LFT-D (Long Fiber Reinforced Thermoplastic Direct) forming process of composite building template

Abstract

The invention provides an LFT-D (Long Fiber Reinforced Thermoplastic Direct) forming process of a composite building template. The forming process comprises the following steps of (10) performing quantitative measurement on resin from a vacuum feeding system to a vector type weighing system according to the weight of the template; then feeding the resin to a first-stage twin-screw extruder to be heated and fused; feeding into a second-stage twin-screw extruder in a feed opening of the second-stage twin-screw extruder together with glass fibers, so as to be mixed and plasticized, wherein the glass fibers are cut according to the set length of 24 to 25mm by a glass fiber measuring and cutting device and then are added into the fused resin; performing the secondary length change under the shearing action of the fused resin; and (20) uniformly plasticizing by the second-stage twin-screw extruder, cutting raw materials by a second-stage screw die cutter according to the weight of the template, then insulating and conveying to a material taking and displacement position and putting the raw materials into a press mold by a manipulator for pressing and forming. By using the forming process, the glass fibers in a product are long, and the performance of a product is effectively improved.

Description

technical field [0001] The invention relates to a molding process of building templates, in particular to an LFT-D molding process of composite material building templates. Background technique [0002] Most of the internal fiber lengths of the composite templates currently being produced are in the range of 0.2 to 0.4mm due to their technology. Fiber length is the most important factor determining the performance of fiber-reinforced composite materials. Long fibers have a stronger reinforcing effect than short fibers. . The traditional LFT (LFT is the abbreviation of Long-Fiber Reinforce Thermoplastic in English, translated into Chinese as long fiber reinforced thermoplastics or customarily called long fiber reinforced thermoplastic composites) process is a prepreg process, including melt impregnation, solution impregnation and powder Dipping etc. The process of prepreg tape is complicated and the cost is high, which limits the application of LFT process. [0003] The LF...

AI Technical Summary

Problems solved by technology

Although this invention can obtain longer fiber lengths to reach the requirements of the final product, the D step in the process has the following defects in cutting the roving by the screw in the twin-screw extruder: 1. the process passes the number of screw revolutions and the glass fiber The amount of glass fiber added is controlled by the number of roots, so it is impossible to flexibly and accurately control the weight of glass fiber added, and it is not easy to change the proportion of glass fiber added; ②The method of screw shearing cannot ensure that the glass fiber is evenly mixed in the resin melt; ③Using the present invention The glass fiber is pre-cut by the metering and cutting system to ensure that the glass fiber is pre-dispersed to a certain extent in the PP melt before the two are mixed and dispersed in the screw, which reduces the wear of the screw; ④ the process of the present invention occurs when the glass fiber It can be automatically connected when it is interrupted abnormally, without stopping the processing

[0005] In addition, there is no specific information about the LFT-D process used to prepare building templates.

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