Extrusion.

Blown film exhibits reflect trends toward higher outputs and higher-barrier structures. For barrier coex film, suppliers will introduce a brand-new "triple-bubble" process and a five-layer double-bubble approach. At least three exhibitors will be promoting shorter and smaller lines for three-layer and monolayer blown films. There will also be new dies and cooling systems on display.

Flat-web news includes high-speed casting lines and novel coextrusions - such as thick PVC skin/foam/skin sheet and peelable LLDPE cap layers over TPU. In pipe and profiles, more strands than ever are coming out of one large extruder. In controls, there is an explosion of new Windows NT-based software and remote diagnostics, as well as a novel use of process simulation to aid set-up.

News in blown film

Kuhne GmbH (American Kuhne Corp. is in Norwich, Conn.) will introduce a "triple bubble" process, to be demonstrated during the show at its plant in St. Augustin, Germany. The system makes five-layer, bi-oriented nylon barrier film with very consistent shrink rate for sausage casings. Several major processors have proprietary lines that make similar film, but Kuhne says this is the first commercially available system.

Kuhne has applied for patents on the concept, which first extrudes a bubble downward into a water quench while vacuum sucks the bubble wall against a calibration sleeve. The tube is then reheated and inflated in an orienting station, and then goes to an annealing and stretching stage. Kuhne plans to extend the process to seven and nine layers for shrink-bag applications.

Reifenhauser (U.S. offices in Lawrence, Mass.) will show its new "Triplex" double-bubble process for the first time. It reportedly makes very clear and tough three- or five-layer barrier packaging, including shrink film. The process starts with downward extrusion of a bubble into a water quench, then reheats the tube and blows an orienting bubble.

Contradicting the conventional wisdom that bigger lines are more efficient, Macro Engineering & Technology Inc., Mississauga, Ont., will bring the first prototype of its new concept of substituting multiple small, standardized blown film lines for one big one. Macro's new Unistretch machine uses high-quality components but sticks to basics to keep costs low. Unistretch has an air ring but no IBC and a simplified die suited to a range of resins, including metallocene PE and nylon. The line is fully automatic: Finished rolls drop into shipping containers. "For the same money as one big stretch-film line, a processor can buy six Unistretch machines and make a lot more film," says Macro president, Mirek Planeta. He also notes that no operators are needed. The 120-lb/hr prototype line has a 1.75-in., 30:1 extruder, 4-in. die, and 14-ft collapsible tower. Price will start at under $200,000 for a max. layflat of 30 in. [Circle 38]

A new player in blown film is ERWE-PA Davis-Standard GmbH, Erkrath, Germany, which will show its first line for making heavy-duty sacks at its plant open house. The new Propak three-layer spiral die, together with high-volume IBC and the new Wesjet air ring, gives "25% higher output than known industry levels," says Hassan Helmy, v.p. of Davis-Standard Corp., Pawcatuck, Conn. "It can also change color completely in under 15 min with LL or LDPE, whereas competing dies take 40 min."

Hosokawa Alpine (U.S. office in Natick, Mass.) will introduce a new simplified spiral die for up to threelayer coextrusion. The BF 14-35K die distributes melt horizontally to a cylindrical mandrel. Because it has no vertical passages, the die is one meter shorter than a conventional spiral mandrel, in which melt flows upward from the bottom of the die. Its simpler horizontal flow passages are entirely chromed, whereas in a conventional spiral mandrel, parts of flow channels are inaccessible for chroming.

Kiefel (U.S. office in Wrentham, Mass.) will also show a new short three-layer blown film line. The die is again side-fed, introducing melt horizontally to the spiral mandrel.

Windmoeller & Hoelscher (U.S. office in Lincoln, R.I.) will show a seven-layer Varex blown film line with a 47-in. layflat. It will be the first public display of W&H's new Multicone coex die. The line will have seven extruders and a new dual surface winder. W&H will also demonstrate new remote diagnostics.

Remote diagnostics, called "Extrol Anywhere," have also been added to the Extrol controls from Battenfeld Gloucester Engineering Co., Gloucester, Mass. They will be shown on a seven-layer high-barrier film line like the one at NPE '97.

News in cooling systems

Addex Inc., Boston, will unveil a new all-digital IBC system said to control layflat width 10% better than any previous commercial system. It has ultrasonic sensors for automatic bubble-width control. Addex says the system reacts significantly faster than competing products.

Addex will also bring to K a new high-pressure air ring suited to low-melt-strength resins like PP, LLDPE, and metallocene PE. Addex will also reintroduce a double-barrier screw that is said to have double the usual life. The design equalizes forces around the screw, reducing deformation and wear.

