Auto highlights from Engel

Engel (W1303) is presenting eight innovative applications at NPE 2015 from March 23 to 27 in Orlando, Florida, including two from the automotive sector.

The machine builder and its partner ZF-Friedrichshafen (Germany) will present a geometrically optimized and stress-resistant plastic brake pedal that also made its presence known at the Composites Europe show in October in Germany. The concept for manufacturing a hybrid, brake pedal from thermoplastic fabric received the Composite Innovations Award in 2011, and has been consistently enhanced by ZF since then.

Engel will be offering a glimpse into the efficiency of the new manufacturing process at its stand at the exhibition. Using a vertical Engel insert 1050H/230 single US injection molding machine with an Engel easix multi-axis industrial robot and infrared oven, a continuous-fiber-reinforced thermoplastic semi-finished product (known as thermoplastic fabric) will be heated, pre-formed in a mold and immediately overmolded with polyamide. The system produces ready-to-fit components; no cutting is necessary.

Thermoplastic fabric reportedly offers offer high strength and rigidity. In addition, the product developers at ZF have adapted the layer structure to the component load when designing the brake pedal. This enabled the component weight to be reduced by around 30% compared to conventional steel brake pedals—without impairing load-bearing capacity. In addition, the lightweight construction method makes many conventional manufacturing process steps unnecessary, thereby increasing productivity and cutting unit costs.
The control unit of the Engel easix multi-axis robot is fully integrated into the control unit of the injection molding machine. As a result, besides making it easy to operate and program the robot, the movements of the machine and robot are precisely coordinated with each other. Since the robot has access to the machine parameters, the gripper can enter the mold area during the opening movement, which in turn significantly reduces cycle times. Synchronous movements are particularly important when it comes to handling pre-heated semi-finished products, because semi-finished products must not be allowed to cool too rapidly in advance of the forming process. Another factor that determines quality in this application is the high positional accuracy of the multi-axis robot.

Dual technology integration opens new horizons
Process integration leads to greater efficiency, safety and quality according to Engel. Using an Engel duo 2550/610 US injection molding machine with an integrated Engel viper 20 robot, Engel will demonstrate the fact that not only can process steps upstream or downstream of the injection molding machine be combined, but also different process technologies.

To produce center console components molded from a polycarbonate-ABS (PC-ABS) alloy, Engel will combine two technologies: Engel foammelt (the MuCell foam injection molding process developed by Trexel (Wilmington, MA) and the variothermal injection molding process from Roctool (Le Bourget du Lac, France). The goal is to produce thin-walled parts with very high surface quality along with the excellent reproduction of fine structure using just a single injection molding step.

To demonstrate the versatility of this combination of processes, the part being molded will have varying wall thicknesses and surface structures. Thanks to Engel foammelt, the cavity is completely filled, including the undercuts, and the component has no sink marks after cooling. At the same time, the Roctool technology provides a high-gloss finish in piano black. Apart from applications aimed at car interiors, this dual technology integration opens up new horizons for efficiency and quality in white goods and household products.

On exhibit for the first time in North America, this system solution introduces the new design of the Engel duo injection molding machine. Users will benefit in particular from improved ergonomics thanks to a lower operating height providing easier access to the mold and nozzle area. Other features of the new machine generation include roller rail systems for the moving platen, energy-efficient mold movement and a much cleaner mold area thanks to the removal of central lubrication.