Published On: Sat, Oct 22nd, 2016

Stäubli champions all-round automation solutions for injection moulding at K 2016

Stäubli has brought a demonstration cell to K 2016 in order to demystify just how automation solutions for injection moulding can open up a new world of productivity, process reliability and flexibility.

Increasingly stringent demands on the design and quality of injection moulded parts presents a challenge for plastics processors. This coupled with the trend for greater numbers of product variants, which leads to a commensurate reduction in batch sizes, leads to frequent mould changes which, for some manufacturers, can amount to several times per shift.

Injection Moulding Machine

Stäubli champions all-round automation solutions for injection moulding at K 2016

All of the above has a negative effect on the productivity of injection moulding machines, with the unproductive setup and idle times of these expensive capital goods becoming a serious problem. As a partner to the plastics industry with over 60 years of shared experience, Stäubli is aware of the issues and has come up with a globally unique range of integrated solutions that derive from its core competencies in connectors, QMC (Quick Mould Change) and robotics.

Exchanging injection moulds: Pure unadulterated SMED

Stäubli’s stand in Hall 11 has been home to a pioneering demo cell for K 2016, in which all the essential process steps of a fully automated injection moulding machine can be observed. Visitors have been shown how networked Industry 4.0-compatible components enable the individual processes to be coordinated and optimised. This automation solution illustrates how easily a complex task can be mastered with integrated Stäubli technology.

But above all, the realistic trade fair demo application exemplifies the Stäubli concept of Quick Mould Change and SMED (Single-Minute Exchange of Die). These superior QMC solutions allow the exchange of injection moulds to be performed to the highest safety standards within minutes.

Top of the class in Quick Mould Change

The demo cell for trade visitors at K 2016 is a step-by-step presentation of the technologies involved in achieving such outstanding performance. The starting point is the preparation of the injection mould with integrated preheating, during which the next mould in line is being made ready in parallel with ongoing production.

The tricky aspect here is the preheating of the mould, without which there would be a delay before it was ready for use in the machine itself. The operator starts by switching on all media, power and signal connections with a single control on a Stäubli multi-coupling system. If desired, this manual operation can also be performed automatically. Thanks to the superior multi-coupling technology, manual connection takes only a few seconds, and the possibility of faulty connections is absolutely excluded.

The preheating now begins at the work station. Here too, the Industry 4.0 capability of the coupling technology has a positive effect: thanks to integrated sensors, the connectors are able to detect the condition of the mould and feed the data collected into the subsequent process. Any faults, such as a failure to reach the correct operating temperature, can thus be recognised at an early stage. This allows correction of the fault before the mould is inserted into the machine, thereby avoiding unnecessary costs and expensive downtimes.

Safe transport of injection moulds in an Industry 4.0 environment

When the mould has reached the prescribed temperature, it is ready for transportation. In the demo application at K 2016, this demanding task is performed by a die cart on rails. However, manual or induction guided solutions are also available as an alternative. The tool shuttle conveys the new mould from the preparatory station to the injection moulding machine and collects the one previously in use. Even before the machine performs the final shot of the current batch, the die cart with the production-ready mould is standing next to the machine, waiting for the signal to be given for the exchange to start. Now everything has to happen quickly. Firstly, the Stäubli mechanism automatically locks both halves of the mould. The fully automatic multi-couplers immediately disconnect all signalling and media, while the automatic ejector (also a standard Stäubli product) separates the mould. Before the machine opens and releases the mould, it is automatically declamped by the Stäubli magnetic clamping system.

A heavy-duty, electrically powered mechanism now handles the exchange with high precision. The process is, of course, fully monitored by sensors. At one point in the procedure, both moulds are briefly on board the shuttle at the same time. Despite the extra weight, the transport and in particular the positioning of the new mould must be effected with a precision of just a few tenths of a millimetre. Sensors detect the position of the mould and the cart.

To ensure maximum process reliability, the machine and the die cart automatically coordinate their status at every step. The die cart works with the data from both the mould and the machine, adjusting transfer height accurately. The Stäubli tool-centring unit then ensures precise positioning before the mould is magnetically clamped, a process that takes just a few seconds.