f fuel injection is to coat the surface of the product with a coat of paint to make it more comfortable for customers to wear . Oil injection has a good effect on the dust-proof and sticky-proof properties of silica gel bracelets . For example , some customers will assilsilicone braceletsicone braceletsk us why the silicone wristband are often covered with dust . Actually , the reason why rubber bracelet often stick to dust is that they don"t have any spray hand-feeling oil . The effect of silicone bracelets sprayed with hand-feeling oil is hard to see with the naked eye , and there is a distinction between the wristband sprayed with hand-feeling oil and non-spraying hand-feeling oil when we touch it . The main features of oil-sprayed silica gel hand rings are smooth handle , high surface finish and smoothness , no dust contamination . Silicone hand rings without spray-feeling oil have low gloss , feel less smooth with hands , and their service life is not long .