The use of passive RFID sensors as insert parts enables wireless monitoring of the injection molding process. In contrast to conventional methods, the injection mold and the sensor technology are separated. The individual, part-integrated process monitoring, control and documentation can be extended with the same sensor element also to the further life cycle of the injection molding part. 

Part Integrated Temperature Monitoring of Injection Molding Parts with RFID Sensor Tags 

RFID

Industrie 4.0

Spritzgießwerkzeuge

Spritzgießen

Temperatursensoren

Rückverfolgbarkeit, Traceability

Wireless Life Cycle Monitoring in the Injection Molded Part 

In the injection molding of engineering plastics, mold temperature control consumes more than one third of the total energy input. A novel technology offers the opportunity to reduce this continuous major cost factor – and eliminate hotspots.

Fig. 1. The temperature control units have the highest energy share in the injection molding process

Source: M. Schläger et al [2]; graphic: © Hanser

Reduced Energy Consumption and Shorter Cycle Times due to Structurally Integrated  Heat Pipe Mold Cores

Kunststoffverarbeitung: Verfahren

Temperiertechnik

Kunststoffverarbeitung: Maschinen und Komponenten

Werkzeuge für die Kunststoffverarbeitung

Cooling with Heat Pipes

The resource-economical determination of an optimized operating point in injection molding is still a challenge. Machine learning offers great potential for re-using knowledge from a flow simulation that has already been generated.

Significant reduction of the effort for determining the optimum operating point by machine learning

Machine Learning: Combining Simulation and Experimental Test Data

Spritzgießsimulation

Software

Simulation

DOE-Software

Qualitätsmethoden

Industrie 4.0 für die Kunststoffverarbeitung

Digitaler Zwilling

Quicker Evaluation of the Optimum Operating Point

In plastics processing, efficient production methods are required, especially for articles with high volumes and exacting quality requirements, and these must be constantly optimized. The container specialist Walther Faltsysteme has been successfully working together with the Austrian moldmaker Haidlmair for many years.

Left: products which are manufactured using the technologies of the Haidlmair Group companies. Right: an application example with folding boxes

Walther Faltsysteme Combines Three Mold Technologies from the Haidlmair Group

Industrie 4.0 für die Qualitätssicherung

Condition Monitoring / Prozessüberwachung

Instandhaltung

Paletten und Behälter

Logistik

Verpackungstechnik

Dienstleistungen

Werkzeug-, Formen- und Modellbau

Heißkanalsysteme

Komponenten für die Kunststoffverarbeitung

With Broad Sword and Data Collector

The spring clamping cylinder ESZS for a nominal clamping force range from 16k N to 350 kN enables hydromechanical clamping.

The ESZS spring clamping cylinder can be used wherever shiftable or movable machine parts have to be fixed or clamped

Werkzeug- und Formenbau

Presswerkzeuge, Kunststoff

Werkzeugspanntechnik

Spanntechnik

Robust and Reliable Clamping

Aside from offering high mechanical strength, versatility and durability, polymer materials are ideal for applications in the electrical industry because of their ability to isolate electrical current.

For the conduction cooled MicroTCA systems, Harting processes LCP, a material that is flame-resistant, dimensionally stable at high temperatures, chemically resistant, and has only a low thermal expansion

Connectors for Industrial Lifelines: High-Tech Injection Molding at Harting

Hybridtechnik

Polymere, flüssigkristalline

Kunststoff Werkstoffe

Thermoplaste

Stanzen

Verfahren für die spanlose Fertigung

Schneiden

Hybrid-Spritzgießen (Metall / Kunststoff)

Steckverbinder

Elektromechanik

Well-Balanced Hot Runner Technology for LCP Processing

The Reversecube two-part cube mold is used to produce 60 million multicomponent parts per year on one production line and in the same process. The cycle times must be kept very short while at the same time maintaining stable processes and a high part quality. Sensor-based monitoring and automatic process control is therefore deployed in the form of Fillcontrol from Priamus. It consists of hot-runner balancing, viscosity and compression control as well as automatic holding pressure changeover.

