Thermoforming

At a show dominated by other processes, several suppliers of thermoforming equipment took the opportunity to bring new or improved machinery to NPE. They expanded existing lines, added safety and accuracy features, and in some cases specifically targeted polypropylene food packaging.

Brown Machine LLC marked its 50th year in the business by introducing two advances for its thermoforming products. Brown billed the first upgrade as a safety advance, adding a sheet cutoff system to its C and C-D Series thermoformers. The new feature eliminates the need for machine operators to cut sheet material by hand.

The thermoforming machine, which handles material thicknesses up to .100 inch (2.54 mm) thick and 10 inches (254 mm) in height, features the automated cutoff systems as options on new equipment or as a retrofit. The cutoff can be situated at the infeed end (to assist in square-cut sheet feeding) and/or the exit end of the thermoformer. The wheel-type cutter uses a positive transverse motion that’s driven by a variable-frequency a-c drive coupled to a timing belt. A heavy-duty roller is said to withstand rigorous applications, and cutting pressure can be changed via an air regulator.

Another advance from Brown allows thermoformers to speed up and slow down material travel via a servopowered pusher system, making product repeatability possible with only a few parameter changes at the operator interface. The new Servo Flex Feed works in conjunction with a redesigned cage for close-tolerance accuracy. Sheet guides are positioned during setup or run modes, and they close during production to capture the formed web. A pneumatic cylinder opens the guides for adjustments or to remove the web during setup. The sheet guide’s fingers are mounted on scaled treadle bars for easy, accurate changes in their position. The Servo Flex Feed is available on all new Brown T-Series machines and can be retrofitted to most existing lines.

Targeting an array of PP products including yogurt and water cups, Irwin Research & Development brought a new small-bed thermoformer to NPE for display. The Model 3060’s bed measures 28 by 12 inches and it uses forming and trim-in-place tooling specifically for PP. The machine has Irwin’s Ballerina PC-based control to precisely control the female cavity and male plug assist motions.

Irwin dry ran the unit at NPE to demonstrate motion profiles and speeds. Sheet width for the 3060 measures 762 mm, and the maximum mold size is 305 by 711 mm. All axes are servodriven, and a cup collator and sheet-sag support are listed as optional features.

OMV-USA launched its sixth new-generation inline extrusion/thermoforming system, which has an extrusion capacity of up to 7000 lb/hr for PS and 6200 lb/hr for PP. The F57 system is suitable for production of rigid containers, plates, and trays. Maximum forming area is 60 by 57 inches.

Together with the thermoforming system the F57 can be equipped with a horizontal trim press, vertical trim press, inmold trim, or inline rim rolling. The turnkey system is complete with one or more extruders, calender, thermoforming machine, mold, rim-rolling station, and automatic counting, stacking, and handling equipment for the finished product. Material handling is provided, with a granulator for recycling the skeleton web, automatic feeding of virgin material and color, and metering and mixing of a designated virgin/regrind ratio. The fully computerized system allows complete control from plastic pellet to finished and packed parts.

In other news from OMV, a newly developed D160 (160-mm diameter) extruder and screw design increase throughput of high-quality PP sheet up to 1400 kg (3110 lb)—even with 50 percent regrind. Also, a new compact calender is especially designed for inline systems, and OMV showed a new oven design used prior to thermoforming to prevent sheet sag.