Silicone can be seen everywhere in life, such as medical supplies (oxygen masks, medical materials, etc.), household products (baking supplies, kitchenware, etc.), infant products (pacifiers, tableware, etc.), and even in places that are not usually seen, such as wearable 3C (waterproof gaskets, watch straps, etc.), smart phone components (waterproof switches, waterproof connectors, etc.), and automotive components (waterproof connectors, lamps, etc.), etc. There are traces of the use of silicone (silica gel), the following describes the different production methods of silicone and the scope of application.
 

What is silicone molding?

Silicone raw materials usually come in two forms, solid and liquid. Different forms of silica gel silicone use different production methods and application ranges. Solid silicone is usually used in more economical products. , The precision requirements are relatively low, such as common household kitchen utensils, heat insulation pads, etc., liquid silicone is usually used for products with high precision and special needs, such as sealing components and optical grades Most of the application parts choose to use liquid silicone molding.
 

What are the silicone types?

Solid state silicone (HTV)

As the name suggests, the appearance is solid, with low transparency. If there are other colors required, the color needs to be mixed with roller equipment, and cut to the size of the mold before it can be sent to the production line for hot pressing production. The curing mechanism is heat vulcanization. The curing time is longer than that of liquid silicone, which is often used in household goods, industrial parts, and automotive components.
 

Liquid silicone rubber (LSR)

Liquid silica gel is packaged in two-liquid type. Commonly, one package is 20 liters or 200 liters in two barrels, that is, agents A and B are often referred to. Agent A is usually a catalyst, and agent B is usually silicone , but it may vary depending on the brand used. The curing mechanism of liquid silicone is a platinum bridge mechanism, and the two agents A and B will be cured after mixing. If there is a color requirement, agent C will be used as the Using color additives, the curing time of the product is shorter than that of solid silicon, and it is common to produce medical or special process products.

Silicone molding method

Compression Molding

Solid-state hot pressing is to use solid silicone to be placed in a heated mold. With a high-pressure clamping unit, the solid silicone is forcibly deformed to conform to the product structure of the mold. ) in a short time to achieve the molding effect and can produce products with low precision requirements but large quantities. Generally, the number of production holes at one time will be greater than that of the liquid silicone process, but the thermal curing time is longer than that of the liquid silicone. The advantage is that the cost is low, the difficulty of the process is also low, and the disadvantage is that it cannot produce products with high precision or function.
 

LSR Injection Molding

Liquid silicone molding is to use a liquid silicone feeder to feed the liquid silicone special injection machine for injection molding. The raw materials are all liquid before molding, and the feeder is 1:1. After the liquid A and B are statically kneaded, they are transported to the injection unit of the injection machine for storage. After completion, the liquid silicone is injected into the mold. If the product has the needs of color and additives, it can be Add the C agent and adjust it simultaneously in the process. The common ratio of A, B, and C is 100:100:0.5-5. The advantage of liquid silicone injection is that it can produce products with high precision requirements, such as the application of high-precision seals, P+R, M+R, R+R, the recently popular automotive Matrix LED LENS is also made by the liquid silicone process, as well as the application of medical supplies. 
​〈Extended reading: What is the difference between rubber injection and silicone injection?〉
 

Types of LSR injection machine

Vertical type LSR injection molding machine

Advantage: insert molding, high precise and stability require.

Application: P+R、M+R，R+R

〈Recommend products: LSR Vertical Series Liquid Silicone Rubber〉

 

Horizontal type LSR injection molding machine

Advantage: High quantity and precise mass production.

Application: baby accessories, medical parts

〈Recommend products: LSR Horizontal Series Liquid Silicone Rubber〉

Conclusion

After the above description of the application of various types of silicone, we believe readers can learn more about the raw materials and equipment types corresponding to various processes. If you have any LSR process development needs, please contact our company.

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