Laminate molding is a production process in which prepregs are cut and stacked according to the shape and size of the product, then placed between two polished metal molds, and heated and pressurized to form composite products. It is an earlier and more mature forming method in composite material forming process. This process is mainly used to produce electrical insulation boards and printed circuit boards. Now, printed circuit boards have been widely used in all types of radios, televisions, telephones and mobile phones, computer products, various control circuits, and all other products that require planar integrated circuits.
The lamination process is mainly used to produce various specifications of composite material plates. It has the characteristics of mechanization, high degree of automation, and stable product quality. However, it has a large one-time investment and is suitable for mass production. It can only produce plates and the specifications are subject to equipment. limits.
The lamination process generally includes: prepreg preparation, tape cutting and stacking, hot pressing, cooling, demoulding, processing, post-treatment and other processes, as shown in the figure:
The tube forming machine is a composite material product forming method that uses a prepreg tape to be hot-rolled on a tube reel. The principle is to soften the tape and melt the resin on the tape with the help of a hot roller on the tube reel. Under a certain tension, during the operation of the roller, with the help of the friction between the roller and the core mold, the rubber cloth is continuously rolled onto the core tube until the required thickness, and then cooled and shaped by the cold roller. Take it off from the machine and send it to the curing oven for curing. After the pipe is cured, the core mold is removed to obtain a composite coiled pipe.
roll tube forming can be divided into two kinds of manual cloth method and continuous mechanical method according to the different cloth method. The basic process is: first clean each roller, then heat the hot roller to the set temperature, and adjust the tape tension. When the pressure roller does not apply pressure, wrap the leader cloth on the core mold coated with release agent for about one turn, then lower the pressure roller, stick the leader cloth on the heat roller, and apply the tape at the same time Pull up, cover the heating part of the leader cloth, and overlap the leader cloth. The length of the leader cloth is about 800-1200mm, depending on the pipe diameter, the overlap length of the leader cloth and the tape is generally 150-250mm. When rolling thick-walled pipes, the rotation speed of the core mold can be appropriately increased after the rolling operation is normal, and the rotation speed can be slowed down when the thickness is close to the design wall thickness. When the design thickness is reached, the tape is cut off. Then, while maintaining the pressure of the pressure roller, continue to rotate the core mold for 1 to 2 turns. Finally, the pressure roller is lifted to measure the outer diameter of the tube blank. After it is qualified, it is taken out of the tube coiling machine and sent to the curing furnace for curing.
(1) Raw materials: The main raw materials required for the production of prepregs include reinforcing materials (such as glass cloth, asbestos cloth, synthetic fiber cloth, glass fiber mat, asbestos mat, carbon fiber, aramid fiber, asbestos paper, cowhide, etc.) and synthetic Resins (such as phenolic resin, amino resin, epoxy resin, unsaturated polyester resin, silicone resin, etc.).
(2) Preparation process of prepreg tape. The preparation process of prepreg tape is to use heat-treated or chemically treated glass cloth, impregnated with resin glue solution through a dipping tank, and control the resin content of the tape through a squeegee device and a traction device. Under the temperature, after a certain time of flooding, the resin will be transferred from the A-stage to the B-stage, so as to obtain the required prepreg. This process is usually called the dipping of glass.