Liquid Silicone rubber inject - How do you inject Silicone Rubber? - ZSR

How do you inject Silicone Rubber?

When we ask this question, how do you inject silicone rubber? Do we trust what you would like to know the process of silicone rubber injection molding?

Liquid silicone is a food-grade/Medical Grade material with high transparency and high safety. No auxiliary materials such as vulcanizing agent are added during molding, and it is sealed and fed for injection molding;

Liquid silicone is injection molding liquid silicone rubber (LSR): its full name is injection molding liquid silicone rubber, and vulcanization equipment is an injection molding machine.

The injection molding machine has a very simple process (no need for manual processes such as batching, rubber mixing, cutting, and placing in the high-temperature glue process, only one worker needs to take the product), and the product has high accuracy (all manual procedures before molding All are replaced by machines), high output (A / B glue mixed at a temperature of 130 degrees for a few seconds), many advantages such as saving labor, electricity, and materials, can produce all products produced by high-temperature glue.

LSR molding process

Liquid Silicone rubber inject - How do you inject Silicone Rubber? - ZSR
  1. LSR A + B components typically come in suitable injection molding equipment and then heat-cured into a molded rubber part. A process controlled pumping kit presses down on the buckets to force the material into static mixer and feed into the injection unit.
  2. Then, streams of pigment can be added and controlled. In the injection, press material will be mixed together additionally with a screw and pushed forward to create a “shot” of material, or the amount needed to fill the mold.
  3. After the material is injected into the mold, it will then stay clamped together to cure the LSR. Then, either an operator or a robot will remove the cured product from the mold and the cycle repeats. It is a very quick efficient process.
  4. Secondary steps like post bake can help reduce volatilities and improve compression set. And the deflashing process removes unwanted flashing. It’s then cleaned to remove foreign material and packaged for shipment.

The Equipment for the silicone rubber inject

In order for the liquid injection molding process to fully occur, several mechanical components must be in place. Typically, a molding machine requires a metered pumping device in conjunction with an injection unit—a dynamic or static mixer is attached. An integrated system can aid in precision and process efficiency. The critical components of a liquid injection molding machine include:[2]

Injectors. An injecting device is responsible for pressurizing the liquid silicone to aid in the injection of the material into the pumping section of the machine. Pressure and injection rates can be adjusted at the operator’s discretion.

Metering Units. Metering units pump the two primary liquid materials, the catalyst and the base forming silicone, ensuring that the two materials maintain a constant ratio while being simultaneously released.

Supply Drums. Supply drums, also called plungers, serve as the primary containers for mixing materials. Both the supply drums and a container of pigment connect to the main pumping system.

Mixers. A static or dynamic mixer combines materials after they exit the metering units. Once combined, pressure is used to drive the mixture into a designated mold.

Nozzle. To facilitate the deposition of the mixture into the mold, a nozzle is used. Often, the nozzle features an automatic shut-off valve to help prevent leaking and overfilling the mold.

Mold Clamp. A mold clamp secures the mold during the injection molding process and opens the mold upon completion.

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About Author: Z.S.R International Group

Z.S.R International Group(Hong Kong) co., Limited,  is a one-stop supplier for molded silicone products and silicone products molding solution provider in the consumer products field. We offer OEM services from product design to Silicone products contact manufacturing. We have the capability for LSR molded silicone products, solid silicone molded products, molded silicone multi-colored products. We also can custom molded silicone, custom molded LSR, custom molded dripping injection dispensing (co-injection) silicone multi-colored products, custom tooling.