Why there are so many bubbles on the surface of th...

Why there are so many bubbles on the surface of the silicone mold? 　　A bubble means when making the silicone mold did not cause the liquid silicone vacuum, otherwise this  kind of circumstance would not happen,a guest maybe said clearly that it is vacuum, but the bubble  still appear,when you asked how long he did to vacuum the liquid silicone,he said 30 minutes,for such circumstance,3 minutes is ok,so don't make a simple thing complicated.Another thing to remember is that before the process of pumping air into vacuum state, mix the  silicone group A and group B evenly,if not even ,there also exist A bubble. 　　Let's take the silicone keybord buttons for an example,to illustrate why there is a bubble?              　　The process of molding silicone keybord button is firstly putting the refined good silicone raw  materials according to certain proportion in the forming extrusion dies, under a few minutes of high  temperature and high pressure sulfide in the vacuum forming machine, so that the rubber silicone  keybord buttons formed .the process look asy, but there are many kinds of bad effect if not pay  attention to some importent details ,you can't do it if less than 5 year's experience. 　　The details is following: 　　1, the forming die is not clean. 　　When putting the good material in silicone rubber molding, not completely emiss the air,and there is  no way to make gas and silicone rubber in a fusion, this is one of the main factors forming bubbles. 　　2, the temperature of the vacuum forming machine set too low. 　　Vacuum forming machine, heating and curing temperature are important parameters in the forming  generally the curing temperature is 160 ~ 200 °, but sometimes the silicone button molding curing  time is too long or mould temperature too high or too low, so silicon keybord button surface will  exist a bubble. 　　3, silicone buttons forming die structure is not reasonable. 　　More question,please feel free to send us a email,or click here to leave a feedback.