Nowhere are the demands imposed on materials higher than in the area of medical technology. That is understandable because, after all, what is ultimately at stake here is the patient’s health. But any materials manufacturers seeking to use hot runner technology to process polymers in compliance with strict directives and differentiated legal regulations also need the expertise possessed by the hot runner manufacturer’s application engineers.

Günther has recently installed two new injection-molding machines for customer trials in its technical center.

16:9

Testing the Processing Limits of Modified POM Copolymer

Spritzgießen

Kunststoffverarbeitung: Verfahren

Polyoxymethylen

Kunststoff Werkstoffe

Thermoplaste

Normalien und Heißkanaltechnik

Kunststoffverarbeitung: Maschinen und Komponenten

Komponenten für die Kunststoffverarbeitung

Heißkanalsysteme

Medizintechnik

Looking over the Application  Engineer’s Shoulder

Production systems for large molded parts can be flexibly and economically reconfigured or expanded using hot runner adapter plates.

Melt transfer from two on the side injection units of an Engel v-duo 2300 RTM into the middle of the hot runner intermediate plate mounted on the sliding table. 

Economical Solution for the Production of Thermoplastic Large-Structure Components

Spritzgießwerkzeuge

Werkzeuge für die Kunststoffverarbeitung

Co-Injektion (Barriere-/Sandwich-Spritzgießen)

Kunststoff-Rezyklat

Flexible Injection Solutions  with Adapter Plates

We look behind the cavity walls and along the data cable at what hot runner technology now offers in terms of mechanical, electronic and digital expertise.

The smart Control monitoring unit permits integrated monitoring of the injection molding production cell, including the mold, hot runner system and all ancillary components. The “Luer connector” application case was on show at K 2022.

State-of-the-Art Injection Molding Solutions at K 2022: Hot Runner Technology

Doriat, Clemens, Dr.

Mikrospritzgießen

Digitale Transformation

Wirtschaft

Innovationen und neue Technologie

Mess-, Steuer- und Regelgeräte

Qualitätssicherung

Qualitätssicherung Kunststoff

Temperaturregler

Messtechnik

Sensoren / Messwertaufnehmer

Additive Fertigung

Everything under Control

Witosa is replacing titanium with 3D-printed steel elements in its hot runner systems. Its long-term goal is carbon neutrality.

Reducing the CCF through Titanium-Free Mold Constructions

Hot Runner, Carbon Neutral

Jessica Poliner has been appointed President of Barnes Molding Solutions. She replaces Norbert Scheid, who retired from Barnes Group in December 2020.

Jessica Poliner has been appointed President of Barnes Molding Solutions

Werkzeug- und Formenbau

Dienstleistungen

Werkzeug-, Formen- und Modellbau

New Management to Head Barnes Molding Solutions

According to the company, the UltraShot Injection System provides part design freedom, while improving part quality and speed of mold qualification.

The UltraShot Injection System filled the entire part where a conventional injection molding process at 2758 bar could not

Husky introduces the UltraShot Injection System

Kunststoffverarbeitung allgemein

Kunststoffverarbeitung

Spritzgießmaschinen, allgemein

Spritzgießmaschinen

Kunststoffverarbeitungsmaschinen

Next Generation Melt Delivery and Control System

The completion of the transaction is subject to customary regulatory approvals and is expected by the second quarter of 2021.

Oerlikon acquires Italian company INglass S.p.A. and its market-leading HRSflow business unit for hot runner system technologies

Oberflächentechnik

Oerlikon Signs Agreement to Purchase INglass

For the further development of the Streamrunner and also for customer demonstration purposes, Hasco hot runner has developed an innovative 32 cavity injection mold tool.

The special feature of the mold is the 32-cavity Hasco Streamrunner

New Design Possibilities in Moldmaking

With the Streamrunner from Hasco, the first additively manufactured hot runner, now completely new and space-saving options are also available for valve gate systems.

Fully balanced 20-cavity system with valve gate technology with an outer dimension of the 3D-printed manifold of just 124 x 124 mm. 

Heißkanaltechnik

Messung von Umgebung (Klima)

Additively Manufactured Hot Runner Manifolds with Needle Valve

It is a hot runner nozzle such as had never been seen before Fakuma 2021: with a honeycomb structure on the outside and, in the nozzle interior, integrated insulation gaps manufactured in one part by the additive SLM process, in which even the fastening nut is captively printed on the nozzle body. The pride of the concept is the special algorithmic modification of the nozzles for any application case.

