At the 2019 K fair, Arburg and Simcon showcased a filling process proceeding in real-time, as a 3D animation, on the display of a machine control panel, for an example of sunglasses, made of PA12. All that was needed to prepare this, was to load the simulation model, as well as the geometry of the part, directly onto the machine controls. This sounds almost too easy to be true. Right?

Interview with Eberhard Duffner and Paul F. Filz by the Magazine Kunststoffe

Spritzgießen

Kunststoffverarbeitung: Verfahren

Doriat, Clemens, Dr.

Spritzgießwerkzeuge

Kunststoffverarbeitung: Maschinen und Komponenten

Werkzeuge für die Kunststoffverarbeitung

Dienstleistungen

Werkzeug-, Formen- und Modellbau

Spritzgießsimulation

Software

Simulation

Interview

Anyone seeking to replace a metal component by a plastic one, to reduce the number of component parts from eight to three and simultaneously cut both the weight and manufacturing costs needs to take great care to ensure that all specifications are met – especially if the component is used in a hot gearbox and is subject to high mechanical stress.

Production-Ready Plastic Shifter Fork Offers a Maximum of Functional Integration

Kohlenstofffasern / -matten

Kunststoff Werkstoffe

Verstärkungsstoffe

Produktentwicklung (F+E)

Innovationsentwicklung

Wirtschaft

Innovationen und neue Technologie

Inserttechnik

Verbundwerkstoffe / Werkstoffverbunde

Hybrid-Spritzgießen (Metall / Kunststoff)

Replacing Metal in the Gearbox

A recently developed variant for processing continuous fiber-reinforced semi-finished products by injection molding, involves positioning a defined number of UD laminates appropriate to the specific requirements in the mold and then overmolding them. The resultant lightweight, three-dimensional parts have rigidity and strength which are markedly anisotropic and optimized for their particular loading situations. 

UD Tape Reinforcement Minimizes Weight while Maximizing Local Loading Capacity 

Handling, Handhabungstechnik

Greifer

Faserverarbeitung

Halbzeuge und Zwischenprodukte

Werkstoffprüfung, mechanisch

Zug-und Druckfestigkeitsprüfgeräte

Having a Good Grip on Hot Laminates  

To be able to cost efficiently design complex molds, e. g. for BMC components, it is essential to take into account the mold cooling. Thus, the mold costs increase in a linear relationship with the number of heating cartridges provided. It is therefore desirable to aim for as few cartridges as possible, but at the same time, this can have a disadvantageous effect on the homogeneity of the temperature distribution and the robustness of the process. Until now, these conflicting goals were largely resolved based on experience. But it can also be done systematically. 

Simple Answers to Complex Questions in Mold Design 

Temperiertechnik

DOE-Software

Determining the Optimum Heating Concept for BMC 

Marbling is often a real eye-catcher in plastic components. However, the effect is difficult to create and there are some pitfalls when it comes to reproducibility. Novel nozzles for injection molding machines in combination with a special dosing technology allow marbled molded parts to be produced far more easily in a much more robust process.

A 3D-Printed Nozzle and Modified Dosing Method Deliver Reproducible Marbling  in a Robust Process

Kunststoffe

Photonik

Optik

Additive Fertigung

Farben, flüssig

Additive

Exciting Design instead of  Exciting Manufacturing

Hybrid production chains have been increasingly in the spotlight in recent years. This also applies to the combination of conventional manufacturing and additive processes in tool construction. With the example of an injection molding tool, it is shown how mold inserts produced by additive manufacturing can greatly shorten cycle times, and thereby significantly reduce unit costs. The important thing is to find a suitable combination of processes from the variety available.

