05/24/2011

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Mold'n Seal at Arburg Technology Days - Injection moulding and sealing of parts in a single process saves time and money

Mold'n Seal combines the production and the sealing of an injected-moulded part in an inline process. Firstly, the part is produced on an Arburg injection moulding machine. This step is followed directly by the application of a polyurethane gasket which is done by a dosing and mixing system in combination with a six arm-robot. Whereas in the past the injection moulding process and the application of the foam gasket were two temporarily and locally separated procedures, it is now possible to combine both actions inline in one single process. This saves time, money and also space in the production zone. The required space for the injection moulding and the dispensing machines can be significantly reduced. In Loßburg at the Arburg Technology Days only 50 m² were needed to position the injection moulding machine, the dosing and mixing system, the six-axis handling robot and the line balancing belt. In addition there is only one single six-axis robot necessary for both processes which has a positive effect on the associated costs as well. In the first step of the new process the six axis robot takes the warm injection moulded parts out of the mould, moves them under the mixing head of the Sonderhoff dispensing machine DM 402/403 and exactly applies the sealing according to the given contour. The intentional use of the residual warmth of the moulded parts the polyurethane foam leads to significantly faster curing so that the six-axis robot can transfer the finished parts for further processing directly after the gasket is applied. At the Arburg Technology Days the seals inside the freshly injection moulded parts cured completely within 3 min. The complete process cycle can be significantly reduced by the new procedure. In Loßburg four plastic components were injection moulded, taken out of the mould, foamed and placed on a line balancing belt for curing and further processing within 35 s. Contrary to former production concepts finished injection mouldings no longer need to be prefabricated and stored temporarily before they are placed on to a dispensing machine for foam gasketing plant by a conveyor belt later on. In order to meet the specific material needs of this kind of process Sonderhoff has enlarged its Fermapor K31 foam gasket product range by newly developed polyurethane formulations which enable the direct sealing of injection moulded parts according to the cycle time of the moulding process. Breaks for cleaning the mixing head provided with reactive material are no longer required. Even with a complete 8 h shift the parts can be foamed in consistently high quality without cleaning the mixing head in between. During 8 h more than 3,200 parts could be injection moulded, foamed and transferred for further processing within 35 s per process cycle. The new Mold'n Seal procedure which interlinks moulding and formed-in-place foam gasketing processes handled by one single six-axis robot offers a cost and time saving alternative by intelligent process technology. About the author
Peter Fischer
p.fischer@sonderhoff.com
Marketing Director
Sonderhoff Holding GmbH,
Cologne, Germany

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