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.

Two thermally separated cube molds rotate in opposite directions at a 90° angle. Bottom: injection and cooling of component 1 (roller made of PP) and component 2 (female connection made of POM), staggered by 180°

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

Spritzgießen

Kunststoffverarbeitung: Verfahren

Montage

Montagetechnik

Steuern, Regeln

Software

Mehrkomponenten-Spritzgießen

Spritzgießwerkzeuge

Kunststoffverarbeitung: Maschinen und Komponenten

Werkzeuge für die Kunststoffverarbeitung

Werkzeugtemperatursensoren

Messtechnik

Sensoren / Messwertaufnehmer

Industrieroboter

Heißkanalsysteme

Komponenten für die Kunststoffverarbeitung

Spritzgießmaschinen

Reverse Rotation

Making a racket is part of the trade. In the past, tradesmen would do this at markets by swinging wooden rattles to attract attention. Today, instead, it is the industry which is trying to make its developments heard and accepted, for example at trade fairs and in the media. What has injection molding technology had to offer recently, aside from Industry 4.0? The answer is process developments that in the main expand the range of applications for plastic parts, mechanical assistance systems that enable consistently high part quality to be achieved more reliably, and the huge field of temperature control. 

New Ways to Attain Special Part Properties Are Advancing the Art of Injection Molding 

Industrie 4.0

Verbundwerkstoffe / Werkstoffverbunde

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

Schaumspritzgießen

Temperiertechnik

Qualitätssicherung

Making a Racket for Plastics  

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

Künstliche Intelligenz für die Qualitätssicherung

Industrie 4.0 für die Qualitätssicherung

Digitale Transformation

Wirtschaft

Innovationen und neue Technologie

Biokunststoffe

Kunststoff Werkstoffe

Spritzgieß-Sonderverfahren

Nachhaltigkeit

Umweltmanagement

Spritzgießsimulation

Simulation

Schnecken und Plastifiziersysteme

Industrie 4.0 für die Kunststoffverarbeitung

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

Qualitätssicherung Kunststoff

Kreislaufwirtschaft

There Is More beyond the Horizon

Arburg has adopted a clear message for its trade fair appearance at the K 2022 in Düsseldorf: „There is only a Plan A“.

In the arburgGreenworld pavilion of the VDMA Circular Economy Forum, an Allrounder 370 A with recyclate package is manufacturing “Greenline” wall plugs from Fischer.

16:9

Messe K-Kunststoffmesse

kunststoffe-international.com

Energieeffizienz

Sustainability thanks to Digitalization

This year, the world’s leading trade show K has succeeded in presenting practical solutions for greater resource efficiency on a broad front. A first foray through the trade show grounds.

K 2022 gave numerous practical examples showing visitors how recyclates can be reliably processed with digital aids.

State-of-the-Art Injection Molding Solutions for Greater Resource Efficiency.

State-of-the-Art Injection Molding Solutions at K 2022

Doriat, Clemens, Dr.

Solar / PV

Energieerzeugung

Erneuerbare Energie

Condition Monitoring / Prozessüberwachung

Instandhaltung

Handling, Handhabungstechnik

Automatisierungstechnik

Elastomer-Spritzgießen

Digitalisierung

Kunststoff-Rezyklat

Silikonkautschuk

Kautschuk / Elastomere

Compoundieren

It Can Be Done!

Injection molding cell combines high article variance with automated product changeover.

With the turnkey solution, 159 product variants can be manufactured.

Flexible Production Concept Combines High Article Variance with Automation

Automatisierungszellen

Automatisierungskomponenten

Inserttechnik

Linearroboter für die Kunststoffverarbeitung

Multiaxialroboter für die Kunststoffverarbeitung

One System, 159 Variants

In the production of an electronic parking aid, 8-pin connectors ensure a reliable connection between the cameras and the electronic system. A seal made of liquid silicone rubber (LSR) molded onto a second tool in a two-component process protects the components against spray water and dust. H&B Electronic produce these icam connectors for systems provider Bosch on a two-component rotary table machine. 