Additive Manufacturing and Hybrid Molds in Combination with Conventional Machining

HSC- / HPC-Bearbeitung

Spanende Verfahren

Werkzeugkonstruktion

Anlagen Additive Fertigung / 3D-Druck, Metall

Anlagen für die Additive Fertigung

The Potential of Redesign and  Part Consolidation

Starting with the systematic design of manufacturing processes and the precise simulation of part manufacture, through smart tooling technology and sophisticated melt guidance, to efficient mold temperature control, numerous exhibitors have many innovations in the field of tooling technology on offer at K 2019.The current debates concerning marine pollution as well as anthropogenic climate change and its consequences seem to be having an effect at this world-leading trade show for plastics processing in Düsseldorf, Germany. A number of companies are noting the growing customer interest in sustainable, carbon-neutral and resource-efficient modes of production, and offering products and services intended to satisfy this interest.

Resource-Efficient and Environmentally Friendly Products Are the Trend in  Tooling Technology

Werkzeuginnendrucksensoren

Messtechnik

Sensoren / Messwertaufnehmer

Temperiergeräte

Gießanlagen

Normalien für die Kunststofffertigung

Normalien

Heißkanalsysteme

Komponenten für die Kunststoffverarbeitung

Kaltkanalsysteme

Exhibitors See Green

In addition to excellent mechanical characteristics and suitability for recycling, the key feature of hybrid lightweight structures made of fiber-reinforced thermoplastics is that automated, large series production is possible. New mold and process technologies were successfully developed within the scope of the ReLei research project, enabling the production of complex shaped sandwich elements in an efficient combined process.

Thermoplastic Sandwich Structures for Large Series Applications

Schaumspritzgießen

Fasern

Kunststoff-Halbzeuge

Spritzgieß-Sonderverfahren

Industrieroboter

Montagetechnik

Faserverbundwerkstoffe

Andere Werkstoffe

Making It Big with Small Bubbles

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

Smart Factory

Energieeffizienz

Mikrospritzgießen

Mehrkomponenten-Spritzgießen

Spritzgießmaschinen, allgemein

Spritzgießmaschinen

Fließpressen

Handling, Handhabungstechnik für die spanende Fertigung

Automatisierungstechnik

Elastomer-Spritzgießen

Linearroboter für die Kunststoffverarbeitung

Industrie 4.0 für die Kunststoffverarbeitung

Industrie 4.0

Montage-Spritzgießen

Knickarmroboter

Co-Injektion (Barriere-/Sandwich-Spritzgießen)

Ressourcenmanagement

Produktion

Technical Excellence thanks  to Digital Assistance

Flexflow is an innovative, servo-driven, finely adjustable valve gate system for cascade injection molding. Especially with large-format parts as are used in the automotive industry for interior and exterior applications, the technology can be used to attain significant improvements in the surface quality of the part while reducing the required clamping force and even the part weight. It also avoids the dreaded pressure marks on the molding that often occur with the cascade injection molding process. 

The Italian Hot Runner Specialist HRSflow Focuses on the Quality of Large-Format Parts 

Steuern, Regeln

Normalien und Heißkanaltechnik

Intelligently Controlled Cascade  Injection Molding  

At the K 2016 in Dusseldorf, Germany, four project partners demonstrate the end-to-end networked process chain from the product development, simulation and the design of the sensor-fitted tool to testing the first sample on the injection molding machine and finally manufacturing within interconnected production. Thanks to the transparency of this process, the partners are able to set the production course toward the overriding principles of the production concept ‘Industry 4.0’.  

Interconnecting all Elements of the Value Chain from the Product Idea to Injection Molding in the Production Line 

Thermographie

Druck- / Kraftsensoren

Produktentwicklung(sprozess)

Finding our Way through the Labyrinth 

"Think of it like this: the clip is bent when it leaves the machine, and you can see it straightening as it cools", states Georg Schlöser. "And that is how we calculated it", he adds satisfied, since he analyzed the required shrinkage allowance with Sigmasoft, so that the mold could deliver dimensionally true parts from the first shot.  

With Sigmasoft Virtual Molding, F. & G. Hachtel Manufactures Accurate Parts from the First Shot  

Qualitätssicherung

Getting Warpage under Control  

Bielefeld University of Applied Sciences has succeeded in developing an injection mold that does not require conventional liquid-based temperature control. Heat equalization is effected by means of heat pipes instead. Mold design and heat-pipe selection are based on the outcome of thermal simulations, which yield reliable results thanks to an unconventional approach. 

