An essential process for silicone mold manufacturers to manufacture silicone products is liquid silicone molding. Its rheological behavior is mainly manifested as low viscosity, rapid curing, shear-thinning, and a high coefficient of thermal expansion.
On the basis of liquid silicone molding, and then injection molding production, the liquid silicone into the hot runner mold, the production of silicone products, can achieve A molding, no waste, and automation advantages.
How to take advantage of liquid silicone molding
Silicone rubber and polytetrgas ethylene are the most superficial materials, so it is particularly difficult to bond a class of special materials, so how to use the coating (compound injection molding) process to prepare both soft and hard products in the technology involving liquid silicone rubber and other substrates, this is indeed a difficult problem. The silicone mold manufacturer must solve it.
Although there are some surface treatments, such as applying primer, using the ultraviolet treatment, and other methods to deal with the surface of the substrate, these methods are cumbersome, in fact, mainly from the process of strict control, it is possible to achieve good bonding of silicone rubber-hard resin coating. This is a well-understood operation for liquid silicone molding,
The method that silicone mold manufacturer will use
NEWTOP has 20 years of experience in the liquid silicone injection molding process, its exquisite technology, strong engineering and technical team, and quite a strong packaging manufacturer. How does liquid silicone compound injection on other materials? As we usually use glue to bond objects needs to be cleaned, the surface of the cleaning for the adhesive is also very important, of course, but also need to keep the base material fully dry, otherwise dirty and water will seriously affect the bond. This will test the scientific research ability of silicone mold manufacturer.
Is the basic condition of the two aspects: forming technique of high temperature, mold temperature mainly consider the reaction of liquid silicone rubber curing temperature, the typical liquid silicone rubber molding temperature is 150-205 ℃, liquid silicone rubber is often at high temperature is needed to fully cured, and to have good bonding performance, thus maintain base material products of high molding temperature Very critical. This is an important step in liquid silicone molding and the foundation of the entire silicone production.
Don’t add lubrication or demoulding agent: silicone rubber itself is close to love sex as a kind of release agent product, if these products will add, is not conducive to product caking, so try not to outside the base material used in the mold release agent, stripper or self-lubricating additives, these additives may not affect the bonding effect. The silicone mold manufacturer needs to recognize its characteristics.
Careful stripping and solidification process of liquid silicone rubber is slow, so even if liquid silicone injection molding again just after demoulding, seemingly has good bonding strength, but in fact, in the cavity of the curing time is not necessarily the most complete, so try not to pull hard in the process of stripping liquid silicone rubber, such as its slow cooling after will keep very good bonding effect. This effect is very helpful for liquid silicone molding.
In a word, it is still possible to get good self-adhesive liquid silicone rubber products by strictly using the above methods. In fact, this is not because of how good the adhesive property of liquid silicone rubber is, but because of its better liquid , impregnation and permeability. The above is how liquid silicone in other materials on the composite injection method.