CHICAGO (July 27, 2:30 p.m. EDT) — Cooling is more than a matter of temperature for plastics extruders. It is also time and cash for processors that find their flow limited by the pace of removing the heat.
Now Conair says it has a nitrogen-gas cooling system that can speed up processing by a minimum of 20 percent and make plastic lumber, fencing and decking systems cost-competitive with wood.
"It will change everything," Conair Vice President Conrad M. Bessemer said in a June 19 interview at NPE 2000 in Chicago. "There is a huge market out there just waiting."
A 1-inch-by-6-inch plastic fencing system now running at 12 feet per minute can advance to 22 feet per minute — an 80 percent jump, Bessemer said. Faster speeds mean reduced costs, and a better chance to lure customers away from traditional building materials.
"It´s the first truly new thing in extrusion I´ve ever seen," Bessemer said.
The system on display at NPE was developed by Material Enhancement Inc. of Effingham, Ill., and licensed to Pittsburgh-based Conair.
Conventional water cooling is limited by water´s freezing temperature of 32° F. Liquid nitrogen goes too far to the other extreme, dropping temperatures so rapidly the plastic fractures under the strain, said Dick Christopher, Conair´s vice president of sales and marketing.
With nitrogen gas, the extruded pieces pass through a chamber where the gas has replaced the ambient air, and a controlled temperature drop runs from 35° F to as low as minus 300° F.
That allows for a rapid decrease, without harming the part, Christopher said.
The technology has existed for years, used as a flash-freezing system for the food industry, he said. Aluminum processors even used the system to produce baseball bats.
The patented MEI and Conair system marks its debut in plastics.
In addition to improving speed, the nitrogen-gas system is smaller, saving up to 70 percent of the space on a shop floor.
That is a major cutback for PVC piping makers that now have up to 120 feet of cooling tanks, Bessemer said.
Processors also can expand capacity without an actual brick-and-mortar expansion, since they can use less space for existing lines, he said. They also cut back on environmental concerns, with no waste water to treat and only naturally occurring nitrogen gas as an emission, he said.
The gas system is more expensive, but with faster processing, extruders can earn back their investment in less than two months, Christopher said.
Future developments may expand the cooling program to other plastics processes, but Bessemer expects the push for machine makers now will force them to speed up other extrusion elements to bring them in line with the faster lines.
Other introductions from Conair for NPE include:
* System One, a new, personal-computer-based controller that runs all Conair auxiliary equipment in a factory. It ties all auxiliaries into a integrated system, then the PC can be networked to other computers. The Conair software comes pre-installed on a Dell Pentium III computer running on Windows NT.
* Conair´s new AirPak System is a low-pressure air-injection system that helps molders eliminate common part defects like sink marks. It can easily be applied to existing molds and used on any size of injection press, the company said. AirPak replaces conventional ejector or core pins with an air-injection pin. It then directs low-pressure plant air into the mold near any boss, standoff or rib that can cause problems on the outer, cosmetic side of a part.
* For vertical-clamp insert molding machines, Conair demonstrated an automated cell manufacturing system at its booth. The system at NPE included a six-axis articulated-arm robot with end-of-arm tooling, automatic insert feeders, degating fixtures, automatic vision inspection, cavity-separation, conveyors and guarding. The robot´s tooling rotated to both pick up the install inserts and remove parts, then move them through the inspection and degating fixtures. The cell automatically separated out rejected parts and moved good parts to a conveyor.