The two halves of the Reversecube cube mold, in stacked arrangement, rotate in 90° steps. Bottom: injection and cooling component 1, analogous to the component 2 above, which is offset by 180°

Automating Injection Molding with Process Control – with the Example of a Cube Mold

Werkzeuginnendrucksensoren

Messtechnik

Sensoren / Messwertaufnehmer

Steuern, Regeln

Mehrkomponenten-Spritzgießen

Werkzeugtemperatursensoren

Qualitätssicherung Kunststoff

Qualitätssicherung

Quality Assurance for Multiple Cavities

Zahoransky Automation & Molds GmbH has entered into a partnership with the Swiss company Kebo AG. The result of this collaboration is a new mold concept for the production of pipette tips, which features a double quick-change system.

If a core breaks during production, it can be replaced quickly

Messe Fakuma

kunststoffe-international.com

Medizintechnik

Double Quick-Change System Speeds up Production

The area of application of cube molds has expanded to take in the production of technical parts. The new Allrounder Cube 1800 from Arburg with a clamping force of 1800 kN is providing the response to this trend. With its compact cube, this machine completes the portfolio of products at the lower end of the range.

At the heart of the cube machine is a compact cube designed by our partner Foboha which can be easily accessed from above. The rotation of the cube is powered servo-electrically and the horizontal movement relies on rack and pinion mechanisms

Spritzgießmaschinen, allgemein

Spritzgießmaschinen

Arburg Expands Hybrid Cube Series

The aim of the project was clear: a highly automated turnkey system must replace several decentralized, operator-guided machines in order to be able to mass produce enclosures for a vacuum sensor with three inserted pins in a way that is smooth, automated and therefore faster than before in large-scale production, and error-free. The plastics processor Goerlich chose the machine manufacturer Arburg as a partner in its goal of achieving greater production efficiency.

All upstream process steps are integrated in a very small space: after the pins have been  punched out (right), a Scara robot places them in the correct position on a loading plate (left) so that the Multilift V robotic system can pick up 24 pins and insert them into the mold

16:9

At Goerlich, a Turnkey Plant Replaces Two Machines with a Vertical Clamping Unit

Automatisierungszellen

Automatisierungstechnik

Linearroboter für die Kunststoffverarbeitung

Handling, Handhabungstechnik

A Machine Strategy with  Extra Automation

Electrical components are made from conductive and nonconductive materials. Pressure of competition makes it necessary to reduce the number of components and work steps and to streamline assembly. The moldmaker Mühlbeyer uses a hybrid technology for manufacturing stators and rotors, in which the contact material and plastic are permanently bonded in one production step.

Various plastic-coated stators. During overmolding of the sheet components, not only insulation but also technical functions can be incorporated

Overmolding as a Prerequisite for Cost-Efficient, High-Quality Electric Motors

Elektromotoren

Antriebe

Injection Molds for Insulating  Stators and Rotors

For a cutlery series made of a new biopolymer, three full hot runner molds with digital process monitoring were developed in close cooperation with mold maker Uniform and hot runner specialist Ewikon.

The 16-drop family mold on the machine. The removal and packaging of the parts are fully automated

Complete Digital Hot Runner Solution for Automated Biopolymer Processing

Biokunststoffe

Virtual Reality für die Qualitätssicherung

Process Reliability Is Crucial

Over past months, many in-house workflows and development processes have slowed down and also changed. Nevertheless, time has not stood still, also not in injection molding technology. The debate and development have been shaped by two themes: digitalization and the circular economy. Below are some examples of developments and projects that underpin this trend.

Two displays are seamlessly integrated into the continuously 3D-formed instrument panel

Innovative Injection Molding in Times of Pandemic

Schaumspritzgießen

Künstliche Intelligenz für die Qualitätssicherung

Folientechnik (IMD, IML, FIM, u.a.)

Digitale Transformation

Wirtschaft

Innovationen und neue Technologie

Spritzgieß-Sonderverfahren

Nachhaltigkeit

Umweltmanagement

Schnecken und Plastifiziersysteme

Machine Learning / Künstliche Intelligenz für die spanende Fertigung

Industrie 4.0 für die spanende Fertigung

Kunststoff-Recycling

Kunststoff-Aufbereitung

Lasermarkieren

Oberflächentechnik

Laserbearbeitungen

Inline- / Online-Messsysteme

Kreislaufwirtschaft

There Is More beyond the Horizon

For the first time a readable digital watermark, imperceptible to the naked eye, has been incorporated into an injection-molded flip cap.

