ImpulsTec sets up coated plastic scrap facility

Hansgrohe Group, a Germany-based 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 says galvanized plastic parts coated with a metallic outer layer are among "the last big challenges for recycling." However, it says the system it designed for Hansgrohe achieves material purity of greater than 99.8 percent for reuse in products.

“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," ImpulsTec says.

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

However, 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 preshredding and magnetic separation equipment.

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

“The chrome-plated ABS [acrylonitrile butadiene styrene] plastic parts used to be a particular thorn in our side,” says David Zapf of Hansgrohe Group, 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."

The facility deploying the designed system has been operating 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,” ImpulsTec Managing Director Stefan Eisert asys, 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 preshredding and a screening column. The size-reduced shreds are then subject to the shockwave treatment in the second stage, which involves placing the shreds 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.

Water is 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, 70 to 80 percent, is plastic, according to ImpulsTec.

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,” Eisert says. “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,” Zapf says. “This represents a major step toward our circular economy goal. 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,” Eisert says. “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.”