Thermoforming Close-Up

New Hardware Was the Big Draw at SPE Thermoforming Conference

Exhibits by three new or relatively little-known suppliers of forming machines were among of the highlights of the SPE's Ninth Annual Thermoforming Conference, which was held last month in Chicago. The four-day meeting drew a record 1243 attendees and hosted more than 100 company exhibits. Other news from the meeting included a cut-in-place mold that produces rim-rolled cups, higher-temperature gas catalytic heaters, adjustable clamp frames that cut changeover time, and robot systems that perform secondary operations faster than CNC machines.

New names in machinery

Vector Machinery, Asheboro, N.C., opened in January as a supplier of plc-controlled three- and four-station rotary units with optional pressure-forming or twin-sheet forming. They are offered in sizes from 3 x 4 to 10 x 12 ft and sold at 15-20% less than competitive brands, the company says. The models have variable-speed electric drives on the platens and wheel index. One special feature is the Vector-Vac two-stage vacuum system, which draws a full vacuum (28-29 in. H20) during both initial air evacuation from the mold and sheet forming. While typical systems have less than full vacuum capability remaining after evacuating the mold cavity, the Vector system retains full vacuum throughout to provide greater part detail and better cooling, says president Richard Brashier. During the first vacuum stage, the Vector system pulls air from the mold into the vacuum surge tank and then through the vacuum pump. During the second stage, when the sheet is drawn into the mold, the vacuum bypasses the vacuum tank, so air is drawn from the mold cavity directly to the vacuum pump. A computer-controlled valve allows for programmed time and volume control of the transition from first to second stage.

A second "new" machine supplier is Lamco Machine Tool of Morehead City, N.C. Actually, the firm has built plc-controlled single-station, double-ender, and rotary formers for a decade. But this supplier is only now making the leap from regional marketing to nationwide and Canada. Lamco machines are custom built and range in size from 2 x 3 to 12 x 20 ft, with 12-72 in. depth of draw. All machines feature color-screen operator interface with recipe storage and retrieval. A rotary unit costs between $150,000 and $200,000. Options include variable-speed electric, dual-speed electric, or air-driven platens and custom clamp frames or vacuum systems.

Another supplier seeking to raise its profile nationally is five-year old Advanced Ventures in Technology Inc., Gladwin, Mich. It builds single-station machines, double-enders, and three- or four-station rotaries sized from 3 x 5 to 10 x 13 ft. The firm's programming software uses a flow chart of command triangles, ovals, squares, and connecting arrows to speed set-up and operation. The machines have electric servo-driven platens, automated sheet clamping, top-and-bottom heating, 15-84 in. forming stroke, and up to 100 psi forming pressure. Prices range from $120,000 to $350,000.

A 'new' old approach

PLC temperature control updates an old design concept in a new line of single-station thermoformers from Monark Equipment Technologies Co., Auburn, Mich. Although new offerings for Monark, these models embrace old-fashioned design principles of simplicity, manual operation, and low cost. They offer a choice of roll-in or conveyor-fed ovens. In the former, operators roll the whole mold on a cart with sheet clamped over it into and out of a large stationary oven with a single top heater bank. Alternatively, sheets up to 2 x 3 ft are placed by hand on a heat-resistant belt that indexes into the oven. The heated sheet is then manually removed from the conveyor and draped over the mold. This version has integrated control of conveyor speed and oven temperature. Conveyor length, width, and height from the floor can be customized. One unit that was specified with a 32-ft-long x 48-in.-wide conveyor, 50 x 20 in. heating area, and 30-in. conveyor height from the floor cost $55,000.

Tooling that does more

Produce drinking cups with rolled lips right from the mold with a new trim-in-place tool that coins the cup during forming. Marbach Tool & Equipment Inc., Elkhart, Ind., introduced the new coining tool, which eliminates downstream lip rolling. A special clamp-ring booster in each cavity raises clamp-ring pressure by 80% for the coining effect. The tool has six guide posts instead of the usual two, which reportedly provides more precise cutting and doubles the cutting life of the tool. A new die-plate design is said to enhance cooling. Marbach has built the first tool of this type for a U.S. firm that will form 9-oz, 3-in.-diam. PP cups 15 up.

