Polyurethane duct insulation board is also a kind of polyurethane "sandwich board", the outer surface of which is about 0.66mm aluminum foil, and the middle is 2.5cm polyurethane hard foam. The production process is similar to the previous "sandwich board" production line, except that it is relatively simple before foaming, there is no unwinding roller, etc., but there are rolled aluminum foils on the top and bottom, and the polyurethane is poured onto the plane running the lower aluminum foil. When the foam is to be foamed, the upper aluminum foil is composited.
It is worth noting that the polyurethane duct insulation board has high requirements on polyurethane. One is the oxygen index of more than 32 and the smoke density of less than 70. Such high flame retardant requirements have greatly limited its large-scale use. Most of these products do not meet the flame retardant requirements. Many domestic manufacturers are quietly reducing the flame retardant standard and entering the market. Second, the foaming parameters of polyurethane are required to be harsh, otherwise it is very easy to appear defective plates, such as plates. There are pits, grooves and blister on the surface, and the polyurethane is required to be solidified quickly. There is no deformation after the ripening stage, otherwise the surface of the finished board will be distorted. Good products should look like mirrors, and some defects are obvious. In addition, the foam should have a certain flexibility so as not to be broken when making the air duct.
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Die Spring includes: Japanese Standard Die Spring, German standard die spring, Spring, polyurethane spring, usually refers to the rectangular die spring. The rectangular die spring has the characteristics of small volume, good elasticity, high rigidity, high precision, rectangular material, color-separated spraying (plating) to distinguish different load, beautiful appearance and so on. The production standards of standardized die spring are: ISO9001:2000, Jis, ISO10243, NAAMS (North American automobile metric standard) , according to different standards of the production of Spring Day Standard Spring, American Standard Spring, ISO10243 German standard die spring and so on.
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