A relatively normal foam is generated inside

Core material foam plastic'>The core material foam plastic has two types: hard and soft. A relatively normal foam is generated inside, but no bubbles or few bubbles are generated on the surface part. Quality foam plastic means that at room temperature, the polymer constituting the foam plastic is crystalline or amorphous, and their glass transition temperature is higher than normal temperature, so the texture of foam plastic is relatively hard at room temperature. According to the foam density method, it can be divided into high, medium, low and Ultra-low-density foams and self-

skied foams with large density differences are also called whole skin foams.5 cm, if it does not break, the test sample is soft High-quality foam; on the contrary, it is a rigid foam. Usually, the foaming ratio is less than 5 is called low foaming, and the foaming ratio is greater than 5 is called high foaming. A dense skin layer with a much higher density than the inteal foam is formed on the outer surface of the foam. Advantages and application of core material foam plastic.

At a temperature of 18 to 29 ℃, within 5 seconds, around a round bar with a diameter of 2. A very obvious change. For example, according to the processing method, it can be roughly divided into two-step method, semi-prepolymer method, one-step method and spray method. There are many classifications of polyurethane foam. There is a density drop gradient from the skin to the center of the core.

Soft foam plastic constitutes foam plastic The melting point of the polymer is lower than normal temperature, or the glass transition temperature of amorphous polymer is lower than normal temperature, structural foam and the material is soft at normal temperature; semi-rigid or semi-flexible foam is a foam between the above two types.

Core material foam, PMI foam, high temperature resistant foam Reinforcement method of carbon fiber sandwich foam. The latter is a special foam form, which does not have the same density as the previous foams. Foams can be divided into two types: low foaming and high foaming.ufeffThe intercoected micropores are called open-cell foams, and the closed-cell foams are called closed-cell foams