LFT-D molding process for glass fiber reinforced PA

Abstract

The invention provides an LFT-D molding process for glass fiber reinforced PA. The molding process comprises the following steps: step 10, adding PA into a one-band double-screw extruder, carrying out melting and plasticizing and allowing a molten PA material to form a polymer film through the die head of the one-band double-screw extruder; step 20, cutting a glass fiber into sections, wherein each section is 24 to 25 mm long; step 30, combining the cut glass fiber sections and the polymer film and dispersing the cut glass fiber sections into the polymer film; step 40, allowing the combined glass fiber sections and the polymer film to enter a double-band double-screw extruder together, uniformly mixing the glass fiber and the PA under the shearing effects of screws and carrying out extrusion; and step 50, cutting a mixture of the glass fiber and the PA and placing the cut mixture in a compacting die for compression molding in virtue of a manipulator. The process has the following main advantages: the step of preparation of a semi-finished product is omitted, direct one-step production is realized, and possibility that the fiber is cut is improved.

Description

【Technical field】 [0001] The invention relates to an LFT-D molding process of glass fiber reinforced PA. 【Background technique】 [0002] Both GMT (fiber-reinforced thermoplastic sheet, GMT for short) and LFT-G (a long fiber-reinforced thermoplastic material) require two mature processes, namely: sheet (pre-impregnated) molding and product compression molding / long Forming of pellets and injection molding or compression molding of articles. Among them, it is difficult to realize the granulation process of long glass fiber reinforced PA (PA, polyamide, commonly known as nylon). Long glass fiber reinforced thermoplastic pellets are long fibers that are evenly dispersed and wrapped in a resin matrix after passing through a special die. In, and cut into strips of different lengths according to needs, the fiber length is the same as the length of the pellets. Due to the high viscosity of PA, the melt is easy to cool and solidify, which is not conducive to the full infiltration of...

AI Technical Summary

Problems solved by technology

Due to the high viscosity of PA, the melt is easy to cool and solidify, which is not conducive to the full infiltration of fibers, and it is difficult to achieve uniform dispersion of long fibers in the resin matrix, and poor impregnation makes it difficult to cut during the granulation process, and pumping will occur during the cutting process. silk, flying silk, etc.

Moreover, during the extrusion process, the fiber length is shortened after being sheared by the screw, and the fiber is further sheared after injection molding to become shorter, and the reinforcing effect of the glass fiber is further weakened.

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