Dual Spiral Systems Die Trials
		Highly layered films continue to gain market share. By far the most significant factor that affects mechanical properties of film aside from the actual materials in the film is the number of independent layers in the film structure. Among the benefits of increasing the number of layers are improved gauge distribution, better physical properties, and the ability to manufacture many different film structures.


		Doubling the number of layers in the film structure creates films that have improved flex crack resistance making the film softer with less curl in asymmetrical structures resulting in increased deep draw characteristics and improved thermoformability. Using two thin layers of the same material instead of one thick one reduces pinholes and improves consistency. Statistically the two layers will have a better gauge deviation than the single layer. Correspondingly, a coextruded film has higher melt strength and can be produced at a higher output rate with better bubble stability. Pinhole reduction is obtained by a reduction in the possibility that a pinhole in one layer will line up with a pinhole in the adjacent layer.


		The main concept behind DSS research is to provide an initial basis for an ongoing study into the effects of highly layered film structures over films of fewer layers. This research is done in conjunction with the Canadian National Research Council (CNRC).


		The experimental setup involves machinery to compare barrier films produced on different coextrusion dies of varying layer numbers. All other processing conditions including temperatures, draw down ratio (DDR), blow up ratio (BUR), frost line height (FLH), die gap, film structure, etc… remain the same. 


		Initially the idea behind the experimental analysis was to measure the physical properties between the 5 layer films made on the conventional stacked coextrusion die, and the Dual Spiral Systems die that divides each melt layer into two layers. Essentially the film from the DSS die is composed of a total of 10 layers in the following arrangement AA/BB/CC/DD/EE while the film from the conventional coextrusion die is A/B/C/D/E.(see below)


		This ongoing research has resulted in a number of intriguing results. Please contact Dual Spiral Systems if you wish to receive full experimental details on the findings of this investigation.