Liquid Silicone Rubber Coffee Cup Lid Plastic Injection Molding Machine

Liquid Silicone Rubber Coffee Cup Lid Molding Machine Reusable Cup Lid Production Equipment

LSR injection molding industry application

Maternal and baby industry: The safety and forming process of liquid silicone materials are non-pollution, and have been widely used in the production of silicone products such as nipples, pacifiers, teether , bottles, spoons, suckers, brushes and so on in the maternal and baby industry.

Medical industry: The good biological characteristics and high-quality forming technology of liquid silicone materials have been widely used in the silicone accessories such as catheter & the joint, gastric tube, laryngeal mask, mask, dental bracket, negative pressure ball, incision protective cover, balloon and so on in the medical industrial.

Electronics industry: The waterproof, elastic and high precision forming process of liquid silicone material has been widely used in the silicone parts such as joint waterproof seals, horn diaphragm, mobile phone case, watch belt, button, earphone and so on in the electronics industry.

Automobile Parts Industry: The high permeability and high efficiency production process of liquid silicone material has been widely used in the silicone accessories such as LED perspective mirror,spark plug protector, wire harness seal ,sealing strips in automobile parts industry.

Liquid silicone injection moulding machines employ cold runner technology. After precisely blending the low-temperature liquid A and B components of silicone in the correct ratio, the mixture is pressurised by a screw and injected into the high-temperature mould cavity. Under the mould's heating action, a rapid chemical cross-linking reaction occurs, causing the material to cure and form. This achieves high-precision, high-efficiency automated production. The core principle lies in the chemical reaction sequence of ‘mixing-injection-heated vulcanisation’, differing fundamentally from traditional injection moulding machines that heat solid raw materials.

Working Principle Flow

1. Raw Material Delivery and Mixing:

Liquid silicone rubber typically comprises two components: A (containing a catalyst) and B (containing a cross-linking agent), stored separately in material barrels.

An automatic feeder or metering system conveys the A and B compounds in a fixed ratio to a static mixer.

Within the mixer, the A and B compounds are thoroughly blended, with additives such as colourants sometimes incorporated.

2.Injection Moulding:

The mixed liquid silicone is propelled by a screw through a non-return valve and switch nozzle into the cold runner system.

The cold runner system maintains the silicone at a low temperature to prevent premature curing within the runner.

The silicone is rapidly and uniformly injected into the preheated mould cavity.

3.High-Temperature Vulcanisation Moulding:

Within the mould, heated to high temperatures via a heating system, the A and B components of the liquid silicone undergo catalysis and initiate a rapid chemical cross-linking reaction, known as thermal curing.

This process rapidly solidifies the liquid silicone into elastic, stable silicone products.

4.Pressure Holding and Cooling:

During curing, constant pressure is maintained to ensure dimensional accuracy of the product.

After moulding, the mould cools and opens to remove the cured product.

5.Automation and Repeat Production:

The entire process operates as a cyclical automated sequence, minimising manual intervention and enhancing production efficiency.

Differences from Conventional Injection Moulding Machines

Raw Material State: Liquid silicone injection moulding machines utilise liquid raw materials, whereas conventional injection moulding machines employ solid raw materials.

Forming Method: Liquid silicone cures through a chemical cross-linking reaction, constituting a thermosetting moulding process; conventional injection moulding machines rely on cooling for solidification.

Temperature Control: Liquid silicone injection requires cold runner technology to maintain low temperatures while mould heating facilitates vulcanisation. Conventional injection moulding machines heat raw materials within the barrel and mould to melt and cool them into shape.