Technical Report 2017-03-10

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Unnoticeably Good - Ehrlich Werkzeug- & Gerätebau GmbH relies on the Koch-Technik technology for drying and conveying plastic materials

Ulrich Mangelsdorf, Werner Koch Maschinentechnik GmbH

Ehrlich Werkzeug- & Gerätebau GmbH delivers almost 95% thermoplastic mouldings produced in Koenigstein to automotive industry suppliers. In addition to these products, strongly hygroscopic plastics with up to 60% ratio of glass fibres are especially used. For drying the material and its consequent transport to injection moulding machines the company relies on peripheral equipment made by Werner Koch Maschinentechnik GmbH, Ispringen.

Auf einer eigens errichteten großen Bühne wurden die Anlagen zur Granulattrocknung installiert. Drei KOCH CKT-Trockner mit Trockenlufttechnik versorgen die Spritzgießproduktion mit jährlich 1800 t vorgetrocknetem Rohmaterial.
Auf einer eigens errichteten großen Bühne wurden die Anlagen zur Granulattrocknung installiert. Drei KOCH CKT-Trockner mit Trockenlufttechnik versorgen die Spritzgießproduktion mit jährlich 1800 t vorgetrocknetem Rohmaterial.
When the board of directors describe the installed peripheral equipment of the brand Koch-Technik as "unnoticeable", they mean it in the positive sense of word. "Unnoticeable means trouble-free. And this is an absolutely critical criterion for an automotive industry supplier as we are. Koch-Technik dryers and transportation systems for material distribution has operated without any troubles since their commissioning," is the explanation.

As early as in the middle of 1990s the company got an overview of the common material transport and granule drying technologies with a view to modernize the production. During their visit at Fakuma in 1996 they were satisfied of the comprehensive, individually adaptable offer of Koch-Technik from Ispringen. Soon after, the first dryer was ordered. This days, plastic moulding machine lines at Ehrlich GmbH is continuously fed by three dryers and two automated material conveying systems made by Koch-Technik.

In 2013 Ehrlich moved from Pirna to a new plant in Koenigstein. A year later the third dryer was installed there and one of the previous dryers was completely modernized. At this dryer, working since 1997, all the control units were replaced and equipment operation was merged in a modern Siemens PLC S7 control unit. By now, all the processes of this dryer are confortably controlled via touch panel – from the dew point control to the patented Koch-Eco control system.

Über das Touch-Panel lassen sich alle Abläufe überwachen und Trocknungstemperaturen, Luftmengen und Verweilzeiten komfortabel regeln.
Über das Touch-Panel lassen sich alle Abläufe überwachen und Trocknungstemperaturen, Luftmengen und Verweilzeiten komfortabel regeln.
High-tech Granulate Drying
The high-tech technology of three dry air dryers of CKT series meets the demands for efficient drying of all plastic granulates friendly to the material. It is because condensate can be formed on the granulate surface in case of insufficiently controlled drying of thermoplastics. During consequent processing defects and bubbles are formed, embrittlement occurs and the final product strength is impaired. To completely exclude occurrence of such adverse effects, CKT dryers operate depending on the dew point with two closed drying circuits which switch over at the moment when the used drying medium (desiccant) is saturated with humidity. During granulate drying the drying air dew point is always maintained at the range of -30 to -60 °C. This corresponds to the maximum absolute water content of 0.33 – 0.011 gram per cubic meter of dry air, and granulate is first of all absolutely safely and economically dried to the necessary residual humidity which is optimum for its processing.

Auf den Spritzgießmaschinen sind KOCH TM-Materialabscheider installiert, die eine wechselweise Förderung von zwei verschiedenen Materialkomponenten zulassen.
Auf den Spritzgießmaschinen sind KOCH TM-Materialabscheider installiert, die eine wechselweise Förderung von zwei verschiedenen Materialkomponenten zulassen.
Protection against Overdrying
The guarantee for maximum energy savings and at the same time for drying which does not damage the material is the Koch-Eco control system. This patented control continuously checks temperatures in the upper part of the drying container. As soon as the temperature in any of the containers rises because material is not needed or only a small quantity is taken away the air inlet and air outlet are closed, heating is switched off and the container is put to standstill. As soon as the material is taken away again, the container is automatically switched on. In case the manufacturer has the ECO control system, it takes advantages of maximum energy saving as well as of safe protection from overdrying of temperature-sensitive material It reliably prevents discolouration and a change in mechanical properties. Drying blowers with frequency converters represent further potential energy savings because they always adjust their performance according to the current need. This means that if more than a half of the containers are paused, another up to 50% of energy can be saved.

The drying process in Ehrlich GmbH can be controlled and adjusted by means of a large touch screen which offers the user a comfortable overview of the whole equipment. Thanks to this control it is possible to clearly detect and comfortably set the drying temperature, air volume control, the dwell time, throughput rate and energy flap control.

