WOBURN, MASS. — Three more injection press makers have signed on to offer Trexel Inc.'s tiny-bubbles MuCell technology on their equipment: Husky Injection Molding Systems Ltd., Battenfeld GmbH and Japan Steel Works Ltd. The news, announced April 7, doubles the number of injection press manufacturers that hold MuCell licenses. They join Milacron Inc., Engel North America and Arburg Inc.
Trexel wants to spread the technology to more machinery makers, said David Bernstein, president and chief executive officer.
"Our official position on this is that end-user customers should be able to obtain our technology on any platform that they prefer," Bernstein said during a March 29 interview in Woburn at Trexel headquarters.
MuCell works by creating millions of microscopic bubbles in the plastic part, reducing the amount of resin needed to make a part. MuCell also allows molders to run faster cycle times, and make parts on machines with less injection pressure and lower clamping forces than in traditional injection molding, according to Trexel.
Under MuCell, the blowing agents of carbon dioxide and nitrogen achieve properties of both a gas and a liquid, called a supercritical state. Those properties are reached by carefully controlling temperature and pressure.
Bernstein said the six machinery makers are offering MuCell as a standard option on new presses. They also can retrofit the process onto existing machines.
Initially, all three new licensees will emphasize different areas, Trexel said.
Battenfeld is building a coinjection molding machine with the MuCell process for a demonstration facility at its headquarters in Meinerzhagen, Germany.
Husky of Bolton, Ontario, will sell MuCell on its entire product line of presses, with 65-8,800 tons of clamping force. Husky also will target high-speed packaging — the first MuCell-equipped Husky machine will be an S-series 175-ton press.
To maximize the advantage of lower clamping tonnage, Husky is increasing the tie-bar spacing on presses with as much as 1,100 tons of clamping force, so molds can fit into smaller machines.
Tokyo-based JSW, the first Japanese machinery maker to pick up MuCell, has outfitted one of its all-electric presses with the technology. JSW said the machine is designed for thin-wall molding at high speeds. Trexel will provide local support through a contract with Sanpho Group Ltd. of Yokohama, Japan.
Trexel said MuCell should be especially attractive to molders of thin-wall parts, such as packaging. The lower injection pressure means molders can thin down part walls even more, said David Pierick, Trexel's vice president for MuCell molding.
"[Molding] machines have actually reached their limit now, in terms of being able to go thinner. Our process allows them to go thinner," Pierick said.
Bernstein said that means the injection molding process could win back some applications lost to thermoforming.
In other news, DuPont reported that MuCell performed well on early tests at the Wilmington, Del., resin maker. DuPont achieved as much as a 50 percent reduction in injection and clamp pressure on test parts molded from its nylon and polybutylene terephthalate, as compared with solid parts.
The low injection pressures could help MuCell win applications in molding plastic parts used in delicate electronic subassemblies, DuPont said.