On the flip cap, the digital watermark is not visually perceptible, but can be read like a code by specialized high speed camera

Integration of Digital Watermarks in Complex Injection Molded Packaging Products

Bildverarbeitung

Fertigungsautomation

Barcode-Systeme

Identtechnik

Inspektion, Analyse und Sortierung von Rohmaterial

Key to Purity of Recycled Resins

The digital shadow is the core concept of the Cluster of Excellence “Internet of Production” at RWTH Aachen University. It represents the data trace of an asset to describe its real behavior. In the Plastics Innovation Center 4.0 (PIC 4.0), digital shadows, e.g. the data trace of a sensor, are used to optimize processes taking into account real behavior and to determine simulation quality.

The construction of the PIC 4.0 proceeds and throws its shadow on the Campus Melaten.

Part 7 of the Series: How the Digital Shadow Enlightens Real Processes in the PIC 4.0

Sensorik für Kunststoff-Verarbeitungsmaschinen

Out of the Shadow into the Light

How Track-and-Trace Technologies Can Support Mold Management

The article demonstrates the use of digital twins for molds in injection molding through the integration of track-and-trace technologies for data collection.

Industry 4.0 is characterized by autonomous production systems in which the “things”, so-called assets, communicate with each other and decide independently. This can be achieved through digital twins as a virtual representation of these assets and digital shadows as decision supporters. The following article demonstrates the use of digital twins for molds in injection molding through the integration of track-and-trace technologies for data collection.

Industry 4.0 technologies aim to secure the international competitiveness of high-wage countries. This is assisted by the merging of the physical world with the digital world to create so-called cyber-physical systems, in which the separate components (assets) communicate autonomously [1]. Digital twins represent the image of the real assets in the virtual world in order to use the advantages of Industry 4.0 [2]. Characteristic for the digital twin is the ability to influence real systems and interact with them. The digital shadow, on the other hand, exists only for a specific purpose. Therefore, the digital shadow just extracts and processes the data that are relevant to fulfil the purpose. The digital shadow furthermore cannot exert any influence on the real system and therefore serves primarily as data context and not as an active, interacting system component [3].

There are a number of advantages of establishing digital twins of molds. Employees can focus on value-adding operations [4] because time-consuming manual bookings of molds can be reduced or mold data can be automatically passed on [5, 6]. The current state in the production can be transparently observed at any time by molds transmitting their status to a higher-level control system [7], for example information about the current location or the setup status of the mold. Apart from that, information about the mold itself is available, e. g. the number of completed injection cycles, in order to initiate maintenance based on this at the right time [8].

The continuous information on the mold status also influences the behavior of other system components. For example, if a mold is set up on one machine, other machines cannot request it for immediate use. On the other hand, if this data is automatically recorded, potential input errors by employees can also be avoided and consistent data records can be generated [9]. High data consistency ensures, for example, the quality of planning simulation [5] for production control and consequently improves decision-making [4], e. g. for optimal scheduling as regards minimizing mold setups or changeover times. Digital shadows support this by extracting the data needed for the decision-making from the entirety of data and consolidating the data into planning-relevant information [10].

The Asset Administration Shell  as Digital Twin

Besides data acquisition, data structuring of the digital twin is essential. To this end, the concept of “asset administration shells” has been established for the implementation of the digital twin [11]. The asset administration shell consists of two main building blocks: the manifest and the component manager (Fig. 1). The manifest is comparable to an identity card. On the one hand, it clearly identifies the asset and, on the other, it describes the attributes of the asset based on previously defined features. Moreover, the asset administration shell allows the encapsulation of relevant attributes in submodels for a specific application case.

The component manager specifies interfaces for communication between the outside world and the asset, e. g. by the listing of endpoints and permissible communication protocols. The boxing of asset administration shells is also permissible [2]. Both the implementation and the access to the asset administration shell is technology-independent [12, 13]. Therefore, track-and-trace technologies generally are suitable for manipulating the attribute values of asset administration shells. This is shown below using a practical application example for mold management using RFID technology.

Classification of RFID Compared to Other Tracking Technologies

Within the last few decades, different tracking technologies for a variety of applications have achieved industrial maturity. Many of them were fundamentally developed as early as the 1990s. Besides optically identifiable barcode variants (classic barcode, QR codes, 3D and 4D codes), transmitter/receiver-based systems (RFID, NFC) for discreet tracking were also used. Real Time Location Systems (RTLS) like GPS, cellular or also Bluetooth Low Energy (BLE) and ultra-bandwidth technology are suitable for continuous tracking. The appropriate technology must be selected depending on the particular application. The criteria may be e. g. the technology maturity, the costs, the susceptibility to failure, the information content and the automatability. Extensive technology comparisons already exist regarding various criteria [14].

