DSV secures up to 140 pallets an hour using a single packaging line
DSV encountered a specific problem when looking for a new machine for securing pallets. During peak times, the machine had to process up to 140 pallets per hour. However, thanks to an innovative design, based on a Tallpack stretch hood machine and sensor and positioning technology by Leuze, it was possible to create a super-fast packaging line.
Tallpack modified the machine whereby it is now able to simultaneously deal with three stretch hood formats.
Until three years ago, trucks that left DSV's warehouse in Oostrum, to travel to Moscow, encountered many hold ups at the Russian border. The inspections were so stringent that Russian customs officials actually climbed inside trailers to literally measure pallet dimensions to see if they were consistent with measurements filled in on freight documents. These measurements had been calculated using the product specifications in DSV's warehouse management system. “And they always managed to find something. There was always a product with a new packaging, for which the specifications were not yet in our system. And each abnormality was accompanied by a lot of problems”, states site manager Rob Bech of DSV in Oostrum (a stone's throw from Venray).
The problems that DSV experienced at the Russian border were an important reason for investing in a new packaging line with an integrated measurement and weighing system. In 2007, Bech started to look for a suitable solution that could help to create a less labour-intensive and more reliable process. “Such investments are expensive and must thus be cost-efficient. That is why we preferred a fully automatic line”, states Bech.
For a long time, pallets in Oostrum were secured via a semi-automatic process. DSV possessed four banding machines that could be used to tie one or more plastic straps around the pallet. Machines were primarily operated manually, and despatch labels were also manually applied once the plastic straps had been applied. This was a labour-intensive process, explains Bech. “During peak moments, we sometimes had three people standing next to each strapping machine.”
These peak moments were an important criterion when searching for a new packaging machine. The new line needed the capacity to process up to 140 pallets per hour. In addition, DSV wanted to switch from a strap-based method to one that uses wrapping film. “This helps to keep out moisture and dust”, states Bech.
The search led DSV to a stretch hood machine manufactured by Tallpack. This machine automatically slides a hood of stretch film over the pallet from above. When the machine releases the hood, the film shrinks and prevents the load from moving. Because many different pallet formats are encountered in the warehouse, which vary between 60×40 and 140×120 centimetres, it was necessary to implement several film formats. “Analysis showed that we could function with three different stretch hood formats. Tallpack has now modified the machine so it can automatically implement all three stretch hood formats”, says Bech.
Infra-red safety light curtain
The requested capacity of 140 pallets per hour required a comprehensive packaging line with an innovative design. And even the pallet supply needed to be changed, where a simple roller conveyor with one drop position was insufficient. This meant fork-lift trucks were left waiting in line.
Thanks to the expertise of Leuze electronic, Tallpack was able to develop a packaging line with four drop positions. A trolley then drives from left to right behind the four roller conveyors, to transport the pallets from the drop positions to the central packaging line. This involves the trolley using Leuze's bar code positioning system. This transport system is able to accurately determine positions thanks to a long row of bar codes at four drop positions and a bar code scanner under the trolley.
Once the pallet has been dropped on the central roller conveyor, the pallet is centred from both sides using two beams. At the same time, the width of the pallet is measured using sensors next to the roller conveyor, which measure the distance between pallet and the beams. The pallet then passes an infra-red safety light curtain, which measures the length and height of the pallet based on the number of covered light beams. The weight of the pallet is also registered without stopping it.
"DSV-Tallpack The trolley is able to accurately determine the position thanks to Leuze electronic's bar code positioning system."
The next step involves scanning the unique bar codes on each pallet. Because the bar code can be located anywhere on the pallet, two oscillating laser scanners have been placed on both sides of the line, whereby bar codes can be scanned on pallets up to 2.40 metres high. If a bar code is not detected, the pallet will be automatically rotated by ninety degrees.
The stretch hood machine only comes into action once the dimensions, weight and unique bar code have been confirmed. The machine uses the dimensions to automatically select the correct stretch hood format, as well as the height at which the film must be cut and sealed. Thereafter, an applicator automatically sticks the dispatch label on the pallet, which features the address details, dimensions and weight.
Finally, the pallet is transported to one of the four collection positions, which have the same set-up as the drop positions, including trolley and bar code positioning system. The lamp is an eye-catching feature, which comes on when the entire line is full and no new pallets can be processed. When the light is on, this serves as a signal to fork-lift truck drivers to quickly empty the line to create more space.
After three years, Bech is still pleased with his packaging line. And there has been hardly no downtime during these years. “We have a maintenance contract, whereby major maintenance is carried out each summer. In addition, we also have several crucial components in stock. Each shift has two people who are able to resolve malfunctions”, explains Bech.
The advantages mentioned by Bech include a shorter process time, improved quality and improved efficiency. An operator is no longer necessary, let alone three. The site manager is thus also very satisfied by the effectiveness of the investment. “This system is able to pay for itself in four years' time. And as far as problems at the Russian border are concerned, they have now been resolved.”
Who, what, why?
DSV Solutions is logistics service provider with 13 warehouses in the Netherlands, of which Oostrum is one of the largest with 65,000 m2. This warehouse mainly houses goods for Xerox. Around 35 sea containers arrive every day, which feature multi-functional printers and copiers, as well as accessories like toners and power leads.
A new automated packaging line has been installed in Oostrum, with a stretch hood machine by Tallpack and sensor and positioning technology by Leuze electronic.
The new packaging line has replaced four semi-automatic lines and has resulted in improved process times, improved quality and higher efficiency.