In-mold decorating (IMD) – or in-mold labeling (IML) as it’s sometimes called – has been around for decades as a way to enhance product aesthetics and functionality, as well as solidify brand identities in the minds of consumers. However, IMD suppliers are not all created equally. And because IMD can be an involved, complicated process, how can you be sure you’re selecting a provider who best fits your needs? If you’re an OEM who’s ready to move your durable products to the next level with IMD, or you’re looking for a new IMD supplier, this blog post is for you.

First, a quick IMD primer

IMD is used for decorating high-precision plastic parts in the automotive, home appliance, medical device, sports equipment and consumer electronics and other durable goods industries. The process, which combines printing with injection molding, places a pre-printed plastic form that may be shaped and cut to size into an injection mold. The result is a part with outstanding color, detailed graphics and lasting appearance.

IMD offers numerous benefits

• Design flexibility
• Capable of using flat or 3D labels/graphic overlays/decorative appliques
• Can employ multiple colors and effects in a single operation for an eye catching, dramatic look
• Provides high durability of decoration due to second surface graphics
• Eliminates secondary labeling and decorating operations and costs since injection molding and labeling/decorating are in one step
• Ability to achieve high abrasion and chemical resistance

Given the advantages, it’s no wonder that many OEMs are enamored with IMD. However, because IMD is a highly specialized process, it’s wise to thoroughly vet a potential vendor. Factors to determine whether a vendor will be a suitable business partner, according to Eric Larson, owner of Art of Mass Production, in an article published by Plastics Decorating, include:

1. Do they have bandwidth available for tooling and development?
2. Are they capable of providing design support?
3. Do they have expertise in new product development and project management?

Tooling and development

“IMD requires more tooling than standard injection molding – a lot more,” Larson wrote.

Tooling procedures can range from forming to trimming, storage and transporting trimmed appliques, as well as injection molding and, possibly, measurement and quality control.

Because IMD tooling can be complex when a formed applique is involved, be sure your IMD supplier has in place proven project management procedures, as well as properly planned fabrication and production schedules, not to mention quality controls to ensure your project moves along smoothly. However, because all the proper protocols in the world can’t completely immunize an IMD project against unforeseen variables and delays, you want to make sure your vendor comes to the table with trouble-shooting initiative and guaranteed dedication to keeping your schedule on track.

“At DuraTech, we’re constantly optimizing our IMD solutions so our experts can help customers choose the right tooling and materials for the graphic applique,” stated Pat Tully, Program Manager. “We can also offer on-site technical support during the development stages.”

Design

Development procedures for 3-D IMD projects typically require additional steps not normally incurred with flat or 2-D printing processes, which is why expertise in graphic distortion is critical to any IMD design.

A flat printed sheet, when stretched over a three dimensional shape, becomes distorted from its intended appearance. Therefore, it’s necessary to compensate for the distortion to yield a 3-D part with graphics that look normal. This is done by printing the graphic in such a manner that when it’s formed, it will stretch into place and appear normal again. It’s a time-consuming process that, if not done properly, can involve multiple attempts resulting in failure before the correct design is landed upon, which, of course, adds up in terms of budget and time to market, so be sure your vendor uses cutting edge graphic distortion technology that can provide properly distorted artwork on the first attempt.

With flat or 2-D IMD projects, graphic distortion generally isn’t a concern. However, several other design considerations need to be taken into account including inks that can withstand extreme temperatures and pressures, consistently thick film with good clarity, resin that will bond with the film, and, of course, proper tooling to ensure the design is repeatable. “DuraTech works closely with designers to make sure that all of a project’s graphics can be registered to one another, to formed and molded features, and are repeatable,” Tully said.

New product development and project management

Because there are multiple design variables, parts, and tools involved in IMD, expertise in new product development and project management are vital skill sets in your new IMD supplier. As Larson points out: “While most of these tools can be fabricated independently, many of them are interdependent, e.g. parts are needed from the forming tool to debug the trim tool, and parts are needed from the trim tool before the IM tool can be debugged. Then, while the IM tool is being debugged, the forming tool may need to be modified, and the iterative loop of tooling changes and mold trials starts all over again.”

All of these tooling and design components also involve an immense amount of data management consisting of different file formats, programs and systems for design and production as well as supply chain logistics for all sourced materials. Make sure you understand how your prospective IMD vendor ensures proper version control of every component and document.

“Each IMD project at DuraTech is assigned a Program Manager, who will work with all stakeholders to guide the project through all stages of development into production. Our goal is always to deliver the highest quality product on-time and within-budget, at every phase,” Tully said.

Communication

Last, but certainly not least, customers need to assess their prospective vendor’s commitment to thorough and transparent communication. For example, IMD processes take longer than traditional in-mold injection or graphic printing projects, so be sure the supplier is candid about the amount of time it’s going to take to design and develop your part(s).

Cost is another topic about which that your IMD supplier needs to be transparent. Because IMD imbeds the design in substrate plastic, no secondary operations such as post-molding labeling and printing are necessary, which saves on production and equipment costs. However, you can have significant costs for material quality upgrades and, depending on the type of IMD you choose – flat sheets vs 3-D thermoformed parts – IMD can have added cost implications.

And then there’s the potential for bugs needing fixing, as Larson notes. If your project needs troubleshooting, you want your vendor to be honest about the fact that delays occurred and added time may be needed for project completion.

“It’s imperative to get us involved as early as possible,” concluded Tully. “Concurrent development of materials, process, and design is critical to the success of any IMD project.”