Molding the future of thermosets, Part II

Attendees of the 44th Annual Thermoset Molding Conference (TSMC'44, Oct. 15-16 1998, Madison, WI) were presented with the most modern means of making conversion costs for finished thermoset parts as competitive as the cost and performance of thermoset materials. The varied presentations detailed how many of today's hottest thermoplastics injection molding trends are crosslinking with thermoset manufacturing. The presenters also unanimously agreed that closer cooperation between thermoset suppliers and their customers is essential to bringing such competitive technologies to future markets.

Leading thermoset materials suppliers were on the podium discussing how their latest formulations can improve progress. Among them, Alan Smith of Perstorp Compounds said his company's latest round of products for injection molding applications are being formulated for more versatility and tolerance to better handle parts consolidation work. Perstorp offers part, process, and tool design services, including CAE process simulation for optimized gating. Smith encouraged other thermoset suppliers to continue their own processing, materials, and application development.

Plenco's Greg Spaeth discussed present and future applications for his company's solid thermoset polyester molding compounds, available in pelletized form. They bring all the high-performance properties of BMC to the party, but a molder doesn't need to bring a stuffer. Standard hoppers will do. Plenco is helping develop cold-manifold molding to speed cycles and new chemical recipes to facilitate recycling.

Speaking of recycling, Randy Lewis of P.R. Lewis Consulting Inc. came to Wisconsin from his HQ in Puerto Rico to remind attendees of his company's expertise in designing direct phenolic recycling systems. Designs he develops range from beside-press units to centralized plantwide systems. He has already installed systems that help mold products with up to 40 percent phenolic regrind.

Richard Brander of AC Molding compounds, suppliers of urea and melamine, said the future of thermosets may depend on successful development of application-specific materials. These will be designed in close partnership with process engineers and molders willing to champion advanced processing technologies capable of making quality parts that take advantage of the materials' superior performance.

All-Electric Thermoset Molding

Barr Klaus of Milacron's Elektron Technologies business unit came to Madison to better acquaint attendees with electronic machine technologies (EMT). All-electric molding machines, like Milacron's latest Powerline series, which Barr reports far exceeded Hunkar Class 1 ratings in recent tests, offer the same process-improving, low running cost advantages to thermoset molders as they do to molders running thermoplastics, Klaus explained.

Tom Nieswadomy of the Durez Development Center brought attendees up to date on how developments in thermoset injection molding process technology can reduce conversion costs in many instances with just a few minor adjustments to optimize existing equipment. His talk covered the pros and cons of lights-out molding and the latest, fast-cycling, high-temperature thermoset molding methods like hyperthermal runner systems and runnerless injection-compression.

"There are no magic bullets. You have to fit the process to the job," Nieswadomy said. Mold breathing can reduce gas burn and cycle time. Barrier screws can save on cure times while reducing cycle times. Better use of sub- or tunnel-gating and in-mold degating could help improve margins, and live-sprue technology has proven itself in molding small, thin-wall parts economically. Still, Nieswadomy reminded molders to first experiment with basic settings like nozzle temperatures and backpressures before launching into any advanced optimization solutions.

Rapid Thermoset Tooling

Consultant Jim Keegan shared his years of experience in designing thermoset parts and molds and talked about the importance of proper gate and runner design and of drawing a vacuum on the mold. Later, Pat Miller of Uddeholm discussed the options her company offers in wear- and corrosion-resistant materials of construction for thermoset tooling. She concluded her talk, reminding attendees, "Steel costs are a small piece of the other costs incurred if you don't use the right steel."

Scott Schermer, director of the Rapid Solutions Div. of Dickten & Masch Mfg., discussed selective laser sintering (SLS) systems Rapid Solutions uses to build tooling inserts out of DTM's RapidSteel 2.0 in as little as four workdays for molding up to 10,000 thermoset parts. It is just as effective for making mold features as it is for making core and cavity inserts up to 12 by 12 inches: "Cooling lines, ejector pin holes . . . any feature that is machined can be built in SLS."

Schermer said he has learned the more complex the tooling inserts, the more money can be saved using the rapid tooling technology. It is not the best fit for simple geometries. Schermer also announced the formation of a cooperative development project with a Dickten & Masch supplier, BMC Inc. BMC will supply materials for testing rapid tooling and its technical expertise.

"You can cut a mold with other CAD systems . . . you also can cut grass with scissors," said Edward K. Apfelbach, an area development manager with $1-billion Parametric Technology Corp., promoting his company's Pro/Engineer software. Bowing to customer demand, future versions of Pro/E are being designed for greater ease of use, better internet communications, and expert software to further automate the moldmaking process, such as creating parting lines, surfaces, and ejector pins, for quicker transformations of CAD models into quotes.

Molding the future of thermosets, Part I