Two-Component Rotary Table Machine Produces Two Million Connectors per Year for  BMW Parking Assistance 

Optische Mess- und Prüftechnik

KFZ-Zulieferer

Additional Eyes for Parking 

The announcements in the field of injection molding give the impression that the developments of recent years are continuing. These include the increasing digitalization of injection molding production, as well as highly integrated production cells that combine very different competencies. The spotlight shines not only on the machinery, but rather on optimum system solutions for integrating molds and individually configured peripheries in the digital and the real world. 

Fakuma 2018: Injection Molding Networked and Integrated 

Steuerungen (Hardware und Software)

ERP-Systeme

Treibmittel

Spritzprägen

Reinraumsysteme / -technik

The Communicative Machine 

For the production of a container for a disinfectant gel precision mold maker Matrix developed a complex 6+6+6-fold 3-component mold. Two single parts are manufactured in one step and sealed in the tool by overmolding with a third component. The demanding mold design which uses two rotating index plates required a tailored hot runner solution which was supplied by Ewikon. 

Tailored Hot Runner Solution for a Demanding 3-Component Mold Concept 

Normalien und Heißkanaltechnik

Molded and Assembled in One Work Cycle 

Tool manufacturer Vema was looking for a suitable hot runner system for a complicated injection molding component ¿ the LED strip of a luxury SUV center console. The challenges: two temperature-sensitive plastics, extremely low shot weights and extremely high demands on the quality of the finished class A part. Hot runner expert Witosa developed a solution based on its product range and provided assistance with the process optimization. 

Witosa Supplies a Hot Runner System for Complex Applications in a Premium Vehicle 

Feel-Good Ambient Lighting  Demands Perfection 

Low assembly effort, often shorter production times and lower-cost parts production overall are the reasons why 2-component injection molding is often used in hard-soft material combinations, including in the production of seals, cable bushings and handles. If the core-back process is to be used for production, however, mold structure and hot runner system design will pose a challenge. 

Günther Hot Runner System for Two-Component Application Offers Space even  in Tight Conditions 

The Soft Component First 

Jako meditec specializes in the injection molding of tubes, with closure caps and racks, in which blood samples from blood donors are kept deep-frozen for many years. Each sample can be uniquely traced thanks to a DM code. The two-component tubes are produced using a special, patented wet-in-wet injection molding process. 

Jako meditec: Patented Wet-in-Wet Process for Freeze-Stored Blood Sample Tubes 

Medizintechnik

Blood Samples with Origin Code 

Increasing demands on component functionality and the need for efficient manufacturing processes are keeping multi-component injection molding squarely in the focus of plastics processing. Not all materials can be processed reliably in the desired combination. The new InMould-Plasma process, which is fully integrated into the injection molding process, facilitates more-efficient production and paves the way for completely new material combinations.

Demonstration mold for the production of a housing cover by the InMould plasma process

More Material Combinations,  Lower Costs

Thermoplastische Elastomere

Thermoplaste

Plasmabehandlung

Reinigen und Vorbehandeln

Dichtungsschäumen

Schäumen / Reaktive Verarbeitung

InMould-Plasma Streamlines the 2-Component Process and Expands  the Material Spectrum

The newly developed Compactcube mold system from Foboha can be used on slightly modified standard machines in the low to medium clamping force range. This means that the advantages of cube mold technology are now also available for applications with smaller production volumes.

Compactcube Reduces Initial Capital Outlay and Maintenance Requirements

New Application Areas for Cube Molds on Standard Machines

Ambient lighting has captured the car interior – and facilitated orientation for the passengers. There is no need for anyone to fumble for the seat belt buckle in the dark in the Audi A7, as an integrated light guide shows the way. Kunststoff Helmbrechts produces the 3-component part and also developed the tool concept. The trick:  a so-called twin-turn tool which rotates on both sides. The company was awarded the GKV TecPart Innovation Prize for it at the K 2019.

Twin-Turn Tool Provides Solution to Production Problem with a Double Turn

Polycarbonat

Dienstleistungen

Runway Lights for the Seat Belt

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

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.

Plastic parts are becoming more and more challenging and the requirements for functionality and dimensional accuracy are increasing. A design unsuitable for injection molding or fluctuating material quality, for example with the use of recycled or biopolymers, as well as general process fluctuations are other challenges. At the same time, pressure on unit costs is rising.

