ORKELLJUNGA, Sweden – For more than 50 years, Åsljunga Pallen AB has produced pallets and crates to serve markets in southern Sweden. This third-generation company relies on a mix of robotics and automation to give the facility flexibility, efficiency and strong quality control with the minimal workforce required.
Due to the expense involved with human labor in Sweden, Åsljunga Pallen has deployed robots in its pallet manufacturing operation as well as a highly automated Corali nailing machine.
Stefan Nilsson, chief executive officer of Åsljunga Pallen, said, “We use the robotic line for short runs because the changeover time is much shorter, about 20 minutes or less compared to 30 minutes to 1.5 hours for the Corali line.” Also, robotics saves in staff costs, which can be very expensive in Europe. Nilsson added, “The robotic line saves the staff costs of about four workers.”
Robotic Solutions Save Time, Reduce Labor and Improve Operational Flexibility
Åsljunga Pallen has chosen robotic technology sold by Jointec AB, a Swedish pallet equipment supplier specializing in highly automated and unique systems. Jointec has deployed Yaskawa Motoman robots in 20 pallet systems across Europe to assist in everything from basic pallet nailing to pallet dismantling and pallet repair as well as other pallet handling actions.
Having seen this technology up close, it is truly amazing what robots can do. One recent development by Jointec is a patented technology called the No Coil Nailing (NCN) system, which allows for automatically blowing multiple types of nails into nail guns, eliminating manual reloading of nails. The nail feeder can deliver up to 80 nails per minute.
Robots can handle tough three dimensional tasks that basic automation can’t efficiently do, such as dismantling a block pallet or positioning a number of boards in unusual patterns. Robots can be programed to produce or repair a wide variety of pallet types, which can significantly reduce changeover times compared to basic automated systems without robotics.
Karl-Johan Berg of Jointec said that he tries to make sure the payback period is two years or so when designing a robotic system. This is possible because people are very expensive in Scandinavia. Although people may not be as expensive in the United States as Europe, that is starting to change with the onset of Obamacare and tougher fines for workplace safety violations and other employee-related costs. Unlike human counterparts, robots always show up to work and don’t take breaks. Also, robots tend to have less breakage than more conventional automation, such as a normal nailing line. Robots are best deployed in functions where there is a lot of repetitive work and little downtime to ensure that the machines are always working and not sitting idle.
From log to finished pallets and crates, Åsljunga Pallen ensures quality by controlling the process at its own plant. It produces about 1.2 million units per year ranging from the common Europallet to specialty sizes.
Control the Entire Process
A key for Åsljunga Pallen is its vertical integration as it works with a tightly controlled group of log suppliers and processes all of its material at its own sawmill, heat treating operation and pallet production facility.
“Åsljunga Pallen can through our own sawmill ensure quality through every stage which we see as an important part of our service work. All wood that is cut and used in the company undergoes a drying process according to ISPM-15,” said Nilsson. As a third-generation family business, Åsljunga Pallen is committed to maintaining its reputation for quality.
It all starts with logs being cut to length in the forests by select loggers. When logs arrive at the Åsljunga Pallen, each delivery is inspected and then sorted by log size. The log sortation process used to be done by human operators. Now the entire operation is done automatically by Keba scanners that measure the size of the log and sort them into the proper bin after each log has gone through an ABB metal detector. The sorting line is supplied by Brodbeck, a Danish company.
The Åsljunga Pallen sawmill is designed with a mainline split in two separate lines for the center blocks. The sawline from Ari-Vislanda is made for logs in short lengths up to 3-9 meters. Main length is 2-5 meters suitable for EUR-pallet sized boards. The log is processed through a chipper and two sideboards are cut, this two-sided block is turned and the same procedure is repeated in the next machine group. The four-sided block is split with a Soderhamn Bandsaw to the chosen dimension. The blocks are sorted after dimension and designated to one of two multi-ripsaws, one an A Costa brand and the other an Ari Vislanda.
The boards are cut to length and packages are ready for the kilns without further sorting. These packages are presented as is to the nailing machines. The quality of the logs and the proper processing of the material into lumber is critical since poor quality boards can cause problems for robots. The line is manufactured for short length pallet logs, and the reason for two multi-ripsaws is the great number of boards which have to be cut and stacked directly in the flow.
Nilsson explained, “It can be difficult to get wood. We like 17 cm and up material (7 inches and up). The quality of boards can impact the automation with robots.”
Nilsson further commented that the current sawmill design is the only real bottleneck in his operation, and he would like to install a new system in the future. He said, “We are looking at a system for processing bigger logs separately to improve the yield in logs larger than 450 mm. Separating the larger logs from the smaller will also increase the capacity in the existing line.”
