Micro molding capabilities continue to grow among an elite supply base as demand accelerates at about 10 percent annually, more than triple overall American economic growth.
At the Compamed trade show in Germany, machine builder Wittmann Battenfeld is showing a micro filter made of polyacetal with an 80 µm grid and a part weight of 1.1 mg. The part, which is produced in a two-cavity mold with thee-platen injection, is manufactured on a MicroPower 15/10 with a clamping force of 150 kN. Target applications are micro pumps and inhalators.
In another development, MTD Micro Molding of Charlton, Massachusetts, is expanding its overmolding services capabilities with a new vertical injection molding machine.
Executive Vice President Gary Hulecki said that OEMs benefit from precision overmolding by improving shot-to-shot consistency and overall part quality for their medical device parts including catheter tips, suturing devices, sports medicine implants, and orthopedic devices where a PEEK polymer is molded over or through metal. A more unusual project was a five-piece micro assembly device overmolded with glass-filled liquid crystal polymer.
Founded in 1972, MTD Micro Molding has 13 molding presses and 31 employees.
Micro medical projects reported by veteran engineer Donna Bibber include:
· 3 micron molded channels in a glucose monitoring/delivery system,
· A 5mm endoscope device with 22 parts in 1.5mm space, and
· A 25 micro wall thickness Class III neuro implant.
Bibber is vice president of Isometric Medical Molding, New Richmond, Wisconsin, which, operates six Sodick two-stage plunger presses from 20 to 60 tons.
Another player, Accumold of Ankeny, Iowa, manufactures its own custom molding machines, including two-shot. Its smallest commercial part to date measures 800µm x 380µm x 360um. 144,000 parts weigh 1 oz. Handling of the microelectronics part is more of an issue than the molding.
Other American medical micro molders include SMC of Somerset, Wisconsin; BMP Medical of Gardner, Massachusetts; Precision Engineered Products of East Providence, Rhode Island; the newly formed Spectrum Plastics Group of Alpharetta, Georgia; Phillips-Medisize (Molex) of Hudson, Wisconsin; Makuta Technics of Shelbyville, Indiana; American Precision Products of Huntsville, Alabama; and Rapidwerks of Pleasonton, California.