Simulating Heat Flow in Injection Molds with Heat Pipes 

Prozesssimulation

Kupfer

"No Cool" Molds, Properly Simulated 

The optimization of injection molding processes by using software to simulate mold filling and solidification is standard today. However, this has its limits, especially if the material properties or the flow behavior are not known with sufficient accuracy. The services offered by Beaumont, such as material testing, injection molding tests or the optimization of flow channel systems, can help here.  

MF Software Exclusively Distributes Beaumont Products in Europe 

Werkstoffprüfung

Rheologie

Higher Productivity and Better  Process Control 

Users can now precisely simulate and design the mold temperature control already at the planning phase. 

Cooling Simulation with Temp-Flex Hoses 

Precise Simulation of Thermal Behavior 

A Bike Frame from an Injection  Molding Machine

Controlling Complex Development and Manufacturing Processes, Using Simulation

The toolmaker Siebenwurst uses injection molding simulation to optimize part design and production processes in its routine workflows. Among other things, Simcon’s software ensures the quality and dimensional accuracy of the plastic frame for the first series-produced injection molded e-bike.

The small river Altmühl flows peacefully through the valley of the same name in the Bavarian Upper Palatinate. When visitors enter the production hall of the model and mold maker Christian Karl Siebenwurst GmbH & Co KG in Dietfurt, Germany, they quickly leave this tranquility behind.

More than 400 engineers and technicians work here, serving the most prestigious OEMs and suppliers to the German automotive industry. Every year, they design and manufacture around 150 injection molds, mainly for instrument panels, window frames, radiator grilles and many other large plastic components. Other clients of this high-tech supplier include manufacturers of household appliances and companies in the field of climate and environmental technology.

The company, which was named Toolmaker of the Year 2018, has recently created the backbone for the first series-produced e-bike: an injection molded plastic frame (Title figure).

Siebenwurst manufactured the components for the start-up Nuvelos (see Box p. 27), a fully owned subsidiary of the automotive supplier Rehau. Apart from their extraordinary design, the bicycles made a name for themselves especially with their composite frame, which performs at on the same level of strength as aluminum or steel frames. This is also an achievement of the development team led by Frank Bäcker, Head of Development and Design at Siebenwurst.

Bicycle frames are a rather unconventional product for toolmakers. But: “The principle that complex thermoplastic support structures replace traditional aluminum or steel components is becoming increasingly common in the automotive industry. Often, this is also in combination with overmolded steel insert elements”, the industrial engineer Bäcker explains.

The asymmetrical frame is composed of two injection-molded half-shells (Fig. 1), which are joined to form a robust structure, and an additional organic sheet glued into the battery compartment. “The components consist of a polyamide with a 50 % glass fiber content. To ensure that they meet the requirements perfectly and can be injection molded without defects, we first tested all relevant aspects in a feasibility analysis using simulation. This is how we optimized mold, component and process.”

Simulation Reveals Distortion Problems and Gap Formation

To simulate and optimize, the experienced mold designers deploy the software solution Cadmould 3D-F, by simulation specialist Simcon kunststofftechnische Software GmbH, Würselen, Germany. The results were valuable: the simulation showed that shrinkage and warpage would have caused problems in the initial design of the frame halves. Gaps of up to 5 mm would have arisen at the mounting points of the headset and rear wheel.

Cadmould simulation was then used to test numerous compensation measures. At the same time, it was necessary to maintain a balance between the strength of the frame and the use of materials. After all, lightweight construction is at least as important for bicycle frames as it is for vehicles powered solely by engines. By optimizing the mold design (Fig. 2), and by modifying and repositioning reinforcement braces in the part, the designers were able to find a solution. Doing this in a simulation environment helped avoid time-consuming and cost-intensive physical correction loops, down the line.

“Thanks to Cadmould, we can precisely determine filling and temperature behavior, filling pressure, cooling time and holding pressure on the basis of plastic material data, long before a single real component is produced,” summarizes Daniel Maier, Project Manager R&D at Siebenwurst. The calculations help us to identify possible problem areas and potential for improvement at a very early stage. In addition, this helps to identify the best combination of component, tool and process (Fig. 3).

