A new continuous roll-fed machine for high-precision forming and a flexible pressure former for prototyping were among the highlights of the recent 18th Annual SPE Thermoforming Conference in Minneapolis. There was also news in materials—including the first clear oriented PS for freezer packaging and a next-generation TPO resin with high melt strength and ultra-low CLTE. Other advances included a high-efficiency optical temperature scanner and new syntactic foams for plug assists and trim fixtures.
The new CS5454 SP roll-fed former from Brown Machine LLC has 225 tons of forming pressure and 100 tons of coining pressure with minimal deflection, the supplier says. It’s aimed at high-precision packaging like cups and food containers. High-pressure forming for detailed parts is not new, but the addition of high-tonnage coining provides matched-metal forming of precise product dimensions within specific areas of the product.
The machine comes in three sizes with max. mold areas of 40 x 42, 54 x 54, and 64 x 64 in. The sturdy frame structure features independent guiding and toggle systems that reportedly provide near-zero platen deflection and thus consistent material distribution across the entire mold area. Each platen has four center-actuated compound toggles to provide high-tonnage coining and holding force. At maximum tonnage, the company reports deflection of 0.050 in. for the forming-station stretch, 0.002 in per platen, and 0.0025 in. side-to-side platen movement.
Linear bearings and rails on each corner provide precise platen parallelism. Each platen is driven with a single servo motor and gearbox with dual crank-arm connection. The positive alignment of the dual crank arms to the crank shaft eliminates slip and permits easy toggle alignment.
Zed Industries Inc. introduced the Model L-4 pressure former for packaging prototypes. The roll-fed unit features standard top and bottom preheat stations, pin chain indexing system, top and bottom moving platens, and color touchscreen. Automatic cycling allows pre-production tooling to be run-in and debugged without shutting down the main production line. Production runs can also be made when inline trimming is not required. Chain rails are adjustable to accommodate a range of film widths.
FOAMS FOR PLUGS
Two new developments in syntactic foams for plug assists and trim fixtures were introduced by CMT Materials Inc. First, CMT collaborated with Montesino & Associates LLC, a Wilmington, Del., consultancy, on an epoxy-based syntactic foam that is claimed to be a first for plug-assist tooling for pharmaceutical blister packaging. Hytac-Rx is FDA approved for pharmaceutical use and reportedly offers more uniform material distribution (and thus better barrier performance) than plugs of heated aluminum and fluoropolymers. Initial tests show potential for downgauging and higher productivity. Hytac-Rx is available in high-slip and high-stick formulations.
CMT also launched a line of porous materials containing hollow composite spheres (3 mm diam.) for making trim fixtures. New Hyvac products reportedly provide a fast and economical way to hold formed cut-sheet parts in place during trimming. The material is easily shaped using existing parts, eliminating the need for costly machining. The two-part liquid resin system is mixed and transferred to a formed part. A backing plate is attached and the material cures in about 4 hr at room temperature. Upon removal, the fixture is ready for use on an automated router table or manual system. Vacuum evenly distributed through the porous fixture holds the part in place during trimming. This system is reportedly less costly than cast polyester or machined tooling boards.
A new high-speed, non-contact infrared device for measuring sheet temperatures during forming was introduced by Raytek. The MP150 infrared line scanner operates at 150 Hz, three times faster than its predecessor. It measures up to 1024 data points per scan, up from 512 points previously.
A new sheet locator from Advanced Ventures in Technology (AVT) automatically stores and recalls process settings for fast setups. The AVT Auto Sheet Adjustment system performs exact sheet orientation and alignment in the clamp.
CLEAR OPS FOR FREEZERS
Reynolds Packaging Kama launched the industry’s first clear, oriented PS film for freezer-storable clamshells and trays. Compared with PET, Tough OPS film provides superior impact at temperatures down to -40 F, higher stiffness, lower density, and better yield. By optimizing the butadiene rubber content, greater clarity is achieved than in typical OPS. At a 15-mil thickness, the material exhibits 4% haze and 97% clarity. Thicknesses from 0.008 to 0.020 in. and widths up to 40 in. are available.
Sheffield Plastics has come out with a flame-retardant PC/ABS sheet for mass-transit interior parts such as seating components, wall cladding, window reveals, and ceiling panels. Bayblend MTR sheet (using a resin from Bayer MaterialScience) reportedly complies with flammability and smoke emission requirements of the U.S. Federal Railroad Administration and meets the Bombardier Transportation Standard SMP 800-C for Toxic Gas Generation.
The sheet is said to be up to 30% lighter and also stiffer, stronger, and tougher than competitive plastics such as PVC/acrylic alloys and thermoset FRP composites. This results in thinner and lighter parts without secondary reinforcement or stiffeners. Conventional tooling can be used although optimum results are achieved with fluid-heated aluminum tooling.
A “fourth-generation” TPO resin for extruding thermoformable sheet was introduced by LyondellBasell Advanced Polyolefins. Sequel E3000 reportedly offers better melt strength than previous versions for reduced sag, while maintaining ultra-low CLTE and good low-temperature ductility for fenders, roofs, and fairings. Flexural modulus is 325,000 psi compared with 300,000 psi for the previous grade.