The facility is heated using residual bark from its operations while sawdust is sold for wooden pellets for heating. The chips are for pulp production. All the wood used to produce pallets and packaging are heated in its two Valutec dry kilns. This allows Åsljunga Pallen to produce ISPM-15 compliant pallets from all of its material.
Three Distinct Pallet Manufacturing Lines
Thanks to its three unique automated pallet nailing lines, Åsljunga Pallen can efficiently produce a wide variety of pallets with minimal staff. EUR-pallets are manufactured on a Jasonmaskiner machine that dates back to the 1970s. It can produce about 280 EUR-pallets per hour. This system is a conventional nailing machine using hydraulics to press the nails in the pallets.
The most versatile machine that Åsljunga Pallen has is its Corali consisting of a deck machine and three nailing stations to complete the pallet making process. The line is capable of making all types of pallets from 600×800 – 1500×1500 mm. Nilsson explained, “The Corali can make a wider variety of pallet types than the robotic system from Jointec. It also can produce pallets about twice as fast. The Jointec robotic system is a complement to the Corali line due to its quick changeover capabilities and labor saving advantages for small runs.”
The Jointec line is used for orders between 200-2,000 pallets. Nilsson commented, “The Jointec robotic line saves staff, about four workers. It can produce about 3.5 pallets per minute.” When you consider the downtime for the Corali line due to maintenance and switchover between designs the Jointec line has a 20% efficiency advantage. The yield (uptime of the line) is much better in the robotic line, according to Nilsson.
Åsljunga Pallen added the robotic line about three years ago and has been pleased with the result. Nilsson explained, “The robots are exact with tolerances. Robots always come to the point where we wish.” Robotics has helped Åsljunga Pallen improve its quality although robotics can pose some unique challenges.
Nilsson said, “With robotics, the biggest challenge was wood and its tolerances.” But software helped Åsljunga Pallen overcome this challenge. The robot line is programmed to keep perfect exterior visual dimensions meaning that deviations of the boards and blocks are turned inside the pallets. Also, cutting precise blocks and boards has helped to make sure the robotic system keeps running.
Nilsson said, “Robots offer a number of advantages. They don’t take up much space and can be configured in various ways to fill unique space. Robots can handle complex tasks that are difficult for more general automated technologies. You have to utilize robots in the right place to make them work.”
Installing robots into a work environment with humans adds another safety consideration to navigate. But the Motoman robots sold by Jointec are designed to shut down if people are detected near the operating robots. Nilsson stated, “The learning curve wasn’t too hard for us at first. Motoman provided a course to help train our staff.”
The Jointec robotic system starts with Delta block cutters that cut blocks to size. These blocks are fed into the robotic line where they are placed in a frame by a robotic arm. Another robotic arm grabs all nine blocks at once while keeping them properly spaced apart. These blocks are then placed on pre-made pallet tops and nailed one section at a time by a three nail gun nailing station. The robot arms move the pallet tops through the nail chucks one section at a time until half of a pallet is completed.
Another robot arm grabs this half-finished pallet and moves it to the second nailing station. Another robot arm picks up three bottom deck boards that are separated into the proper configuration by automated stops. These two robots work together to move the half-finished pallet and the bottom boards through the second nailing station. Each section is nailed once as three nail guns finish the bottom deck assembly. Another robot grabs the finished pallet and puts it on a conveyor including the corner cutter, where a stacker or robot can be used to create pallet stacks.
The Jointec system uses bulk nails that are fed into the nail chucks. Pallets are produced with only one supervisor looking over the entire system and one operator on the top deck manufacturing line.
Nilsson said that the Jointec line saves significant labor cost compared to producing the pallets by hand in jigs. Åsljunga Pallen has gone from two shifts of manual production to one shift with higher production thanks to the robots. Also, the robots can produce a greater variety of pallets than the semi-automatic process that the company used to deploy.
Local Market Considerations
The European pallet market is fairly mature and is very competitive. Åsljunga Pallen uses only softwoods, which is a very common practice in some parts of Europe. It produces pallets painted green for the Pallet Return System (PRS), which is a pallet pool for the polymers industry. Åsljunga Pallen manufactures more specialty pallets than anything else although it does make a lot of EUR-pallets too. But that has become a very competitive market according to Nilsson. He explained, “The competition is very hard because many companies have specialized in making the Europallet.”
Nilsson said that companies in Germany as well as Eastern Europe have become his company’s greatest competitors in the Europallet sector.
Åsljunga Pallen has 55 employees that produce more than 1.3 million pallets per year in addition to specialty crating and wooden packaging. Nilsson credited his staff with helping Åsljunga Pallen thrive in a very competitive market. Also, the right blend of machinery and automation has allowed Åsljunga Pallen to boost productivity without having to add much personnel. And that is the key driver for many pallet companies around the globe looking toward the future.
For more information about Jointec AB call Karl-Johan Berg at +46 70 633 9717 or email: info@jointec.se
