The normal temperature and pressure method place the pre-release beads in a curing bin made of cotton cloth or screen, and place them at 20-26 ℃ for 18-24 hours. This method is suitable for large-scale production, and the matured pre-release beads can be prepared Foam parts with an apparent density of 0.016 to U.020 g/cm.
The high pressure method will flow the pre-formed beads into the curing bin, so that the pressure in the bin is kept at 35-100kPa, and the temperature is 15-25°C. The aging time is 0.5-3h. This method has a short curing time.
The high-temperature method uses a continuous steam pre-expansion process to obtain pre-expanded beads with an apparent density of 0.016-0.032 g/cm. It is then transferred to a porous receptacle for use.
The steaming cylinder method of the foam molding machine puts the matured pre-formed beads into a mold with many small holes. After the mold is closed, the mold is put into the steaming cylinder, and then steam is passed into the cylinder. At c.05— Under the pressure of 0.25MPa, heat for 3min, open the steam cylinder to take out the mold, and demould after cooling to obtain the product.
When forming, firstly close the mold, pass 0.1-0.2MPa steam into the air chamber, preheat the mold to 100~C or higher, and remove the residual condensed water at the same time, and then use compressed air to send the pre-fired beads to the air. in human mold.
After the cavity of the foam molding machine is filled with the ejection beads, the air outlet is closed. When feeding, a small slit should be opened on the parting surface of the mold. The size of the gap is based on the part without burrs. After the feeding is completed, steam of 0.1 to 0.2 MPa is passed into the air chamber, and heated for 1 to 2 minutes. The material temperature can reach 110~C. The molding of the foam molding machine needs to be carried out through the above steps.