Ammonia foam was first successfully developed in Germany in 1947. The hard polynitrogen foam was first put into industrial production, which was used as a lightweight and high-strength sandwich aviation structure material, a sandwich material for radar structures, and a core material. In 1952, the flexible ammonia foam was successfully researched. At that time, the flexible polyurethane foam invented in Germany used 65/35 toluene diiso acid and hexamethylene.
       Diacid polyol, tertiary amine catalyst, ionic emulsifier and water are foaming agents. This soft foam has good mechanical strength, oil resistance, solvent resistance, excellent flexibility and resilience, and is an excellent cushioning packaging material and cushion material. Since the United States successfully developed flexible polyether polyurethane foam in 1952, polyurethane foam has made a leap in business because of its low price, better flexibility, water resistance, and high elasticity.
       In the 1970s, the United States successfully used sesame oil to produce semi-rigid polyfoam. Its characteristics are excellent impact resistance and excellent cushioning performance. It has a wide range of applications in the automobile transportation industry.
       my country's polyhydrogen industry started in 1958. In the 1960s, it used polyurethane to produce foamed polyurethane synthetic leather. After the Yantai Polyammonia Plant imported equipment and software from Japan and put into production, my country's polyurethane industry moved forward greatly. One step is to provide raw materials for the protective layer of petroleum industry pipelines. Petroleum pipelines need this kind of coating material with excellent heat insulation and rust resistance. The foamed polyurethane produced by this hard casting method not only has a good appearance with steel pipelines Good cohesiveness, and can be cast in sections on site, convenient and simple in construction. Casting foamed polyester is also used in the packaging of machinery with irregular and complex shapes, such as the equipment produced by the oil nozzle and oil pump factory. In order to prevent the oil pipes from being touched during transportation, they are wrapped up with a film, and then the foam is poured in the outer packaging calcium plastic tile box. It is fixed by ammonia and has good resistance.

       At present, the total output of polyurethane foams accounts for about 80% of the total output of polyurethane resins. Among them, soft foam and semi-rigid foam account for 80%, and the quality of the ammonia foam accounts for 20%. The characteristic of ammonia foam is strong adaptability and can be changed by changing the raw materials. The composition and formula to produce foam plastic products with different softness and different properties, such as temperature-resistant foam, flame-retardant foam, low-temperature resistant foam, high-temperature ablation-resistant foam, ultra-soft foam, etc. Low-temperature foam can be used for storage and transportation of liquid chlorine at a temperature of 217℃. High-temperature corrosion foam can work at a temperature of 250℃ for a long time. It can be used in a short-term high-temperature flame of more than 1000 for 1h. It is a foam molding process for material foam in the aviation industry. There are block foaming, pouring oil, flat-top block foaming process, cold and chemical foaming process, secondary foaming process, reverse injection molding (RIM) foaming process, skin hardening molded foaming, no Air spray foaming process, one-component foaming process