MTD Micro Molding customers turn to the Charlton, Mass.-based company to breathe commercial life into ideas for complicated medical products or resuscitate projects too challenging for other manufacturers.
Think extremely small core pins for spray nozzles that deliver drugs to tight cavities, bioabsorbable clips for surgery and steroid-releasing implants for targeted tissue therapy.
With a small but growing staff now at 36 employees, MTD helps develop and produce components and devices that generally need to function with a 1-inch footprint. Some have micro features, such as wall stocks of 0.004 inches or weights so low that 520 parts can come from a single pellet of plastic.
It has taken years of planning and budgeting to acquire the capabilities to build the tools that produce these tiny components made of special materials, and 2018 was no different, according to MTD officials. They invest about 10 percent of sales annually into improving production and capacity for micro-injection molding.
In 2018, MTD put slightly more than $1 million toward its strategy of staying competitive through technological advances, according to President Dennis Tully. Electrical discharge machining (EDM) technology, which allows wires smaller than 50-micron diameters to be used in tool building, topped the list of recent purchases for the 46-year-old business. MTD bought a Mitsubishi MX600 EDM that Tully said is the first of its model to be used in North America.
“This piece of equipment lets machining operators use ultra-small wire in the range of .0008 of an inch to .001 of an inch,” Tully said. “The machine has doubled our wire EDM capacity and has made getting down to the smallest wire diameters much easier. Although our lead time to build new tools is driven by the complexity of it and its components, on average, we were anywhere from six to eight weeks in production. Now we can get components out to our customers in two to three weeks.”
MTD also recently installed gas chromatography equipment in the testing lab to study material characterization and residual monomers for special projects. The GC equipment is used with a differential scanning calorimeter to build profiles for materials to analyze behavior.
About 90 percent of the MTD's business involves implantable products, of which, about 80 percent need to be resorbable. Components and devices made from bioabsorbable materials include staples, microscrews and microplugs that metabolize over time, which eliminates the need for secondary invasive procedures to remove them.
The GC equipment analyzes material characteristics and residual monomers at a molecular level, according to Patrick Haney, a newly hired research and development engineer at MTD whose position is considered part of the company's annual investment in expanding capabilities.
“By analyzing and reducing the amount of residual monomer, our customers can rely on chemically safe products and increased part/property integrity,” Haney said.
With GC, MTD gains the abilities to perform destructive tests on polymer samples to learn more about their composition and to identify and quantify the residual monomers, which Haney said have “unzipped” from the polymer chain.
“They can often be detrimental as these compounds are quite reactive given their unpolymerized state,” he added. “This in turn has the potential of causing detrimental effects to potential patients and/or device functionality.”
MTD also brought two new molding cells on line this year — one a vertical Sodick press and one a Sodick horizontal press — to increase production volume and speed as well as a new six-axis robot for in-line inspection and complex packaging.
Another big investment will happen in 2019. MTD plans to build a 12,000-square-foot expansion following delays last year. The completion date was pushed back for zoning approval, design work and permitting.
