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 

Hammann markets its own developed pulsed flushing process under the name Comprex. The flushing technology is a purely physical process, which does not use any chemicals – just air and water.

Cleaning of Mold Cooling Channels for PET Preforms

Kunststoffverarbeitung: Verfahren

Temperiergeräte

Kunststoffverarbeitung: Maschinen und Komponenten

Gießanlagen

Werkzeuge für die Kunststoffverarbeitung

Werkzeugreinigung, Kunststoffe

Avoiding Shutdowns

Once again, the K 2019 in Düsseldorf, Germany, lived up to its claim to be the leading trade show for plastics technology. At least in the field of injection molding, there were exciting global innovations to see – if you looked closely.

Injection Molding Trends at K 2019

Schaumspritzgießen

Smart Factory

Energieeffizienz

Mikrospritzgießen

Mehrkomponenten-Spritzgießen

Spritzgießmaschinen, allgemein

Spritzgießmaschinen

Fließpressen

Handling, Handhabungstechnik für die spanende Fertigung

Automatisierungstechnik

Handling, Handhabungstechnik

Spritzgieß-Sonderverfahren

Spritzgießsimulation

Software

Simulation

Elastomer-Spritzgießen

Linearroboter für die Kunststoffverarbeitung

Industrieroboter

Montagetechnik

Industrie 4.0 für die Kunststoffverarbeitung

Montage-Spritzgießen

Knickarmroboter

Co-Injektion (Barriere-/Sandwich-Spritzgießen)

Hybrid-Spritzgießen (Metall / Kunststoff)

Ressourcenmanagement

Produktion

Technical Excellence thanks  to Digital Assistance

The new Reverse Cube developed by Foboha manufactures various components or multi-component parts from varying materials in one step and assembles individual parts into finished products independently from the cycle time using an integrated handling robot. The automated process improves quality, accelerates cycle times by up to 40 % compared to separate injection molding and assembly processes, and thus enables substantial productivity gains at lower costs.

Manufacturing and Installing Multi-Component Parts on a Two-Part Cube Mold

Montage

Steuern, Regeln

Werkzeugtemperatursensoren

Messtechnik

Sensoren / Messwertaufnehmer

Heißkanalsysteme

Komponenten für die Kunststoffverarbeitung

Reverse Rotation

A Polish pharmaceutical company is developing inhalation therapy for the treatment of lung disease and the appropriate drug delivery drug. The inhaler has a complex interior and consists of 14 components. In order to be able to produce these with the required precision, Celon Pharma has formed a partnership with the mold making company Glittenberg and its hot runner sister Witosa.

Glittenberg Supplies Tools for Vital Medical Devices to Celon Pharma

Medizintechnik

Medizinprodukte

Plastic in the Service of Medicine

The Institute for Plastics Processing (IKV) at RWTH Aachen University is investigating a new control approach for injection molding in which the cavity pressure is controlled by different positions of the hot runner valve pin. The influence on the cavity pressure of different strokes in the holding pressure phase is investigated.

Cavity-Specific Pressure Control to Increase Process Consistency

Mess-, Steuer- und Regelgeräte

Qualitätssicherung

Qualitätssicherung Kunststoff

The Hot Runner Valve Pin  as Actuating Variable

The consumables required for In-vitro diagnostics are manufactured in a production process that is subject to high requirements in terms of precision and quality, but also the complex cleanroom manufacturing environment. This has implications for the entire plant technology – especially toolmaking.

Strategic Approach through Classification according to Product Groups

Werkzeug- und Formenbau

Dienstleistungen

Werkzeug-, Formen- und Modellbau

Mold Platforms for IVD Consumables

SPS – Industrial Automation Fair (SIAF) Guangzhou and Asiamold, the first China fairs to be hosted by Messe Frankfurt in 2021, concluded on 5 March after three days, with the visit number increasing an impressive 27% to 63,968.

Sensorik für Werkzeugmaschinen

Industrie 4.0 für die spanende Fertigung

Verfahren für die additive Fertigung

Kunststoffverarbeitung

Lohnfertigung

SIAF Guangzhou and Asiamold Conclude Successfully

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.

Machine Learning: Combining Simulation and Experimental Test Data

DOE-Software

Qualitätsmethoden

Digitaler Zwilling

Quicker Evaluation of the Optimum Operating Point

Pipette tips feature a challenging wall thickness/length ratio, an inner geometry that is key for analysis results, and a tip opening just a few tenths of a millimeter wide. They have been in extremely high demand during the coronavirus pandemic, which is why the mold construction and hot runner specialist Männer has developed a mold with an innovative cluster concept.

Pipette Tips: Männer Presents a Mold with Replaceable Clusters

Maintenance During (Nearly)  Uninterrupted Production

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.

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

Temperiertechnik

Cooling with Heat Pipes

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.

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

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.

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.

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

Hybridtechnik

Polymere, flüssigkristalline

Kunststoff Werkstoffe

Thermoplaste

Stanzen

Verfahren für die spanlose Fertigung

Schneiden

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.

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

Werkzeuginnendrucksensoren

Quality Assurance for Multiple Cavities

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

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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.