Automated production processes for molded rubber parts
Injection Transfer Molding (ITM) has several practical advantages: with the right molded parts, the process impresses in particular with its high output in comparison to conventional molded part presses and “pure” injection molding. In comparison to pure injection molding, Injection Transfer Molding allows significantly more nests to be accommodated on the tool plate for many molded rubber items. With the right process management in the filling unit and the transfer pot and with quick transfer in a strong, fast-action clamping unit, the vulcanization time is hardly any longer than that of injection molding.
Production and quality assurance/documentation processes that are ideally suited to the automation requirements of Industry 4.0 have long been a reality with the hardware and software systems offered by WICKERT.
The ITM process provides benefits in terms of cost-effectiveness and quality. A tool system or attachment is often added to allow burr-free production of the items, for example. This is closely linked to the use of tempered or “hot” transfer pots. In contrast to injection molding of rubber, there is no “spray” in the tools. There is no way for the material to escape from the area that provides the shape. With tempered transfer pots, in particular, the ITM process is extremely cost-effective, as the covers for hot transfer pots are no longer required.
WICKERT has combined these advantages with a vacuum chamber that effectively evacuates the entire tool area. Burners and defects are things of the past. An accumulator-pump combination optimized with the latest PLC pushes the evacuation time introduced into the cycle time to an acceptable – i.e. cost-effective – level. Evacuation times are usually halved as a result.
The filling unit is based on the established first-in-first out principle. The machine control system allows the transfer pot to be filled only with the amount of material required for the next shot. As a result, there is practically no dwell time for the material mixture in the transfer pot, which could otherwise deteriorate as a result. Innovative screw geometries ensure optimal intake behavior of the strip or round cord. The strip intake support ensures that there is no disruption to the feed process and that the material does not tear.
Elastomer mixtures have to satisfy ever higher requirements. Very expensive mixtures that are difficult to process and likely to shear are therefore being used increasingly: a special screw geometry design ensures that even mixtures that tend to shear are treated very carefully. With these high-end elastomers, conventionally produced screws and cylinders quickly reach their performance limits. Very heavy wear on the screws can result. WICKERT uses screws that are extremely wear-resistant and provide a service life that in some cases is several times longer than that of traditional screws. Another advantage: the surface finishes can be repaired, which saves significant investment in new screws.
The automation solution truly adds the finishing touch to the ITM concept: the tool parts are moved into the automation system via the sliding table and the tool plates are inserted into the automation modules. The tool plates are first separated in front of the machine by a hydraulic tool separator. The tool plates are moved away on both sides. There they either pass through an article ejection device or, for example, a brush or spraying device that handles other tasks automatically. If the tool plates have to be rotated, whether it’s by 180° into a better ejection position or by 90° into a cleaning position, the movement is also carried out fully automatically.
With the WKP 5000 S, the company unveiled a new generation of system controls and system networking to go with the K 2016. Intelligent solutions in the areas of machines and IT were presented. (Authorized) external access to the system in real time is thus possible, as is real-time tracking of operator actions and process data as part of a new control concept. This integrated approach adopted by the Landau-based press specialist is part of its smart factory concept and allows the entire factory to be networked for all system participants via a central access station using WICKERT Link. Proactive actions of the press during essential maintenance, accident prevention or repair work add the finishing touch to the networked factory for these modern systems. The physical and virtual worlds of systems come together in “Industry 4.0” and WICKERT has adopted the same approach with the K: a large-format WKP 1600 S press was integrated into an overall system of five presses by means of animation.
Wickert Service represents predictive maintenance, proactive service reports for preventive maintenance and remote servicing, monitoring and control of the system via Ethernet/intranet/internet.
Wickert Link means central recipe management, back-up and processing of recipe data in the cloud.
Wickert Log comprises back-up and processing of process and production data in the cloud, process tracking in real time, component tracking and mobile data mirroring.
Wickert Eco includes energy management of the entire system, measurement of energy consumption and model calculation, through integrated system networking for factory efficiency.
The combination of animation and a real press presented this production complex to visitors to the stand in comprehensive detail, despite the huge overall dimensions. WICKERT has been setting the trends in press technology for more than 115 years now.