How are physically cross-linked foams manufactured?
Physically cross-linked polyethylene foam, also named IXPE foam. It has excellent mechanical properties and advanced dimensional stability, which is why it is widely used in various fields.
Physically cross-linked foams are produced in three steps:
- vertical (sometimes horizontal) foaming
First of all, the so-called matrix is extruded using additives. In the next process step, this matrix is crosslinked, which is done by a high-energy particle. Finally, the crosslinked matrix is foamed in a vertical or a horizontal foaming oven. At the end of the oven, the material is rolled up or cut into sheets depending on the material and the frothing furnace.
Importance of cross-linking
Without crosslinking, cell stabilization does not occur, the gas can leave the polymer system, causing the cells to disintegrate. The bonding of the foam molecules during heating together decomposes much more easily due to physical action. With proper crosslinking, a polymeric structure is formed in which the growth of the cells stops in a state of equilibrium that is necessary for the formation of the given foam structure.
IXPE foam not only has a fine cellular structure, but also has a smooth surface. PE foam with high heat resistance can be produced in many thicknesses and densities.