Injection molded plastic parts are used in a wide variety of areas and can have anything from simple flat geometries to highly complex curved geometries. When manufacturing these components, the aim is to automate the production process as much as possible in order to minimize cycle times, reduce costs and ensure uniform quality standards. The automatic removal of the finished components plays a key role here and places high demands on the design of the end-of-arm tools (EOATs).

With the acquisition of SAS and Feba Automation, Piab can offer grippers based on standard square profiles as well as round profiles, depending on the component and customer requirements.

Rectangular profiles are preferred for simple or flat component geometries that are removed from the core side. With this type of removal, the component is removed from the mold using ejector systems. For removal, the component can be picked up by the ejector pins or ejector units with simple components such as suction cups or folding fingers and sprue tongs. Fully automatic removal with sprue separation is possible.

Piab's gripper concept based on round profiles is particularly useful for complex, geometrically complex components, such as those commonly used in the automotive industry for bumpers, which are removed from the die side - i.e. the nozzle side. It allows greater flexibility with regard to the positioning of the components on the gripper. The lower weight of the gripper protects the robot's mechanics and reduces its susceptibility to faults. Accordingly, higher payloads or the use of a smaller robot are possible.

"With die-side removal, in contrast to core-side removal, the gripper removes the part from the mold. Here, the gripper must actively deform the component in the meantime using gripper lifting units and movable vacuum units in order to be able to demold it from the undercuts on the tool side. It is essential to avoid white breakage or scratches on the A-surface of the component, the visible side of the part, as they remain visible after further process steps such as painting or electroplating and are often even more visible and therefore fail quality control processes," explains Felix Geuecke, Managing Director of Piab's Robotic Gripping production site in Schmallenberg.

Chrome plating afterwards
Another special requirement is the removal of components that still need to be electroplated, i.e. chrome-plated, afterwards - any imprint or the smallest scratch on the chrome-plated surface would be immediately visible. Piab has developed a special gripper for the automated removal of such injection-molded parts. This gripper docks onto the injection mold via special centering units. Flocked contour pieces, which correspond to the negative shape of the component, pick up the component gently and carefully. The component is held in the negative mold by gripper fingers that only touch the component on the non-visible side. In this way, even the most sensitive components can be handled easily and automatically with consistently high quality. as