Silicone oil is liquid products made up of polysiloxane, which is colorless, tasteless, odorless and non-toxic fluid. Silicone oil has many special performance, such as temperature coefficient, high and low temperature resistance, oxidation resistance, high flash point, little volatile, good insulation, small surface tension, metal, no corrosion, etc. Due to these features, silicone oil is used in many ways producing good effect. It is also often used in production of silicon pad. Pad printing silicone rubber is applicable to produce printing pads. In the process of making silicon pad, customers often add silicone oil into pad printing silicon. Why do they do that?

 

The first effect of silicone oil is that it can change the hardness of printing silicon pad. Customers should change the hardness of the silicon pad according to the different patterns. Generally, the ratio of pad printing silicon rubber and the silicon oil depends on the size of pattern which customer needs to print. The larger the pattern is, the softer the printing pad should be, and more silicon oil needs to add. Contrarily, if a silicon pad with high hardness needed, silicon oil should be added less or none. Add 30g silicon oil into 100g silicon then hardness of 20A° printing pad we get, which is suitable for the pad printing for alloy car and other products with small patterns and contact areas. If a big contact surface or a soft silicon pad needed, the mixing proportion between the silicon and the silicon oil can be 100:30-100:50. General hardness of the printing pad is 15A°~-25 A°. But please note that if too much silicon oil added in the silicon rubber, the printing pad will be too soft, and this will limit the printing times. For silicon oil will destroy the molecular chain of the silicon rubber, no matter how supreme quality the silicon rubber is. And therefore, the printing pad will be abrasion intolerant and solvent intolerant and easy ageing.

The second function of silicone oil is as a kind of active diluents in order to reduce the viscosity of the liquid silicone rubber. We all know that making the different moulds need different viscosity of silicone rubber. And silicone oil has high and low viscosity, which can adjust the viscosity of the pad printing silicon. Normally we do not advise our customers to add any silicon oil into the silicon rubber. If it is necessary, the ratio must be 5%-10%. 

2017-09-12