Battenfeld Gloucester Engineering Co. Inc. has built and installed one of the world's largest blown film lines - for making three-layer geomembranes in Latin America.
The Gloucester-based company did not identify the customer. Uses for geomembranes include landfill liners and caps, liners to control pollution from mining, and liners for artificial ponds. The liners are extruded of medium density and linear low density polyethylene.
Highlights of the line include a 78-inch die that weighs 88,000 pounds. The machining and assembly of the three-layer die was complex, according to Jorge Goldschmied, director of Latin American sales. The die's channels optimize melt flow, eliminate dead spots and prevent overheating of the resin.
The company said that resin integrity is important for film as wide - 23 feet - and thick - from 0.02-0.10 inch - as the geomembranes.
The big line, with a tower 82 feet high, produces geomembranes at a rate of 2,640 pounds an hour.
Because both outer skins need texturing for better traction during installation, Battenfeld Gloucester developed a system that pumps nitrogen into the A and C extruders. When the gas exits the die, it disrupts the flow of resin and creates a controlled texture on the skins, Goldschmied said.
All three extruders are Contracool models. The A and C extruders for the inner and outer skins, have screws that are 3½ inches in diameter, with a length-to-diameter ratio of 36-1. The relatively long screws increase mixing and homogeneity of the melt, while reducing process heat.
The B extruder, used for the core, has an 8-inch diameter and a 36-1 L-D screw.
In winder-related news, Battenfeld Gloucester wants to win one for The Gripper.
The company has developed a mechanical arm for three of its winders - models 1002, 1002DS and 1027S - that transfer the weight of big-diameter film and sheet rolls from the shaft to the arm. Heavy, larger roll sizes can cause problems because the pivoting mechanisms of some air shafts on the winder are not designed to handle the extra weight of large rolls, and could be damaged.
The pneumatic device hooks onto the end of a winding shaft, lifts it and swings it away from the machine. The Gripper keeps holding on until a cart arrives for roll removal.
At a signal from the winders' controller that the roll is finished, the Gripper arm drops to a point parallel to the end of the shaft and grabs it with a C-shaped clamp. The arm them raises from the cradle and swings it out.
The Gripper can be easily retrofitted to the three winders.
In other news, Battenfeld Gloucester introduced an infrared backscatter gauge and auto-cut assembly for cast film or sheet.
The infrared gauge is more accurate than the beta nuclear gauge, which it replaces.
Battenfeld Gloucester sources the infrared gauge from NDC Infrared Engineering.
The cutter, for stretch film, rotates the blade part of the mechanism into the web, for consistently cleaner cuts, the company said. A typical ``plunge knife'' system, which is positioned to the full mechanism, drops down into a web to make a cut, to finish the roll.
The new system also electrostatically charges the core first, a millisecond before the knife cuts the web. That sequence of charging assures the core is uniformly charged and the cut web lies flat and smooth during the changeover to a new roll.
The cut assembly can be retrofitted to most Battenfeld Gloucester stretch film winders.
Tel. 978-282-9268, fax 978-282-9111, e-mail [email protected]