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Building & Construction
XPS Sheets
Adding value to insulation
Extruded Polystyrene Foam (XPS) is strong and durable, providing high-performance thermal insulation for residential and industrial buildings when used in inverted roofs, floors or ceilings.
Leveraging our extensive experience in this field, we have developed a range of solutions that offer added value to XPS producers, helping them meet the ever-changing demands of both the insulation sector in particular and the wider construction industry.
High-concentrated HBCD-free flame retardant masterbatches
With the use of HBCD restricted by regulations in the EU, North America and other western countries, polymeric brominated FR has become commonly used as a replacement. As a leading producer of FR masterbatches for XPS, we were one of the first to introduce HBCD-free solutions to the market, in compliance with new FR standards.
High stabilization flame retardants for XPS
Recognizing that different XPS producers require different thermal stability, we develop tailor-made solutions that meet stringent thermal stability requirements, as well as low and medium thermal stability packages.
Questions and Answers About XPS Foam
Flame retardants are additives incorporated into XPS foam to enhance its fire resistance. They help slow the spread of flames, reduce fire intensity, and ensure the foam meets necessary fire safety standards. This is particularly crucial for building insulation, where fire performance is a key safety concern.
There are three primary categories of flame retardants used in XPS:
- Polymeric Flame Retardants (pFRs): These are highly effective flame retardants based on grafted brominated butadiene/styrene block copolymers.
- Non-Polymeric Flame Retardants: Typically based on tetra bromo bisphenol A (TBBA), these materials offer excellent thermal stability.
- Blended Flame Retardants: A combination of both polymeric and non-polymeric flame retardant.
The selection of flame retardants is influenced by various factors, including the foaming agent, processing conditions, nucleation level, board thickness, use of recycled polymers, and other key XPS board properties.
For further assistance, please reach out to our flame retardant experts.
When exposed to high temperatures, brominated flame retardants decompose to release bromine radicals. These radicals interfere with the combustion process by neutralizing the reactive species involved in the polymer-oxygen reaction, thereby halting the fire’s progression.
Yes, flame retardants are subject to strict global regulations designed to protect human health and the environment. For instance, in the European Union, the REACH regulation governs the use of chemicals, ensuring only approved substances are incorporated into products. Tosaf complies with these regulations, using only flame retardants that meet both safety and environmental standards.
Historically, substances such as decabromodiphenyl oxide and HBCD-based flame retardants were commonly used, but these have been phased out due to their environmental and health risks. Today, more sustainable alternatives, such as polymeric and non-polymeric flame retardants, are used. Among these, polymeric flame retardants (pFRs) are considered the most eco-friendly, offering fire resistance while minimizing health and environmental impacts.
For construction applications, flame retardants are generally required by local fire safety regulations. However, in non-construction or industrial applications where fire safety is less of a concern, XPS may be produced without flame retardants.
While flame retardants are essential for fire safety, they can impact the foam’s properties under certain circumstances:
- Improper selection or usage can weaken the foam or cause it to collapse.
- Inadequately stabilized flame retardants or overly aggressive manufacturing processes may lead to the release of acids during production, potentially degrading foam quality and reducing the effectiveness of the flame retardant.
- Excessive use of flame retardants can alter the foam’s structure, potentially increasing the thermal conductivity (λ value) and impacting its mechanical properties.
To maintain foam quality, manufacturers carefully select and combine flame retardants with stabilizers. This minimizes risks during production and helps maintain the foam’s strength, durability, and long-term performance.
Certifications validate that XPS foam meets relevant fire safety standards. Key certifications to look for include:
- B2 Rating (DIN 4102): A German standard indicating normal fire resistance.
- Euroclass E (EN 13501-1): A European standard for small flame resistance.
- Limiting Oxygen Index (LOI): Measures the minimum oxygen concentration required to sustain combustion. A higher LOI indicates better fire resistance.
