In-mold decorating (IMD) is used across industries as a valuable way to create durable, aesthetically pleasing plastic parts for a wide range of applications. There are many ways injection molders can benefit from adding IMD to their list of services, including higher dollar value projects, access to higher value markets, a larger customer base and other strategic benefits. But IMD isn’t like your typical “shoot and ship” injection molding project. There are some significant differences both in the actual manufacturing process and in the expectations for the overall product development cycle. Here are some things injection molders should know before getting into in-mold decorating (IMD).

Product development and processing time

IMD development takes longer than traditional injection molding. There are many reasons for this, but multiple trials are often required and additional processing time is typically needed before all part issues are resolved. It’s important for molders and OEMs to manage timeline expectations before launching an IMD project.

Fallout rates

IMD projects typically experience a higher percentage of fallout, or higher scrap rates, than other injection molding projects. That’s because the inclusion of graphics and the need to achieve the desired look and feel add complexity and nuance to the finished product. This is why it’s valuable for molders to work with an experienced printer early in the IMD process to help identify and solve potential problems related to materials or production processes.

Gate location

When doing IMD, if gates are located in the wrong place, the force of the injected resin flow can damage the applique or blow it away completely, while the heat can potentially melt inks and applique substrates. So, it’s vital gate placement is executed with the unique challenges of IMD in mind. An experienced printer like DuraTech can collaborate with molders to design gate placement for optimal project success rates.

Insert material options

IMD labels or films need to be dimensionally stable due to the heat and pressures of the IMD process. Film thickness is also a factor as this can impact gate wash and other manufacturability considerations. DuraTech regularly supplies IMD labels from a wide range of materials including polycarbonate, acrylic, polyester, blends and laminates, polypropylene and more.

Tooling costs

Adding IMD to an injection molder’s list of capabilities requires some level of investment. While existing molding equipment may be acceptable, gate locations and venting may have to be changed. For 3D IMD projects, forming and cutting tools are often required, and IMD is not common to a lot of mold tool makers. However, these costs are offset by the fact that IMD products demand a higher price point and offering IMD services can open molders up to higher value projects.

Specialty ink considerations

Inks used for second surface printing need to have special properties because resin to ink adhesion can be challenging and the use of tie coats or binder passes may be necessary. Inks need to be able to adhere to the film and resin, be printable, offer gate wash resistance and be formable (for 3D IMD projects). Molders should work with their printing partner to identify and test appropriate inks based on application requirements.

Testing requirements

In-mold decorating requires a number of different tests that molders may not be familiar with because they are unnecessary for traditional molding projects. For example, IMD products may be subject to testing for stain resistance, color stability, UV resistance, exposure, actuation, abrasion resistance, chemical resistance and more. An experienced printer like DuraTech can recommend vetted IMD label materials, inks and process improvements to help molders meet testing requirements.

The benefits of working with a printer early in the IMD process

The success of any IMD project depends on early collaboration between injection molders, printers and OEMs. Partnering with an experienced printer like DuraTech early in the product development process can help molders optimize molding processes, ensure film, ink and resin compatibility, shorten lead times and avoid materials sourcing issues.

DuraTech offers customized in-mold decorating solutions using cutting edge technology and backed by extensive IMD experience. We’ve created IMD applications for customers in the automotive, home appliances, medical devices, and consumer electronics industries. By working with DuraTech, injection molders can successfully launch IMD services, shorten lead times, reduce fallout and enhance overall IMD quality.