Optimising Mixing Performance in Polymer Compounding

When it was time to replace the ageing Hosokawa Micron mixer on their compounding line, Milliken Chemical saw an opportunity. Rather than immediately ordering a like-for-like replacement, they worked closely with the Hosokawa team to reassess the specific requirements and explore concrete opportunities to further improve production efficiency. This collaborative approach has ensured that the new mixing solution is optimally aligned with Milliken’s needs.

Milliken Chemical, a US company which has its EMEA headquarters in the Belgian city of Ghent, is trusted by leaders in polymer manufacturing, plastic conversion and recycling around the world. The group’s innovative solutions enhance processing efficiency, product quality and sustainability for customers across these industries. In Bad Bentheim, Germany, at the state-of-the-art compounding facility of Zebra-chem GmbH, which was acquired by Milliken Chemical in 2021, they specialize in high-performance blowing agents for foaming lightweight plastic products, and peroxide master batches that are used to decrease viscosity in the recycling sector.

“Although we were very happy with the operational performance of the existing mixer, I saw this as an opportunity for a continuous improvement project that could possibly add some extra features to the replacement model,” recalls Bart Gabriëls, who was plant manager at Zebra-chem GmbH at that time. “In particular, I was keen to see whether there was a way to save time by making the mixer even easier to clean during product changeovers.”

“In my time as a plant manager, I’ve previously worked on other projects with Hosokawa and I’ve always found them to be very helpful and supportive whenever we needed tailor-made solutions. In fact, our two companies have a similar mindset, so it’s a good fit,” he adds.

Co-development partners

“At Milliken, we position ourselves as a co-development partner, working closely with our clients to design solutions that meet both their performance and their sustainability targets. This collaborative model is a key differentiator in the chemical additives space, and we also recognize the same approach at Hosokawa Micron. Therefore, it felt natural to share my wants and needs with Hosokawa and ask them for ideas for the replacement mixer,” continues Gabriëls. 

Coordinated by Raymond Fels, Application Engineer at Hosokawa Micron, the engineering team presented several concrete proposals. “Together, we brainstormed ideas and came up with various technical possibilities, such as making it easier to disconnect and reconnect the mixing screw, adding a hatch for better access, or installing nozzles to facilitate cleaning in place. For each option, we discussed not only the investment required, but also the potential gains in terms of efficiency, safety and ease of operation,” explains Fels.

Total cost of ownership

“The Hosokawa team responded to our requests with strong dedication, presenting several well-considered options that reflected a thoughtful and structured approach, each accompanied by clear cost estimates. During the evaluation phase, the open communication and discussions with the Hosokawa team members greatly supported us in making the right decision about the replacement mixing unit,” comments Gabriëls. 

Communicative and supportive

The entire decision-making process ran smoothly and was conducted within a well-managed timeframe, according to Gabriëls: “The initial project discussions started in early 2024, and the factory acceptance testing at Hosokawa’s premises in the Netherlands was completed by early 2025. Throughout the whole process, Hosokawa remained communicative, helpful and highly supportive.”

Smooth-running solution

“The commissioning went smoothly, and the new mixer is up and running without any problems,” states Vandewijngaarden. “Based on this project and previous collaborations, we truly value Hosokawa’s fast and clear communication, the engineering team’s support in addressing specific questions and requests, their proximity to our plant, and the reliability of their after-sales service,” he concludes.