Cast film machine technology fuels growing stretch film market

In general, cast film markets worldwide are healthy, and the cast stretch film market is particularly strong and growing. It's solid in North America, growing at nearly 3 percent annually, while growth is even higher in many emerging economies around the world. Despite the slowdown that's taken place in many of those economies, as well as in many economically mature regions, globalization of manufacturing means that a lot of shipping is going on.

Steve Post, VP of cast film at extrusion and converting system supplier Davis-Standard LLC, Pawcatuck, Conn., says about 80 percent of the total cast film machine market consists of stretch wrap, hygiene film (diaper back sheets, hospital gowns and bed sheets, etc.) and cast polypropylene. Stretch is by far the biggest part, hygiene film is growing and so is cast PP, TPU film, PE film, though almost all in Asia.

Suppliers of stretch film in North America are bullish about a market that's growing at close to a 3 percent annual clip, says Post. And, he points out, it's growing from a relatively large base. Suppliers feel resin prices will drop as natural gas supplies increase. Shipping film made in the U.S. to Europe is well within the realm of possibility.

Most cast film processes are limited by line speed: how fast you can cool the film, or pin the web to the chill roll out of the die. As film keeps getting thinner with machines like PE film machine, TPU film machine, EVA film machine, etc., if line speed doesn't increase the net output of the line drops. Most cast stretch film, both hand and machine rolls, is sold by the pound. Lower machine output is a problem for the processor. Post says that with in-line pre-stretch, the processor can make film from the die at a slower speed — conventional process limits are 1,600 to 1,800 feet per minute — but if the film is stretched three times in-line the result can be an effective line speed greater than 3,000 feet per minute.

One additional benefit of pre-stretching worth mentioning: It results in a stiffer film, and that means better load retention and much lower load movement on stretch-wrapped pallets. Since the pallets and their contents are better supported during the transportation cycle, there should be less waste caused by damaged goods and more smiling shippers.

Steve Post, VP of cast film at extrusion and converting system supplier Davis-Standard LLC, Pawcatuck, Conn., says about 80 percent of the total cast film machine market consists of stretch wrap, hygiene film (diaper back sheets, hospital gowns and bed sheets, etc.) and cast polypropylene. Stretch is by far the biggest part, hygiene film is growing and so is cast PP, TPU film, PE film, though almost all in Asia.

Most cast film processes are limited by line speed: how fast you can cool the film, or pin the web to the chill roll out of the die. As film keeps getting thinner with machines like PE film machine, TPU film machine, EVA film machine, etc., if line speed doesn't increase the net output of the line drops. Most cast stretch film, both hand and machine rolls, is sold by the pound. Lower machine output is a problem for the processor. Post says that with in-line pre-stretch, the processor can make film from the die at a slower speed — conventional process limits are 1,600 to 1,800 feet per minute — but if the film is stretched three times in-line the result can be an effective line speed greater than 3,000 feet per minute.