Kiefel also has a new cooling system, called Aero-Cool, which combines mechanical improvements with new electronics for significantly improved control of bubble size.

News in cast film & sheet

Black Clawson Converting Machinery Corp., Fulton, N.Y., will introduce new winders for stretch film and new diebolts and deckles that allow faster changeovers of its internally deckled die.

W&H will show a three-layer Varex cast film line with new patented software for Roll Profile Control that compensates for neck-in thickness and other gauge variations to avoid banding on the roll. Slight oscillation distributes repeating thick or thin areas.

Battenfeld Gloucester says its new Model 700 film caster is the world's fastest. One installed in the U.S. runs 120-in.-wide LLDPE at up to 1900 ft/min. Another runs a 232-in. web at over 1500 ft/min. Model 700 has flux-vector drives claimed to have [+ or -]0.01% accuracy, vs. [+ or -]0.5% for standard DC drives.

Battenfeld will also show a new 124-in. Autogauge V die from the Cloeren Co., Orange, Texas, that has a new deckle design and a "Soft Box" in place of an air knife to hold PP film against the chill roll.

The big news at K from Extrusion Dies Inc., Chippewa Falls, Wis., is a modular feedblock that lets processors add or subtract layers by two-layer increments. It's considerably thinner (12 in.) than a standard feedblock. Combined with EDI's recently developed Ultra flow I-S feedblock technology, which changes layer sequence by inserting cores with alternative flow paths, EDI can offer feedblocks to add or subtract layers and rearrange them. EDI will also show a modular Autoflex VI-R flexible-lip die designed for quicker disassembly.

Cincinnati Milacron Austria (sub. of Cincinnati Milacron in Batavia, Ohio) will show off new three-layer foamed PVC sheet technology that uses a special feedblock to make thicker sheet of this type than has ever been possible - up to 19 mm thick and over two meters wide. The previous limit reportedly was 12 mm. Milacron uses an endothermic blowing agent to reduce core density from 1.4 g/cc to 0.5-0.6 g/cc. The line at K will have an Argos 132 single-screw extruder (Atlas 132 in the U.S.) with a Titan 58 satellite extruder for the skin layers.

Davis-Standard Killion Systems, Cedar Grove, N.J., will show a three-layer R&D line coextruding sheet and cast film with very thin cap layers of LLDPE over TP urethane. The LLDPE layers, which aid in processing the sticky TPU, can be peeled off and recycled.

Welex Inc. of Blue Boll, Pa., is expanding its World Standard line of no-frills sheet extruders with a new 5-in. Mark III model for 2200 lb/hr. This model fills a gap between the 4.5-in. and 6-in. sizes.

News in pipe and profiles

One way to increase output is to extrude more strands from one big extruder. Krauss-Maffei will show a reportedly unique four-strand system making 25-mm-diam., thin-wall PVC pipe. The new-generation high-output twin-screw extruder has a new screw design and throughput of 2600 lb/hr. K-M will also show new remote diagnostics.

Battenfeld Extrusionstechnik GmbH will show two new-generation twin-screw extruders for PVC, developed by its American Maplan subsidiary in McPherson, Kans. Model BEX 2-68-28 V/1 runs 440 lb/hr of profiles and 660 lb/hr of pipe. BEX2-110-28 V/I extrudes 1300 lb/hr of profiles and 2000 lb/hr of pipe. A new screw is said to raise outputs while reducing wear.

Cincinnati Milacron Austria will also add a new 93-mm parallel twin-screw extruder, to be supplied here as the Atlas 93 model by year's end. It has 26:1 L/D and output of 830 lb/hr for profiles or 1300 lb/hr for pipe.

News in controls

Eurotherm Gauging Systems, Billerica, Mass., is launching its first new product line since it acquired LFE Industrial Systems last year. System 21 will eventually be a complete Windows NT-based thickness-measurement and control software package. The first module, Profitmaster System 21, adds an NT-based operator interface to LFE's Profitmaster automatic gauge control.

Honeywell-Measurex, Cupertino, Calif., will show off a Windows NT-based gauge measurement and control system for film and sheet, called MXProLine. It supports a new line of computerized sensors and high-speed scanners networked to a new operator interface.

Davis-Standard will roll out new extrusion process-simulation software, developed jointly with Compuplast Canada, Bramalea, Ont. Simulation capability is now imbedded in Davis-Standard's Epic III and Exact-S process-control systems, which are based on Windows NT. (The simulation software can also be purchased on its own.) It simulates the extrusion process in order to help the operator generate line set-up parameters such as extruder and cooling-roll temperatures, flat-die profile adjustments, and line speeds. Using a resin data bank, the software predicts extrusion rates, melt temperature and system pressures. It will simulate a seven-layer sheet line at K.