We Understand Light, Not Just Rubber

Asahi Rubber is not just a rubber supplier, and not just optical specialists.

We have the strengths of both, to create the right design–and bring that design to reality.

Asahi Rubber has decades of experience in optical engineering with an in-house team.

And with our core competency in rubber manufacturing, leveraging over a half century of experience with a broad array of rubber types, we know how to maximize the material potentials of silicone to produce parts from both liquid and millable polymers, using both injection and compression techniques.

Track Record (Select)


  • Headlight active matrix primary optics
  • IR auxiliary light source for door mirror camera or driver monitoring
  • IR transceiver signal send and capture optics
  • Number plate illumination
  • Puddle light design projection


  • Ink curing
  • Additive manufacturing curing
  • Non-destructive inspection

Other Lighting

  • Street/area lighting
  • Roadway signage
  • Flashlights
  • Mobile phone light Fresnel lens
  • Luminaires
  • Medical exam lighting

A Rubber Lens

In a broad comparison, silicone rubber occupies a middle ground in the three general types of optics materials, between thermoplastics and glass.

Specifics vary, but as optical performance improves and overall durability goes up, so does cost.

In comparison with other materials, silicone rubber is ideally suited to UV and IR applications, or visible light applications with demanding heat/UV/weathering requirements or a design incorporating fine details of lens geometry.

Silicone is typically not suitable for imaging applications.

Material ComparisonSiliconePMMAPCGlass
Avg. Visible Light Transparency (%)949388~9095
Refractive Index1.411.491.581.52
UV Resistance
Chemical Resistance
Service Temp Max (°C)>15090120>200
Fine Detail Transcription
Min. Molding Thickness<0.5mm2mm2mm
Molding Draft Angle<0°1°~2°1°~2°

Material Varieties

365nm+ UVA/Visible ASR-A80MC Material

265nm+ UVC/UVB DUV280 Material


Silicone has inherent advantages over glass and thermoplastics in fine-detail transcription.

Our extensive experience enables full exploitation of this potential, achieving geometries difficult or impossible in other materials.

This fine-detail transcription makes applications such as advanced active matrix headlights possible.

Thermosetting materials perform better in completely filling all fine details of a mold before curing, where thermoplastics tend to have difficulties achieving the same.

Glass can be worked into fine details to some extent, but it is difficult and costly.

Siloxane & Outgassing Concern

Silicone is well known as having the drawback of outgassing complications. Outgassing can foul other optics or electronics, and the mass loss can alter the optical characteristics of the outgassing part.

We have a proprietary processing that all but eliminates these concerns. An additional step after secondary vulcanization reduces residual D3-D20 volatile siloxanes by over 98%; D3-D10 volatile siloxanes are reduced by over 96%!

Our lenses are used in demanding watertight-sealed automotive headlight applications.