Using quick release connectors in place of fixed connections for mould cooling water, hydraulics, nitrogen and electronics systems produces significant reduction in mould change times.
The total time taken to change moulds is determined by the sequence of the specific steps involved Each changeover will require the disconnection and reconnection of the mould’s cooling water and other services such as hydraulics and electrics, the mechanical handling of the moulds onto and off the machine and the heating of the mould to operating temperature.
A detailed review of each of these stages is required to ensure that mould changeover times are reduced to a minimum.
Staubli, are specialists in mould connection and clamping systems and is ideally placed to objectively analyse mould changeover requirements and recommend solutions.
This expertise and knowledge of coupling solutions is available from the initial design stage onwards to ensure that the installed systems are effective, easy to use and will only require minimum maintenance.
Speeding up mould service connections – one of the first improvements to be considered, said Staubli, should be the method used to make connections to the mould for cooling water, hydraulics, nitrogen, electronics, etc.
The use of quick release connectors in place of fixed connections can often bring the single most significant reduction in mould change times.
Further reduction can be achieved by a move to a multiple connection plate system.
Placing all the quick release couplings together on a pair of plates enables the connections to be made safely and securely in one swift operation.
An additional bonus is the elimination of wrong connections.
* Automatic coupling – an automatic multi coupling system should also be considered at this stage.
It would bring additional savings in downtime and reduces the operators’ machine servicing requirements, frequently allowing a larger batch of machines to be monitored with reduced manning levels.
* Handling – the mechanical handling of moulds onto and away from the injection moulding machine can be a slow process.
Datum lines on the tool holders and crane positions can save time in positioning the mould.
Balance weights on the lifting straps, to avoid tilting, is also a useful idea that can save time manoeuvring the mould into place on the machine.
With side loaded moulds a dedicated loading and/or insertion table may be required to ease handling of the mould.
This may be a simple scissor lift roller table or a tailor made handling system fully integrated in to the control systems of the moulding machine.
* Preheating – moulds need to be heated to operating temperature before moulding can take place.
The installation of a specially designed pre-heat station can ensure that the next mould is brought up to temperature and ready for production just when required.
Staubli told manufacturingtalk that his improvement alone has frequently reduced changeover times for moulds dramatically.
Finally, after each of the above improvements has been implemented, investment in a quick mould clamping system should be evaluated.
There are three different technologies available – mechanical, hydraulic and magnetic.
Each one offers individual benefits and several different design approaches in each technology.
Selecting the most appropriate for each application requires detailed analysis.
Through this rigorous, step by step, evaluation process, mould changeover times will be reduced significantly.
As a ‘rule of thumb’ if your mould changeover time is reduced to below 10 min then it is at this stage that the additional benefits a quick mould clamping system should be evaluated.
* About Staubli – Staubli is an international family owned group founded over 100 years ago in Switzerland employing 3500 world-wide.
The Couplings Division manufacturing facilities are located in France, Germany and Italy, with offices across Europe, North and South America and the Far East; the UK base is in Telford.
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