What are the classification of MI foam? 1. Rigid foam, […]
What are the classification of MI foam?
1. Rigid foam, that is, at room temperature, the polymers constituting the foam are crystalline or amorphous, and their glass transition temperature is higher than normal temperature, so the texture of the foam is hard at normal temperature; flexible foam That is, the melting point of the polymer constituting the foam plastic is lower than normal temperature, or the glass transition temperature of the amorphous polymer is lower than normal temperature, and the material is soft in texture at normal temperature.
2. Semi-rigid or semi-flexible foam is a foam between the above two categories. Can also be divided into two types of low foaming and high foaming. Generally speaking, the expansion ratio of less than 5 is called low foaming, the greater than 5 is called high foaming. Foam plastic is a type of polymer material formed by a large number of gas micropores dispersed in solid plastics. It has the characteristics of light weight, heat insulation, sound absorption, shock absorption, etc., and its dielectric properties are superior to the matrix resin.
3. Foam plastic is also called porous plastic, a plastic made of resin as the main raw material with countless micropores inside. Compared with pure plastic, it has low density, light weight and high specific strength. Its strength increases with density. It has the ability to absorb impact loads. It has excellent cushioning and shock absorption performance, sound insulation and sound absorption performance, and low thermal conductivity. Good heat insulation performance, excellent electrical insulation performance, corrosion resistance and mold resistance. Flexible PMI foam has excellent elasticity and other properties.