The trend toward rapidly rising prices for medical plastics may work strongly in favor of a new micro injection molding technology that uses ultrasonic power to melt plastics instead of the pressure and heat normally used.
"One important fit for us we are still evaluating is molding of PEEK and other high-cost resins because of the big savings of materials in our process," said Enric Sirera, sales director for Ultrasion (Barcelona, Spain) in an interview with Plastics Today.
He estimates materials' savings of 30% to 60% with the Sonorus 1G, which uses a specially developed ultrasonic welding process to melt plastic in a conventional injection mold. Only the shot size necessary for each shot is fed using standard pellets at room temperature. Sirera said there is a small runner. Melt occurs in milliseconds.
There is also potential for fewer rejects because melt pressures are very low compared to conventional injection molding.
The cost of medical-grade PEEK can be 20 times or more higher than the price of industrial-grade PEEK because of demands for purity and certifications. Sirera also said that the process has been tested successfully on bioresorbable resins such as polylactic acid used in micro plastics implants.
The process is described as particularly beneficial for long, thin and flat parts because of the fluidity created by the ultrasonic process. Medical tips are already in production. Two companies using the process to make medical parts are Microson, the only hearing aid manufacturer in Spain, and Oratech, an American healthcare contract manufacturer that will be exhibiting at MD&M West next month.
Ultrasion SL describes itself as a company dedicated to design, manufacture and commercialize industrial solutions based on high-power ultrasound, and the first to launch a molding machine with the technology.
Note: Photo shows hearing aid parts made by Microson.