Rubber sealing gasket is made of natural rubber at first because of its high elasticity,dense frame, and softness,and also because it can be made into different shape.But it is not good at resistance of high temperature mineral oil and corrosion.So it cannot be used as some special sealing material.In recent years,the development and producing of synthetic rubber has make up the defect of natural rubber.Polymer is sulfurated at first,and then packing,pigment,and additive is Aadded into the polymer to compound the synthetic rubber.It could be used on rough flange and it gives an effect of decorationg.