Dishwashers are getting increasingly quieter, bringing more comfort to our kitchens. This is thanks largely to automatically produced plastic parts and components with integrated functions. In the case of the housing for the hot water pump that Veeser produces as a platform component for Bosch Siemens Hausgeräte (BSH), a TPE with a hard/ soft combination prevents the transmission of vibrations.
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This part connects the dishwasher to the hose and is joined with the motors by Italian company Sisme Italy Spa to produce the finished pump unit. The components are then shipped to BSH for final assembly.
Product meets stringent requirements
High demands are placed on the housing parts and mould: the washers must remain undamaged when demoulded under force; the necessary void-free injection moulding requires optimum mould venting.
The parts themselves must form a highly efficient seal and must be resistant to high temperatures and lyes. This is the only way that the hard/soft combinations can prevent leaks, protect against vibrations and ensure the required smooth-running operation.
In technical terms the process is as follows: the TPE component cushions the vibration noises that are necessarily produced from the large resonating chamber of the dishwasher, thereby ensuring quieter operations. The inserted ring is “internally undermoulded” by the TPE component. This replaces a clamp and ensures that the washers are pressed onto the connector hose with a constant pressure. The hose simply needs to be pushed into place and, because no further fixing is required, assembly is significantly simplified.
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Thanks to the hard/soft combination, the pump housing on dishwashers |
Complex turnkey system
The housing is produced on a turnkey system from variants of the PP TV and TPE V materials that are suitable for use in dishwashers. The turnkey system consists of a two-component ALLROUNDER 820 S with 4-cavity mould and a KUKA six-axis robot. The automation components, such as the gripper, washer feed system, impeller wheel supply system and assembly unit, all come from Kiki.
The first step is the overmoulding of the hard PP component. After the mould has been opened, the six-axis robot removes the finished parts and the TPE runner system and inserts the four automatically separated plastic rings on the nozzle end. The ejector side then rotates electrically, the mould closes and the insert is bonded with the main body by the TPE. At the same time, more pre-moulded parts are produced from PP. The time required for the entire process is 38 seconds.
The robotic system transfers the finished moulded parts to the assembly station, where they are joined to the impeller wheels supplied there. The assembled parts are placed on a conveyor belt and fed out, while the sprue ends up on a separate conveyor belt.
This in-line solution is not just cost-efficient but also adheres to the stringent quality standards required for the entire automated production line.
Convincing expertise from ARBURG
Managing partner Michael Veeser explains the reasons behind the decision in favour of this turnkey system: ”In addition to the automation expertise offered by ARBURG as a central contact, the full integration of the robot system in the SELOGICA controller and the high level of reliability of the ALLROUNDERs were the factors that clinched our choice. Because we see ourselves as a partner to our customers when it comes to functional integration solutions like this, we also depend on end-to-end reliable technical solutions such as those provided by ARBURG.”
