ImpulsTec sets up coated plastic scrap facility

Schiltach, Germany-based Hansgrohe Group, a maker of kitchen and bath fixtures, has worked with technology provider ImpulsTec GmbH to commission what the companies call the world’s first electrohydraulic shredding and material separation facility for end-of-life or off-spec galvanized plastic components.

ImpulsTec describes galvanized plastic parts coated with a metallic outer layer as “among the last big challenges for recycling,” The Radebeul, Germany-based vendor, however, says the system it designed for Hansgrohe “achieves material purity of greater than 99.8 percent for reuse in premium products.”

States ImpulsTec, “Because recovering the materials they contain is very technically complex, previous procedures have generally only concentrated on one of the material fractions—usually the metals.”

Those processes, says the firm, achieved a relatively low material purity that resulted in the “downcycling” of components collected for recycling in a system it describes as “barely economically viable.”

However, ImpulsTec GmbH says it has “taken up the gauntlet and is implementing shockwave or electrohydraulic shredding technology – which is as yet not at all widespread in Germany – for separation of complex material compounds in industrial processes.”

Early this year, a custom-designed facility for stripping chrome-plated plastic parts through shockwave treatment was commissioned by Hansgrohe, in combination with pre-shredding and magnetic separation equipment.

States ImpulsTec, “Because Hansgrohe Group sets very high quality standards in terms of shower, bath and kitchen fittings, a certain level of production scrap is unavoidable.”

Comments David Zapf of Hansgrohe Group, “The chrome-plated ABS [acrylonitrile butadiene styrene] plastic parts used to be a particular thorn in our side,” referring to housings for hand showers, pipe collars and knobs and buttons on fittings.

“Because it was previously not possible for us to internally separate the thin galvanic layer from the ABS while preserving both material fractions before this project, we used to hand chrome-plated parts over to external recycling partners,” says Zapf.

Zapf became aware of ImpulsTec’s shockwave technology in 2019, says the technology supplier. From 2021 to early 2023, the two companies worked together to develop a procedure for stripping the galvanized plastic components, which involved combining the shockwave treatment with pre-shredding and subsequent magnetic separation.

The facility deploying the designed system has now been in operation at a Hansgrohe production site in Offenburg-Elgersweier, Germany, since early 2024.

“Due to local circumstances, the new facility had to be suitable for installation outdoors,” says ImpulsTec Managing Director Stefan Eisert, adding it also needed to stay within a tight footprint. “That’s why we designed the pilot facility to operate within three weather-proof container units.”

Since galvanized parts to be recycled are of different sizes and complexity levels, the first container hosts pre-shredding and a screening column. The size-reduced shreds are then subject to the shockwave treatment in the second stage.

That involves the shreds being placed into a water bath. Then, the brief ignition of an electric arc between two electrodes within the medium creates mechanical shockwaves that “gradually separate the individual material fractions from one another,” says ImpusTec.

The technology supplier says used water is then filtered and subsequently returned to the shockwave process in a closed loop.

The material is dried in the third container and then separated using magnetic technology. The majority of this material, from 70 to 80 percent, is plastic, according to ImpulsTec, for which the 99.8 percent purity level is sought.

The remaining material fraction is composed of copper, nickel and chrome from the galvanic coating, which subsequently is delivered to metal processing companies.

“As this facility is a completely new concept, in the course of development we had to thoroughly try out and optimize all process steps as well as their interlinking and interaction,” says Eisert. “Doing so means we are now able to fulfil Hansgrohe’s demanding requirements in terms of material purity.”

The Hansgrohe facility is processing an annual throughput of 100,000 kilograms (22,000 pounds) of chrome-plated plastic. “Thanks to electrohydraulic shredding, we can now reuse 98 percent of raw materials from our production scrap in this area,” says Zapf.

“This represents a major step toward our circular economy goal,” he continues. “After all, every resource that does not need to be obtained in the first place protects our ecosystems in the long term and saves energy as well as water in production processes.”

The fixture manufacturer is marketing a Hansgrohe Pulsify Planet Edition product line, launched in 2023, which consists of components made from recycled plastic.

According to ImpulsTec, Hansgrohe is examining the extent to which shockwave technology can even be used for future recycling of products such as end of life fittings obtained from customers.

“The application of our newly developed stripping process for [unused] products was only the first step,” says Eisert. “In the automotive industry as well as in the electronics sector, our technology also opens up new possibilities for reuse of production scrap as well as product components at the end of their life cycle.”