It is a kind of soft foam with excellent performance due to its high forming resilience. It has the characteristics of light weight, softness, high resilience and high hand comfort, and is also widely used in daily life related industries such as automobiles and furniture.
With the improvement of people's living standards, the awareness of environmental protection is becoming stronger and stronger, and the quality requirements for daily necessities are also getting higher and higher. In recent years, people have put forward new requirements for car cushions and various products. 1、 Reduce material consumption without reducing the overall quality; Second, reduce odor.
In view of the above two points, the mainstream development direction of future molded foam is also discussed in two parts. First, in order to reduce weight, you can choose high molecular weight polyether and high solid content POP, adjust the formula, reduce the density and mechanical properties. Then, low VOC. In the national standard, the raw materials of many domestic companies in the aspect of ethylbenzene trialdehyde are difficult to reach the standard. The simple adjustment method is to replace it with imported products, such as polyether and catalyst. The effect is remarkable.
The reaction molding mechanism of the whole high resilience foam plastic mainly includes four reactions
1. Polyether+isocyanate → carbamate
2. Water+isocyanate → urea+carbon dioxide
3. Carbamate+isocyanate → carbamate
4. Urea+isocyanate → biuret
The reaction between polyols and isocyanates is a reaction that exists in all polyurethane foam. Because most polyols are trifunctional, this reaction is also called cross-linking reaction.
R-NCO+- OH → NHCOO - (carbamate)
A+HOH-NCO → NHCONH+CO2,
In the presence of water, due to the release of gas, this reaction is usually called foaming reaction.
