When a new contract for 60,000 pieces came through the door at Rose Polymer Composites (Milwaukee, WI), Mechanical Engineer Chuck Patrick knew he needed to find new ways to expedite manufacturing.
Specializing in thermoset composites, Rose Polymer Composites is a contract molding shop with presses ranging from 75 to 400 tons. Thermoset composites are used in a wide range of applications because they fill the performance gap between thermoplastics and metals.
"This part is for an insulator for a new electric rail system in southern China. The insulator is manufactured from a thermoset composite material, overmolded on a structural steel threaded stud," explained Patrick. "The process is purposely designed in such a way that there is excess flash to trim from around the parting line of the mold."
Early into production for the new contract, Patrick identified the trimming process as a bottleneck. To remove excess flashing, each part had to be hand trimmed on the factory floor with a bench grinder. The more complex geometry of the insulator meant that the manual trim operation was too slow to keep up with the molding cycle.
This resulted in lost time, and it was adding up quickly for the line, which runs 24/7.
"Soon after we took on the insulator contract, we started looking for an affordable solution to automate part trimming," said Patrick. "We considered a CNC router table, but narrowed in on the Tormach PCNC 770 because the mill would lend itself to a much more rigid setup."
Patrick and Rose Polymer Composites' owner Robert Uhren made a short day trip on I-94 to the Tormach showroom in Waunakee, WI to see a demo of the PCNC 770 in person.
"We made the decision to go ahead with the purchase on the ride home," recalled Patrick. Since receiving the PCNC 770 in August of last year, Rose has shipped over 30,000 pieces.
"We measure efficiency by the number of parts per shift. Since we installed the Tormach, our efficiency is up by 25 percent," said Patrick. "We've decreased the trim cycle time to under three minutes and could probably reduce that further, but it's not a bottleneck anymore."
With the demonstrated success of this project, Patrick explained that the company also has future plans to add additional PCNC 770 mills as they roll out automatic trimming on Rose Polymer Composites' other molding lines.