Tuesday 17 November 2015

Cyber physical production systems (CPPS) in plastics industry - Part II: How injection moulding machine manufacturer will change polymer processing

Welcome to the second part of this series about Cyber Physical Production Systems (CPPS) in plastics industry. (Here is link to part I). In this part, we will have a detailed look on how parts will be produced by the injection moulding technique in the future using CPPS applications. I would like to present to you the point of views of the major injection moulding machine manufacturers regarding future developments. These will have a major influence on, whether the CPPS will be a successful story in the future, or not.
Arburg: The concept of Arburg is based on the individualization of plastic parts in a large production series. This can be made by combining additive manufacturing with the injection moulding technique in a digitally networked process chain. In the opinion of Arburg, Industry 4.0 consists in an individual solution integrated in mass production.  For example, Arburg presented at the Hannover Fair 2015 (Germany) the production of a “rocker-type light switch”. This is a mass produced part by injection moulding. However, it can combine an individualization step by using the Arburg’s Freeformer. For example, the customer can “paint” his/her signature in a digital terminal (e.g: tablet).This information is stored on a chip card, which is later placed in the controlling unit of the injection moulding machine, where part of the information is converted by laser  into a data matrix code on the backside of the produced light switch. Then, the light switch is placed into the Freeformer (additive manufacturing unit), where the information from the chip card is again read and the signature printed on the surface of the light switch. After this process, an automated quality check is done and the light switch is packed. In parallel, a homepage with all the relevant production information is set up enabling worldwide accessibility. The following youtube-video helps understanding it better.

ENGEL’s injection 4.0 approach aims at reaching optimal efficiency, productivity, availability, quality, and flexibility on the production site. Injection 4.0 has basically 3 core elements: smart machines (focus on self-adapting, decentralized systems), smart production (horizontal and vertical data integration) and smart services (focus on remote maintenance tools). How those three work along each other was shown at the FAKUMA 2015 (Germany). Apart of that, injection moulding machines can be equipped with the iQ (intelligent Quality)-weight control as well as with the iQ-clamp control. The iQ-weight control enables a response to viscosity changes during processing. Every final part will have consistency in weight through the right timed switch over from the injection pressure to the packing pressure. The iQ-clamp control estimates the mould breathing and applies the necessary amount of clamping force. This allows keeping the mould breathing constant although process conditions might change.

Prof. Helmar Franz from Haitian pointed out at the 2nd International Injection Moulding Conference 2015(Germany) that the future challenges are in the integration of injection moulding techniques into other technologies such as thermoforming, die casting, and additive manufacturing, as well as to integrate other conversion techniques into the injection moulding technique. Apart of that, future challenge lies in using the, as he calls it “big data meet machinery”, which can result in the development of new business models.

Krauss Maffei continuous its way towards Industry 4.0 with the Adaptive Process Control (APC), which facilitates quality control by analyzing material induced interferences over a viscosity number. As a consequence, underfilling and overfilling processes are minimized. The change-over point will be estimated for each shot ensuring that switch-over follows at the right time. We still tend to have a constant process replication, which is from a quality point of view not efficient enough to resolve influences of material and external manufacturing conditions.

Sumitomo Heavy Industries is known for all-electric injection moulding machines. They put their future outlook in improving the “Zero Molding”, which was implemented in 2008. The idea of “Zero Molding” together with its functions Flow Front Control (FFC), Minimum Clamping Mold (MCM), and Simple Process Setting (SPS) is to enable an optimal production of plastic parts with minimum defects, faults, and losses. The future zero failure technology, which meets also the idea of CPPS will contain a web based dialog between production sites, local affiliates, and SHI Demag. Furthermore, Sumitomo will also provide platforms for data storage, informatics visualization, and diagnostic processing.

Let’s jump to the last but not least manufacturer: Wittman-Battenfeld: “Wittmann 4.0” is called their main key stone in realizing an overall integration. The new B6p controlling unit of the injection moulding machine allows to connect and control all attached robotics and periphery devices in one uniform windows surface. This allows an optimal organization of the whole production process, starting from material supply to automation process. The data is collected and stored in the central mould database. In case the mould is changed to other machines, the central computer will provide the devices with the right data. Another learning effect is reached by storing all production errors and make them accessible. Summing it up: Battenfeld believes that together with the Internet of things approach, the injection moulding machines will start communicating, “talking” more to the peripheral equipment allowing to increase productivity.

To sum up: there are already similarities in the approaches of all the manufactures, especially when it comes to control occurring process instabilities caused by material or external influences (ENGEL’s iQ weight control; Kraus Maffei’s Adaptive Process Control or Sumitomo’s Zero Moulidng strategy). Furthermore, allover production strategies, where the injection moulding machine is not just a well-connected piece within the production, have entered the prototype phase. Fact is that we still plan our products in a linear way but the world around us changes in an exponential way. CPPS might helping combating a more exponential way of thinking in the world of plastics manufacturing. I believe that in the next five years fully integrated CPPS will be state of the art in plastics industry.

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[1] Proceedings 2nd IIMC, IKV Aachen

[2] Kunstoffe, 9/2015, p.103

[3] Kunstoffe, 9/2015, p.32 - 40