Complex technologies have to be easy to operate to become accepted – for example when producing fibre-reinforced lightweight components.

KraussMaffei has perfected its FiberForm process even further and will present a close-to-production manufacturing cell at the K 2016 trade show in Düsseldorf, where visitors can observe the manufacturing of a prototype component for the automotive industry.

Significantly improved mechanical properties

FiberForm entails the thermoforming and over-moulding of organic sheets, which are plate-shaped semi-finished products with continuous fibres made of glass, carbon or aramid embedded in a thermoplastic matrix made of polyamide (PA), polypropylene (PP) or other matrix systems.

In this process, these semi-finished products are first heated, reshaped in the injection mould and then back-injected with a fibre-reinforced polymer.

“Parts with integrated organic sheets have significantly better mechanical properties compared to those that are purely composed of shortfiber-reinforced injection moulding material. For example, manufacturing complex structural components results in completely new design options,” explains Dr. Hans Ulrich Golz, president of the Injection Molding Machinery segment of the KraussMaffei Group and Managing Director of KraussMaffei.

A significant part of the process is heating the organic sheet, because overheating the organic sheet leads to thermal degradation of the matrix and, therefore, to scrap. Thus, KraussMaffei developed a control process for infrared emitters that is fully integrated into the MC6 machine control system.

Here, the new control process not only enables a fast heating process without exceeding the set temperature, but also makes it possible to check the current heating curves in process data acquisition. Finally, heating time and actual temperatures are stored for each individual component – important for customers who have to produce safety-related articles and document all process steps.

Intelligent automation concept saves cycle time

Another new innovation concerns automation within the manufacturing cell. Within the protective housing of the CX-300 machine, two LRX-250 linear robots were installed, which are coupled on a shared Z-axis.

They do something that may be seen as inefficient at first glance: they transfer the organic sheet. Actually, this trick saves cycle time, because the semifinished product is heated and the finished component is removed simultaneously.

Robot 1 picks up the organic sheet and hands it to robot 2. Then, the robot moves to the position for component demoulding. Robot 2 feeds the semifinished product into the infrared oven and brings it into the injection mould after heating it. From there, robot 1 removes the finished part.

“Compared to earlier versions of automation, the process was able to be harmoniseded even further. This improved the process capability even more,” explains Thomas Marufke, Managing Director of Automation Technology at KraussMaffei.

Overall, the revised FiberForm system provides its users with extremely robust processes, high availability and the efficiency required for high-volume series projects. Development partners for the project included Lanxess Deutschland GmbH (Tepex organic sheets), Bond-Laminates GmbH and Christian Karl Siebenwurst GmbH & Co. KG.

Catch KraussMaffei at K 2016, Hall 15, B27/C24/C27/D24