Product details

Structural Foam Molding belongs to chemical foaming, which is a revolution in injection molding technology. It retains many advantages of the traditional injection molding process and avoids some problems encountered in the traditional injection molding process, such as insufficient product strength, too long production cycle, low molding rate, etc. In addition, the structural foaming technology can also be used to mold large and complex products, and multiple cavities can be operated simultaneously, thereby reducing the production cost of products. Structural foamed product is a kind of integrated foamed material with dense surface layer, and its unit weight strength and stiffness are 3~4 times higher than that of the same non foamed material. In recent years, structural foam injection molding technology has been widely developed, and there are many molding methods, but it can be summarized into three types: low-pressure foaming method; High pressure foaming method (note: the low pressure and high pressure here refer to the pressure in the mold cavity); Two component foaming method.

Our company adopts the low-pressure foaming method. The difference between low-pressure foaming injection molding and ordinary injection molding is that the cavity pressure of the mold is low, about 2~7Mpa, while that of ordinary injection molding is between 30~60Mpa. Low pressure foaming injection molding generally adopts under injection method, that is, a certain amount of plastic melt (containing foaming agent) (not filling the mold cavity) is injected into the mold cavity, and the gas decomposed from the foaming agent makes the plastic expand and fill the mold cavity. For low-pressure foaming injection molding on an ordinary injection molding machine, the chemical foaming agent is generally mixed with plastic and plasticized in the barrel, and a self-locking nozzle must be used. During injection, due to the rapid diffusion of gas, the surface of the product will be rough, so the injection speed of the injection molding machine should be fast enough. Generally, supercharger is used to improve the injection speed and injection volume, so that the injection can be completed in an instant.