EuroWire January 2020

Technology News

THE DS-Blend is the latest option in Davis-Standard’s award-winning feedscrew line. The patent-pending design improves the performance of a single screw extruder for demanding applications by providing distributive and dissipative melt mixing. The two-stage approach achieves outputs similar to those of a single-stage barrier screw, but with a lower melt temperature and reduced energy requirements. It can be installed on new or existing single screw Davis-Standard extruders as well as other brands. Building feedscrews for non Davis-Standard extruders has been an area of growth for the company as customers realise the benefits of the technology. According to John Christiano, vice president of technology at Davis-Standard, “This is one of our most versatile and energy-efficient feedscrews to date … As with all of our feedscrew designs, we are focused on product line performance, improved outputs, material homogeneity and feedscrew longevity. We are also proud of the fact that we can build a feedscrew for any extruder brand.” Davis-Standard’s feedscrews are available from 19 to 300mm ( 3 / 4 " to 12") in diameter, with varying L/Ds. Each screw is engineered for specific polymers and processes, with customisation available depending on the end product. Davis-Standard feedscrews accommodate the full range of extrusion and converting applications, including blown film, blow moulding, cast film, compounding, elastomer, extrusion coating and fibre. Sales and service engineers work alongside customers to find the right solution based on manufacturing parameters. Testing and trials are available to fine-tune the process prior to purchase. In Davis-Standard’s feedscrew manufacturing process, plasma arc welding stations provide wear-resistant materials such as Colmonoy 56 and 83. Three whirlers are used for screw cutting and milling for screws made of stainless steel, 4340 steel or Inconel materials. These machines produce screw surfaces at very tight tolerances. After screws are milled and polished, they are treated with chrome plating or other wear-resistant coatings, based on the application. Screws receive a final inspection and polish before shipment. Feedscrew extruder with improved performance ▲ ▲ DS-Blend feedscrew from Davis-Standard

Davis-Standard, LLC www.davis-standard.com

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