THE SHORT LIST: 4 Ways to Leverage Rapid Overmolding

Rapid Overmolding is the latest addition to our injection molding service. Now, you have a fast way to create injection-molded parts with two different materials. We use a pick ‘n place method.

rapid overmolding services sample

That means we follow a two-step process. First we mold the substrate part. Then we place the substrate part into the mold and a second material is injected to form the final, two-material part.

Here are a few benefits of rapid overmolding.

Vibration dampening: Dampen vibration by adding liquid silicone rubber to parts made of hard plastic, like ABS, or if it’s a handhold device (think toothbrush), it can even be used to improve grip.

rapid overmolding services sample orange partMulti-color aesthetics: Add a stylistic flair to your product with overmolding. Using two materials, means two colors for high-quality looking products and can enhance your product’s design.

Fast, flexible volumes: Often, manufacturers will not process low-volume overmolding orders, but now you have the ability to manufacture 25 to 10,000+ overmolded parts within just a few weeks.

Simplify multi-part assemblies: Reduce cost and save time spent assembling parts by combining two materials in one molded part.

For information on rapid overmolding like designing mechanical interlocks or understanding chemical bonding compatibility, visit our rapid overmolding service page to see overmolding design guidelines and get free DFM feedback.

WEBINAR: Rapid Prototyping for Accelerated Medical Device Development

In our next webinar, we’re taking a look at medical device development. Specifically, how using rapid manufacturing can accelerate prototyping and get you to FDA submissions more quickly.

The presentation will cover:

  • Reaching validation and FDA  510K approval fast
  • Reducing costs with rapid manufacturing
  • Selecting materials for 3D printing, CNC machining and injection molding

And come prepared with questions! At the end we’ll have an open Q&A session.

TITLE: How Rapid Prototyping Accelerates Medical Device Development
DATE: Thursday, July 28 at 1 p.m. CDT
REGISTER: Click here to sign up

Already have plans that day? That’s okay. We’ll send you an on-demand version that can be watched at any time. Also, feel free to forward this invite to your colleagues.

DESIGN TIP: Cutting Corners on Injection-Molded Parts

Sharp corners definitely have their place in part design, but they often spell trouble when injection molding plastic parts. Accordingly, designers should be aware of the pitfalls associated with “being square” when developing parts. Indeed, part accuracy, strength, and aesthetics suffer without the right amount of corner rounding and filleting.

This month’s design tip explores ways to strengthen injection-molded parts while reducing costs with proper placement of corner radii and fillet. You’ll learn about:

  • Material selection. Some plastics are more forgiving of sharp-cornered parts. Choosing the right one for your application is a necessary step towards accurate, functional parts.
  • Wall thickness. Beefing up adjacent walls may absorb some of the stress associated with sharp internal corners, but can create other design challenges.
  • Part geometry. Some parts are simply more “moldable” than others. Achieving proper form, fit and function depends on sound part design, a large piece of which is appropriate corner radii.


WATCH: Talkin’ Cosmetic Defect Blues

The next short video in our Fundamentals of Molding series takes a trip down the Mississippi River to explore different cosmetic flaws like sink, warp and blush, which can find their way into injection-molded parts.


For a lengthier examination on avoiding cosmetic defects when designing for injection molding, read our free white paper.

Thirsty for more quick tips? Here’s our previous video on draft considerations:


NEW JOURNAL: How Technology is Transforming Injection Molding

The new issue of Proto Labs Journal is out and includes a cover story focusing on the digital transformation of injection molding. A related, second feature story explores the pros and cons of printed plastic molds.

The cover story reports on how automating the front-end of the manufacturing process has reinvented injection molding, and served as a game-changer for the entire industry.

The related feature, “3D-Printed Molds,” advises product designers, engineers and developers to take a careful look at part finish, size, design capabilities, mold longevity considerations and cost when comparing printed plastic molds to aluminum tooling.

Elsewhere in the Journal, look for our Eye on Innovation feature, which highlights cool new products and technology you should know about.

Read the entire Journal here.

We’re always on the hunt for though-provoking content, so send your cool project or article idea to our editor at

Thanks and enjoy the issue!