Vertical hydraulic presses are the main equipment for thermoforming plastic molding because the hydraulic press has the required forming pressure and ejector force. When compressing, an upper hydraulic press is usually used, and the working hydraulic cylinder moves the upper table up and down at the top. The middle through hole of the lower table, the fixed bar of the machine and the push plate of the die are connected with the post to reset the pushing mechanism. The compression molding process of the thermosetting plastic on the hydraulic press is mainly divided into three stages:
1. Preparation stage.
Compression powder is placed in an oven and preheated. The pressure-molded powder is weighed with a balance and poured into a mold cavity to be heated and melted.
2. Pressure stage
The hydraulic machine is started, the upper table moves downwards, the upper table moves downwards, and the upper punch enters the lower mold cavity. Under pressure, the plastic flows and fills the flow cavity. After a period of pressure keeping, the plastic takes place in physics and chemistry. Variety. Cross-linking establishes the body reticular molecular structure, hardening stereotypes.
3. Set the plastic stage.
After the mold is opened, the ejector of the hydraulic press pushes the ejector mechanism to eject the plastic member, and the ejector mechanism is reset. After the mold is cleaned, the next stroke is prepared, and the compression process of the product batch is continued in succession.