Processes are therefore being increasingly automated, cycle times shortened and numbers of cavities increased. However, increasing process complexity requires improved monitoring and control.

“With cycle rates becoming shorter and the injection-molded parts more complicated, the number of cavities increasing and batch-to-batch fluctuations increasing, there are ever more problems with part quality, for example because not all the cavities are filled simultaneously. Under these conditions, manual monitoring and control of the processes is no longer satisfactory,” says Erwin König, CEO of Priamus System Technologies GmbH in Salach, Germany, about current requirements. The company headquartered in Schaffhausen, Switzerland, specializes in systems for quality assurance, and open- and closed-loop control in injection molding processes.

With the example of the Reversecube inversely rotating cube mold from Foboha (Title figure, Info box), König describes how complex processes are monitored and open- and closed-loop controlled today. “At the plastics processor Hermann Hauff, production by conventional manufacturing of multicomponent parts was operating almost flat out. With the new Reversecube, it was also a priority to ensure uniform filling in the 2 x 24 cavities, and therefore maintain high process stability, and a high product quality.” With Fillcontrol from Priamus, Hauff deploys sensor-based monitoring and process control.

For this purpose, mold wall temperature and cavity pressure sensors register real process data within the mold. They detect the filling time differences in the cavities, monitor the viscosity and compression in order to optimize the processes adaptively.

Hot-Runner Balancing Evens out Differences in Filling Time

“In multicavity molds, filing all the cavities simultaneously is crucial for the part quality. With mold wall temperature sensors, we identify different volumetric filling degrees in the cavities and can automatically equalize them depending on the particular melt flow, until they are balanced out. Then the changeover point is suitable for all cavities, not only for some of them,” is how Erwin König explains the control principle (Fig. 1). The temperature sensors at the end of the flow path recognize when the individual cavities are filled by a steep temperature rise.

“The differences in filling time are compensated by the automatic adjustment of the hot-runner nozzles. That is how we achieve uniform cavity filling. It is a continuous process, which also compensates for fluctuations in the process and between batches. Manual adjustment with, for example, 2 x 24 cavities would be very laborious, particularly for multicomponent applications. By automatic hot-runner balancing, we improve the filling time differences by a factor of around 10, depending on the application,” says König.

An additional control switches to holding pressure at the correct time, depending on the viscosity of the melt. The patented changeover process is based on recognizing the melt front. In distinction to a rigid changeover via the screw volume or cavity pressure threshold, the automatic changeover also takes into account viscosity fluctuations. It is thereby changed over when the cavity is volumetrically filled (Fig. 2).

Control Loop Reduces Viscosity Fluctuations

Because fluctuations in the viscosity and melt flow affect the dimensional stability and part quality, the viscosity is monitored with cavity pressure and cavity temperature sensors. The pressure and temperature are used to determine the shearing stress and shearing rate, from which the viscosity is derived.

“In new molds, the processes are first set up manually and the shear stress and shear rate values determined are saved as reference values. If departures from these values appear in ongoing production, the system makes automatic corrections. The temperatures in the hot-runner manifold and in the injection unit as well as the injection profile are adjusted accordingly. We can thus reduce fluctuations by more than a half,” is how Erwin König describes the viscosity regulation.

Compression Regulation Monitors the  Melt Compression

The strength, dimensional accuracy and surface quality of an injection-molded part depend on how strongly the melt is compressed during injection molding. In the sampling of a component, the desired compression values are therefore saved as reference and the cavity pressure is continually monitored during production. If the measured compression deviates from the reference value due to process fluctuations, the holding pressure profile is adjusted until the optimum compression in the cavity is reached during the holding pressure phase.

“Only with sensors can we gain a genuine insight into the processes. Previously we had to apply trial and error until we had achieved satisfactory results. Now we reach stable processes with good results much faster because we can gain a good deal of process-relevant information from the measurement data.” says Erwin König about the advantages of sensors.

Without online monitoring, quality control would be limited to sampling and problems due to process fluctuations would often remain unrecognized. With sensor-based monitoring, 100 % quality control of all parts throughout the entire production process can be implemented for the first time. Process deviations are immediately recognized by the measurement and corrected by the system. As a result, rejects are significantly reduced. If unacceptable parts are nevertheless produced, they are automatically sorted out. The 100 % parts control also allows end-to-end documentation of the injection molding process and traceability of each individual part.

