New thermoplastic work cell to test overmolding

LANXESS subsidiary Bond-Laminates GmbH (Brilon, Germany) has begun operation of  a demonstration cell for processing Tepex continuous-fiber-reinforced thermoplastic composites. The cell will form Tepex in a fully automated, near-series process and also allow simultaneous forming and overmolding in a hybrid molding process.

“We plan to use the facility as a platform for transferring technology to customers. We want to familiarize our customers with the strengths of Tepex and how it is processed, as well as supporting the development of innovative components,” explains Ulrich Jecmeniza, applications engineer with Bond-Laminates. In addition, production processes of Tepex customers will be simulated for quality assurance and improvement purposes. Not least, Bond-Laminates aims to use the facility to drive forward its own material development. This new demonstration cell supplements a Technical Service Center facility that LANXESS already operates at its Dormagen, Germany site.

The cell is manufactured by ENGEL AUSTRIA GmbH (Schwertberg, Austria). The Tepex inserts are introduced to the machine using a magazine with separation function, so that various Tepex sections can be processed in a single production run. A highlight of the facility is two pyrometrically-controlled infrared furnaces with a “drawer system” that have been newly developed by ENGEL. These enable the inserts to be heated quickly in an even, material-specific way, without causing any damage to the thermoplastic matrix. An ENGEL six-axis articulated arm robot with vacuum grippers adapted to Tepex takes over the handling of the inserts. “The high speed involved in heating and handling the inserts ensures a high degree of reproducibility for the entire production process, even for very thin-walled components,” says Jecmeniza. The injection molding facility in which the Tepex inserts are shaped and overmolded has a clamping force of 130 metric tons. The maximum projected size for the molded parts is 330 x 280 millimeters, which means that both structural and visible parts in these dimensions can easily be processed. Heat management in the mold can be either isothermal or variothermal as required. Variothermal mold temperature control results in distortion-free, high-gloss surfaces.

The work cell is also equipped with a clamping system and associated grippers for inserts with standardized section sizes. These kinds of sections are used to manufacture the specimens needed for testing to standard requirements in material development or shaping experiments, for example. “The inclusion of both a clamping and a magazine system makes our demonstration cell very flexible and versatile, enabling it to cover a
broad range of applications,” says Jecmeniza.

The new facility will initially be fitted with a mold for the sporting goods industry. The relevant component consists of a Tepex section with TPU matrix that is overmolded with TPU on both sides after shaping. Other near-series molds will soon be available, adds Jecmeniza: “This will enable us to cover applications for our most important customer groups – that is to say the automobile, consumer electronics and sports goods industries.”

The hybrid molding process is arousing considerable interest worldwide because it enables the cost-effective production of very lightweight, but still immensely strong structural components in large to extremely large volumes. Numerous international manufacturers of plastics machines have therefore now developed appropriate production plants and presented these at trade fairs. Manufacturers of other components in the hybrid molding process – such as furnaces, fully automated handling systems, testing technology or molds – are also hard at work, which opens up a wide range of possibilities for processors when they are selecting equipment.