Macro Engineering & Technology Inc., Mississauga, Ontario, has developed new feedblock technology that permits solid or gas-foamed film to be run on the same line. In the system, individual layers are foamed by nitrogen gas injection through a proprietary feedblock that distributes each layer of the melt flow. The design of the feedblock is said to eliminate the need for multi-manifold systems that can add significant cost to the system.
Macro’s cast barrier film lines are used to produce structures up to 11-layers and up to 3-meter-wide using a variety of materials, including PA, EVOH and PVdC. The films produced are most typically used in food and medical packaging applications. “The addition of individual layer foaming broadens the possibilities of end-use applications,” states Andrew Erskine, Macro’s marketing manager. “Not only can foaming reduce weight and lead to raw material savings, but it can also create favorable properties in the film. By foaming one or more layers embedded in the coextruded film, thermal and sound insulation can be improved, flexibility and conformability can be enhanced, and opacity can be obtained without using fillers.”
With the addition of foaming technology the applications for Macro’s cast barrier film line can be extended to thermoformed trays, insulation pouches, value-added lamination materials and stiffer, glossy films for shelf appeal, the company said.