15/02/2010

Hilma-Römheld GmbH Werkzeugspann- und Wechseltechnik

PRODUCING SMALL BATCHES WITH SWIFT CHANGES-MAGNETIC CLAMPING TECHNOLOGY

Shorter set-up times and less scrap.
When it came to the purchase of new rubber presses, the CEO, Theodor Knäbe, decided on the basis of his long experience in favour of vulcanising presses made by Rucks, Glauchau, which were equipped with magnetic clamping systems produced by Hilma-Römheld, Hilchenbach,. With clamping surfaces of 600 mm x 600 mm, the two vulcanising presses each with one pair of magnetic clamping plates, are large enough to vulcanise moulds of the same size in one single operation. The presses are networked with the three existing frame presses and the injection moulding machine and can be controlled centrally. A computer administers the control programme for each mould. When the mould is used, only the relevant data has to be loaded. This ensures exact reproduction in the case of all repeat orders.
In addition to easy reproduction of repeat orders, operators are very appreciative of the enormous time saving when changing moulds. With the introduction of the new clamping technology the time for clamping and unclamping of a mould has been reduced by 30 minutes to 5 minutes. Thus, the company not only saves several hours of set-up time every day but is only now in a position to meet very short delivery times. Another point which is very important to Mehlau is the improvement in quality: "As the pressing forces are higher than those of our old machines and as they are evenly distributed through the magnetic clamping plates to the mould, the resulting rubber products are very homogeneous. The amount of scrap arising has been significantly reduced."
Using magnetic clamping technology, most moulds can be clamped rapidly and precisely, regardless of whether they are intended for use in horizontal or vertical applications. Once the mould has been placed and positioned, it is magnetised on the magnetic clamping plate by applying electrical energy for 2 – 3 seconds. During production, current-independent permanent magnets provide the force required for retaining mould halves even with a weight of several tons without any deformation, true to position, parallel and reliably. As the magnetic field penetrates the surface of the mould by just a few millimetres, it has no influence on production. Even in the case of power failure, the moulds safely adhere to the clamping plates thanks to the permanent magnetic technique; application of electrical power is only required for demagnetising and unclamping the moulds.