It was the middle of a Midwestern summer – hot, humid days filled with swamp-like fug – and a molder’s frustration rose as steadily as the temperature outside because the in-mold decorated (IMD) part on which they were working kept resulting in splay, or streaks in the resin. Elsewhere, a different molder struggled with locating a part within the mold without using static, which can attract debris in some cases. Yet another molder halfway around the world was experiencing continual issues with gatewash and couldn’t figure the cause.

What do these three manufacturers have in common – besides their headaches and vexation? They each brought their problem to DuraTech, and together in partnership we worked out effective solutions.

Molders Mold – Printers Print

As a rule, screen printers… well, print. And molders mold parts. Separate industries, separate areas of expertise. However, since in-mold decorating (IMD) has matured over the years, the need for the two to integrate has also arisen. The challenge for molders is that the majority of screen printers don’t have the molding or IMD background and knowledge needed to forge effective partnerships.

That’s where DuraTech differs. For more than 20 years, our team has been partnering with molders to design, develop and tool IMD projects – from large refrigeration components to motorcycle badges and medical equipment panels – even in-mold electronics (IME). What’s more, troubleshooting IMD projects has become an area of expertise for our team.

Take, for example, the time a customer was dealing with infiltration (also known as overmold), resulting in an obscured label. They called DuraTech to see if we could pinpoint the trouble. After a thorough examination, we concluded that tool design was the culprit, but that by changing the label, the problem could be eliminated more cost effectively for the customer. There was room in the tool to make the label taller, which redirected the resin flow so that, instead of catching the top edge and overmolding, the taller label caught the back of the top edge and pinned it more securely against the mold. Case closed.

“Because they’re experts at molding, molders might not see, for example, that resin flows are coming in a certain way, or that backing off on pressure a little bit will cause a product to behave differently in the mold,” stated BJ Tully, DuraTech Appliance Program Manager. “Molders appreciate their partner helping them come up with these kinds of solutions. After all, time is money, especially in the molding process.”

Keys to successful partnerships

Over the past two decades, DuraTech has developed a broad – and deep – base of expertise upon which we can draw each time an IMD project is presented.

“A customer may come to us and say, ‘I really like that look’,” BJ explained by way of example. “And we’ll say that, in order to obtain that look, you have to use a certain ink system. However, if you’re using a specific resin, it might not adhere well. Some ink systems work very well for printing, but they don’t work for molding. We’ve identified ink systems that can adhere to the printed substrate and resin to create a bonded piece.”

As in the following case:

A customer was working with another printer on a large window for a refrigerator drawer. The part had a 1-2” printed boarder along three sides, which was either white or gray. During the molding process, the resin (heated to approximately 500 degrees Fahrenheit) pushed the ink, spraying it into the molded area where it didn’t belong. “They were getting a lot of fallout and they didn’t know why,” BJ said. “But, what’s important to remember is that your ink systems have to be able to handle the heat, and the substrate that’s being printed on has to handle the heat to the point that it’s not going to melt and push the ink throughout the part. After studying the problem, we came to the customer with six different solutions.” DuraTech was able to solve the issue and win the account.

Over the years, our company has identified parameters that are key to a successful molder/printer relationship.

Among those parameters are:

Involvement at the beginning

Having the printer present at mold trials is key, BJ said, from assisting with developmental stages to following up with calls, Zoom meetings, emails, etc. Trials can be as short as 20 minutes or last as long as few weeks (as well as somewhere in between), depending on the situation. “You want to do full runs so you can watch the whole process and identify variables to change or tweak that could make a big difference in the part,” he said.

Constant communication throughout the process

A commitment to transparent communication from both the printer and the molder is vital. IMD processes can take longer than traditional in-mold injection or graphic printing projects, so it’s important to be candid about the amount of time it’s going to take to design and develop a part, as well as be clear about bug fixes and associated budget ramifications.

Willingness to keep an open mind

“If it’s physically possible to help our customers, we will,” stated Pat Tully, DuraTech Program Manager (and BJ’s father). “DuraTech has a company culture devoted to learning and continuous improvement. We’ve discovered over the years that you have to keep an open mind when it comes to IMD because every project is different.”

An open mind for both parties – printer and molder – is important. He points to an example where a customer was dealing with gatewash while running the resin at a certain temperature. “Thankfully, the operator was open to the suggestion of increasing the temperature,” Pat remembers. “Normally, increasing the resin’s temperature can cause gatewash, and here I am, asking him to increase it. But, sometimes the resin flows more easily, and you can decrease shear.”

“And, so, the operator increased the temperature by about 30 degrees, and it worked perfectly,” Pat concludes. “This is where keeping an open mind is key. Willingness to try is huge.”

Classes and webinars

To enhance working relationships, DuraTech also offers various IML/IMD classes for molders. “We like to teach our process,” BJ said, “so when a customer is engineering their product, they can better fit it toward what’s feasible. We offer everything from two-hour presentations to multiple day classes on IMD and IME.”

DuraTech also offers sessions on pressure sensitive adhesive labels, flexographic printing and digital printing. “We like to encompass everything a customer would be interested in,” BJ said.

Solutions

In the first instance with the Midwestern molder, DuraTech discovered that, in this case, the splay was being caused by excess humidity because the facility wasn’t a controlled environment; our label was picking up humidity from the air. We were able to adjust the ink formulation so the ink wouldn’t capture as much moisture.

For the second project, we worked with the molder to create locating holes to better position the part in the mold. Within just a couple iterations, our customer was able to go into production.

Lastly, we quickly resolved the gatewash issue by changing the thickness of the material on which the part was running from 10 mil to 7 mil. The thinner material took up less of the cavity space, which decreased the shear that led to friction heat. That heat was causing gatewash because the material became too volatile for the inks to adhere to.