Promix systems are compatible with most types and sizes of extrusion lines, whether single-screw or twin-screw. “Our systems are designed for foam extrusion applications where the desired density reduction is anywhere from 5 percent to 75 percent,” Promix President Andy Caufman said.
Promix gas-dosing systems can be used for a range of physical foam extrusion applications including the manufacture of sheet and film for product packaging or food trays; profiles for window and door seals; and foamed-core pipe and corrugated tubing. They are compatible with a broad range of polymers, including PP, LDPE, HDPE and PVC.
According to Caufman, whose company is a wholly owned division of Promix Solutions AG, Winterthur, Switzerland, the upgrades will consist of “a redesign of the internal components to reduce the overall size slightly, but, more importantly, to arrange the internal components more ergonomically so the system interior can be more easily accessed when the need arises for routine maintenance or reconfiguration for another range of gas flow rates, for example.” The software update includes changes to the interface and graphics.
The upgrades will be applied to the Promix Z400mc, which is a carbon-dioxide dosing system, and nitrogen-dosing systems N400mc and N700mc. Promix’s newest dosing system, the NC300, was introduced to the U.S. market last year and can handle either CO2 or N2. It will also be part of this summer’s upgrades.
“For R&D applications, [the NC300] is a nice system because customers who are developing a process can purchase one system for about 10 percent to 15 percent more than an N2-only or CO2-only gas-dosing system,” Caufman said. “The limitation at present is the maximum allowable output pressure — 300 bar rather than the 400 bar of the other systems.”
All of Promix’s gas-dosing systems can work with bottled gas or a processor’s plantwide gas supply system, as long as the available pressure is adequate.
Caufman said that Promix’s dosing systems are valuable in part because of their precision. He said they are designed to handle flow rates as low as 1 or 2 grams per hour and up to 4,000 grams per hour.
Whether using CO2 or N2 as the foaming agent, it is critical for systems to deliver a precise pressure and flow rate. “The ratio of N2 or CO2 to the polymer being foamed is only a small fraction of the total fluid stream,” he said. “Sometimes the gas is only one-tenth of 1 percent by weight compared to the polymer. So, at these very low flow rates, deviations … can be seriously detrimental to the foam structure of the end product. Therefore, our gas-dosing systems are designed for exacting delivery of pressure and flow of the gas with no overshooting and no fluctuations in process setpoints.”
Caufman said Promix also can be a resource for processors who need expert advice when considering a gas-dosing system. The company can help with anything from specifying screw design to properly matching melt homogenizers and melt coolers to a foam application.
“Over the last seven years, Promix Solutions has built a significant database with respect to foam extrusion applications covering a wide variety of polymers and end products,” he said. “With this previous knowledge and experience, coupled with customer trials at our lab in Switzerland, we offer custom systems with the assurance that the extruded foam end product will meet or exceed expectations.”
David Tillett, copy editor
Contact:
Promix Solutions LLC Doylestown, Pa., 215-348-4668,
David Tillett
Associate Editor David Tillett writes and edits for Plastics Machinery & Manufacturing, Plastics Recycling and The Journal of Blow Molding. He covers new products, industry news, patents and consumer and business equipment. He has more than 20 years of experience in daily newspaper, online and magazine journalism.
