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LSR & Plastic Overmolding Solutions

At Minnesota Rubber and Plastics, we specialize in rubber, liquid silicone rubber (LSR) and plastic overmolding for your most critical applications.

From formulation and design, prototyping and testing, through manufacturing and assembly, we have the overmolding solution to solve your most complex component challenge.

Design Solution

Through superior engineering expertise, our team will provide preliminary engineering assistance and mechanical design review, ultimately providing a recommendation of the best solution for your application. We’ll help you with decisions that drive performance and cost to ensure a successful project.

Our team can:

  • Determine if your component requires overmolding or assembly
  • Recommend when to chemically or mechanically bond.
  • Can advise about the overmolded substrate, whether metal or plastic, taking into account the operating environment, production method, cost, and weight.
  • Provide detailed guidance about the necessary mechanical design features that will promote a durable, high-performance bond.
  • Model the solution with our best-in-class, non-linear finite element analysis (FEA).

Selecting the right material

Part of the mission of our Advance Materials Group, is to work hand-in-hand with our design team to recommend the right materials for bonding and overmolding. We work with a multitude of different chemical bonding agents and technologies to meet the toughest of application operating conditions, while ensuring a repeatable process in our production environment.

Overmolding Substrates

Liquid Silicone Rubber (LSR)

Turn to us to help you design and manufacture hard-to-build custom over-molded Liquid Silicone Rubber (LSR) parts. Learn more about our LSR capabilities.


Overmolding onto plastic inserts can solve many design problems. The flexibility, toughness, solvent and chemical resistance of rubber is combined with rigidity, light weight, and cost savings of plastic.

Plastic materials commonly used in the bonding process include nylon, polycarbonate, modified PPO, polysulfone, and polyphyenylene sulfide.

Other Resources

Have an overmolding project you’re working on?

Global manufacturing gives you more options

Your over-molded components can be manufactured and supported from any one of several locations we have around the world: United States, France, Mexico and China. Our worldwide manufacturing facilities operate under strict ISO guidelines including ISO 13485, and ISO 9000. These facilities operate under a corporate-wide Environmental Management System registered to the International Standards Organization series ISO-14001.


Design Engineers: Read our Design Guide

We wrote this for design engineers because you don’t have time to become an over-molded rubber and plastics expert. That’s our job.

To gain a better understanding of the processes, materials and technical considerations involved in the design and manufacture of over-molded rubber or thermoplastic components, read through our Engineer Design Guide. This comprehensive design tool details both rubber and plastic design issues including a materials overview and prototype mold design considerations.