Flame protection for PUR cast elastomers - modes of action and challenges of additives

Due to their mechanical properties, such as high abrasion resistance and elasticity, encapsulated polyurethanes are indispensable in many industries. However, their chemical structure makes them susceptible to ignition and fire, which is a disadvantage, particularly in safety-critical applications. Within a PUR system, flame retardant additives are therefore an essential component for reducing flammability and intensive fire behavior in order to minimize damage in the event of a fire. But how do these additives work and which chemical processes and reactions result in plastics containing flame retardants resisting ignition or fire?

Challenges when adding PUR cast elastomers

The implementation of flame retardant additives in PUR cast elastomers is chemically demanding. The additives must be compatible with the polyurethane system without interfering with the chemical crosslinking between polyols and isocyanates, or reacting with other additives present. Some additives can impair mechanical properties such as elasticity and hardness. An important point for production is the thermal stability of the selected additives: They must survive the typical processing temperatures of PUR casting systems of up to 140 °C without damage. Attention should also be paid to environmentally friendly additives. Halogen-free flame retardants are becoming increasingly important as environmental regulations and sustainability requirements increase. Phosphorus-nitrogen systems offer a promising alternative here.

The selection of the right flame retardant additives is therefore essential in order to specifically adapt PUR cast elastomers to the requirements of a wide range of applications. The balance between effective fire protection, mechanical performance and long-term durability is crucial. As a manufacturer of tailor-made PUR casting solutions, we not only offer targeted additives, but also cast the finished articles for our customers. With our expertise in targeted material testing and manufacturing technology, we develop individually optimized PUR systems that are perfectly tailored to the specific requirements of your application. Whether it's thermally resilient, mechanically robust or environmentally optimized solutions — we support you from the initial idea to the finished product. Contact us to implement powerful and secure solutions together!

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