Meet the World’s Largest Seven-Layer Blown Film System

Published 07/30/2012

Meet the World’s Largest Seven-Layer Blown Film System

Processor Strategies: Raven Industries

Raven will process barrier blown film for energy, industrial, environmental, construction, and agricultural markets on giant new Davis-Standard seven-layer line.

Jim Callari

Editorial Director, Plastics Technology

Raven Industries will produce barrier blown film for energy, industrial, environmental, construction, and agricultural markets on giant new Davis-Standard seven-layer line.

It started out making high-altitude research balloons, and over the past 56 years the firm has evolved into a producer of high-tech blown films for markets ranging from agriculture to building construction. In another step in that direction, the Engineered Films Div. of . recently announced the commissioning of what’s reportedly the world’s largest seven-layer blown film system. Engineered by Davis-Standard, the new system is capable of processing the widest and thickest seven-layer blown film barrier structures (EVOH and nylon) available in the industry today. This includes films up to 32 ft (9.7 meters) in circumference and sheeting up to 80 mils (2 mm) thick with optional surface texturing.

This latest installation positions Raven to expand its multi-layer manufacturing capabilities for barrier membrane, vapor/gas barrier, agricultural barrier films, and large covering markets where wider films with barrier properties offer extra value.

The line is housed at Raven’s 300,000 ft² facility in Sioux Falls, S.D., where it joins numerous other production lines for blown film and sheeting, laminating/coating, and other converting capabilities, in addition to a Technology Solutions Center that Raven opened about a year ago. In South Dakota, Raven produces film from virtually all types of polyethylene, as well as polypropylene and TPO.

“Our investment in this cutting-edge technology aligns with our commitment to product research and development. It inspires barrier membrane advancements by providing exceptional performance and value to the industries we serve,” says Jim Groninger, division v.p. and general manager. “This is the fourth time we have collaborated with Davis-Standard to create innovative film technology for our processes. We continue to be pleased with their expertise, technical guidance, professionalism, and ability to deliver.”

The Technology Solutions Center provides full-spectrum product development through research, analysis, processing, and optimization of new product formulations. The center houses two state-of-the-art pilot extrusion lines. The first is a nine-layer blown film and sheeting line capable of producing a broad range of complex multi-layer products, including highly engineered barrier layers. The second is a versatile cast film/coating line able to introduce various preformed scrims or fabric substrates.

The pilot lines are located directly outside a full-service accredited laboratory along with a development/meeting area designed to promote creativity and innovation in a stimulating work environment. “By creating the Center we have invested substantially in future product innovation and are fully committed in research and development to assure continuous advancements in polymer film and sheeting solutions,” states Groninger.

The new, giant blown film line from Davis-Standard incorporates a 60-in. (1500-mm), seven-layer Centrex die. It features an insulated IBC system with unique internal and external heating to help reduce melt fracture and increase throughput. The die also enables production of structures using a variety of polymers and blends, essential to Raven’s operation. Seven MAC extruders feed the die, including nitrogen-injection skin extruders to facilitate the creation of textured skin surfaces.

The new line supports applications in energy, industrial, environmental, construction, and agricultural markets. One of Raven’s innovative product lines is called the Absolute Barrier. This is a line of seven-layer geomembrane films consisting of a very flexible LLDPE and an inner core of EVOH, designed specifically as a barrier against radon, methane, and other VOCs. High-strength LLDPE provides exceptional tear and impact resistance.

Another special film is the Vaporblock Plus Series. These are seven-layer barrier structures of PE and EVOH that provide maximum impact strength as well as superior resistance to gas and moisture transmission. VaporBlock Plus is a highly resilient underslab and vertical-wall barrier designed to restrict naturally occurring gases such as radon and methane from migrating through the ground and concrete slab.