The Tandem Extrusion Coating Line from Bobst

The Bobst tandem extrusion coating line essentially adds a third layer to the laminated structure, thanks to an additional unwinder (tertiary material), additional primer coating station and a second extrusion coating system. In this case, three or more materials are bonded. Pet food bags and coffee bags are a couple of structures that are made in one single pass with a tandem extrusion coating line. Extreme care is taken to engineer and design the line with the highly sensitive and constant web tension control, and the primer coating is generally applied with a gravure coating cylinder. Operating speeds of 2300 feet per minute are possible, with maximum web widths in excess of 100 inches. The Bobst extrusion coating lines are capable of handling a wide assortment of materials including thin aluminum foils, film substrates as well as paper and paperboard.