Ultra-high molecular weight polyethylene's very low friction helps keep packages moving at DHL hubs in the US and in Europe
Cladding in low-friction ultra-high molecular weight polyethylene has solved movement problems on package transport chutes at international express courier company DHL's sorting centres in the USA and in Europe. Tivar DrySlide PE-UHMW also took care of retrofitting many of the chutes.
DHL initially had the chutes installed in its hubs at Wilmington, Ohio airport and at East Midlands airport near Nottingham in England. DHL decided to use Tivar DrySlide because packages often were stuck on its original unlined metallic chutes, especially when going around right-angled corners. Alternative solutions the company tested, including PTFE, wore off quickly because of their poor abrasion resistance. DHL had also been lubricating the chutes by spraying them with silicon or graphite, but was looking for a more environment-friendly solution that would not contaminate the parcels, nor require ongoing maintenance, cleaning and downtime.
''We at DHL save thousands of dollars each month in reduced manning needs from package jams, material costs, operational run time and reduced customer damage,'' says Daniel Schlake, a senior project manager with DHL US. ''This is thanks to the improved package flow on the miles of conveyors, chutes and slides lined with Quadrant EPP's Tivar DrySlide used to move DHL customer packages. ven damp boxes and parcels covered in shrink-wrap now move freely.''
Following the positive experience DHL enjoyed at Wilmington and East Midlands, Quadrant EPP has also installed a trial chute in the DHL hub at Brussels airport. ''The people from DHL Belgium had tested lot of potentially promising materials without positive results in the past. They were very sceptical when we first presented Tivar, despite the positive US and UK experiences,'' says Jan Van Ysacker, sales engineer for Quadrant EPP in Belgium.
''So we suggested we install one critical chute, with a 90° corner, as a practical test. Supervisors say the effect of the material could be noticed from the first night in operation.'' In the meantime, he says, DHL has tested the material in other critical positions with similarly positive results.
Specialist companies normally do cladding of the chutes (new installations and retrofits). For the Brussels airport trial, Quadrant EPP installed the cladding itself, cutting the sheets to size, and simply drilling fixing holes to fix them in place on the chute. For European customers, Quadrant EPP produces sheets between 6 and 50mm thick in dimensions of 1 by 2m at its plant in Vreden, Germany.
With immediate results, no drop-off in performance over time and no maintenance requirements, DHL Belgium is now convinced by Quadrant EPP's solution. Other critically shaped chutes should shortly be equipped. For the hubs at Wilmington in the US and East Midlands in England, the installation of the new material has already become a systematic requirement when installing new chutes.
Although Tivar DrySlide is a plastic, it has electrostatic dissipation properties, so it works well in dusty environments. It has a high abrasion resistance, a high impact resistance and it also helps reduce noise. There are no wet lubricants to mar packages (dry lubricants are incorporated into the sheet during production to give it a 0.08 coefficient of friction, the lowest of any of Quadrant EPP's Tivar PE-UHMW products), and the material does not corrode or degrade in any way. It is very hard (Shore D 60), moisture absorption is virtually zero, which is key for this application, and the material is stabilized against UV radiation.
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