There is no need for continuous recording of tracking molds, therefore the choice must be made between optical identifiable markings (QR codes) and transmitter/receiver-based systems. Optical markings must be reliably visible for the reader and, because of that, have limited suitability for the tracking of molds. Based on its good scalability, RFID as a transmitter/receiver-based system offers itself for automated applications [15]. Both transponders and corresponding readers are, unlike other transmitter/receiver-based systems, cost-efficient and very flexible in terms of the range, the demarcation of the area to be recorded and the modularity.

Some applications in the industry, e. g. moldmaking from Phoenix Contact [16], have already made use of RFID technology. For these reasons, the application described below uses RFID systems.

In the demonstrated application, molds are equipped with RFID transponders and specific storage positions and current locations of the molds are continuously monitored by corresponding antennas. As a result, mold movements can be recorded at any time and relevant data can be transferred into the system.

To increase the transparency of the production, the digital mold twin should show the current location of the real mold in real time and without manual intervention. Apart from that, the storage position should be optimized based on the number of mold movements, whereby the position of frequently used molds is located near the base so that these molds are more easily and quickly accessible. For this purpose, the asset administration shell submodel ”mold storage” will be modelled, which contains the relevant attributes plus possible characteristics (Fig. 2). Besides the attribute Current_location recorded via RFID, the submodel includes the attributes Status, Opt_storage_position (the optimal storage position) and Time_of_removal.

If the relevant attributes should change over time, the asset administration shells can be adapted easily. The structuring of the data took place in the JSON format, which is a versatile exchange format that can be easily integrated into many software applications.

The digital shadow should support logistics staff with the determination of a suitable mold storage position in the form of an assistance system. Relevant for that are the attributes Opt_storage_position and Time_of_removal, the attributes Current_location and Status are not addressed by the digital shadow. Through this automatic logging, a history of moving times is created, which is saved in the attribute Time_of_removal.

The digital shadow takes this history for every mold and combines it into a data trace. Using an algorithm, it establishes a ranking in which the molds are sorted by their number of movements and assigned to a corresponding storage place. The updated storage position is automatically logged into the attribute Opt_storage_position after confirmation by a logistic staff member (Fig. 3). If necessary, the algorithm could be expanded by any additional conditions, e. g. by taking into account the size and weight of the mold for the selection of its storage position. The only requirements for this are corresponding attributes in the asset administration shell and the correct recording of relevant data.

One advantage of attribute-based asset administration shells is the standardized database, which can use different services. These services can be deployed modularly, so that, using an asset administration shell, a service-oriented architecture (SOA) can be realized. Also, the “Plug and Play” idea is practicable with asset administration shells that are structured in a standardized manner.

To illustrate the described application, the Institute for Plastics Processing (IKV) in Aachen, Germany, is working on a demonstrator. On the one hand, the data structure of the digital shadow will be developed and, on the other, an exemplary recording of molds using RFID will be implemented in the technical center.

The concept of digital twins and digital shadows can be applied to the management of molds. Through the standardized asset administration shells, which include all relevant attributes, digital twins can be implemented for the virtual mapping of molds. Track- and-trace technologies like RFID are suitable for manipulating attributes. All in all, the digital twin can increase the transparency of production. In addition, the digital shadow can be used as a service module, as this article shows, based on the optimization of the storage position of molds.

Further studies are dealing with the creation of other asset administration shells and submodels for other assets, so that all relevant assets of injection molding production are transferred to the virtual world and supported by the digital shadow.

