Walk into the EPP foam manufacturers and understand the EPP foaming process

EPP material is called a universal material because it has excellent shock resistance and energy absorption performance, high recovery rate after deformation, high temperature resistance, chemical resistance, oil resistance, thermal insulation and other characteristics, and it is an environmentally friendly material with light weight. It is widely used in many fields such as automobile, construction, home furnishing, food, cold chain logistics, packaging, etc. Many friends are curious, how are EPP products produced? Let us walk into the EPP foam manufacturers together today to understand the EPP foaming process.
EPP products use pp as the main raw material, and use physical foaming technology to support foamed beads. They are mainly used for mold sintering and forming into various shapes and sizes for use in different occasions. The initial form of EPP raw materials is transparent particles, and EPP foam manufacturerss add color masterbatch to color, so we can get colorful EPP products.

Walk into the EPP foam manufacturers and understand the EPP foaming process. We have summarized that the EPP foaming process mainly includes the following steps: mold closing, feeding, heating molding, cooling demoulding, drying and setting.

First, the EPP foam manufacturers will preheat the mold so that the surface temperature of the mold reaches the melting point of pp. The mold will be customized according to different products. The function of the mold is to shape the EPP particles into a fixed shape. When the mold reaches a certain temperature, the EPP particles are blown into the mold with high-speed wind from the inlet of the mold. During this process, it is necessary to ensure that the air outlet is unobstructed, and the air volume is greater than the air volume, so that the raw materials can fill the mold everywhere.

EPP foam manufacturerss mold EPP products by heating water vapor. The EPP molding process is physical molding, which is different from chemical molding of other foam products. EPP foam molding does not need to add catalysts, only water vapor is needed, which is also the non-toxic nature of EPP products. One of the reasons for the tastelessness.
Longitudinal Steam: Steam flushes from top to bottom to push air out of the steam chamber and condensate out. During this process, the EPP foam manufacturers needs to open the upper steam inlet valve and the lower condensate discharge valve.

Horizontal steam: Make steam sweep from one side of the steam chamber to the raw material, penetrate the raw material and reach the other side. At this time, close the condensate valve on one side and open the steam inlet valve. At the same time, the steam inlet valve on the opposite side is closed, and the condensate valve is opened, so that the steam is ejected from the opposite direction. If there are thin flanges in the mold, it is best for the steam to pass around the flanges so that the raw materials sandwiched in the flanges can also be steamed and melted. After passing the steam horizontally, it needs to go through the process of pressure assurance or double-sided steaming and melting. In this link, open the steam inlet valve and close the condensate discharge valve to make the pressure gradually reach its peak value. A good EPP foam manufacturers's equipment will be equipped with an electronic display screen to monitor the changes in pressure and temperature inside, and have an out-of-tolerance alarm function.

After filling with steam, the temperature inside the mold usually reaches 140°C. In order to ensure the smooth release of the product, it must be rinsed with cold water to reduce the mold temperature to 70°C. It is worth noting that EPP foam manufacturerss will recycle the water condensed from water vapor.

Because it is heated by water vapor, there will be a lot of water remaining on the surface of all EPP products, and the products need to be dried in a drying room. EPP foam manufacturerss usually set the drying treatment temperature at 60°C to 80°C, and the drying treatment room should ensure dry air and good ventilation.