Robots carry out work that would not be economically viable in a high wage economy. Robots increase productivity. They speed up production time and improve quality. Please find examples below:
Kawasaki, Germany - IFR-Partner
Sustainable automation of pallet production at the Wulf Paletten company
The medium-sized Wulf Paletten GmbH & Co. KG Company has been using robots by the Kawasaki Robotics GmbH for 5 years now in its robot-assisted pallet production line. The company has 25 employees and produces pallets with different and, most notably, customized dimensions in two-shift operation. Production starts from batch sizes of one pallet and is based on a random manufacturing principle. Up to 3,000 finished pallets leave the company at the end of each production day.
Due to the general pricing pressure in the pallet manufacuring segment, the company did not have the chance to work with a higher number of employees in the market niche of special pallet production. This would have been necessary in combination with conventional manufacturing for customized pallets, but would be impossible with regard to the given prices. In order to ensure a stable position of the company, the route led to production automation, keeping the same number of employees. At the same time, the in-house machine park was extended and thus it was possible to provide new jobs outside pallet production, with increasing production capacity and utilization. Six employees per shift work in actual manufacturing. Their main work is to load the sawing unit and to provide a safe and sustainable transfer between this production system and the robot-assisted section.
Two Kawasaki robots are used in the Wulf Paletten production line and they are significantly involved in ensuring smooth operations and production cycles. The first robot type ZX165U in the production flow is responible for transferring the top layers into the nailing machine for the purpose of downstream nailing, and simultaneously fills an intermediate buffer to minimize waiting time. The second robot type ZD130S stacks the pallets at the discharge end of the plant in a nested arrangement and ready for dispatch. Both robots are equipped with automatically adjustable grippers which are adapted automatically, infinitely and without the need for stopping the process.
Robot programming is done by variable programming. In the actual robot AS program (AS is Kawasaki's own programming language), variables are registered and stored as place markers for the individual positions of the different pallet sizes. They are replaced automatically by real position data according to the selected list of variables. Thus, an extremely fast product change without the need for any set-up operations ("on the fly") is made possible.
"I was sure that we were able to arrange this even more effectively though", states Frank Theisen, technical manager at Wulff Paletten. For him, it was important to avoid even those short plant downtimes occurring during manual adjustment in case of altered production data. "Small lot sizes and individual, customized pallet dimensions are our specialty. The downtimes ocurring when readjusting the variables carry the more weight the smaller the individual lots are. However, this should set no limits for us", says Frank Theisen.
Little by litte, he elaborated all installation details and designed a bar code system for his pallets. All required data as well as variables as length, width, number and orientation of skids, and, if required, information like additionally putting on a plastic foil on the finished pallet, are stored in these codes. A bar code is allocated to each job and the job is transferred to the saw in the first step. The code is read and the sawing plant is automatically matched by this. The code is passed on to the pallet manufacturing plant together with the sawn individual parts and read again there. This second code reading operation is mandatory. The grippers of the two robots as well as the foil supply operation and the setting widths of the nailing machine are matched and readjusted automatically. The pallet manufacting operation is started after this.
Subsequent to taking the bar code via TCP/IP, the data are transmitted to a Siemens S7 PLC. The data are further transmitted via Profibus to the robot controllers integrated into the overall system as slave modules.
In addition to an extremely quick plant readjustment, Frank Theisen has concurrently eliminated misentries as a source of error and thus reduced the production error rate almost down to zero. This saves both time and material and minimizes the incurred manufacturing costs.
"The Kawasaki robots are the most stable plant components. We are sure that we made a good choice", states Theisen as regards his plant structure.
All told, the conversion of production resulting in a high degree of automation together with the courage to show self-initiative has brought flexibility increased to the maximum to the Wulf Paletten GmbH & Co. KG - just what the company needs for steady and further-proof operations in its market niche.