally be made in three areas: Technique process, equipment and mould.
01-Technique-Process
The back pressure needs to be reduced to avoid excessive shear and the screw speed should be slowed down to avoid solid, unmelted material damaging the fibres. Therefore, the melting of the material is largely dependent on the heating of the barrel and should be set at a higher processing temperature. The injection speed should be as low as possible to minimise the effect of shear on fibre length as long as the filling can be complete.
02-Equipment
A screw with less compression and a non-return valve with a smaller shearing action can be chosen. The nozzle can be a straight-through nozzle, as the higher viscosity of the LFT material will not cause salivation and will also reduce the shearing effect of the nozzle on the glass fibre.
03-Molds
Small diameter gates should be avoided to introduce shear and fracture the fibres. Due to the high viscosity of the fibre reinforced resin, it is recommended to use fan gates or round gates instead of point gates. For the runners, a rounded structural design and circular cross-section should also be chosen in order to reduce the loss to the fibres. Long fibre composites require twice the amount of gas emissions than unreinforced materials. To provide additional venting, deeper venting slots can be used. Due to the high viscosity of long fibre materials, the problem of flying edges can be avoided.
Xiamen LFT composite plastic Co., Ltd. is a high-tech enterprise specializing in the development and operation of polymer materials industry.Focus on the production of engineering plastics and special engineering plastics, widely used in high-speed rail, aviation, electrical appliances, automobiles, electronics and other industries.For the fundamental purpose of reducing the weight of structural performance components, the long fiber reinforced modification is developed into an economical and functional plastic instead of metal.Reduce the investment risk of customers, for customers to bring greater benefits.
