After the pre-formed and matured EPS particles are filled into the mold, the state is loose, and it needs to be heated to about 110~C with steam to make it secondary foam bonding. It is particularly important to note here that this heating is mainly transmitted by convection, and the conduction is only slightly effective on the inner surface of the mold, and the radiation is minimal.
At present, such EPS forming molds are generally made of alloy aluminum, and stainless steel sheets can also be used in the sheet forming machine, and the main part of the packaging forming mold is generally cast aluminum. In order to enhance the convection heating, the mold wall of the part in contact with the EPS material needs to be drilled with a steam hole, or a steam trap, or a steam plug. From the point of view of increasing the production speed, it seems advantageous to increase the steaming area. For products with thicker EPS products, the steaming area is slightly smaller, which also helps to increase the vapor pressure, so the middle part of the product can also be stuck. Good connection. Of course, for various EPS materials and different densities, the sticking performance is slightly different.