CHARLOTTE, N.C. (March 30, 3:25 p.m. EST) — Multicomponent injection molding has won fans by turning out small, high-production parts, but Milacron Inc.'s head engineer said the process is evolving for use on some complex, large parts — and as proof, Milacron is planning a giant, 4,400-ton multicomponent press with a spinning stack.
Milacron is “actively quoting” the big press right now for an automotive part, said Ronald Hertzer, chief engineer for Milacron's injection machinery business.
Multicomponent molding uses two, three or four injection units — or possibly even more — to mold parts with several materials or colors. The process cuts out the need for assembly by turning out a complex, finished part.
In spin-stack technology, the mold rotates 90 or 180 degrees to match up with the separate injection units.
“We've shipped roughly about 100 systems of this type since 1999. Now we're seeing a move into larger applications,” Hertzer said March 23 at the annual conference of the Society of the Plastics Industry Inc.'s Structural Plastics Division.
Hertzer declined to identify any customer information for the giant machine, which will be Milacron's largest by far. But he did give SPD members a few technical details of how to move such a large mold stack, which weighs 100,000 pounds.
“The center carrier is guided by the strain rods, for good alignment. And all the weight is supported down through the foundation to the base,” he said.
The center platen rotates 180 degrees. To get the big iron moving quickly, Hertzer said, Milacron would use a Fanuc servo-electric motor — the same-size motor used to mold 5-gallon buckets on a 500-ton all-electric injection press.
Who would need such a huge multishot machine? Hertzer cited several complex automotive applications as a likely market, such as fascias, bumper assemblies, interior door panels and instrument panels.
Historically, multicomponent technology has been used on presses with clamping forces of 400, 500 and 600 tons, he said.
“What we're seeing is a move from small, very high-production parts to machine designs in automotive and structural parts, where you can be cost-effective and combine functions in much lower production quantities,” Hertzer said.