A method for preparing table tennis racket by adopting hsm molding process

Abstract

The invention discloses a method for preparing a ping-pong bat through an HSM forming process. The method comprises the steps that thermally-self-expansion high-energy glue capable of being subjected to shaping pre-forming is placed in a product core material die and the die is tightly closed, the thermally-self-expansion high-energy glue capable of being subjected to shaping pre-forming is heated for 3-30 minutes at 80-100 DEG C, and micro-expansion is carried out, wherein a volume multiplying power before and after the micro-expansion is 1.01-1.5, a core material die cavity is fully filled with the thermally-self-expansion high-energy glue capable of being subjected to shaping pre-forming, cooling and die release are carried out, then the thermally-self-expansion high-energy glue capable of being subjected to shaping pre-forming is wrapped with a fiber prepreg and placed in a forming die, and the die is tightly closed, and the thermally-self-expansion high-energy glue capable of being subjected to shaping pre-forming is heated for 10-60 minutes at 120-180 DEG C, wherein the thermally-self-expansion high-energy glue capable of being subjected to shaping pre-forming continues to be heated to generate an expansion force from inside to outside, and the fiber prepreg is subjected to high-temperature curing forming; and cooling and die release are carried out, and a product is taken. The ping-pong bat prepared by the method disclosed by the invention is high in strength and low in reject ratio.

Description

technical field [0001] The invention relates to the field of fiber composite molding, in particular to a method for preparing a table tennis racket by using an HSM molding process. 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 materials used include PMI , PU, ​​PVC, balsa wood, etc. need to be cut int...

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-shaped high-energy glue is only suitable for the preparation of products with 2D effects when it is preformed with 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 0.5cm, carbon The size of the cloth preform and the size after molding are quite different, 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

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