24 Spritzgießmaschinen mit Schließkräften von 25 bis 800 t werden mit den KOCH-Zentralförderanlagen mit Material versorgt.
24 Spritzgießmaschinen mit Schließkräften von 25 bis 800 t werden mit den KOCH-Zentralförderanlagen mit Material versorgt.
Supplying 1,800 t of Material a Year
Using peripheral equipment made by Koch-Technik , this eastern Saxony producer that has been dealing with the production of plastic parts since 1982 produces thermoplastic components. In approximately 95 per cent they include air bag covers, cable ducts and parts for vehicle interiors which are delivered to automotive industry suppliers supplying Volkswagen, BMW, Mercedes and General Motors car manufacturers. Products for the production of instruments for medical devices and consumer industry should also be mentioned. To manufacture mouldings in high volumes, the total of 24 injection moulding machines with clamping forces from 25 to 800 t must be continuously fed by the material using the Koch-Technik systems. Approximately 180 million pieces with the weight from 0.5 to 1,000 g are annually produced here. The consumption of the material for vehicle parts is about 1,400 tons of plastics per year, which especially include TPE, PE, PA, PC, POM and PP with glass fibre content up to 60 per cent. As the company also deals with the production of tools, a large number of various materials need to be added. Tools for injection moulding intended for external customers are tested at injection moulding machines connected to the material supply equipment. Depending on the purpose of use, a large number of different types of materials, which are not processed in the mass production in the company, are used.

Umlenkungen im Materialstrang wurden mit sanft geschwungenen Bögen aus Spezialglas realisiert, um Abrieb beim Transport des glasfaserhaltigen Materials auszuschließen.
Umlenkungen im Materialstrang wurden mit sanft geschwungenen Bögen aus Spezialglas realisiert, um Abrieb beim Transport des glasfaserhaltigen Materials auszuschließen.
Adjusted Material Supply
The material supply starts in two large twin-compartment silos. Granulate is conveyed from the silos to dryers and then to processing. Connection units are guiding the material to the correct material separators on top the injection moulding machines. This is performed at the speed preventing undesirable abrasion and damage to the pipeline. Two large vacuum pumps, each with the output of 5.5 kW, ensure the necessary vacuum, and two Sa3 safety filters remove foreign particles from dusty air during the transport. The equipment is controlled by means of large touch screens of the central control. Authorised operators can modify all transportation parameters via them. The pipeline is led by means of elbows made of special glass in curves. This prevents wear which would be otherwise caused by abrasion resulting from the use of a glass fibre granulate. Glass flaps in separators ensure that the abrasive material only hits a hard-wearing glass and thus improve resistance of transport systems at periphery. In Ehrlich, material separators which enable alternative supply of two types of materials are almost always installed on injection moulding machines. Thanks to these conveyors for two components (Tm), if needed, it is possible to process an additional percentage of milled material – either directly from the attached mill, or from the stock material of previously ground wastes.

Die zentrale Materialversorgung mit Rohmaterial startet bei den beiden großen Silos im Außenbereich des Unternehmens.
Die zentrale Materialversorgung mit Rohmaterial startet bei den beiden großen Silos im Außenbereich des Unternehmens.
The thermoplastic product manufacturing of Ehrlich is mainly focused on the precise workmanship. Dimensional accuracy is more and more important especially for engine parts. Appearance of course plays an important role in visual parts. The Koch-Technik equipment significantly contributes to its quality. Customers of Ehrlich GmbH seem to appreciate this high quality. The company's turnover increased from EUR 7.8 million in 2013 to more than EUR 10.8 million in 2014, and to EUR 12.6 million in 2015.

Ehrlich Werkzeug - & Gerätebau GmbH
The company founded by Kurt Ehrlich in Pirna, Germany in 1954 started to deal with plastic processing in 1982. After the re-privatisation in 1990, Gunter Ehrlich rebuilt the company to a modern performance tool production and production of thermoplastic mouldings. Since 2013 Ehrlich GmbH has been a part of Amphenol Corporation, a large electrical technology company. At the new headquarter of the company in Koenigstein, 120 employees produce thermoplastic mouldings and tools for injection moulding at three-shift operation for internal as well as external customers.

Werner Koch Maschinentechnik GmbH
Die Werner Koch Maschinentechnik GmbH, Ispringen with its brand Koch-Technik is one of few providers of complete peripheral equipment for the processing of plastics. The portfolio of company's products includes units and systems designed for mixing, dosing, conveying, drying and storage of plastic granulates. Koch-Technik offers various customized solutions under using of its modular system to its customers – regardless of whether they require the use of individual devices, or the installation of comprehensive central systems. Units and systems used by more than 5,000 plastic moulding producers worldwide prove the acceptance and the high utility value of these peripherals in the manufacturing practice.

Werner Koch Maschinentechnik GmbH

Industriestraße 3
75228 Ispringen/Pforzheim, Germany

Phone:  +49(0)7231 80 09 - 0
Fax:      +49(0)7231 80 09 - 60
Email: info@koch-technik.de

Internet: www.koch-technik.com


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