WHITE PAPER: Aluminum Tooling for Optical Moldable Silicone

Dow Corning recently published a comprehensive white paper on the use of aluminum tooling for moldable optical silicone. It examines two big questions:

  1. To achieve a high-quality finish on the molded parts, what type of optical-grade surface finish is required for the tooling used to mold the silicone optics?
  2. Can this be achieved with an aluminum injection mold or is tool steel required to provide parts with an optical finish?

Proto Labs’ aluminum tooling is a reliable indicator of future optical silicone moldability.

Read why integrating optical silicone into your development cycle with rapid injection molding is an effective strategy, and why aluminum tooling is a reliable indicator of future moldability.

DOWNLOAD WHITE PAPER HERE.

Why use optical moldable silicone? It’s a relatively new material to the market, but it is quickly gaining popularity as a replacement for glass components in many optical and lighting applications. Its benefits include:

  • clarity
  • heat resistance
  • durability for use in outdoor and automotive applications
  • design flexibility for fine features
  • an ability to combine multiple parts into a single unit

Learn more about optical silicone with our “14 Reasons Why Optical LSR is Good for Lighting Applications” design tip.

13 Cosmetic Defects and How to Avoid Them

As with any manufacturing process, injection molding comes with its own set of design guidelines, and design engineers who understand these best practices will increase their chances of developing structurally sound and cosmetically appealing parts and products.

Learn about different cosmetic issues that commonly occur on injection-molded parts, and how to eliminate them to improve overall part appearance and performance. This month’s tip discusses sink, warp, flash, knit lines, drag, vestiges, jetting, splay and other cosmetic issues.

Read the full design tip here.

Strategies in Light Underway in California

The big lighting and optics show, Strategies in Light, starts today in Santa Clara, California. We’ll be talking with designers and engineers over the next three days about how industrial 3D printing, machining and injection molding processes can help them develop well-designed, more efficient products and devices. Track us down at booth #102.

One topic that is certain to dominate the conversation is the relatively new thermoset material, optical liquid silicone rubber (LSR), which has many advantages during lighting development versus plastics like polycarbonate and acrylic.

Optical liquid silicone rubber prototype from automotive company MagWerks LED.

Optical LSR is changing the lighting industry with its superior material and optical properties that improve:

  • durability
  • lightweighting
  • heat resistance
  • UV stability
  • light transmission
In addition to ongoing optical LSR discussions in the booth, we’re co-hosting a presentation with Dow Corning on prototyping with optical moldable silicone on Wednesday, March 2 at 1 p.m. in the presentation theater. Proto Labs’ global segmentation manager Jeff Schipper and Dow Corning senior application engineer John Nelson will cover why optical LSR works well for prototyping and low-volume injection molding and the results of recent research on implementing aluminum versus steel tooling when molding with optical silicone.
We hope to see you at the show!

TIPS WITH TONY: High-Temperature Thermoplastics

We offer two high-temperature thermoplastics: PEEK and PEI. Both high-performance materials can be machined and injection molded, and produce parts that can withstand extreme temperatures.

PEEK
PEEK parts contain excellent mechanical and chemical resistance during high-temperature applications. Its mechanical properties consist of tensile modulus strengths of 90-200 MPa and a melting temperature of 662˚F (343˚C). Some grades of PEEK have operating temperatures around 482˚F (250˚C).

Because of its robustness, PEEK is commonly used in applications for mechanical and medical instruments. PEEK is also used widely in the aerospace, automotive and chemical industries due to the insulating properties and creep resistance of any dimensional changes in high-temperature applications.

PEI
Like PEEK, PEI (often called by its trade name Ultem) offers outstanding elevated thermal resistance, high strength, stiffness and chemical resistance. PEI consists of tensile modulus strengths of 96-190 MPa and with a melting temperature above 420˚F.

PEI is available in transparent and opaque colors including glass additives for improved mechanical properties. Unlike other thermoplastics, PEI provides optimal strength and resists stress cracking when the material is exposed to hydrocarbons, alcohols and acids that makes them ideal for automotive and aerospace applications.

Which Manufacturing Process is Best?
If you’re in need of small quantities (up to 200) of PEEK and PEI parts, we can machined them in less than 3 days. For increased quantities in the thousands, rapid injection molding can produce parts in 15 days or less.

The physical properties vary little between processes, so please test out one sample using machining before moving to injection molding if you are unsure if your parts design is complete or not.

Contact us if you have any further questions about high-temp plastics and specific questions regarding PEEK or PEI. We have a full staff of customer service engineers who can be reached at customerservice@protolabs.com or 877-479-3680.

WATCH: How Draft Makes Your Drink Cold

We’re kicking off an animated series that takes a quirky look at the fundamentals of molding. The first short video is on draft, one of the most important consideration during injection molding part design.

Check it out:

 
For more information on designing with draft, read our recent tip on 5 ways to improve part moldability with draft.