Release time: 2020-02-07 15:53:14
2 Functional high-activity 4000 molecular weight polyether, which can be used in the preparation of footwear materials, improve the elongation at break of the material while increasing the curing speed, and shorten the demolding time.
Compared with other coatings, water-based polyurethane coatings not only have a good appearance, but also have a short drying time. They have a unique advantage in the field of wood coatings. The traditional solvent-based acrylic leather coatings have gradually been replaced by water-based polyurethane leather coatings. With their advantages in chemical resistance and low temperature resistance, they have attracted much attention and attention from people in the field of leather coatings. In addition, this kind of material also plays a very precise application value in related fields such as plastics, vehicles, industry, and anticorrosion, and has a considerable space for development.
Polyurethane cold storage insulation must wear protective glasses, work clothes and work caps when operating isocyanates and combined polyethers; clean rubber gloves should be worn when operating isocyanates. The working environment must be well ventilated and clean. When the ambient temperature is high, the foaming agent in the combined polyether will partially vaporize and generate pressure, so the exhaust cover should be opened before the pressure of the exhaust gas is released, and then the bucket cover is opened. When the foam is flame-retardant (Note: self-extinguishing from fire), an additive flame retardant can be used. The amount of ordinary flame retardant is 15-20% by weight of the white material. The flame retardant must be stirred into the white material. Foaming can be carried out evenly. The proportion of black and white materials should refer to the technical data sheet of the combined polyether for related models. Customers using flame retardants should pay attention to the flame retardants when calculating the proportion of white materials after adding flame retardants. At 1: 1, if 100 kg of white material is added with 15 kg of flame retardant, the amount of black material used is 115 kg.
Polyurethane foams generally do not use MDI directly. Liquid MDI is a modified MDI developed in the 1970s. It overcomes the above shortcomings and can be used to produce polyurethane skin molded products with special performance requirements to increase the product's flame resistance and other properties.
Polyurethane delay catalysts are a very special type of catalysts in polyurethane catalysts. These catalysts can provide the catalytic activity required for curing of polyurethane, and at the same time can extend the product life and provide more operating time for construction. Unlike inhibitors, polyurethane delayed catalysts are relatively delayed rather than absolute delayed. Compared with conventional catalysts, the front-stage activity is lower and the overall activity is comparable. It cannot play the role of delaying the reaction in the system without adding catalyst.
In recent years, China's annual growth rate of MDI demand has been above 18%, and this year it is more likely to exceed 20%, replacing Germany as the world's second largest MDI demand country.
The product produced by polyurethane foaming machine is foam, and what is needed in the production process is also foam. Therefore, the quality of the foam is the criterion for judging the performance of the foaming machine. To judge the foaming quality of the foaming machine, three The main aspects are foam density, foam uniformity and foam bleeding. Foam density refers to the size of the bubble diameter. The smaller the bubble diameter, the smaller and denser the foam, the better the stability of the foam, the higher the strength of the product produced, and the better the thermal insulation performance.
Polyurethane composite board as a building energy-saving insulation material has been widely used in developed countries such as Europe, the United States, and Japan, with a penetration rate of 80%, and its application in China is less than 10%. Polyurethane sandwich panel is an excellent energy-saving insulation material. Its excellent thermal insulation, fire resistance and thermal insulation performance can provide an efficient solution to China's energy consumption crisis.