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September 1, 2003

6 Min Read
New priorities widen demand for cast stretch wrap film

The world of stretch wrap manufacturing is in for change if equipment makers are to be believed.

It is a cutthroat market, where profit margins have been downgauged as much as today's modern films. Yet, it nevertheless is seen as "an overall growth market," says Thilo Schreiber, product manager cast film, Windmoller & Holscher (Lengerich, Germany). Dirk Luschen sales manager film division, Reifenhauser (Troisdorf, Germany), claims a processor can still make money in this business if he gets his machinery needs and film-structure makeup in order.

Annual European demand for stretch film is growing at 5 to 7 percent. In North America, annual growth in demand is about 5 percent, while in Asia-Pacific, it's running about 8 percent, says Reiner Bunnenberg, sales director at equipment maker SMS Folientechnik (Vienna, Austria). Mauro Andreoli, marketing director at equipment maker Polytech (Marano Ticino, Italy) says demand is growing in Eastern Europe as much as 15 percent a year, and in Russia, although starting at low levels, it is increasing by 30 percent annually.

Once different approaches

By tradition, the European and North American markets have developed significantly different polyethylene cast stretch film production approaches. Europe, long dominated by Italian equipment builders' standards, has stuck to generally non-dedicated film lines in widths of 1.5 to 2m, incorporating high speeds (today generally 600 m/min) and high levels of automation to reduce labor costs. "European producers, which number more than 80, see short-width lines as offering the flexibility they need for fast product changes," says Matteo Spinola, marketing manager of equipment maker Dolci Extrusion (Biassono, Italy).

By contrast, the North American cast stretch film market, which is dominated by eight out of 26 players, has targeted product-dedicated lines-generally 2.5 to 6m wide, with slower running speeds (often 300 to 350 m/min) and less emphasis on equipment automation. Asia has not yet locked itself into either one of these philosophies, says Allen F. Hall, group product sales manager cast film, Battenfeld Gloucester Engineering (Gloucester, MA).

That all may be changing now, however. According to Pierdamiano Sordo, managing director of cast film line maker Primplast (Melzo, Italy) the two philosophies are merging. (The company says 40 percent of all European PE stretch film produced is made on equipment it supplies-most of it to Italy, which produces 43 percent of the European total.)

"Processors need to maximize capacity and output, and reduce labor costs," he says. "We see European customers who are now interested in lines up to 4m wide while maintaining output speed," says Sordo. He says his potential North American customers are now looking for high throughput, perhaps narrower lines as previously, and automatic roll handling.

Battenfeld's Hall concurs, saying recent interest in high throughput, while keeping the die width manageable, has been strong. To gain a better foothold in Europe, the company's European division, SMS Folientechnik, recently launched its 2- to 2.5m-wide Cast 2020 line with throughput rates of 1200 kg/hr at 580 m/min.

The machine line includes automatic flat dies and feedblocks from Cloeren (Orange, TX), reverse winders, an integrated automatic roll handling system, and an edge trim re-feed system that can be integrated into this plug-and-play metric unit.

Dave Finnemore, product group manager cast film, says American equipment producers in the past may not have been successful in penetrating European markets because they offered lines designed with the wrong speed, output, and width-and didn't have enough flexibility for potential buyers. This new line is intended to overcome those market-related shortcomings.

Conversely, European cast line producers have not always been successful in offering what the North American market wanted, says Polytech's Andreoli. He points to high labor costs in Europe, which have traditionally promoted full automation. "Average operator wages in Europe run about €30/hour compared to about half that in the U.S.," he says. "It's easy to see why, in Europe, producers have placed more emphasis on non-worker handling of finished film rolls."

Convergent thinking

There has been movement toward automatic handling on both sides of the Atlantic as wages rise, and health and safety regulations-determining how much a worker can lift, for example- take effect. Paragon Films (Broken Arrow, OK), America's sixth-largest industrial stretch film producer, recently invested about $50 million in robotic roll off-loading and packaging.

Primplast's Sordo says cast stretch operations have, in the past, operated at the mercy of their winders, which often are not able to keep up with the output. "We expect a more global market in the future, with more standardized equipment," he says. "But the winder will be the key to any operation." His company has just come out with a patented multi-winder system which "allows one machine to become a complete stretch film factory, producing a variety of widths and roll diameters on different cores at the same time."

Staggered winders can handle smaller, lighter (15 kg) handwrap rolls (100 to 159 prestretch or elongation), while other winders produce larger width and diameter machine wrap (200 to 240 percent prestretch). In the future, Sordo sees more emphasis on inline winding, which reportedly can save up to 6 percent over separate slitting/rewinding of film from jumbo rolls.

"Since 40 percent of the 700,000 tonnes a year of European PE stretchwrap production is handwrap, it makes more sense to do this inline to save costs on this low-margin product," he says.

Dolci's Spinola says it will be a hard sell to convince stretch wrap producers in low-labor-cost countries to include more handling automation. He points to a new three-layer cast line the company delivered to a Russian processor in August, which, despite running at 600 m/min, does not include robotic roll palletizing. Andreoli says in countries like Russia, where operator wages start at €3/hour and labor is abundant, there is little incentive for such high-tech investments.

Film-layer structure is another area moving toward more uniformity. Europe has traditionally stuck to three-layer stretch wrap structures, while in North America, five to seven layers predominate. Windmoller & Holscher's Schreiber says five-layer lines may become the global norm.

"Five layers give you better possibilities to hide the defects you will always get in the center layers from the inclusion of regrind, which has a higher gel and speck tendency than virgin material." Multi-layer films offer a plywood effect claimed to provide better strength and bonding power, he says.

Processors are also headed toward a more unified approach regarding resins. Gary Oliver, VP sales/marketing, Cloeren, says North America has traditionally processed cheaper butene (C4) LLDPE with a blend of hexene (C6) to get the right stretch retention and clarity for barcode reading, as well as gloss and cling, at low prices. European processors tend to concentrate on octene (C8), very low- and ultra-low-density PE, and metallocene (mPE) grades.

But Oliver says that today, there aren't substantial benefits to be had using expensive mPE, when compared to new C8 grades. Also, mPE tends to cut poorer, he says. Alternatives are coming onto the market which offer processors property benefits including lower cost.

Polyethylene producer Polimeri Europa (Milan) came out this year with a super hexene LLDPE grade for Super Power stretch (270 to 350 percent prestretch used to machine wrap odd-shaped objects). Clearflex CL166 gives the mechanical performance of C8 and mPE grades, but with better processability than metallocene, and at lower cost.

Robert Colvin [email protected]

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