A Critical Application in Medical Molding

Liefveld said it’s important to note that cavity and core inserts are assembled into a mold base, and the two halves of the mold base must match. The company designs parting line interlocks, or straight interlocks, into the base to keep the alignment proper, and that way all of the cavity and core blocks have individual alignment built into the cavity and core blocks themselves. The objective is to get a dual alignment to make sure that everything stays concentric. “Machining them is difficult, and then we have to hold everything as closely as possible to print.

You’re not building a Frisbee mold.” Another CMM is used to check the plastic parts that a mold produces, he said. SyBridge performs extended trials to verify that the plastic parts coming out of a mold’s cavities meet all requirements. “Once the mold is complete, we put it in the press, shoot it and get the first article of the parts that come out.

We take a look at the parts, and we’ll make a modification at that time to help these parts run. It’s continuous improvement even ongoing during the original build.” SyBridge’s primary customer base includes both medical OEMs and global contract manufacturers, according to Schoelmberger. Many OEMs operate their own in-house, or captive, molding capabilities, while contract manufacturers produce on their behalf. “In both cases,” he said, “we’re supporting critical programs that ultimately serve the same end-use medical applications.”

Complex Mold Actions

SyBridge reports that it engineers molds with servo-driven systems to deliver the precision, control and adaptability required for the most demanding medical device applications. These motors enable exact movements for unscrewing threads, adjusting core pulls and fine-tuning speed or force during the molding cycle. With closed-loop feedback, the tooling ensures consistent part quality, protects delicate features and extends tool life. Liefveld explained that the molds the company produces need to be monitored and measured while they are running, with sensors and monitoring capabilities that continuously track temperature and molding injection pressure.

Worker Training

As molds become more complex the challenges in attracting and retaining a skilled workforce also increase. “A lot of kids don’t know about the machining trade,” Liefveld said, noting, “It’s not nearly as popular as it used to be.” To help train the next generation of moldmakers, SyBridge has a five-year apprenticeship program. Liefveld noted, however,

that most participants do not complete the program. “Normally, within six months you kind of figure out whether or not this individual is really fit for it. You have to remember that to be a machinist you have to be pretty good with math, pretty good with your hands and have a high capacity for learning on the fly.” When apprentices come in, he added, they have to be ready to work 10-hour days and be completely dedicated to the program.

Adding to the challenge is that California, for instance, cut funding for off-site classes that helped teach apprentices more about subjects such as trigonometry, geometry and metallurgy. “Once they cut that system out, we had to start teaching those and implement that into their daily routines.” For those who complete the program, the rewards can be compelling. One of the highlights of the apprenticeship program, according to SyBridge, is that former students pass on the skills and habits they have learned to newer students.

They share the tacit knowledge picked up from experienced moldmakers and machinists, like securing workpieces, locating the zero point or starting position on the workpiece, and keeping their work area clean. The focus on cleanliness is especially important for the precision work for which SyBridge is known — because starting with a clean mill ensures debris from previous jobs will not alter tolerances for the next job. Another challenge, Liefveld noted, is the lack of trade schools devoted to moldmaking. The only apprenticeships that are available are through shops with programs.

“And mold shops like us are trying to keep that going because the scary part is if we don’t keep having an influx of young moldmakers coming in, pretty soon we’re going to run out of them.” Despite such challenges, SyBridge continues to grow its production of injection mold tooling that meets the high standards of medical, pharmaceutical and veterinary manufacturing. “We design and manufacture high-precision injection molds, and we sample and validate those tools until the molded parts meet all critical tolerances and functional requirements for production,” Schoelmberger said. “That’s where precision, partnership and performance come together — building the tool right, working closely with the customer and delivering a mold that performs reliably in long-term production.”