In addition to the Openair-Plasma Systems for surface treatment Plasmatreat GmbH also offers individual production cells with automated solutions to ensure seamless integration in the production lines. Plasma Treatment Units (PTU) are tailored to the customer's technical processes and are equipped with various operating options. Here Plasmatreat offers the solution of coordinated process automation combining efficient surface treatment and a perfectly coordinated handling of assemblies and components.
"Especially for the production of large quantities which require precise surface treatment of specific contours or for the ongoing receiving and handing over of components in a continuous production process we are repeatedly asked for ready to use production cells", explains Joachim Schüßler, Sales Manager of Plasmatreat GmbH. In most cases this involves repeatable processes that are carried out fully or semi-automatically. The focus lies on surface treatment using Openair-Plasma in combination with a wide variety of automation tools. "The customer or the project determines which systems are to be installed in our PTUs. Within a project, for example, cycle times, quantities and pure processing periods or the budget are defined. These specifications ultimately determine how a system is put together," Schüßler continues. The feeding and handling of the parts can thus be implemented using a variety of systems, such as robots, inline conveyor and pin chain systems, workpiece carriers, rotary tables.
Plasmatreat is currently installing a production cell with the external dimensions 1200x1200x2100mm (width × depth × height) for the automotive industry in which various connector strips are being handled. These components are installed in commercial vehicles, for example in engine or transmission control systems. To manufacture these control units, the polyamide housing of the connector strip must be pre-treated so that a silicone sealant can later adhere to it. For this purpose, the plastic surface is cleaned and activated by using Openair-Plasma. A RD1004 rotary plasma jet is used for this purpose, which generates cold plasma. This plasma jet is particularly suitable for thermally sensitive and geometrically complex surfaces and materials. The patented rotation principle distributes the plasma effect evenly over the materials to be treated. In the process, the surface is briefly and pulsed coated several times, which is a very effective form of cleaning and activation, while at the same time minimizing the heat input.
"Particularly exciting about this project is the fact that a total of 10 different types of connector strips are processed in this PTU within a single type production process. In most variants, the component is guided to the jet by a robot, but in some variants also the jet is guided to the component. This can lead to mix-ups during conversions. In order to rule this out in advance, we provided the customer with a comprehensive monitoring concept: Using RFID transponder and an integrated camera, the system automatically selects which program, which gripper and tray and which jet head must be used and assembled, in order to process the specific type of connector. Our software provides direct information if a setting or component does not match the selected connectors strips program," Schüßler describes the challenge.
The sequence defined by the customer requires the production staff to remove the connectors strips from a tray and place them individually on a rotary table which transports the strips into the production cell. There, the connectors strips are picked up by the robot and held in the plasma jet with the side of the component to be processed. After processing the component, it is placed back on the rotary table and rotated out of the production cell. The cycle time is about 15 seconds per component. "Instead of the employee at the machine, we can integrate another robot to take care of the filling of the system. The same applies to the rotary table, which can be exchanged for a belt system or similar. It is also possible to move the jet system, depending on whether this is necessary for a production process. This enables us to offer highly flexible Openair-Plasma Systems that are perfectly tailored to customer requirements," Schüßler continues.