Siebenwurst also uses the simulation software to evaluate customer specifications such as injection concepts and points, and identify suggestions for better solutions, which are then developed with the customer. The production process is always thought through end-to-end – including part handling and machine requirements for filling pressure, clamping force and demolding.

By testing and comparing numerous variants quickly, easily and cheaply simulation practitioners can achieve the best machine capacity and performance. “Our users simulate the effects of changing parameters like number, dimensions or position of injection nozzles or the flow paths – and so they get the learnings and benefit without having to modify a physical mold.” says Barbara Schumann of Simcon.

Component Changes during the Design Phase of the Tool

More often than not, Siebenwurst accompanies and supports their clients’ project development from the very beginning. This means that the tool designers ongoingly evaluate feasibility of the 5 to 40+ tonne tools, from the very beginning, in parallel to product design. A constant exchange of information and sophisticated time management are crucial for successful simultaneous engineering, with overlapping process steps.

This method also enables the toolmaker to quickly and efficiently adapt to part changes during the design phase of the tool, thus enabling shorter product cycles and an increasing number of variants, according to the requirements of the customer. Even production machine capacity planning and raw materials and standard part procurement are already done during the design phase. This collaborative and parallel process makes it possible to achieve the very best products, together.

At Siebenwurst, design and production are consistently planned centrally using a system in which every design, every production step, and every individual part are represented and scheduled. The production control center includes a display of the real-time status of all projects. In addition to securing project deadlines, this also optimizes the continuous utilization of the more than 50 machines. Project planning for development, construction and sampling is based on weekly templates. These contain appropriate planning sequences and important milestones, depending on the tool size and current capacity utilization.

Precise organization and task control ensures optimal quality for every single tool that is produced in the Altmühltal – and ultimately, this is what made the success of Rehau’s e-bike project possible. “Cadmould has helped to make this possible. Simulation software has been an important component here and in all of our other projects as well. We use it throughout the entire process, from preparing a quote to the completion of a project,” says design and development manager Bäcker. “Simulation software is essential for a thorough evaluation of the feasibility and profitability of projects.”

Simcon GmbH  

www.simcon.com

Christian Karl Siebenwurst Modell- und Formenbau GmbH & Co KG 

www.siebenwurst.de

Ausgabenartikel

The frames give the e-bikes an extraordinary design, with robustness comparable to steel or aluminum

Fig. 1. In the dimensionally stable hollow structure of the frame made of a thermoplastic fiber-plastic composite, the battery, cable and motor can be integrated into a novel, flat design

Fig. 2. Shrinkage and warpage during injection molding were calculated by simulation and the position and wall thickness of reinforcing struts inside the frame were improved 

Fig. 3. Simulation of the cascade injection molding process, from left to right: filling level (30 %) just before opening the second stage; filling level (73 %) just before opening the third stage; filling level (98 %) when switching over

Name - Hauptartikel

Nuvelos is the e-bike project of automotive supplier Rehau AG & Co. The start-up was created in 2016 from the research project TherMobility (“Support frame structures made of fiber-reinforced plastics for single and multi-track vehicles”), funded by the German Federal Ministry of Economics. The first 3D-printed prototypes were produced in 2017. Following the design and manufacture of the tools for the frames, series production of the frame half-shells also started in 2019 at the model and mold maker Siebenwurst.

Nuvelos is the world’s first serially produced e-bike with an injection molded frame. At the end of 2019, Rehau discontinued the product for other strategic reasons. In January 2020, the pedelec was awarded the pro-K-award gold. The riders of the 300 bikes produced therefore own a historic milestone in plastics processing, and a collector’s item with high recognition value.

Tim Hacken is technical editor and managing director of the agency TimTomText in Aachen, Germany.

Daniel Maier is project manager F&E at Siebenwurst; <a href="mailto:d.maier@siebenwurst.de">d.maier@siebenwurst.de</a>