Looks like steel, cuts like butter

Welcome to our first quarterly Moldmaker’s report in the new 12-times-a-year format of Canadian Plastics. Technically, this section is a carryover of the moldmaking section previously seen in the now-retired quarterly tabloid, Canadian Plastics Technology Showcase. While this section of the magazine will still contain moldmaking news and product information once found in our tabloid, there will also be many new value-added changes. There will be regular profiles of Canadian moldmakers, applications stories from home and abroad (technology, after all, knows no boundaries) and other surprises. While we hope this section becomes a regular part of your business reading, we wish to stress that important moldmaking news will continue to be covered in every issue of Canadian Plastics.

– The editor

A Windsor moldmaker is using a recently commercialized epoxy composite board, Cibatool-Express, to quickly manufacture prototype molds for automotive interior parts using high-speed CNC machining. Regal International recently built 20 prototype tools with the material for GM’s Delphi division, with results superior to other prototype tooling materials the company tried in the past, says Mike Cormier, Regal sales engineer.

Cormier says that molds machined from the composite board, supplied by Ciba Specialty Chemicals Corp. (58), can be placed in a standard injection molding press to make 100 to 300 prototype parts in the same thermoplastic resin from which the production part will be made. Cormier says Regal was invited to test the material last year and has found it to be a cheaper, faster and more accurate material for making prototype molds in comparison to other materials, such as aluminum, kirksite or molded epoxies.

“Auto interior guys have never really had a satisfactory material to make prototype molds,” says Cormier. “We can cut this stuff at 300 inches per minute. It’s also a very good material to make engineering changes with.”

The composite board is presently offered in several sizes with thickness up to four inches. Cormier says they have glued up to three blocks of the material together to achieve a starting thickness of 12 in. Regal uses the customer’s math data to surface the mold’s parting lines. Shop operators set their own cutter paths. One mold Regal built has up to 10 lifters, and the material can accommodate mold undercuts, notes Cormier. Because the molds are built without waterlines, mold temperature must be kept between 120 and 150 F. The material requires very little hand work.

Once the tool is complete, it is attached to a clamp plate and placed in a injection press for the prototype run. All prototype tools built by Regal are run at injection molder Proto Plastics’ Windsor facility, a company, Cormier notes, which has experience running prototype tools.

Cormier reports that there are some “tricks” to learn for making good tools with the composite material, especially in achieving even force distribution throughout the mold.

“We can make an injection mold in two to three weeks with this material,” says Cormier. “We’re getting a lot of interest in this because of the opportunities it presents to get quick, dimensionally accurate parts.”