Designing luminaires or lenses with clear materials? Our tip this week looks at the material selection and surface finishes available for prototyping and low-volume production of lighting applications.
If you haven’t considered using additive manufacturing (3D printing) for your lens design, you may want to check it out. Proto Labs offers stereolithography (SL) with three options for clear parts.
- Somos WaterShed XC 11122 — ideal for lens and high-humidity applications
- 3D Systems Accura 60 (10 percent glass-filled) — creates a clear part with slight blue tint and high stiffness
- 3D Systems Accura 5530 — high temperature resistance, suitable for under-the-hood applications
Liquid Silicone Rubber Molding
Liquid silicone rubber (LSR) is also being increasingly used for lighting applications due to its improved light output over polycarbonate and acrylic? Not only does LSR improve light output, the advanced material improves impact, chemical, UV and temperature resistances. UV resistance is very valuable in outdoor luminaires as you don’t have the same yellowing effect that you see in plastics.
We offer three main clear LSR materials:
- Elastosil 3003 (30,50 and 70 shore A) — most commonly used and is clear
- Dow Corning QP1-250 (50 shore A) — uses USP class VI and is water clear
- Dow Corning MS-1002 (70 shore A) — great for primary and secondary lenses, light pipes and light guides
LSR is also extremely mold friendly as part geometries that previously couldn’t be molded in thermoplastics can now be molded. Considerations for thick and thin sections, undercuts and negative draft are nothing to sweat over. We have easily molded features over a large area that are 0.010 in. or greater than 1 in. with very few issues of shorting, sink or voids. With a part flexibility up to 400 percent and a great memory (no part distortion), designing undercuts and negative draft are easily achieved, so if the mold can be milled, the LSR parts can typically be easily produced.
If you would like to learn more about rapid manufacturing with clear materials, please visit our pre-recorded webinar: Custom Prototyping for Lighting Applications. For more information on part design or material questions, please contact one of our customer service engineers at firstname.lastname@example.org or 877.479.3680.