Published On: Sun, Aug 19th, 2012

New medical tool features removable core mandrels

New medical tool features removable core mandrels

New medical tool features removable core mandrels

Matrix Plastic Products (Wood Dale, IL) is bringing up to speed a complicated mold with removable core mandrels to produce a surgical component, a tube with an insert molded needle nearly five inches long.

“The mold has two ejector halves that rotate on the turntable,” says Patrick Collins, molding operations manager at Matrix. “As the one side is being injected with plastic, the other is being ejected and loaded.”

Matrix has three sets of core/insert mandrels that are for now being hand loaded. Design of the core/insert mandrels includes a detent that can be actuated by a lever on the mandrel to hold the stainless-steel needles, allowing the inserts to be held in place as they are being molded.

“Tom Ziegenhorn, one of our design engineers, and I met this new customer while working a trade show. Tom was able to visualize that the customer needed to replace a costly manual process with a more cost-effective insert molding process.”

Ziegenhorn designed a mold that was built by a team led by Mike Martin and Gary Eckman. The tool was qualified by an inspection team led by Gary Johansson.

Matrix is using a new molding system built up around a 45-ton Engel insert 80V/45 vertical injection molding machine that includes dual core-pulls, a two-station rotary table, and a servomotor-controlled injection unit that incorporates a high-temperature barrel package.

One of the attractions of the Engel system is a flexible controller that manages the mechanics of the tool and also allows for future improvements to the process, such as cutting the catheter tube to length within the mold.

More automation planned
“Although we’re still in the initial stages with this project, and we are hand-loading the inserts at the present time, we have realized there are many automation possibilities. We plan to automate this process with a side-entry robot as the production volumes ramp up.”

Matrix operates a 30,000-sq-ft facility employing about 50, working three shifts. It operates 14 electric and hydraulic molding machines ranging from 5 to 300 tons in clamping force, including two presses in a Class 100,000 cleanroom.

Resins processed include polyetheretherketone (PEEK), polyetherimide (PEI), liquid crystal polymer (LCP), polycarbonate, and nyons for medical/surgical, electronics, military and consumer products customers.

New medical tool features removable core mandrels

New medical tool features removable core mandrels

Matrix also molds bioresorbable materials such as polylactic acid (PLA), poly(DL-lactide co-glycolide), and poly lactide carbonate (PLC).

In-house secondary processes include assembly, sonic welding, laser marking, and project-specific labeling. Some secondary operations such as pad printing are outsourced.

Matrix is ISO 9001- and ISO-13485-certified.