Thermosets make sturdy thermoforming tools. (Thermoforming Close-Up).* Two-part epoxy casting compounds and polyurethane boardstock are gaining acceptance as tooling materials for thermoforming high-end industrial and packaging parts. The trend is exemplified by a cast epoxy tool for automotive trim and a machined PTIR PTIR Precision Track Illumination Radar tool for electronic and medical frays. In both cases, the mold materials were supplied by the RenShape Solutions Tooling Group of Vantico's Adhesives & Tooling Div. Kurt Frischmann, v.p. of tooling, says these methods can cut tool delivery times from months to a week or less. Moreover, today's thermoset A polymer-based liquid or powder that becomes solid when heated, placed under pressure, treated with a chemical or via radiation. The curing process creates a chemical bond that, unlike a thermoplastic, prevents the material from being remelted. See thermoplastic. materials are more durable than ever, making the tools viable for volume production as well as prototyping. Thermosets thermosets, materials that can not be softened on heating. In thermosetting polymers, the polymer chains are joined (or cross-linked) by intermolecular bonding. Thermosets are usually supplied as partially polymerized or as monomer-polymer mixtures. also are more easily polishable than before, making them practical for forming clear, high-gloss parts. Frischmann notes that the trend toward "mass customization" results in lower-volume runs of a wider variety of parts. He says this typically swings economics in favor of lower-cost thermoset tools versus more expensive metal or hand lay-up composite versions. Two case histories Molded Plastic Industries in Holt, Mich., replaced aluminum with Vantico's Cast-IT 2000 epoxy when tooling a 200-part-per-month program for ABS automotive trim parts. The tools range from 60 x 6 x 6 in. to 48 x 60 x 18 in. and are mounted on vacuum-chamber bases of 0.125-in, aluminum sheet. The epoxy tool has 90D Shore hardness, 36,400 psi compressive strength Compressive strength is the capacity of a material to withstand axially directed pushing forces. When the limit of compressive strength is reached, materials are crushed. Concrete can be made to have high compressive strength, e.g. , and a glass-transition temperature of 403 F. After making 10,000 parts, it shows no visible wear. Epoxy tools can be modified by simple machining. CMT CMT Certified Medical Transcriptionist. CMT abbr. Certified Medical Transcriptionist CMT California mastitis test. Materials in Attleboro, Mass., a Vantico distributor, says one of its customer is using a low-porosity, easy-to-machine PUR board to make a tool for forming clear, thin-wall medical and electronic trays made of PC and PETG PETG Polyethylene Terephthalate Glycol PETG Performance Evaluation Task Group . RenShape 5169 board reportedly offers excellent edge definition and abrasion-resistance. The tools have 85D Shore hardness and Tg of 206 F. They have produced nearly 1000 parts apiece. The smooth surface and nonporous finish of PUR board makes for efficient tool polishing. And PUR tooling can be repaired or modified using Ben Patch 5169, a color-matched paste. NEED TO KNOW MORE? Vantico Inc., Adhesives & Tooling Div., East Lansing East Lansing, city (1990 pop. 50,677), Ingham co., S central Mich., a suburb of Lansing, on the Red Cedar River; inc. 1907. The city was first known as College Park, but was renamed when it was incorporated. , Mich. Tel: (517) 351-5900 www.vantico.com |
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