EVA foam foaming process

What are the areas we often see in EVA products?

EVA products can be subdivided into: sponge, high foam, rubber, EPE, EVA, PU and other foam products according to the material;

EVA material

According to the process flow, it can be subdivided into: grinding, cold/hot pressing, stamping, silk screen, injection molding and other products,

Sports equipment: Grip grinding products, EVA foam hot-pressed, cold-pressed shaped products and various materials stamping products. Such as all kinds of fishing tackle products, foam balls, handles, toy rockets, toy knives and guns, EVA silk screen puzzles, wheels, mats, packaging boxes, etc.

EVA products are widely used in electronic appliances, sports equipment, automobile industry, toys, craft gifts, packaging and other industries.

Stationery gifts: EVA pen sleeves, EVA letters, EVA building blocks, EVA books, EVA puzzles, EVA smiley faces, EVA seals, sponge Mitsubishi, sponge cylinders, pearl cotton cylinders;

Among eva products, colored eva foam is the most widely used, so how does colored eva foam foam? The process is as follows:

The colored eva foaming tube is made of eva as the base material, adding an appropriate amount of foaming agent and foaming by heating and pressure coaching. When the temperature rises to the decomposition temperature of the foaming agent, the foaming agent decomposes and releases gas to foam.

In addition, eva has a certain degree of crystallinity. Before the temperature reaches the crystal melting temperature, the fluidity is very poor. After reaching the melting temperature, the melt viscosity drops sharply and the fluidity improves quickly. It is the gas generated during the foaming process. It is difficult to maintain.

However, in order to improve this unfavorable factor for foam molding, try to keep the gas in the base material. For the ideal cell structure of gas, a crosslinking agent must be added to crosslink the eva molecular chains to adjust the viscosity of the melt. And viscoelasticity, so that it can meet the requirements of foaming, and improve the physical and mechanical properties of the foam. The organic peroxide crosslinking agent can meet the above requirements. Generally, dicumyl peroxide is more ideal.