Calderys' Technical Contribution at the 5th Formstoff-Forum 2025

🔬 Presentation 1:
"Can fossil raw materials be successfully substituted in molding materials?"
Presented by Sandra Böhnke, Innovation & Technology Engineer.

Bentonite-bonded molding materials, essential for casting, often rely on fossil-based additives that contribute to CO2 emissions. While efforts have been made to reduce the environmental impact of these additives, replacing hard coal—a key component—has proven difficult due to its complex structure and thermal properties, which are critical to maintaining casting quality.

The presentation showcased a study about the development of sustainable alternatives to fossil-based additives in bentonite-bonded molding materials. Through comparative and thermogravimetric analyses, the authors evaluated the performance of alternative additives, both individually and in combination with bentonite. Key factors such as melting behavior, strength, circulation properties, casting results, and compliance with landfill regulations were assessed. Their findings demonstrate that carefully selected and analyzed alternative materials can effectively replace traditional fossil-based additives, reducing the carbon footprint without compromising the quality or strength of the molding materials.

🔬 Presentation 2:
"The influence of thermal treatment on the properties of bentonite used as a molding sand binder – a comparative study of different qualities." Presented by Paraskevi Kantsou, Innovation & Technology Engineer.

Calderys has been providing bentonite as molding sand binder to enhance casting procedure for decades. With the motivation to understand bentonite performance better under the influence of thermal treatment, experts at Calderys conducted this study about bentonite properties variances and how they constitute the quality of the mold material under different thermal conditions. Bentonite coming from different geographic sources bear different performance characteristics and can be affected differently by elevated temperatures that occur during the casting process. 

Through a temperature testing procedure followed by analysis and application on various aspects, the study confirms the significant variations between bentonite qualities in terms of loss of bonding, resulting in different strengths of bentonite-bonded molding materials.  The outcomes of this study support the optimization for the use of bentonite as a molding sand binder in casting process, contributing to Calderys’ continuous effort to drive productivity and efficiency for our customers in foundry industry.

The discussions and feedback we received were incredibly inspiring, and we are grateful for the opportunity to connect with industry peers, share insights, and collaborate on innovative solutions for a more sustainable future.

A big thank you to TU Bergakademie Freiberg and all the organizers for hosting such a well-organized and thought-provoking event. We look forward to continuing these conversations and driving positive change in the foundry industry.

Let’s keep shaping the future of foundry technology together!