A mold-making job with up to 30 nozzles is processed in the SLM machine in about 24 hours. 

The First Additively Manufactured One-Part Hot Runner Nozzle

Selektives Laserschmelzen von Kunststoff, Metall, Keramik

Verfahren für die additive Fertigung

Pulverbettverfahren

Algorithmically Modified  Inner Workings

Family molds belong to the state-of-the-art in injection molding – at least when wall thicknesses and volumes of individual components vary considerably. Using a trial mold soon ready for series production, Synventive demonstrates that – though demanding – optimal process control can be achieved using the right technology. The filling of each mold cavity is controlled individually and in real time. The Kunststoffe editorial team were among the first guests at the new Tech Center.

View into the mold space of the Engel Duo 2700 at the Tech Center. In the background, a 6-axis robot with 180 kg load-bearing capacity which removes the components.

Single-Shot Injection Molding of Heterogeneous Components

Schröder, Susanne

Leading-Edge Process Control

The new “Heat-Inject” product from Incoe International Europe stands out in that it uses the hot runner system as a carrier platform, but instead of melt, it brings heat into the cavity.

The heat pulse from heat-inject ensures good surface quality where a weld line may otherwise be visible due to the part geometry and gating.

Targeted Heat Pulses in the Cavity

With immediate effect, a new generation of compact linear servo motors is available for Ewikon‘s electric needle valve systems.

Ewikon has now fitted the electric needle valve system with a new generation of compact linear servo motors.

Messe K-Kunststoffmesse

kunststoffe-international.com

kunststoffe.de

Servo Motors for Needle Valve Technology

Bio-Fed and Günther Heisskanaltechnik have performed various trials, which show that even supposedly sensitive bioplastics can be reliably processed in hot runner molds.

Fig. 4. Interchangeable inserts for various test samples can be installed in the two-cavity trial mold.

Bio-Fed and Günther Heisskanaltechnik have performed trials, which show that even supposedly sensitive bioplastics can be reliably processed in hot runner molds.

While Processing Trials Proved Highly Successful, an Intuitive Feeling Is Required

Biokunststoffe

Processing Bioplastics  in Hot Runners

Moldmaster uses thermoanalysis to identify melt leakage in the manifold outlet.

The TempMaster control unit detects leakages in the manifold recess by thermoanalysis.

Leak Detection in Manifolds

Sequential Injection with a 6-Fold Valve Gate System for a Floor Grate

Products intended for use in building services must meet very high quality requirements in terms of both their constituent materials and functionality. A single-cavity mold for a floor grate made by Barku, which appears to be a simple part at first glance, called for a certain level of technical sophistication. This was provided by a moldmaker with the necessary technical understanding and hot-runner manufacturer Witosa who, between them, devised the right solution for what proved nevertheless to be a complex mold.

Experienced polymer engineers are only too aware that a product which at first sight appears incredibly simple and, moreover, is to be made in a single-cavity mold is not necessarily easy to realize in practice. So, too, with the floor grate that Andreas Stietz, project manager at Barnstorfer Kunststofftechnik GmbH & Co. KG (or to use its short form, “Barku”), worked on most recently.

Barku designed a mold for the part, which measures 1500 x 600 x 30 mm, is used as a protective grating in animal husbandry and is intended for the American market.

As Stietz puts it, the part posed a number of challenges: “A part might look simple but the production of large plastic parts is not a simple matter. This application is designed for modular use and requires that certain dimensions be maintained – e. g., shrinkage and warpage must be kept in check – and sink marks eliminated. This only works if the right technology is used.”

In order to successfully test this technology at the end of such a project on one of the 50 injection molding machines at the main plant in Barnstorf, Germany, the various pieces of the puzzle would first have to be brought together, coordinated and then slotted into place, says Stietz.

Long before a part and mold concept are created, several items have already made it onto the checklist. Right from the design stage, Barku’s vast experience in material deployment, mold concepts, and determination of injection points, play a key role. Even aspects that come right at the very end of a process, such as part handling on the machine or packaging, are factored into all deliberations from the very start.

A regional mold maker with whom Barku already had a long-standing business relationship was contacted about making the mold. First, though, Barku commissioned Witosa GmbH to conduct a 3D filling simulation because the insert floor, expected to weigh from 3200 to 3300 g, would require a complex injection molding process.

The simulation was needed, on one hand, to determine the pressure requirement, the flow behavior and the heat distribution in the mold, and on the other, to identify the location of flow lines.

