Brückner Maschinenbau GmbH & Co. reports that, as the profit margins for standard biaxially oriented polypropylene films, BOPP producers are looking to move into value-added specialty films, such as barrier films to give cost reduction, sustainability, longer shelf life, substitution of aluminum foil and the replacement of lamination steps.
Among the transparent high barrier films, Brückner said, the fastest-growing types are EVOH and SiOX coated film structures. EVOH, or ethylene vinyl alcohol, allows you to integrate the barrier function in the film orientation process.
The German machinery company reported on its pilot-scale evaluation, based on different EVOH grades with varying ethylene content. The proportion of ethylene has a significant influence on the stretching performance and the oxygen transmission rates. Typically, a higher ethylene content gives better orientation, but results in lower OTR barrier properties.
According to Brückner's evaluations, standard EVOH grades with ethylene content of 48 percent or more, a modified grade with 44 percent ethylene as well as modified grades with 38 percent ethylene can be biaxially stretched in the sequential mode with excellent optics and OTR values.
Also, the company said that, as an alternative to a new sequential BOPP line, it is technically and economically very feasible to upgrade an existing sequential line to a seven-layer structure.
Brückner issued many more findings in its report.
The company's U.S. operation, Bruckner Inc., is in Portsmouth, N.H.
Tel. 603-766-7577, email [email protected].