[1] Kagermann, H.; Lukas, W. D.; Wahlster, W.: Industrie 4.0: Mit dem Internet der Dinge auf dem Weg zur vierten industriellen Revolution. VDI Nachrichten 13 (2011)

[2] Adolphs, P. et al.: Struktur der Verwaltungsschale – Fortentwicklung des Referenzmodells für die Industrie 4.0-Komponente. Bundesministerium für Wirtschaft und Energie (BMWi), Berlin 2016

[3] Kritzinger, W. et al.: Digital Twin in manufacturing: A categorical literature review and classification. IFAC-PapersOnLine 51 (2018) 11, pp. 1016–1622

[4] Kagermann, H. (Hrsg.) et al.: Umsetzungsempfehlungen für das Zukunftsprojekt Industrie 4.0 – Abschlussbericht des Arbeitskreises Industrie 4.0. acatech 2013

[5] Niehues, M. et al.: Organisation, Qualität und IT-Systeme für Planung und Betrieb. In: Reinhart, G. (Hrsg.): Handbuch Industrie 4.0. Hanser, München 2017, pp. 137–167

[6] Schuh, G.; Stich, V.: Produktion am Standort Deutschland. FIR e. V. an der RWTH Aachen, Aachen 2013

[7] Obermaier, R. (Hrsg.): Handbuch Industrie 4.0 und Digitale Transformation. Springer Fachmedien, Wiesbaden 2019

[8] Münzl, M.: Werkzeugverwaltung mit RFID für Spritzgießer – Ein Schritt zu Industrie 4.0. Firmenschrift der Balluff GmbH, Neuhausen a.d.F. 2016

[9] Bartneck, N. (Hrsg.): Prozesse optimieren mit RFID und Auto-ID: Grundlagen, Problemlösung und Anwendungsbeispiele. Publicis Corporate Publishing, Erlangen 2008

[10] Schuh, G. et al.: Effizientere Produktion mit Digitalen Schatten. Zeitschrift für wirtschaftlichen Fabrikbetrieb 115 (2020) S1, pp. 105–107

[11] Wagner, C. et al.: The role of the Industry 4.0 asset administration shell and the digital twin during the life cycle of a plant. 22nd IEEE International Conference on Emerging Technologies and Factory Automation (ETFA), Limassol 2017

[12] Plattform Industrie 4.0 (Hrsg.): VWS-Referenzmodellierung. Berlin 2021

[13] Plattform Industrie 4.0 (Hrsg.): Functional View of the Asset Administration Shell in an Industrie 4.0 System Environment. Berlin 2021

[14] Bauer, M.; Bienzeisler, B.; Rohm, M.: Track and Trace Technologien im Überblick. Kurzstudie des Fraunhofer-Instituts für Arbeitswirtschaft und Organisation (IAO), Stuttgart 2019

[15] Tamm, G.; Tribowski, C.: RFID. Springer, Berlin, Heidelberg 2010

[16] Moldehn, A.: Beispiel für IoT: der RFID Tool Finder. Firmenschrift der Phoenix Contact GmbH & Co. KG, URL: <a href="https://blog.phoenixcontact.com/hr-de/beispiel-fuer-iot-der-rfid-tool-finder/" target="_blank">https://blog.phoenixcontact.com/hr-de/beispiel-fuer-iot-der-rfid-tool-finder/</a> abgerufen am 06.09.2021

RWTH Aachen Inst. f. Kunststoffverarbeitung IKV 

Institut für Kunststoffverarbeitung (IKV) in Industrie und Handwerk an der RWTH Aachen

https://www.ikv-aachen.de

Ausgabenartikel

An RFID reader records whether a mold is ready for the setup process

Fig. 1. Basic structure of the asset administration shell, consisting of the manifest and the components manager

Fig. 2. Using the asset administration shell, the mold is represented as a digital twin and exchanges information via RFID with its environment,  e. g. with the storage position, the injection molding machines and unloading stations

Fig. 3. The digital shadow uses the data recorded by RFID to suggest an optimum storage position for the mold and to carry this out if a staff member confirms it

Name - Hauptartikel

Patrick Sapel, M.Sc., is a scientific assistant at IKV. His research area includes production planning and automation in injection molding; <a href="mailto:patrick.sapel@ikv.rwth-aachen.de">patrick.sapel@ikv.rwth-aachen.de</a>

Fabian Becker, M.Sc. RWTH, is a scientific assistant at IKV and is working on intelligent production systems. His research focus is the development of a production data infrastructure in the sense of an internet of production; <a href="mailto:fabian.becker.sg@ikv.rwth-aachen.de">fabian.becker.sg@ikv.rwth-aachen.de</a>

Univ.-Prof. Dr.-Ing. Christian Hopmann has held the Chair of Plastics Processing since 2011 and is head of the Institute for Plastics Processing (IKV) in Industry and Craft at RWTH Aachen University.

Funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany’s Excellence Strategy – EXC-2023 Internet of Production – 390621612.