Overmolding is a value-added injection molding method for improving plastic and metal substrate performance and aesthetics. While seemingly simple, the process has a number of underlying complexities that must be carefully considered to ensure your overmolding project meets all goals and expectations.

Injection-molded and blow-molded plastic parts are so pervasive in everyday life that the two processes are sometimes thought of as interchangeable. While the two may be used in an individual application — perhaps a blow-molded fluid reservoir is attached to a custom injection-molded medical device — injection molding and blow molding serve different purposes and markets.

An increased speed to market is a distinct competitive advantage, but making speed your first priority can jeopardize injection molding process efficiencies — and product performance.

Accelerating speed to market and upholding quality doesn’t need to be an "either or" proposition. Early in the design phase, seek out an injection molding partner that thinks and delivers beyond the standard injection molding process. If your ultimate goals include preventing costly rework, and eliminating defects and unanticipated product failure, look for an injection molder with expertise in mold filling analysis, scientific molding, and other time and cost saving process methodologies.

There are several prototype tooling options for your designs — the one you choose really depends on what you expect to accomplish with the prototype. For example, will the prototype be subjected to testing? Does it need to be "dressed up" for presentation? Will it need to meet tight tolerance requirements?

The most common prototyping options are SLA/SLS, urethane cast, soft tooling, and hard tooling. But which is right for your component? Read on to discover the advantages and disadvantages of each.

Overmolding is a unique injection molding process that results in a seamless combination of multiple materials into a single part or product. It typically includes a rigid, plastic-base component overlaid with a thin, pliable, rubber-like thermoplastic elastomer (TPE) exterior layer or other materials using either a single-shot (insert molding) or two-shot (multiple-shot molding) technique.

Custom injection molding is a viable solution for many projects, but there’s often hesitation in using it because of confusion about which material matches the job. While “thermoplastic” and “thermoset” sound similar and both are appropriate for a wide range of applications, the material properties of these two resin categories and how they behave during processing ultimately reveal the best choice for your injection molding project.

According to a recent study, about half of industrial buyers make decisions about adding suppliers in less than 30 days. In that time they vet an average of five suppliers, evaluating each on criteria including market presence, brand strength, and reputation. The most heavily weighted criterion, however, is delivery performance.

Some injection molders claim to provide custom services, but the industry lacks a clear definition of what “custom” really means — resulting in some manufacturers contracting with molders that are woefully unqualified to accurately produce highly specialized designs. Just because a molder can facilitate development of an original tool doesn’t constitute a truly custom service (or ensure a desirable outcome). Many of these molders are limited to producing simplistic designs and lack the ability to engineer complex plastic parts with precise specifications and tight tolerances.

Total delivered cost (TDC) is the amount of money it takes for a company to manufacture and deliver a product. The definition sounds simple enough, yet all that TDC entails — sourcing raw materials, manufacturing bulk and intermediate products, finished goods packaging, inventory holding, transportation, distribution, and final delivery — reveals its complexity and considerable impact on the bottom line.