Custom Prototyping for Lighting Applications How to use rapid injection molding and 3D printing for housings, fixtures and optical parts Tony Holtz | Technical Specialist, Proto Labs

Do you currently use rapid manufacturing during product development of custom optical and lighting prototypes?

Additive manufacturing (3D printing) and injection molding provide quick-turn parts for several industries. Learn how you can leverage these services during development, and bring products to market faster and more cost effectively.

Low-volume Injection Molding 25 to 10,000+ parts in 1 to 15 days SPI-A2 quality clear parts Great for lens, light pipe, housings and all injection-molded prototypes and low-volume production parts Hundreds of clear, transparent and opaque thermoplastic materials available Thermally conductive materials available for lighting housings to dissipate heat

Thermoplastic Materials PC Lexan and Makrolon Improved impact resistance over PMMA Up to 89% transmittance PMMA (Acrylic) Can improve part quality in thick parts over PC Up to 92% transmittance K-Resin Improved flexibility over PC and ABS; can be used in a living hinge part design Fills well in thin parts Up to 93% transmittance Styron Medical and packaging industries High tensile strength Up to 90% transmittance

Thermally Conductive Plastic Do you need heat dissipation? Plastics can: Reduce weight up to 50% over other materials Lower cost of manufacturing over die casting and machining Improve features with traditional injection molding techniques Reduce assembly costs with part consolidation Improve thermal conductivity by 50-500 times over conventional plastics Can reach 35+W/(m.k) compared to 167+W/(m.k) for aluminum, so please do your homework Used extensively in LED luminaire, electronics and aerospace industries Applications like automotive cooling systems, battery/motor housings and sensors Materials like CoolPoly and Therma-Tech are just two examples of advanced materials that are making an impact in the industries.

Design Considerations: Plastics Ejection Will ejector pins be on a cosmetic surface or are alternative ejection possible? Gating Is your gate on a cosmetic surface and how will the knit lines effect your cosmetics? Part thickness Will your part have sink or voids in thick areas? Undercuts Undercuts can be achieved, but some may not be possible Surface finish Does your part need to be clear, textured a combination? Draft Surfaces that are highly cosmetic may require more draft for improved mold release

Liquid Silicone Rubber (LSR) Molding 25 to 5,000+ parts in 1 to 15 days Up to 94% light transmission Extreme thin and thick parts Improved light pipes, LED and outdoor lighting designs Lightweight, flexible, non-yellowing, vibration control, scratch, crack, UV and heat resistant Up to 400% flexibility -49 to 392°F (-45 to 200°C) Easily cleaned and chemical resistant No ejection required and minimal gate vestige

Material Selection: LSR Clear Elastosil 3003 (30,50 and 70 durometer) Most commonly used Water Clear Dow Corning QP1-250 (50 durometer) Medical devices or components, USP class VI Optically Clear Dow Corning MS-1002 (70 durometer) Primary or secondary lenses, light pipes and light guides

Design Considerations: LSR Are you able to combine parts to minimize assembly? Does your part require a gasket? An LSR lens can eliminate multiple components You don’t have the typical molding constraints that you do for PC or acrylic Mold your part with thick and thin walls Mold your part using negative draft Mold your part using no ejection or concern of where the gate would be located Mold your part with minimized knit lines, sink and voids Surface finish Does your part need to be clear, textured or a combination?

Design Considerations: LSR .

Design Considerations: LSR

Side-by-Side Comparison   Silicone PC PMMA Glass Light Transmission 94% 88-90% 93% 95% Refractive Index 1.42 1.58 1.49 1.52 UV Resistance High Low Medium Chemical Resistance Temperature >150°C 120°C 90°C >200°C Yellowing No Yes Micro Detail Thick Part Yes >1 in. >PC Minimum Part Thickness <0.020 in. 0.040 in. -

3D Printing: Stereolithography (SL) 1 to 50+ parts in 1 to 7 days Nearly any geometry possible Small complex parts Thick cross-sectioned parts Post processing for optically finished part Hand polish and sprayed with clear coat Near distortion-free appearance similar to molding High clarity and transparent materials or finishes available Not truly optical — some level of distortion is possible and should be considered Produce multiple parts together Custom finishes allow multiple colors or finishes on each part

Material Selection: Clear SL Somos WaterShed XC 11122 (ABS) Ideal for lens applications in high-humidity applications 3D Systems Accura 60 (10% GF PC) Clear with blue tint and high stiffness Accura 5530

Design Considerations: SL Avoid thin ribs or internal cavities that would be difficult to polish Part orientation for build — where would support structures be located? Is your surface completely flat? If so, can a substrate such as an acrylic sheet be used? This helps on flat surfaces, but internal surfaces may still be hazy

Design Considerations: SL

Manufacturing Processes at Proto Labs

Benefits of using Proto Labs Reduced up-front investment Increased speed to market Design for manufacturability (DFM) analysis is built into quote Talk with on-hand experts regarding design and process Quick return time on quotes Instantaneous for additive manufacturing Within hours for machining and molding

Interactive Quote for Molding

Complete DFM Analysis for Molding

Mold Flow Analysis for Molding

Do you think a custom prototype manufacturer can help during product development? Upload a 3D CAD model online at protolabs.com for an interactive quote with free design and cost analysis.

Questions? Tony Holtz | Technical Specialist, Proto Labs 763-479-3680 or customerservice@protolabs.com www.protolabs.com