A sophisticated production system needs to be created: injection molding with various metal inserts and downstream in-line quality checks for flashing to ensure the seal is good. Such a project can involve contacts with many companies. Or just one, if you take advantage of the system expertise of KraussMaffei. The automotive supplier POLYTEC PLASTICS GmbH & Co KG in Lohne, Germany, a company of the POLYTEC GROUP, has done just that and is thrilled about the 25 percent efficiency increase
The POLYTEC GROUP, which has about 4200 employees at 25 locations in 12 countries, manufactures components for the automotive industry and, in the process, has gained a good deal of expertise in the area of the engine bay. The technological demand in the powertrain area is substantially higher than in the interior, because the complex interaction of temperature resistance, weight, acoustic capacity and modular design in the narrow engine bay repeatedly present great challenges to the development and production of functional plastic parts. POLYTEC operates as a successful development partner and system provider for large automakers; the largest customer is the VW Group.
At the location in Lohne in Lower Saxony, another production cell was needed for manufacturing oil pans, but a significantly higher productivity was desired compared to their existing system. Therefore, the requirements specifications asked for a high degree of automation combined with low space requirements and robust processes. Accordingly, the KraussMaffei project team collaborated with the customer POLYTEC to develop a process in which six-axis robots feed and load various sleeves as well as threaded pins and bushings, and then prepare them on a rotary table with correct mold spacing.There they are taken over by a LRX-1000 linear robot, which puts them into the mold, which is installed in a GX 450/4300 from KraussMaffei. The LRX removes the finished oil pan, the sprue is separated and the component is passed on to another six-axes robot. An in-line camera check is carried out there. All sleeves and bushings are checked to make sure they are present and to detect flashing. The latter could impair the seal of the oil pan. Then the OK parts are taken by a conveyor belt with a cooling section to the area for further processing.
The concept was appealing—and so was the flexibility of the KraussMaffei employees because, as so often, the timeline was critical. Concerning this, Michael Benzien, Head of Purchasing at POLYTEC PLASTICS, said, “the long procurement times on the market are a big challenge for us. We need providers with pro-active sales, to whom we can say ‘We are planning a new system concept; start thinking about potential approaches to implementing it,’ because by the time we are able to set the specific order it is usually too late for the SoP (Start of Production) defined by the customer. KraussMaffei supported us greatly in this.”
Now the system runs in three-shift operation and autonomously for up to three hours. The availability is at 96 percent; the increased productivity we hoped for has been realized. Jörg Kippermann, Head of Operations at POLYTEC PLASTICS explains, “our productivity has increased by 25 percent.” The optimum coordination of all individual components is a major factor here. They work together like clockwork. Even the control panel of the PLC control system was adapted to the design of the MC6 control system to give the user a comprehensive feeling of control.
In the case of such complex manufacturing sequences, the injection molding itself represents just one—however critical—step, which is why the requirements for employees change. Gerd Tönjes from Launch Management at POLYTEC PLASTICS explains, “we are increasingly requiring our colleagues to understand the complex processes of injection molding, and when it comes to readjustments we now rely more on mechatronics engineers and electronics engineers than just on process engineers in a strict sense. This is because the productivity of the systems can be optimally utilized only if you are able to understand and control the entire sequence.”
And what is extremely productive awakens the desire for more. The logical consequence: the successful model will be multiplied. At the POLYTEC location in Tianjin in China, the same production line is currently being built—without sacrificing the automation, as one might expect in view of lower employee wages. The desire for process reliability and guaranteed function at POLYTEC exceeds the striving for savings, especially since it pays when in-house technicians worldwide find a trusted standard. The oil pan is delivered to a global model platform, and the demand for international delivery capability placed by the OEM on its first-tier POLYTEC is also conveyed to the machine partner. Michael Benzien explains, “for us it was extremely important that KraussMaffei is globally represented with manufacturing and support. In the future, processes are to be jointly developed with the employee team in Tianjin as well as in Lohne, and then be directly installed locally. For that POLYTEC needs partners who are positioned just as strongly in the target markets.”
Hiltrud Wilke-Bröring from Central Purchasing Investments knows that the collaboration between POLYTEC and KraussMaffei has already stood the test of time since the company was founded in the 1980s. “We particularly value the good service and the procurement of spare parts at very short notice. With that KraussMaffei provides a clear added value.”