A Beginner’s Guide to Liquid Silicone Rubber Molding

Are you new to manufacturing and are curious about liquid silicone rubber molding?

You are on the right article, we will discuss the details about liquid silicone rubber molding, its benefits, and other important facts about it.

What is Liquid Silicone Rubber Molding?

Since the invention of liquid silicone rubber in the 1970s, it has become the preferred material for making rubber products and parts. It’s no wonder why because it is pliable yet durable and can be manufactured in large quantities. The liquid silicone rubber has excellent stability too and can resist hot and cold temperatures making it fit for products that demand better quality.

Unlike thermoplastics, liquid silicone rubber can offer more options and has better-finished products. Liquid silicone rubber molding is the best manufacturing option if you are after speed, maximizing cost, and efficiency. Compared with compression molding, this process involves introducing the material into the cavities with a system of runners, sub runners, and sprues. After curing the part, it is removed and the process can be repeated.

This process has thousands of applications in different industries, including infant care, medical, automotive, electronics, aerospace, and many other specialized industries.

The Liquid Silicone Molding Process

The liquid silicone rubber molding is a two-part process that begins with tooling. In building the mold,  There are two most common machining processes that use EDM (electrical-discharge machining) and CNC milling. Creating the LSR mold takes a great deal of time and accuracy because it needs high-temperature LSR mold that can withstand its challenges.

It has to have the precision to achieve the viscosity of liquid silicone rubber, 400 degrees temperature, and the abrasiveness of LSR. In liquid silicone rubber molding, tooling is the longest process and the most expensive part. However, it has no complicated design because it only requires the liquid to flow into thin cross-sections with thick or thin features.

Another requirement of the mold is it needs to have a high-quality polished finish with draft angles to easily remove the finished components. When the solidification phase is through, the molded part should be ejected without distortion.

The second phase of the process is the liquid silicone rubber molding process is the molding process where the silicone rubber is made into products and parts. In the liquid injection molding process, there is a mechanical mixing of the components in the mold.

In this process, the liquid silicone is in two containers connected to the pumping system. The first part is the base material, and the second the catalyst. This machine is fully automated and can program the approximate shot for each product.

With the molding machine heats the mold to an appropriate temperature, it will close and work in simultaneous with the injector, supply, and power. The combined heat and pressure will cure the material and will solidify. After the curing process, the mold will eject the final product.


Liquid silicone rubber molding can bring consistency and cost-effectiveness for making a variety of products. These products can be applied for electronic, automotive, medical, and many other industries.

Pooja sharma

Pooja is a digital nomad and founder of HotMail Log. She travels the world while freelancing & blogging. She has over 5 years of experience in the field with multiple awards. She enjoys pie, as should all right-thinking people.

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