Speed job changeovers with a clamp frame that has 0.25-in. incremental adjustable width and length down to 12 x 12 in. New from Maac Machinery Corp., Itasca, Ill., the X-Y Clamp Frame System is offered on all Maac's heavy-gauge cut-sheet formers from 3 x 4 to 10 x 20 ft. The system will also be part of a new Year 2000 concept machine now in development, which will also feature a new digital controller, multi-level security system, pendant-arm control console, and Windows software.

Another new clamp frame with adjustable width and length comes from Modern Machinery, Beaverton, Mich. The slide-and-lock system reportedly can be adjusted in 5 min or less without removal from the machine.

Changeover times reportedly can be cut at least 85% using a new motorized clamp-frame adjustment system from National Extruded Sheet Clamping Co. (NescCo) Inc., Gladwin, Mich., a sister company to Advanced Ventures. The system provides infinitely adjustable length and width down to 4 x 4 in. anywhere within the forming area (not just in the center). It positions the clamp frame automatically, while a PC control stores and retrieves settings. The system is said to be applicable to any machine.

Plugs progress

Three new developments in syntactic-foam material used to make plug assists were introduced by CMT Materials Inc., Dedham, Mass. First, new Hytac-LP is a compound of epoxy filled with low-cost hollow microspheres that's said to be less expensive than solid epoxy plug materials.

New Hytac-B1X is an engineering-thermoplastic syntactic foam that supports a 1600-lb load and has high pull-out strength plus low thermal conductivity. Conventional epoxy syntactic foam reportedly has lower pull-out strength and supports only 700-lb loads.

CMT says it can eliminate haze caused by epoxy syntactic-foam plugs in forming HDPE and PET sheet. New Hytac-WF is said to have fewer micro-voids and thus a smoother surface, providing lower friction and thermal conductivity.

Gas catalytic: hotter than ever

Vulcan Catalytic Infra-Red Heaters, Portsmouth, R.I., introduced InfraCat gas catalytic heaters that operate at 25% higher temperatures than previous models. They reach 1000 F and emit 18 w/sq in. or 8000 Btu/sq ft of heater surface. Previous units operated at 400-750 F with 16 w/sq in. or 6000 Btu/sq ft. The new heaters reportedly allow HDPE sheet to be heated about as fast as with ceramic elements. The higher temperatures and wattage come from a redesigned internal plenum and new gas dispersion technology.

New Windows NT software and electronic gas-flow control let you adjust the temperature of gas catalytic heaters in one process cycle. In this system from American Catalytic Technologies, Branford, Conn., a mouse-click or touchscreen control adjusts voltage to the valve that controls gas to the heater. Controls also monitor heater performance.

Robots beat out CNC

You can trim and rout more parts per hour with lower capital cost using rail-mounted robots rather than conventional CNC machines, according to CMS North America Inc., Caledonia, Mich. Its new PK 4800 five-axis trimmer for thermoforming has a fixed table in sizes from 5 x 14 to 8 x 18 ft and an open bottom frame that lets trim scrap and fines fall away from the part. The robotic trimmer/router traverses the rail at speeds up to 65,000 mm/min. A tool crib holds eight tools that can be changed in 8 sec.

Robotic Production Technology (RPT), Auburn Hills, Mich., has supplied robot systems for 12 years but is new to thermoforming. It offers 6-axis trimming, routing, and parts-handling tools on rail, wall-, or floor-mounted robots from Fanuc Robotics, Rochester Hills, Mich.

Off to the races

The first all-thermoformed auto bodies in the U.S. are mounted on 50 race cars at the Panoz Auto Racing School in Hoschton, Ga. The Panoz GT-RA training car has 14 exterior panels made from 1/8-in. sheet of Terluran ABS with a cap layer of Luran S ASA, both resins from BASF Corp. Plastic Materials, Mt. Olive, N.J. The coex sheet is made by Primex Plastics Corp., Richmond, Ind., and formed by Multiplastics of Mt. Pleasant, S.C. By replacing fiberglass/thermoset panels, it reportedly provides faster manufacturing, lighter weight, higher gloss, and easier cleaning.

Thermoformed sheet is glued over aluminum to form the six exterior body panels of the Ligier, a two-door diesel car made by a French firm of the same name. The integrally colored sheet is said to eliminate painting. It was extruded by Senoplast Klepsch & Co. in Austria, which recently set up an office in St. Peters, Mo., and plans to open a plant in Mexico next year. The company's Senosan ABS and Senotop ASA/PC sheet (both with acrylic caps) are said to provide a weatherable Class-A finish.