CN

News center

Company news

Understanding the production processes of EVA high foaming and EVA low foaming
Time:2022-04-10    View:397

Understanding the production processes of EVA high foaming and EVA low foaming
EVA low foaming (commonly known as one-step method) is the process of making a certain form of sheet material by mixing and thoroughly mixing materials, heating and pressurizing it in a press mold, decomposing the resin chains to a certain degree of cross-linking through a cross-linking machine, and then further increasing the temperature to decompose the foaming agent, with a temperature of 150-180 ℃ and a pressure of 5-21Mpa. Wait for the foaming agent to completely decompose (30-60 minutes) to relieve pressure, allowing the hot object to expand and eject from the mold, and complete foaming within 2-3 seconds. Its foaming rate is generally 5-15 times.
EVA high foaming (also known as secondary foaming) will undergo sufficient mixing of materials in the mold to complete cross-linking under heating and pressure, and some foaming agents will decompose to produce partial foaming. The mold will be cooled to a certain temperature and taken out for secondary heating foaming under normal pressure. Its foaming rate can be between 30-45 times. Purpose: Generally used for pressing high-frequency materials to achieve a three-dimensional appearance of the material.