Arburg focuses on efficiency at Technology Days

World-leading machine manufacturer Arburg GmbH + Co. KG held its traditional Technology Days last March. An annual event that has become an international one for the plastic injection moulding industry over the years since it was first launched in 1999, the Technology Days events have recorded 54,000 visitors in total to Lossburg, where Arburg’s headquarters is located. This year, 6,900 invited guests attended the event, a record in history.

“Our Technology Days have been a major attraction for the international plastics world for many years. Despite the huge numbers, what counts for us at this event is and remains quality rather than quantity,” commented Michael Hehl, Managing Partner and Spokesperson for the Arburg Management Team.

Production efficiency stressed

Production efficiency remained this year’s topic, which was well demonstrated through five innovative examples of efficiency in the Efficiency Arena, from the small-volume production of one-off parts with Freeformer to the mass production of articles on an electric Allrounder. Industry 4.0 was also covered with a specific practical example in this area.

The Freeformer, which made its debut at K 2013 trade fair, was shown producing one-off parts or small-volume batches cost-effectively without the need for a mould. Arburg is also the first injection moulding machine manufacturer that has so far developed an industrial 3D printer for additive manufacturing. There’s nothing uniquely special about how it works as compared with other 3D printers in the market, despite that Arburg calls its process Arburg Plastic Freeforming (ASF), where 3D CAD files are processed directly by the Freeformer, standard plastic granulate is melted in an integrated manner in the same way as in the injection moulding process and tiny droplets are generated from the liquid melt.

What makes it different from other 3D printers is that it is designed to use conventional plastic granulates rather than ready-made forms of supplied materials such as powders or strands, which are usually encrypted by the supplier and very expensive. The principle of moving and stationary machine components has also been re-thought. In the Freeformer, the discharge unit and its nozzle remain in a fixed vertical position, while the component carrier moves. In addition to a standard component carrier that can move along three axes, a version with five axes is available, e.g. for implementing undercuts without the need for a support structure.

The high degree of processing flexibility was one of the main criteria taken into account during the development of the Freeformer. This means, for example, that two materials or colours can be processed on a single Freeformer equipped with two discharge units. As a result, even movable hard-soft combinations or parts with a special appearance or texture can be produced, in which both components are firmly joined.

At Efficiency Arena, a housing for Allrounder injection moulding machines made from ABS and weighing 5.3 grams was printed. The time required to produce 12 parts was around 24 hours. One complete production step can be omitted in comparison with injection moulding because there is no need to design and build an expensive mould. Moreover, products can be changed in a very short space of time.

According to Helmut Heinson, Arburg’s Managing Director Sales, the market launch of the Freeformer will take place in 2014 solely in Germany and only involve specially selected pilot customers. The first Freeformers will be delivered in the middle of this year.

Interaction of human and robot

Automation solutions can be worthwhile, even when producing small and medium-sized batches – for example when operators and robotic systems work hand-in-hand. Arburg demonstrated how human and automation system worked together to achieve maximum efficiency through production of a toy buggy.

The operator first manually positions the buggy’s metal axles in the gripper of a Multilift V robotic system in the running injection molding cycle. This dispenses with the need for complex feed systems. In the next step, the robotic system automatically places the inserts into the mould of a hydraulic Allrounder 370 S, keeping the cycle times short. Fast and flexible product changeovers are possible. In the example shown, the setup time was reduced from 5 to 3.5 hours in comparison with a complete automation solution. The human/machine interaction thus reduces the capital expenditure on the automation solution and, thanks to the reproducible processes, enhances process reliability and productivity.

Parts-based online data acquisition ensures transparent production and 100% traceability. This entails the data integration of machines, order information and process data. Online integration of independent process steps improves production processes and facilitates remote diagnostics. At the Efficiency Arena, Arburg presented an Industry 4.0 future project based on the example of the toy buggy with a designed process.

Visitors were able to have their own buggy produced for themselves. They first need to input an ID at a data entry terminal and then will receive a personalized chip card. The card then is read into the Selogica control system in the production cell. A hydraulic Allrounder 370 S then produced the corresponding buggy in the next cycle.

A laser printing system in the production cell marks an individualized QR code onto the roof of the buggy. At the same time, the Selogica control system transfers the relevant product data to the Arburg host computer system (ALS). Next, the assembled buggy vision can be checked at a camera test station to see whether or not the roof, front and rear axles have been mounted correctly on the chassis. Finally, a “test run” measures the speed achieved by the buggy as it rolls down a ramp. A screen on the site will display the high scores. The Arburg host computer system (ALS) will also record and archive the test results and transmit the data to a web server.

A Multilift V robotic system with a new, dynamic mould-entry axis was used in the Efficiency Arena to demonstrate how a standard robotic system can significantly reduce the removal time and consequently the cycle time, based on the example of a packaging article. Two PP tubs weighing 6.4 grams were produced in a cycle time of just 3.6 seconds. In comparison to a standard robotic system, the action time was cut from 1.32 to 0.99 seconds, a 25% reduction. This shows just how important equipment can be when it comes to saving valuable seconds during production.