Film and sheet extrusion systems supplier Macro Engineering & Technology Inc. (Canada) has added the option of including gas foaming into any layer of the multilayer film structures produced on its cast film coextrusion line.
Macro’s cast barrier film coextrusion system is used to produce multilayer film structures up to 11-layers and up to 3 m 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 favourable 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.
Individual layer foaming is achieved with nitrogen gas injection through a sophisticated feed-block that distributes each layer of the melt flow. The feed-block’s design alleviates the need for a multi-manifold system that can add significant cost to the system.
The line can operate with or without foam injection, providing processing flexibility for the film maker to switch between conventional multilayer films and foamed films without changing machinery configuration. “Versatility is a driving motivation for us”, states Erskine. “Supplying systems with inherent flexibility helps our customers adapt to changing market demands. It also helps mitigate risk on their capital investment”.
Macro recently installed a 7-layer cast coextrusion line in Europe that produces high barrier films with layer foaming in two of the seven layers and inline embossing to create an optimized product for the user’s end application.
For more information visit www.macroeng.com.