In a nutshell, this process produces pliable, durable parts in high volume. Here at Si-Tech, we utilize a unique injection molding process that combines technology and quality to result in custom rubber keypads and other silicone products. Thus, you get complex key shapes, housings and other features in an economical, affordable and fast way.
Silicone injection molding, or liquid injection molding (LIM), is an industrial fabrication process designed to mold materials into several components and products. Rather than use a pressurized impingement mixing, liquid injection molding uses a mechanical-mixing process using mainly liquid silicone rubber (LSR) and other, similar elastomeric materials.
Most manufacturers of rubber parts use this method, and we are no different. We like it because it guarantees excellent end-of-product performance and long-lasting durability.
With silicone injection molding, you can be assured of these qualities:
- Temperature resistance
- Transparency and pigmentation
- Accuracy
- Durability
- Tensile strength
- Biocompatibility
- Flexibility
- Chemical resistance
- 24/7 production
- High levels of automation
Why is it so Flexible?
As you may have guessed, one of the top advantages to silicone injection molding is its flexibility. With a material boasting excellent resistance to high heat and flame, silicone can also withstand temperatures of more than 250°C, and even as low as -90°C. It’s also great in terms of formability and malleability, leading to the transparency or coloring of the end product.
Step By Step
There are many materials used in the process of LIM, mainly silicones and acrylics.
- They are applied with a spring-loaded pin nozzle that prevents clogging of the machine hardware.
- One plunger holds the base forming plastic, which gets stronger with additives and fibers; the other plunger holds the catalyst.
- Each goes into a static mixer.
- This triggers the mixing reaction.
- The liquid mixture is injected into the appropriate mold, heated at temperatures ranging from 355F to 390 F.
- What starts as a fluid gets heated in the mold and starts to cure, or harden.
- Once done, the molding machine pops out the nearly finished part.
- The materials get heated to their melting point.
- They cool off in the mold.
Fairly straightforward, right? For added efficiency, many manufacturers use computer-aided design (CAD) tools so they can evaluate results for a more cost efficient and effective process. On top of that, thermal imaging technology can weed out expensive production mistakes, from design irregularities and molding defects, in order to defray costs.
Who Uses It?
Many industries benefit from using products made with the liquid injection molding process.
- Textile
- Food
- Automotive
- Appliances
- Aerospace
- Medical
- Defense
- Electronics
Contact Si-Tech
LIM is what we use here at Si-Tech. Want to know about the process and how your business can use products made with silicone? Just contact us at 757-887-8488.