Six Individual Drives for  Cascade Control

This moldflow analysis was used by all three parties to optimize the mold concept, which featured a 6-fold valve gate system from Witosa with individual drives for cascade control (Fig. 1) and which Barku ultimately commissioned the mold maker to produce.

The floor grate was to be produced from low-cost HDPE at Barku’s sister plant in the USA. This semi-crystalline thermoplastic, which is considered an easy-to-process polymer, would provide the requisite smooth surface for the part. During processing, however, several challenges arose, because HDPE’s tendency to shrink considerably would lead to warpage in such a large plastic part. Working with this material therefore calls for specialist expertise and a high level of technical know-how along the process chain, from part design and mold construction to hot runner design through to injection molding.

Challenges for the Mold Maker and Hot Runner Manufacturer

Barku had already laid down the injection points during the part design process. Using simulations, it worked with Witosa to locate the nozzles in positions that would allow the thick-walled part to be produced true to shape. The hot runner manufacturer had already used the filling simulation to calculate the optimum flow paths for the material. To ensure that the part would meet the desired level of quality without warpage, sink marks or shrinkage, the 6-fold valve gate system was balanced in such a way as to enable a cascade control system to actuate the valve gate nozzles via individual drives.

Andreas Stietz kept cycle times in production as short as possible and thus economical by paying particular attention to heat control in the mold, in addition to cascade control of the hot runner. The cooling circuits in the mold were incorporated in such a way as to allow individual temperature control of different areas. Furthermore, a Witosa motion controller (type: MC-0.18.16) was incorporated to regulate cascade control and improve cycle times. It offers a convenient way to program time-shifted opening and closing of the needles and thus enables optimum cavity filling.

Barku inspects all molds in Lower Saxony, Germany, before shipping. This also applies to the roughly twelve-ton mold for the floor grate. At the customer’s request, a member of the application engineering staff and the sales manager from Witosa, Stephan Ochse, were on site for the mold trials.

The trials served to work out the final injection molding process. It was already apparent after the first shot that the part had several hot spots upon demolding and that the process, as expected, needed to be optimized. The trick now was to adjust the process so that the part would have an almost constant temperature over its entire surface upon removal from the mold. The cascade process for gating the part provided the necessary scope for making this adjustment. As the material also exhibits quirks during the manufacturing process and material buildup on the valve gate had to be avoided, Witosa used coated needles to help optimize the process.

Once the parties involved had completed each of their optimization cycles – Witosa worked on the hot runner system (Fig. 2), the regional mold maker on the mold and Barku’s process mechanic on the injection molding process – it was now possible to define all the process parameters for cost-effective production of the floor grate.

The single-cavity mold is in production about seven months of the year, with a high utilization rate, on an injection molding machine of 10,000 kN clamping force at Cleveland, TN/USA (Title figure). “People don’t generally give a lot of thought to this clamping force,” Stietz says. “Just to give you some idea: the floor grate is manufactured under a pressure of 1000 tons, which is equivalent to the weight of about 1000 Smart cars stacked one on top of the other.”

Witosa GmbH Heisskanalsysteme  

https://www.witosa.de

Ausgabenartikel

Sebastian Lotzin, CEO of Barku’s U. S. subsidiary, with floor grate (3250 g) in the 10,000-kN injection molding machine that makes the part

Fig. 1. Fully wired 6-fold valve gate system (DS-40.200) including tubing for pneumatic control of the individual NK4 drive units 

Fig. 2. Simulated temperature distribution of the hot runner system in the heated state

Name - Hauptartikel

Franciska Thomas works in the marketing department of Witosa GmbH Heisskanalsysteme, Frankenberg, Germany; <a href="mailto:franciska.thomas@witosa.de">franciska.thomas@witosa.de</a>

Barnstorfer Kunststofftechnik GmbH & Co. KG was founded on October 1, 1977, as a subsidiary of Lubing Maschinenfabrik GmbH. Barku has long since become an autonomous and independent company with headquarters in Barnstorf, Germany, where it injection molds precision parts and extrudes profiles and pipes.

<a href="http://www.barku.de">www.barku.de</a>

Aside from hot runner nozzles and hot runner systems featuring open gating or valve gates, Witosa GmbH Heisskanalsysteme offers control technology. The product range offered by this family-run company, which was founded in 2006, is developed and manufactured at the Frankenberg site in northern Hesse, Germany.

<a href="http://www.witosa.de">www.witosa.de</a>

issue 02/2023

issue 01/2023

issue 09/2022

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