Liquid Silicone Rubber is a low viscosity and high purity thermoset elastomer maintaining mechanical properties over a wide range of temperatures (from -50°C to 250°C). This heat-cured elastomer provides excellent optical clarity, durability and design freedom. This innovative transparent material serves diverse applications such as high power LED lighting, electronics, automotive lighting and many others.

Benefits gained by using Liquid Silicone Rubber

Why using Liquid Silicone Rubber?

Liquid Silicone Rubber is an excellent solution to consider if you're looking for highly optical clarity combined with long-term durability in harsh environment (high temperature, UV etc...).

Have a look at each feature below to see in details how this excellent combination of optical clarity, durability, design freedom and productivity can match your application.

Optical Clarity
  • 94% transmission
  • <1% haze
  • Abbe number of approx. 50
  • Strong color stability
  • High temperature resistance even above 150°C
  • UV light resistance
  • Micro-crack resistance
Design Freedom
  • Enhance options for part integration
  • Reduce weight in design
  • Excellent processability for injection / compression moldability
  • Material waste may be minimized in the coldrunner based LSR injection process

Outstanding optical clarity of Liquid Silicone Rubber

Liquid Silicone Rubber displays outstanding transparent properties, as you can see in the following table. It is therefore a right alternative to traditional plastic materials and a suitable choice for applications requiring ultra clear features.

  Liquid Silicone Rubber PC PMMA Glass
Transmission [%] 94 86-89 89-92 92
Index of refraction (RI) 1.41 1.59 1.49 1.5~1.6
Haze [%] <1 1.59 1.49 -
Abbe number 50 34 57 39~59
Yellowness index <1 1.0~3.0 1.0~3.0 -
Table 1 – Optical clarity properties (2mm)

By using liquid silicone rubber, how can you get a very high light output? This material is able to maintain the level of transmission to 94% over a wide range of wavelengths in both visible and non-visible light. Optical applications require a good refractive index of the material used in order to display high performance. Liquid Silicone Rubber has a lower refractive index than traditional thermoplastics which allow improved optical performance, due to lower Fresnel losses.

Long-term durability of Liquid Silicone Rubber

One main advantage of using this liquid silicone rubber is that its performance will stand overtime and environment has minimized effect on it. Liquid silicone rubber highly resists from harsh environment by having long-term color transparency and displaying anti-crack resistance.

By keeping high transparency and transmission level, liquid silicone rubber is the best solution to consider if your application requires long-term durability.

If you select this innovative LSR, you will not get any micro-cracks in your parts whereas common thermoplastics usually display this cracking.

Get more design freedom with Liquid Silicone Rubber

What if Liquid Silicone Rubber enabled you to:
  • Design a part made of a single complex piece, integrating light and at the same time exceed standard transparent material performance?
  • Upgrade to long-term durability even in harsh environment?

This cutting edge technology allows you now to free your design from usual ties. In summary, what is possible now?

  • Design a unique and complex piece by combining different thicknesses
  • Create precise micro-structures
  • Ease light integration into your parts
  • Reduce weight
  • Dial-in the level of rigidity / flexibility of your parts
  • Develop parts suitable to harsh environments (heat, UV, humidity etc…)

Liquid Silicone Rubber is a source of design freedom because you can generate complex geometric parts and high precision micro-structures thanks to the high process flowability of the material.

Table 2 - Comparison of design freedom

Improve productivity with Liquid Silicone Rubber

Liquid Silicone Rubber is exclusively processed by injection molding and heat-cured during the molding process. The main advantage of LSR is the possible integration of multiple parts into one, allowing drastic cost reduction. This material highly boosts productivity by decreasing cycle time, reducing material waste and using smaller machines.

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