New co-ex die splits film layers

Mississauga, Ont.-based Techflow Design Inc. has introduced a patented concept for co-extrusion blown film and blow molding called the Dual Spiral System (DSS). When applied to blown film, the DSS die concept splits individual film layers into two side-by-side layers, thus enabling processors to add layers without adding additional equipment and costs, according to company literature. By dividing each individual layer into two separate layers, enhanced structural and physical properties, such as improved barrier properties, are added to a film. The same principle applies to blow molding — for example, a five extruder DSS blow molding die would produce a 10-layer parison. The company has sold a 180 mm three-layer DSS line to a customer in Chile extruding HDPE and LLDPE in a film structure. It is also in the process of building a five-layer 259 mm DSS die for a customer in Italy and a seven-layer line for a customer in South America.