Coreless winding cuts transport costs, pleases Walmart

According to Dave Finnemore, VP sales EMEA at Gloucester Engineering (Vienna, Austria), the technology’s introduction is being pushed by environmental sensibilities. “The main aims behind developing [film] products with thinner cardboard cores or even with no core at all are reducing costs or removing the need for management and disposal of the used cores, reducing waste taxes, eliminating shipping and storage costs by optimizing film meterage on a pallet, and lowering production costs,” he says.

Finnemore says an estimated 350 million cardboard cores are disposed of annually in Europe, Russia/CIS countries, and the Middle East. While some Central European core suppliers offer collection systems for recycling, in other regions such schemes don’t exist. He says global multinationals such as Walmart, Coco-Cola, P&G, and the Carrefour group are implementing environmental policies for waste reduction that foresee not accepting hand- and machine-stretch pallet-wrap film if the retailers have to dispose of paperboard cores.

While resin costs for cast stretch-film production typically represent 80% of total cost, processors of course always are on the outlook for other ways to save, and cores represent one of the latest areas of consideration. Finnemore says in an average in-line handwrap production of four 17-µm film reels of 300 m/reel, processors generally use a paper core with a wall thickness of 5 mm. This represents €0.15 or 23.3% of the total conversion cost. Machine film conversion costs of four reels of 23-µm film running 1500m, and assuming a core with wall thickness of 11 mm, will represent an average core cost of €0.42.

But the question remains whether cast-film extrusion operations will accept new solutions such as handwrap cores of only 1-2 mm in wall thickness, and machine film with core wall thickness of only 5 mm or even coreless, Finnemore says. “Reduction in core weight or elimination will ultimately reduce the overall cost/kg of film transportation. Walmart CEO Lee Scott reported back in 2007 that the company was pressing vendors to go more green, and both handwrap and machine wrap were target areas.” Suppliers [who deliver to Walmart] are being asked to cut their packaging by 5% by 2013.

Finnemore says generally 8360 reels of hand wrap (5-mm wall cores at 300g) fit into an average truck. Using 2-inch cores with a 2-mm wall thickness at 115g, the core weight savings represents 1546 kg per 22 tonnes of film, a potential reduction of 7%. Without cores, an additional 250,800m of film could fit in each truck representing a €0.005/kg reduction in film transport costs.
With machine wrap, by using 3-inch cores with a 5-mm wall thickness at 450g compared to 11mm wall cores at 1.1 kg, the core weight savings is 858 kg/23 tonnes’ film load, where 1320 reels fit into a truck. This represents a 3.67% reduction of transportation weight. The thinner cores would allow 132,000m more film per truck, for a transport cost savings of €0.003/kg.

Finnemore sees thin cores being an intermediary step and the ultimate goal is to produce reels of stretch wrap without the need for any cores. His company, along with competitors Colines (Nibbia, Italy), Dolci Extrusion (Milan, Italy), and SML (Lenzing, Austria) are all working together with Syncro (Busto Arsizio, Italy) to develop coreless winding that could be used on existing and new winding equipment. Gabriele Caccia, managing director of Syncro, says the past two years of R&D has produced its latest development, the patented Easycoreless technology introduced at the Plast 09 show in Milan, which has already been tested for what soon will be offered by the partners on new equipment and retrofitting on installed machines.

The proprietary rotating shafts have up to 250 expanding and contracting parts to wind, then deliver a wound film roll from the shaft; they are able to convert to winding with thin-walled cores or regular thickness cores as well, Caccia says.

Development proceeds on the other side of the Atlantic as well, and at last month’s NPE, Canada-based Cooper Machine & Tool (Concord, ON) was talking about its turret coreless winder. The winder is said to be fully automatic and winds coreless rolls of perforated tear-off bags at up to 20 cycles/minute, claimed to double traditional coreless winder speeds. Operators can adjust the winding width individually on both sides and on the fly. Also, NO.EL Industrial Automation (San Pietro Mosezzo, Italy), as reported in our August 2008 issue (p. 41), will import its coreless rewinding equipment to North America. —Robert Colvin