Siemens Smart Infrastructure has unveiled its latest SIRIUS 3RQ4 coupling relay series, featuring housings manufactured from Akulon® K225-KS B-MB, a bio-based plastic developed by Envalior. The innovative material contains 70% renewable content, sourced from biomass waste such as used cooking oil (UCO)—a byproduct from the food industry and households. By utilizing waste oil that is no longer fit for consumption, this initiative prevents competition with food resources and supports circular material use. Instead of being converted into biodiesel or incinerated, the UCO is repurposed by Envalior into high-performance engineering plastics through a mass balance production process.
Commenting on the partnership, Andreas Matthé, CEO of Electrical Products at Siemens Smart Infrastructure, stated, “Working with Envalior to develop this bio-based plastic represents a major step in making our electrical products more sustainable. This collaboration reflects our ongoing effort to reduce environmental impact while maintaining the same high-quality performance our customers expect.”
The SIRIUS 3RQ4 coupling relay series has been introduced in three distinct variants, each tailored to meet diverse industrial requirements. The first variant comes with an integrated relay output, specifically engineered to operate reliably under demanding environmental conditions. It also meets ATEX certification standards, making it suitable for deployment in potentially explosive atmospheres where safety and performance are critical.
The second variant is a plug-in relay configuration, designed for applications that require quick and easy replacement during operation. This version offers the added flexibility of gold-plated contacts, which enhance durability and ensure stable performance in low-current switching scenarios. The design simplifies maintenance, reducing downtime in industrial systems.
The third variant incorporates semiconductor outputs, delivering silent, high-speed, and frequent switching capabilities with virtually unlimited service life. This solid-state option achieves a switching capacity of up to 6A, matching the output performance of traditional electromechanical relays. It is ideal for installations where longevity, precision, and efficiency are essential, making it a robust choice for advanced automation and control environments.
All models meet the Siemens EcoTech label standards, offering up to 33% lower energy losses in semiconductor versions and eliminating the use of harmful materials such as halogens or PFAS. Designed for recyclability, the relays can be easily dismantled at the end of their lifecycle. Their compact, slim-line design optimizes space in control cabinets, and production takes place at Siemens’ Amberg facility, ensuring efficient supply for European markets. Packaging is now more eco-friendly, and product documentation is accessible digitally via a QR code.
At Envalior, the new material’s success demonstrates its engineering excellence. “Our partnership with Siemens highlights the potential of bio-based materials in industrial applications. Achieving a UL94 V-0 flame rating at 0.4 mm thickness while maintaining superior flow and mechanical performance was a key breakthrough,” said Dr Marc Rudolf, Global Key Account Manager at Envalior.
Beyond product development, Envalior continues to advance its sustainability goals. In 2024, the company sourced over 50% of its global electricity from renewables and aims to reach 100% renewable energy by 2030, along with a 35% reduction in emissions.
Formed in 2023 from the merger of Lanxess Performance Materials and DSM Engineering Materials, Envalior is a global leader in high-performance, sustainable engineering materials, serving industries including mobility, electronics, and consumer goods. The company employs over 4,000 people worldwide.
Headquartered in Zug, Switzerland, Siemens Smart Infrastructure connects energy systems, buildings, and industries, providing end-to-end solutions that promote efficiency and sustainability. As part of Siemens AG, the company contributes to the group’s mission of combining the real and digital worlds to enable greener, more resilient operations globally.
