Compression Mould
Compression molding process is based on the characteristics of each stage of the curing reaction of thermosetting plastics or other composite materials.
Compression mold normally uses a hydraulic press in which a mold is fixed on the top and bottom platens of the press. The mold consists of a top cavity and a bottom cavity designed to produce the part to be manufactured and heated to the desired molding temperature. The molds can be classified as hand molds, used for trial runs; semiautomatic, in which the press follows a programmed cycle but the operator manually loads and unloads the press, and automatic, which operate under a fully automatic press cycle (including automatic loading and unloading).
The process of compression molding is as follows:
- Step1 - Powdery, granular or fibrous plastic is put into the cavity of mold at the molding temperature.
- Step2 - mold is closed and pressurized to form and cure it.
- Step3 - The product is ejected by ejector, repairing the flash.
Compression molding Vs Injection molding
injection molding can produce high quality products with complex structures. However, the strength of products is not enough, while compression molding allows longer fiber materials with very good strength and toughness. Compression molds are generally simpler than their injection mold counterparts. There is no sprue and runner system in a compression mold and the process itself is generally limited to simpler part geometries due to the lower flow capabilities of the starting thermosetting materials.
- 1. At present, it is not suitable for molding complex products with depressions, side slopes or small holes.
- 2. Burrs must be trimmed manually.
- 3. For thermosetting plastics, when the molded products have slight defects, they are often unable to be recycled.
Disadvantages of Compression mold
- 1. Suitable for mass production, short cycle and high efficiency;
- 2. The loss of raw materials is small, and the mold wear is small, and the maintenance cost of the mold is low.
- 3. It can be used to form large flat products. High dimensional accuracy, small shrinkage, low internal stress, the mechanical properties are relatively stable. The surface is smooth without secondary modification.
- 4. Advanced composite materials are used to ensure better mechanical properties of the products.
Advantages of Compression mold
Compression mold are one of MDC's largest products, including SMC mold, BMC mold, and the design, produce, manufacture of carbon fiber mold. MDC thinks that for compression molds, material, shape, pressure, temperature, part thickness, cycle time must be considered. MDC has mastered and innovated the molding process, analyzed the characteristics of the materials and the requirements of the products, and considered the applied pressure, temperature, time and other factors to ensure the uniform flow of the materials in the cavity of mold and fill the gaps to obtain the perfect products.
