Classification of compression molding process

According to the physical state of the reinforcement material and the type of molding material, the molding process can be divided into the following types:

1. Fiber forming method: Put the pre-mixed or pre-impregnated fiber forming material into the forming machine. Metal molds and composite products are formed under certain temperature and pressure.

2. Chopped cloth molding method: cut the residue of glass fiber cloth or other cloth impregnated with resin glue (such as linen cloth, organic fiber cloth, asbestos cloth or cotton cloth) into small pieces, and then heat and compress it in a mold to form a composite product. This method is suitable for forming products with simple shapes and general performance requirements.

3. Fabric forming method: the two-dimensional or three-dimensional fabric woven into the desired shape is impregnated with resin glue, and then placed in a metal mold to heat and press to form a composite product.

4. Laminating method: Cut glass fiber cloth or other fabric impregnated with resin glue into the required shape, and then heat or press into a metal mold to form a composite product.

5. Winding molding method: the continuous fiber or cloth (tape) impregnated with resin glue is wound on the core mold through a special winding machine to provide a certain tension and temperature, and then it is put into the mold and added for hot pressing. Composite products.

6. Sheet plastic (SMC) Auto Parts Mold method: Cut the SMC sheet according to the size, shape, thickness, etc. of the product, and then put the multilayer sheet into the metal mold for heating and pressing the product.

7. Prefabricated blank molding method: First, put a prefabricated blank of chopped fibers of similar shape and size into a metal mold, and then inject the prepared binder (resin) into the mold. Mixture), molded at a certain temperature and pressure.

8. Orientation assisted molding: Place unidirectional prepreg in the direction of main stress, and then perform compression molding. The fiber content of the product can reach 70%, which is suitable for products with higher requirements for unidirectional strength.

9. Molding method of molding powder: molding powder is mainly composed of resin, filler, curing agent, coloring agent and release agent. The resin is mainly thermosetting resin (such as phenolic resin, epoxy resin, amino resin, etc.). Thermoplastic resins with high molecular weight, poor fluidity and high melting temperature, which are difficult to inject and extrude, can also be made into molding powder. The molding process of molding powder is basically the same as that of other molding materials. The main difference between the two is that the former does not contain reinforcing materials, so its product strength is lower, and it is mainly used for secondary stress parts.

10. Adsorption parison molding method: Adopt the adsorption method (air adsorption or wet slurry adsorption) to preform the glass fiber into a parison with a structure similar to the molded product, then put it into the mold, and then pour it into the resin. Paste it on and shape it under certain temperature and pressure. The method uses low material cost, can use long and short fibers, and is suitable for forming products with more complex shapes. It can be automated, but the equipment cost is higher.