Imports of seal ring NBR NBR manufacturers import manufacturers of rubber products produced by this method, there has been a series of shortcomings, the article is weighed setting plastic material to mold filling process is performed after the mold cavity, in order to prevent lack of material and produce waste, methods used to make the plastic material quality pre-weighed taken significantly larger than the finished product quality, and the remaining gum can not be reused in the form of flash loss; at the same time get rid of the fly on the edge of the finished product, Also supporting human resource consumption; molding process products can not achieve mechanization and automation, the dragon it is thick-walled products, curing cycle lasts quite long. 2) rubber injection molding method - the current O-rings and other sealing products molding method used rubber injection molding of plastic material is preheated by injection molding machine screw or plunger, through the nozzle high pressure, high speed injection mold type chamber, and vulcanization molding production methods. Rubber injection molding process is a new method developed on the basis of molding method. Rubber injection molding curing process is the biggest characteristic cure cycle is short, less flash, high production efficiency; reduce production preparation process, greatly reduce labor intensity, Long complexity of rubber for large, thick-walled, thin-walled and shape product effect is more significant. It is the molding and curing process into one simple process, to improve the mechanization degree of automation, the molding process repeatable, uniform product quality, improve the quality, it can improve the economic value of rubber products and rubber industry, and has broad Prospects.