Two-step preparation method for light and high-strength fiber composite material product through heat self molding (HSM) heat self-expansion prefabricated core material

Abstract

The invention discloses a two-step preparation method for a light and high-strength fiber composite material product through a heat self molding (HSM) heat self-expansion prefabricated core material. Firstly, shapable pre-forming heat self-expansion high-energy glue is put into a product core material mould, and the mould is closed tightly, and heating is conducted at the temperature of 80-100 DEG C for 3-30 min; the glue is expanded slightly, wherein the volume multiplying power before and after slight expansion is 1.01-1.5, a core material mould cavity is fully filled with the glue, and cooling and demoulding are conducted; and then the glue is wrapped with a fiber prepreg cloth and then put into a forming mould, the forming mould is closed tightly, heating is conducted at the temperature of 120-180 DEG C for 10-60 min, the shapable pre-forming heat self-expansion high-energy glue in the mould continues to be heated to generate inside-to-outside expansion force, and the fiber prepreg cloth is solidified and formed at the high temperature; and cooling, demoulding and product taking are conducted. The two-step preparation method for the light and high-strength fiber composite material product through the HSM heat self-expansion prefabricated core material is suitable for a piece which is wrapped with the fiber prepreg cloth and needs stereo supporting, and the product with the thickness being larger than 1cm and with the complex shape.

Description

technical field [0001] The invention relates to the field of fiber composite molding, in particular to a two-step preparation method for a light-weight and high-strength fiber composite product using HSM thermal self-expanding prefabricated core material. Background technique [0002] The traditional preparation methods of fiber composite products are as follows; [0003] First, the hand lay-up process has problems in an atmospheric pressure environment. Most of the hand-lay-up resins are solvent-based, which has a heavy smell and is not environmentally friendly, which is not conducive to the health of the operators. It requires a long room temperature curing production cycle and is basically in a phase-out state; [0004] Second, the core material molding process, the pressure of the product during molding comes from an external press, that is, the hard foam core material is used to outsource the cement layer and then the fiber prepreg is wrapped to preform. The hard foam m...

AI Technical Summary

Problems solved by technology

[0003] First, the hand lay-up process has problems in an atmospheric pressure environment. Most of the hand-lay-up resins are solvent-based, which has a heavy smell and is not environmentally friendly, which is not conducive to the health of the operators. It requires a long room temperature curing production cycle and is basically in a phase-out state;

[0004] Second, the core material molding process, the pressure of the product during molding comes from an external press, that is, the hard foam core material is used to outsource the cement layer and then the fiber prepreg is wrapped to preform. The hard foam materials used include PMI , PU, ​​PVC, balsa wood, etc. need to be cut into pre-shaped core materials by CNC, put into the mold cavity, heated and pressurized, and the resin is cured to form the product. The efficiency is high, and the existing problems: 1. The process is complicated and hard The foam core material needs to be cut by CNC in advance, which increases equipment investment. 2. An additional bonding layer must be added between the foam core material and the fiber prepreg, which increases the material cost. 3. Due to uneven force, it is difficult to obtain an excellent product appearance; 4. 1. There is no expansion force from the inside to the outside of the core material during the molding process, so the interlayer bonding force of the fiber is not good, the bonding is uneven, and it is easy to delaminate, resulting in a decrease in the overall strength of the product; 5. Large-sized workpieces require large tonnage high equipment investment, which is not conducive to popularization

[0007] 1. Sheet-like high-energy glue is only suitable for preparing products with 2D effects when preforming carbon cloth; 2. The dimensional accuracy of preformed products is not accurately controlled, and the defect rate is high; 3. The thickness of the product exceeds 1cm, carbon cloth The difference between the size of the preform and the size after molding is large, which will cause the fibers to be pulled by the expansion force during the expansion molding process, resulting in stress concentration, and the interlayer bonding force inside the product is inconsistent, especially the quality of complex and thick products is uncontrollable