Toolmaker and processor Proper Group International Inc. has signed agreements with two companies that develop technologies for rapidly heating and cooling mold surfaces.

Proper Group Vice President Joe Grippe is working with RocTool of Le Bourget du Lac, France, and Hochdorf, Germany-based Single Temperiertechnik GmbH. RocTool uses induction to rapidly heat the mold surface, then cool it down quickly with water. Single does that by cycling between hot and cold water or oil.

Both processes can improve the surface of parts, including those made by the MuCell process from Trexel Inc.

Grippe participated in a panel discussion on microcellular foaming at the Plastics in Lightweight Vehicles conference, held Nov. 6-7 in Livonia. Plastics News coordinated the event.

The other speakers were Steve Beasley, regional sales manager for injection press supplier KraussMaffei Corp., and Brent Strawbridge, Trexel’s vice president of sales.

Warren, Mich.-based Proper Group tries to offer new ideas for molding, Grippe said. Proper and KraussMaffei have a joint venture operation at Proper’s site in Warren, where Proper runs two large-tonnage KraussMaffei presses, both equipped with MuCell. The mold maker also works with KM’s SkinForm process, which molds polyurethane foam over a thermoplastic part.

Grippe said Proper Group also will use RocTool to move into molds for composites. And Proper is branching out into thermoforming, working with machinery maker Kiefel GmbH.

Beasley said KraussMaffei offers injection presses and reaction injection molding machines to process PU.

He said auto molders are combining several processes in one, for example, injection molding and thermoforming of textiles.

“We see more and more production going to cellular-type applications where we integrate the secondary operations rather than have work in progress,” Beasley said.

Strawbridge said MuCell parts can be molded on lower-tonnage machines and offer improved fill, less molded-in stress and no sink marks.