Why is silicone mould easy to break?
Many customers pose questions like this. When asked about the time of breaking, some people say the silicone mould easy to break in demoulding time for some small parts, and most people reflect that the silicone mould has a short service life. All customers wish that silicone mould has relatively higher reproducing times, and be able to copy large quantities of products, because the cost to produce a silicone mould is relatively high, especially for large and complex products. So, it’s time we explore the reasons why silicone molds are easy to break.
This problem may be largely due to improper hardness of silicone rubber to make silicone mould. There is a limit for silicone rubber, if its hardness is above 50 shore A, the tensile and tear strength will be reduced, and it will be easily broken after the silicone mould has solidified. We should choose favorable hardness of silicone rubber to make mould. Normally, the silicone mould will be in a weak and flimsy manner using the silicone rubber with a high hardness to make moulds for small sized products or intricate and delicate designs.
The explanation for this phenomenon of silicone mould easily breaking may be that the mixing ratio of catalysts is incorrect. The amount of curing agent has a close relationship with the operating time. The higher the room temperature, the less the amount added. And the silicone mould goes to harden and brittle for excessive use of the curing agent(higher than 2% at room temperature 25℃).
Thirdly, why silicone mould is easy to break involves the reason of too frequent use. In the process of work, silicone mould often leads to fatigue fracture under the long-term effect of cyclic stress. The properties of fatigue and fracture for silicone mould are dependent on the performance of the silicone rubber, such as its strength, toughness, hardness, and the content of inclusions in material.
From what has been discussed above, we may draw the conclusion that choosing a high quality silicone rubber with features of proper hardness, wear resistance, toughness, high temperature resistance, resistance to fatigue and corrosion resistance is very important to ensure that the silicone mould is not easy to break. Of course, we can’t ignore these small details during the operation and maintenance.