By Jan H. Schut
The parts competition at the SPE’s recent 19th Annual Thermoforming Conference in Milwaukee in September was especially closely watched by its audience of members and practitioners. They always analyze parts carefully as harbingers of trends and indicators of how far technology has advanced in a year. But in this case it had been two years (the 2009 thermoforming conference was cancelled because of the recession). So this was the industry’s first opportunity to evaluate the state of its art since before the recession.
“The biggest thing that had changed in two years was that people are willing to spend more on creative tooling,” notes Steve Hasselbach, CEO and founder of CMI Plastics Inc., a thin-gauge roll-fed former of packaging for medical, cosmetic and other industries in Ayden, NC (www.cmiplastics.com). “Typically this isn’t an industry that likes to invest a lot in tooling.”
If the parts competition is any indicator, tooling for both molds and trimming is becoming more complex. The competition drew 38 entries from 29 companies in four countries (U.S., Canada, New Zealand, and Belgium), including 17 roll-fed thin gauge parts and 22 sheet-fed heavy gauge parts. (As an aside, this author did not attend the conference, but spoke to over a dozen program participants, including moderators, speakers, organizers, and many of the experts participating in panel discussions at the conference.)
The parts that aroused the most technical curiosity this year didn’t necessarily win prizes. Among the heavy gauge entries in the competition, two stood out as probably the most advanced and unusual according to several experts. Neither won a prize. They were components made of unusually difficult materials, which perhaps didn’t look as impressive asentires which were finished products, but made conventionally. As Roger Kipp, vice president of marketing and engineering at McClarin Plastics in Hanover, Pa. (and this year’s Thermoformer of the Year) commented, “As an industry develops, new technology comes along. Sometimes you don’t keep up with the prize categories. Moving forward, we should have an advanced technology category.”
NEW TECHNOLOGY IN HEAVY GAUGE PARTS
The two most unusual heavy-gauge parts both involved forming of complex shapes out of a multi-material composite sheet without distorting a decorative surface material. One part was so unusual that it didn’t fit into any of the three heavy gauge categories in the competition–vacuum, pressure or twin sheet. So it couldn’t be considered for any of the heavy gauge sheet awards. It could only have won the Judges’ Award or Peoples’ Choice Award, both of which went to a spectacular product design rather than to advanced technology. (The Judge’s and Peoples’ Choice Awards went to a low-energy clothes dryer developed by Grimm Brothers Plastics Corp. in Wapello, Ia. (www.grimmbros.com, www.breezedry.com), which was assembled out of a combination of vacuum, pressure and twin-sheet formed parts into a cabinet-like appliance.)
The heavy gauge part that didn’t fit any heavy gauge category was a deep-drawn (approximately 12 in. deep) acoustical upholstery part for the cab of a John Deere tractor. It was made by Federal Foam Technologies Inc. in New Richmond, Wis., (www.federalfoam.com) out of a four-material sandwich: low-gloss, soft-feel vinyl backed by a special textile with 100% elongation in any direction, laminated to polyurethane foam for noise absorption, and then adhesive laminated onto Azdel SuperLite XLT sheet from Azdel Inc., Forest, Va. (www.azdel.com). The deep draw was achieved with matched cast aluminum molds. The part was also probably “slip molded,” experts speculated, a technique in which sheet is held by its four corners, not by its four sides, allowing the edges of the sheet to be pulled into the mold like fabric, a technique typically used for carpeted auto parts. But carpet is a more forgiving material to squish than soft vinyl. The vinyl surface was also perforated to allow noise to penetrate and be absorbed by the PU and Azdel. The part was trimmed by a 6-axis robotic water jet, Federal Foam said in its part submission.
The other unusual non-prize winner in sheet forming was a boomerang-shaped automotive trim piece from Eimo Technologies Inc. in Vicksburg, Mich., a division of Nissha Printing Co. in Japan (www.eimotech.com, http://www.nissha.co.jp). It was a decorative trim part for an instrument panel made from a multi-material thin-gauge sheet. The sheet is made of thin (0.5 mm) ABS film, printed with a geometric pattern. This printed ABS film is then formed in a six-cavity thermoforming tool. In the next step, each part is trimmed in a single cavity matched-metal trim die, which cuts the formed piece to the exact geometry of the decorative “appliqué,” Eimo explains. The cutting tool was specially designed to trim a two-sided undercut. The formed appliqué is inserted, much like an in-mold label, into an injection mold cavity and then filled with ABS, which chemically bonds to the thin ABS film. The decorative films are made by Eimo’s parent company, Nissha Printing. This technique has been used in automotive applications for over a decade, but the part on exhibition had especially severe undercuts.
TECHNICAL HIGHLIGHTS IN THIN-GAUGE PARTS
Thin gauge parts that were made with new or advanced tooling technologies included a sophisticated quadruple fold medical dispenser; a deep-drawn domed clamshell; and a temper-evident tray. The “quad fold” package and deep clamshell won prizes. The tamper evident clamshell tray, which is believed to be a first, did not.
The tamper evident tray was made by Precision Packaging Products Inc. in Holley, N.Y. (www.prepackpro.com), which added a strip of micro-perforated tamper-evident tape to the opening edge of a clamshell after forming, but before trimming. That strip is later ultrasonically welded at the customer or packer’s plant after the tray has been filled. The patent pending tray eliminates the cost of a PVC shrink band and the energy cost of a heat tunnel and has advantages for temperature sensitive package contents.
The quad-fold package for medical pipettes, made by Tegrant Corp.’s Alloyd Brands unit in Decalb, Ill. (www.tegrant.com) for Thermo Scientific, won second prize in the roll-fed medical category. It was one of the most complex quad-fold parts that several experts had seen. Electronics packaging has used triple and even quadruple folds for years, and multiple flutes or small folds in series have also been formed in sheet for decades for corrugated protective packaging. But Alloyd Brand’s complex package forms a rigid box, which is both package and dispenser. It was developed in record time to replace a similar injection molded box, which cost more because it weighed much more and required secondary tacking.
Alloyd Brands makes the part in three heights, the largest measuring 7 ¼ x 18 ¼ in. before folding. The flat part is folded in one direction around the bottom of the box and snaps together. The thermoformed part includes small extruded profiles that are molded in as rails, which have precise interference to hold the nested trays of pipettes. As trays are used, the cover on the box goes down. By comparison, quad-fold electronics packages are typically disposable and don’t involve tight clearances or secondary dispensing functions. After the original design was tested, the customer decided to use thinner gauge PVC sheet, and the tooling had to be completely redesigned because the interference between the rails and trays of pipettes had changed.
The domed package for a single cupcake or muffin, which won first prize in the roll-fed food category, is made by Lindar Corp. in Baxter, Minn. (www.lindar.com). It comes in a choice of PET, RPET or PLA and in two sizes, regular or jumbo. The base and dome design present the muffin as if it was on a plate under glass. The shape involves multilevel trimming of a complex parting line, excellent clarity, and deep draw. The traditional size is 2 ¼ in. deep with a 4 in. trim diameter. The jumbo is 3 1/8 in. deep with a 5 ¼ in. trim diameter. The design also incorporates several flat areas for labels and stackability for displays. Lindar showed it in both PET and PLA. Surprisingly, the PLA version was the only biopolymer package in the entire parts competition.