Cost Efficiency
& Decarbonization
Crerax Microspheres are thermoplastic hollow polymer spheres composed of a thermoplastic polymer shell encapsulating a blowing agent. Upon heating, the shell softens, and the internal pressure increases dramatically, causing the microspheres to expand to 80–100 times their original volume—a key mechanism for how to reduce density of EPDM rubber. After expansion, Crerax Microspheres exhibit an extremely low density, making them an ideal lightweight filler and blowing agent for various materials such as plastics and rubber.
In the production of automotive EPDM sealing strips, the addition of Crerax Microspheres facilitates the formation of a dense and uniform microcellular foam structure (invisible to the naked eye). This effectively reduces the density of the rubber strips, supporting the automotive industry’s lightweighting goals and providing cost-effective lightweight sealing solutions.
Crerax Expandable Microspheres, with an initial density close to 1 g/cm³, are typically incorporated as an additive during the latter stages of EPDM compound mixing. During the rubber vulcanization process, the microspheres expand under heat, resulting in a significantly reduced density of 0.02–0.04 g/cm³. As a result, the density of the vulcanized rubber containing expanded microspheres is markedly decreased—a proven method for how to reduce density of EPDM rubber. Moreover, since the expanded microspheres occupy a substantial volume within the rubber, the consumption of base material is reduced, leading to cost savings and improved efficiency.
Crerax Microspheres deliver the following key benefits in automotive EPDM sealing strips:
● Density Reduction:
With a theoretical dosage of 1–2%, Crerax Microspheres can significantly reduce rubber density by 15–40%. The actual weight reduction effect depends on factors such as microsphere type, dosage, and processing conditions. This addresses the industry's need for lightweight automotive materials.
● Cost Reduction:
The expanded Crerax Microspheres occupy considerable volume within the rubber, reducing material usage per unit area and achieving approximately 6–7% cost savings. The extent of cost reduction is influenced by microsphere type, dosage, and processing conditions, contributing to more cost-effective lightweight sealing solutions.
● Improved Thermal and Acoustic Insulation:
Crerax Microspheres form a uniform and stable closed-cell foam structure within the rubber, enhancing the insulation (thermal and acoustic) and electrical insulation properties of the finished sealing strips. This improvement also contributes to better surface quality and product stability, which is critical for sound damping in vehicles.
● Enhanced Compression Set Resistance and Flex Durability:
Thanks to their controllable particle size and uniform distribution, Crerax Microspheres improve the diameter and distribution consistency of foam cells in rubber, ensuring effective closed-cell formation. This results in superior compression set resistance and flex durability of the sealing strips, effectively demonstrating how to improve compression set in rubber seals.
Notable Advantages of Crerax Microspheres Over Conventional Blowing Agents:
When evaluating the benefits of physical vs chemical blowing agent, Crerax Microspheres offer clear advantages. Compared to chemical blowing agents (e.g., AC), Crerax Microspheres operate via a physical expansion mechanism. This allows flexible selection of suitable grades tailored to different processing conditions, offering broader adaptability and a wider processing window. Chemical blowing agents tend to produce large, irregular cells, whereas Crerax Microspheres form a uniform and controllable closed-cell foam structure, ensuring more consistent performance in products such as automotive EPDM sealing strips. Furthermore, unlike azo-based blowing agents that release harmful substances, the physical expansion process of Crerax Microspheres is more environmentally friendly and safe, supporting sustainable automotive manufacturing.