Sensor Technology Reduces Process Costs and Increases Parts Quality

“Technically speaking, injection molding processes can now run completely autonomously without corrections by users. In practice, the automation leads to the machine operator simultaneously supervising more machines than used to be the case. Less downtime means higher productivity. Cycle times can be further shortened because processes are optimized by measurement of pressure and temperature,” is how Erwin König describes the improvements.

“Smaller, more effective, more robust and more practical,” the CEO also says about the advances in sensor technology. As an example, he names the compact sensors from Priamus, which are also used in this application. A typical cavity temperature sensor has a diameter of only 1mm, which is no longer a problem in the design. It is no longer directly connected to the cable but to a coupling via a spacer. This results in a compact and easy-to-handle solution. For cleaning and maintenance work, the mold no longer has to be dismantled and the cable no longer removed.

Compact sensors are both available as temperature sensors but also as pressure sensors. For strongly abrasive molding compounds, specially wear resistant sensors are available, which normally have an improved lifetime of at least a factor of 10. At Priamus, the pressure sensors are exclusively equipped with a patented sensor and sensitivity identification (type: Priased), which greatly simplifies the handling and avoids setting errors and confusions – especially if several sensors are installed in the mold.

Ortgies Marketing&Communications  

https://marketing-fuer-b2b.de

Otto Männer GmbH  

https://www.maenner-group.com

PRIAMUS SYSTEM TECHNOLOGIES, branch of Barnes Group Suisse Industries LLC 

https://www.priamus.com

Hermann Hauff GmbH & Co. KG  

http://www.hauff.de/

Priamus System Technologies GmbH  

Ausgabenartikel

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°

Fig. 1. Different volumetric degrees of filling in the cavities can be identified with cavity temperature sensors. This balancing is evened out until all the cavities are filled simultaneously

Fig. 2. Changeover via fixed values, such as screw path or cavity pressure threshold causes different degrees of filling in the event of viscosity fluctuations (1). The automatic changeover via the flow-front position balances out viscosity fluctuations (2). SL – switch level (limit value for manual configuration); SLP – switch level point (limit value accurately detected by the program/chip)

Priamus - Hauptartikel Kuint5

The mold system developed by Foboha <a href="http://[1]">[1]</a> can manufacture two and more parts from different materials or colors and assemble them simultaneously with the injection cycle. The system uses mold areas separated into two stacked cube halves, for operations occurring simultaneously. The molding compounds for two individual parts are simultaneously injected into the cavities of the closing planes via hot-runner needle valve systems. The cube halves rotate through 90° with respect to one another. After each rotation, the next injection operation takes place. With the rotation, the individual components manufactured simultaneously are free for removal at the side opposite the operator. For this, a six-axis robot is integrated in the system. Simultaneously with the injection cycle, it removes the parts from the lower cube and places them in the second part, which is still located in the cavities of the upper cube half. The cube concept with the counter-rotating halves allows the manufacturing and assembly of two (and more) components in a very confined space in a shorter cycle.

 Martin Ortgies is a freelance technical journalist and works for the Barnes Molding Solutions Group, <a href="mailto:mails@ortgies.com">mails@ortgies.com</a>

Foboha and Priamus, like Männer, Synventive, Thermoplay and Gammaflux, are companies within the “Molding Solutions” strategic business unit of the Barnes Group Inc. This unit’s goal is the development and sale of high-tech injection molding solutions:

<a href="http://www.barnesgroupinc.de/bgi-businesses/">www.barnesgroupinc.de/bgi-businesses/</a> industrial-segment/<a href="http://molding-solutions.aspx">molding-solutions.aspx</a>

<ol><li>Ortgies, M.: Reverse Rotation Kunststoffe international 109 (2019) 09, pp. 20–24</li></ol>

Read the German version of the  article in our magazine Kunststoffe or at  <a href="https://www.kunststoffe.de/a/fachartikel/qualitaetssicherung-fuer-viele-kavitaete-325986" target="_blank">www.kunststoffe.de</a>