New Alpha die technology allows blown film flexibility
Alpha Marathon Film Extrusion Technologies has introduced its new Layer Sequence Alpha Dual Spiral System (LSADSS) die technology, which offers blown film manufacturers more flexibility to design rugged film structures for use in end markets such as packaging, health care, food, agriculture and construction.
The design is based on Alpha’s ADSS die module, which has two identical spiral channels flowing in opposite directions, officials said. This lessens the gauge variation of each individual layer and improves the overall thickness uniformity. By combining these two layers, any gauge variation in one layer will be cancelled by the other, and this produces a stronger final product with improved flex crack resistance.
A computer simulation program designs the geometry of the low-pressure, multilayer ADSS dies based on the resin’s behavior as it flows through a blown film die, officials said. The dies have a flow-mixing channel that ensures proper homogenization of the melt flow. These patent-pending, layer sequence flow-mixing channels are used to homogenize the melt entering the die pin area just before the layering of the film structure, officials said. This will allow processors to modify the film’s structure to meet future requirements in packaging, health care, food, agriculture and construction industries.
Decreased residence time and streamlined polymer distribution modules allow for rapid purging and order changes. This results in dramatic improvements in productivity and scrap reduction.
The LSADSS has a stackable design, which provides superior streamlining and mixing of melt flow, officials said. The design features interlayer temperature isolation, which helps improve film properties. There is a feedblock system, which is newly patented, that allows the two separate layers of melt to flow in two different directions. This means that processors can extrude two different materials in the same disk and duplicate the number of layers but also allow new materials to be introduced to the film’s structure. The LSADSS dies are designed for simplicity and flexibility to add layers to the die configuration. They are available with three to 50 modules (up to 100 layers) and in die sizes of 100mm to 1,000mm.
The multilayer film market is seeing more demand, according to several sources. In its most recent analysis, Transparency Market Research, Albany, N.Y., provided an eight-year forecast of the global multilayer blown film market between last year and 2026. The research firm said that in terms of value, the global market is expected to expand at a compounded annual growth rate of 4.4 percent for that period. In terms of resin types, PE, polyamide, PP, ethylene vinyl acetate, polyvinylidene chloride and ethylene vinyl alcohol can be used in multilayer blown films.
Alpha Marathon makes blown film lines, cast film lines, sheet lines, biaxially oriented multilayer film lines and lab lines. Through its components business, it offers products such as manual and hydraulic screen changers, air rings, horizontal film oscillators, bubble cages and bubble chambers.
Angie DeRosa, managing editor
Alpha Marathon Film Extrusion Technologies Inc.
Woodbridge, Ontario, 905-265-2055,