TPE over-molding widely used in the thermoplastic elastomer industry. In recent years, with the rise of liquid silicone applications and the excellent properties of liquid silicone rubber materials, TPE over-molding products are gradually being replaced by liquid silicone rubber. The liquid silicone rubber has excellent comprehensive performance. LSR has high-temperature resistance than thermoplastics, soft-touch, high quality of materials meet with the medical-grade requirements. It is the best soft material for over-molding and injection molding and two-color injection molding.

Silicone over-molding is a process that is used to cover, bond, or encapsulate an existing part with silicone material.

Liquid silicone rubber overmolding silicone overmolding


The main advantages of liquid silicone over-molding

The liquid silicone rubber(LSR) material has excellent slip resistance and soft elastic touch, which can improve the touch feeling of the product and enhance the grip.

liquid silicone rubber has different hardness range Shore 10-90A according to the physical properties of the product, as well as suitable physical properties (such as abrasion resistance, adhesion, melt index, etc.). A variety of possible material application options are available for different products.

Liquid silicone rubber is an environmentally friendly raw material. It does not contain phthalates, halogens, and does not include 38 SVHC substances of REACH. It meets the environmental testing standards of ROHS, REACH, NP, EN71, and PAHS, and can fully meet the environmental protection requirements.


Liquid silicone rubber over-molding processing technology

Silicone rubber over-mold injection molding process involves two steps wherein a completed plastic or metal entity is placed into the mold site of an LSR mold, after which the LSR is over-molded directly onto the part.

The injection molding temperature is different depending on the hard material. The commonly plastic substrate is PC or PA, and aluminum alloy can also be over-molded by liquid silicone rubber.


Common problems and solutions for liquid silicone rubber over-molding processing

1) Lack of silicone – the product is trapped air, or the silicone is not enough.

2) blunt, overflow edge – increase the clamping force; reduce the injection pressure.

3) Poor viscosity – choose the right adhesive. Check the plastic or metal substrate is clean.

4) out of shape during Injection molding – lowering the molding temperature; using a high-temperature resistant substrate.


Ukong is a liquid silicone product OEM/ODM manufacturer. We are committed to the development of new processes for liquid silicone (LSR) products and custom products. We have advanced molding techniques such as the high speed of injection molding, short vulcanization time, automatic, self-removing, and no burrs.

Our products including the liquid silicone rubber baby care, medical liquid silicone products, mobile phone 3C waterproof accessories, automotive electronic accessories, liquid silicone kitchen products, industrial sealed liquid silicone Products, etc. and has rich experience in the liquid silicone rubber over-molding parts. (liquid silicone rubber to plastic, liquid silicone rubber to metals, liquid silicone rubber to glass or ceramic, silicone two-color products)