Webinar: Designing for Overmolding

Join us for a webinar alongside RTP Company as we address common questions related to overmolding. We’ll discuss how to design more durable overmolded parts and what it takes to achieve strong adhesion between your part’s two materials.

gasket-overmolding

Overmolding produces two-material, plastic parts.

The presentation will include the following:

  • 12 key overmolding materials
  • Design factors that determine quality of flexible-to-rigid bonds
  • Methodology used to measure bonding strength
  • Differences between low- and high-volume overmolding

TITLE: Overmolding: TPE Multi-Material Molding, Achieving Melt Adhesion
PRESENTER: Steve Brenno, Sr. Product Development Engineer, RTP Company
DATE: Tuesday, November 15 at 1 p.m. CDT
REGISTER: Click here to sign up

And, if you can’t attend, you can still register and receive an on-demand version. Also, feel free to forward this invite to your colleagues.

Overmolding: Chemical and Mechanical Bonding

Learn more about overmolding in our free webinar we’re hosting with RTP Company on Tuesday, Nov. 15 at 1 p.m. CT. REGISTER TODAY!

Overmolding is not a new manufacturing technology, but there is still some confusion about how to design for the two-part process. One of the largest areas to consider? Bonding. A number of materials can be used to overmold components together, but without a chemical bond or mechanical interlock, some overmolded parts won’t stand the test of time.

Chemical Bonding
This bonding process involves two chemically compatible materials that are molded together to form a strong bond with each other. It’s important to note that not all materials play well with one another.

The compatibility chart below indicate whether a chemical or mechanical bond is recommended for key thermoplastic and thermoset materials.

mechanical bonding

Three types of mechanical bonding techniques.

Mechanical Interlocking
What happens when your materials are not compatible, the desired bonding strength cannot be achieved, or you want to ensure your materials don’t peel apart from repeated use? This is where designing a mechanical interlock, which physically holds the overmolded material to the substrate, makes sense. There are many ways to design these into parts (see example), so discuss the options with your manufacturer.

Overmoling

Learn more about overmolding in our free webinar we’re hosting with RTP Company on Tuesday, Nov. 15 at 1 p.m. CT. REGISTER TODAY!

If you have further questions regarding rapid overmolding at Proto Labs, contact one of our application engineers at 877.479.3680 or customerservice@protolabs.com.

Rapid Overmolding: Consider These 3 Elements

Injection molding is a common, cost-effective method for manufacturing parts, but, sometimes, those parts need a little help. Low impact or vibration resistance, slippery surfaces, poor ergonomics, and cosmetic concerns are only a few of the reasons why a second molded part is often added as a grip, handle, cover, or sleeve.

Proto Labs now offers rapid overmolding for parts, including the three samples pictured here.

The process of rapid overmolding will get the job done. This method, which Proto Labs now offers, and is the focus of our October design tip, uses a mechanical or chemical bond (or both) to permanently marry two parts together.

This month’s tip discusses:

  • Bonding: A strong bond between the two materials is critical to overmolding.
  • Materials: This is a key consideration in overmolding.
  • Principles: Overmolding uses the same playbook as injection molding, but with a few quirks.

READ FULL DESIGN TIP

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.

THE SHORT LIST: 4 New Capabilities at Proto Labs

The crew at Protoworks (our R&D program) has been busy. Every day they’re pushing the boundaries to advance new rapid manufacturing processes and materials and expand your design possibilities.

We just rolled out a few new capabilities that we’re excited to share.

2 is better than 1: Overmolding

Overmolding expands on our injection molding offering. At Proto Labs, it’s a multi-step process where we mold a substrate part and place it into a second mold, which then molds another material onto the substrate. It’s called pick-n-place molding.

liquid silicone rubber manufacturing facility

A look inside our liquid silicone rubber manufacturing facility

Overmolding can aid in dampening vibration, improving grip as well as two-color aesthetics. We are still in the beta testing phase of our overmolding process, but it’s open to everyone.

Visit our overmolding page for design guidelines or to submit a request for parts.

Extra-strength machined parts: titanium

You asked. We listened. Our CNC machines can now mill and turn parts from titanium. With an excellent strength-to-weight ratio and corrosion resistance, titanium is most suitable for applications in aerospace, medical and other industries where high performance is critical.

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