Activities at the end of the line are coming under greater scrutiny as costs and efficiencies are sought throughout the factory. One area that holds significant potential for cost saving is that of stretch wrapping.
According to GVPS, stretch wrap film remains by far the most common method of stabilising and securing a pallet load. Applying multiple layers of film, either by hand or with automated machines, around the packages on a pallet, not only secures the load but also protects it from exposure to dust, moisture and other contaminants.
However, in a recent paper, GVPS points out that perhaps because stretch wrap is so commonly used, few companies monitor closely how efficiently they are using it. As a result, businesses could be overlooking an area of their supply chain operation where significant cost savings can be made.
“Warehouse managers can tell you precisely how much they are paying for – for example, their forklift truck fleet – but often have no idea what it’s costing them to wrap a pallet,” said Martyn Sumner, who claims that, depending on the type of film and the method used to apply it, the cost differential can be significant.
“Stretch wrap film should stretch by between 150 and 300% of its original length, so a 1,500-metre-long role of stretch wrap film could provide around 6,000 metres of film when applied to a load,” he said. “If the user is, in fact, only getting 5,000 metres from the role, then the cost per pallet wrapped goes up. If, for example, it requires 50 metres of film to wrap an individual pallet, then the price difference between a role of film that stretches to only 5,000 metres instead of 6,000 in a busy warehouse that it is wrapping and shipping 500 pallets a day can be dramatic.”
Performance and maintenance of stretch wrap machines is one cause of the losses, and Sumner points out that as a result of poor maintenance regimes, the gearing that controls the rollers can become slack and the film not stretched to its maximum length.
“Also, it’s common to see Perspex screens covering the control panels of stretch wrap machines,” said Sumner. “These have usually been added to stop operatives absentmindedly interfering with the settings. But, as a result, the equipment’s performance parameters are rarely reprogrammed to suit the film that it’s being applied and therefore optimum efficiency is not achieved.”
Sumner stressed that investing in having equipment serviced by an authorised service engineer at least once a year can bring a rapid return on investment in terms of the price per pallet wrapped.
For pallet wrapping performance, Sumner suggested a test that users of stretch wrap can undertake to ensure that they are achieving the maximum from their film.
“With a felt pen, operators can mark a line on the film, and mark another line 100mm apart,” he said. “Then measure the distance between the two lines after the film has been stretched. Standard pallet wrap film should be capable of stretching by 150%, while power pre-stretch film and super power pre-stretch film will expand by between 250 and 300%. So, the distance between the two lines on a power stretch film should be around 350mm when it has been applied to a pallet.”
Sumner pointed out that the quality of the film being used also has a significant effect on performance, and modern stretch wrap film is becoming thinner and stronger.
“Until recently, pallet wrap machine was 17-20 microns thick for hand-applied film, and around 23 microns thick for machine-applied film,” he said. “Now, machine-applied film is available in 12 micron thickness and it offers greater strength. In some ways, choosing pallet wrapping is a little like putting diesel in your car: specifying premium film is similar to opting for higher grades of fuel; they are slightly more expensive but performance is enhanced. In the same way that higher grade fuel gives more miles per gallon, the newer films will wrap more pallets, which significantly reduces the cost per pallet wrapped.”
© FoodBev Media Ltd 2024