When Michael Kunststofftechnik in Eppingen needed to purchase a new cooling system for injection molding production in 2023, it was clear to Technical Manager Sven Schmitt: "To avoid any more problems with the water quality in the semi-open cooling circuit for tools and machines, we needed a special technology. One that provides clean process water reliably and without chemicals, thus ensuring optimum protection of the system components."

The solution was found by the specialists for the development and production of technical plastic parts at Enwa AS Germany: The "EnwaMatic" system is designed to guarantee crystal-clear water, reliable corrosion protection and a natural bacterial barrier thanks to a patented, self-regulating process.

Schmitt was particularly impressed by the automated mode of operation, the absence of biocides and the low maintenance requirements: "As an environmentally friendly medium-sized company, we no longer wanted to use additives for the system fluid in the new cooling system. This is what the EnwaMatic® does. After integrating it as a bypass filter into the main flow of our cooling system, corrosion on the machines quickly dissolved and our water quality was very good after just a short time. There are no more deposits or biofilms. And all without chemicals! Handling is easy and straightforward, and the system only needs to be serviced once a year. We are very satisfied!"

The right pH value against corrosion and bacteria

At the heart of the system are the patented five filter media without inorganic substances. They ensure a constant pH value between 9 and 10.5, which forms an oxide layer on the pipe materials in contact with the water. This protects the materials from corrosion. The high pH value also serves as a bacterial barrier. In addition, the inorganic filter media do not form a food source for bacteria, fungi, lichens or ferns.

The system also continuously filters sludge and particles down to 5 micrometers. The automatic backwash cleans the filter bed. System flushing is not usually necessary. According to a written statement from the lower water authority in Celle, the wastewater is not assigned to any water hazard class and can be discharged into the drain without any problems. For systems with antifreeze, a special backwash must be carried out in which the concentration of the water-glycol mixture remains unchanged. A special version of the bypass filter is available for this purpose. The system also automatically separates air and micro-bubbles.

Thanks to the reduced personnel requirements for maintenance and the 100% savings on chemicals, the system also reduces running costs and ensures a particularly long service life for all system components with permanently optimized water quality.

The self-regulating processes offer customers a high level of operational reliability, as the treated refill water is also automatically optimized to the desired pH value to protect the system against corrosion - without any intervention by the operator. Typical damage such as clogged strainers, abrasion on pump impellers or deposits in pipes are a thing of the past. Production downtimes are thus avoided. The service life of all system components is significantly increased.

Christian Barth, authorized signatory of Enwa AS Germany, which was founded in 2009 and has been part of the Skion Group since 2024, emphasizes:

"The high quality of the process water not only saves operators trouble and costs. The constant dosing of inhibitors and biocides has also come to an end, as over- or underdosing of chemicals is the main cause of system damage: in other systems, inhibitors are often added, which are intended to protect against corrosion by increasing the pH value, but at the same time also promote bacterial growth due to the organic substances they contain. As a result, biocides have to be used that not only prevent the formation of biofilms, but also lower the pH value and increase the conductivity of the process water at the same time. Inhibitors must therefore be dosed into the circulation water again. For this reason, ENWA only uses inorganic material for its filter media. Of course, not using chemicals also protects the employees in production from contamination by the mostly toxic ingredients of the chemicals."

Demand-oriented installation in semi-open and closed cooling circuits

Depending on requirements and customer wishes, the unit can be used in various designs in both new and existing buildings: for closed (VDI2035) and semi-open heating systems without aluminum (up to 140°C/PN25 - up to 1500 m³), for closed (VDI6044) and semi-open cooling circuits (down to -20°C/PN25 - up to 1500 m³) - also with antifreeze (water-glycol) down to -20°C - as well as for semi-open hydraulic and tool cooling circuits in plastic injection molding. The device is suitable for pipes and fittings made of mixed metals, copper, steel, stainless steel, iron, cast iron and plastic.

The products start at a system volume of approx. 500 liters as a mini version and range up to approx. 130 cubic meters in the normal product line. The design of the larger BS systems treats water circuits of currently up to 500 cubic meters as a single product. A combination of several bypass filters in one system circuit also enables the treatment of even larger hydraulic systems. The decisive factor for the design is always the water content plus any additional water quantities, for example in injection molding. Enwa manufactures all products itself. The space requirement is low: for the smallest model, it is around one square meter of wall space; from three cubic meters of system volume, it is around 0.7 square meters of installation space.

It is not uncommon for an originally corrosive brown process water to have a crystal-clear appearance and be virtually free of particles after just three weeks in the system. This optimizes the cooling and heat transfer in the systems and saves energy costs - especially in manufacturing processes with high wall temperatures at the heat exchanger. The technology is also effective in the case of contaminated sites in existing systems and when suspended particles are actively entering the cooling water.

"The prerequisite for the optimal functioning of our new water treatment system was the comprehensive needs analysis by Enwa," says Sven Schmitt. "We were also impressed by the easy installation and professional support. In general, the cooperation with Enwa is exemplary."

"The successful deployment at Michael Kunststofftechnik is a good example of perfect teamwork. Together, we worked out the best solution for the customer step by step," adds Christian Barth. "This included technical advice, a site inspection, planning and design, component selection and determination of the water quality by the global Eurofins laboratory. This is the only way to achieve optimum water treatment that is precisely tailored to the operation and protects investments in the long term."