Aimed at the Fire Safety of Buildings

Covestro Develops Glass Fiber Reinforced Polyurethane Composite for Fire-Resistant and Thermal Insulated Windows

  • Contains up to 80% glass fiber, with outstanding fire resistance
  • Low expansion coefficient and excellent stability, with dimensional deviation between manufacturing and design of less than 1%
  • Simplifies the production process and greatly improves efficiency
  • Brings together waterborne PU coatings and low VOC emissions to enhance weather-ability, anti-UV, and anti-aging properties 
Due to improvements in architectural technology, modern buildings are getting higher and more dense in order to make the most use of limited space. However, the rising heights of buildings also reduce the capabilities of rescue in a fire. Since there have been a growing number of fire reports in high-rise buildings over recent years, fire protection as well as fire-resistant materials are critical in the planning of fire protection zones. In the light of these facts, Covestro has developed its Baydur® Pultrusion polyurethane composites, by using a patented pultrusion process to incorporate polyurethane resin with reinforced glass fiber. The solution offers air tightness, water tightness, and sound insulation, as well as outstanding fire resistance, themal insulation properties and high mechanical strength. In combination with the latest waterborne polyurethane coating technologies, such as Bayhydrol® and Bayhydur®, these technologies can also be applied to window frame surfaces, further improving their UV light-protection, anti-aging performance. Furthermore, the waterborne coating has low VOC emissions, making it a preferred choice for green building materials.

Effective Themal Insulation, Prevents the Spread of Fire

According to data from the National Fire Agency, at the Ministry of the Interior, 27,922 fires were reported in Taiwan in 2018, where fire in buildings is the second place,  with a total number of 8,765 cases.[1] Given the high numbers of fires involving buildings over recent years, fire-resistant building materials that protect from fire are essential for any design, especially for the openings of the fire doors or the fire protection zones in buildings. The aluminum alloys or plastics that are traditionally used as the main frames for doors and windows, however, may become deformed or lose their sealing properties during a fire, as a consequence of the significant rise in temperature, increasing safety issues.

In order to meet the requirements of fire-resistance inspections, as well as environmental standards, and the mechanical properties including hardness, and strength, Covestro has developed Baydur® Pultrusion, a composite material that is made of polyurethane resin and reinforced glass fiber and produced by a patented pultrusion process. The combination of these two materials has resulted in excellent fire resistance and themal insulation properties. Since the glass has outstanding flame retardancy, while the polyurethane produces a carbon layer on its surface, after contact with fire.


Even in the face of very high temperatures, millions of tiny glass fibers hinders the transmission of thermal energy from one side to the other. Furthermore, this composite material has great dimensional stability, since it has a thickness shrinkage rate of less than 1% in the manufacturing process, resulting in a small deviation from the original design. Additionally, the material effectively prevents dimensional deformations, difficulties in opening and closing, and even sealing issues that are caused by temperature changes. Since the composite contains up to 80% glass fibers, meaning that its expansion coefficient is much lower than those of aluminum alloys and PVC plastics. As the inventor of polyurethanes, Covestro is attempting to combine the individual advantages of different materials to continue to provide the market with innovative materials that have integrated properties,” said Alec Yang, the Head of Field Sales for Polyurethanes, at Covestro Taiwan. We expect to utilize our expertise in material science to help lower the safety concerns for building fires.”

Benefits of Baydur® Pultrusion in a nutshell

  • High fire resistance.
  • Durability, stability, and resistance to corrosion.
  • Outstanding thermal insulation properties, together with high stiffness.
  • Excellent mechanical properties, including high mechanical strength.
  • Does not contain any styrene, resulting in a significant reduction of the impact on the environment and human health.


Covestro, and its partner Zhejiang Deyilong Technology Co. Ltd., have jointly developed fire-resistant window products with the technology as stated above, and the products have successfully been applied to numerous real estate projects.

Protection Upgrade for the Next Gen Waterborne PU Coating Tech

Covestro has also developed a new generation of waterborne polyurethane coating technologies, Bayhydrol® and Bayhydur®, in order to improve the surface protection as well as the aesthetics of Baydur® Pultrusion. This gentle material rarely includes floating fibers, is highly suited to being a base material, and has excellent properties such as weatherability, UV-resistance, and anti-aging. Meanwhile, the waterborne coating can be stored and transported just like regular products. In contrast to traditional solvent coatings, however, the new coatings can reduce up to 80% of VOC emissions, while improving the working environment, by lowering safety concerns during construction. Furthermore, the excellent surface adhesion properties of the glass fiber-reinforced polyurethane result in uniform coverage and improvements in the smoothness of the base material, which can satisfy the diverse aesthetic needs in terms of a product’s color, its appearance, and so on.


About Covestro:

With 2018 sales of EUR 14.6 billion, Covestro is among the world’s largest polymer companies. Business activities are focused on the manufacture of high-tech polymer materials and the development of innovative solutions for products used in many areas of daily life. The main segments served are the automotive, construction, wood processing and furniture, and electrical and electronics industries. Other sectors include sports and leisure, cosmetics, health and the chemical industry itself. Covestro has 30 production sites worldwide and employs approximately 16,800 people (calculated as full-time equivalents) at the end of 2018.


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Forward-looking statements

This news release may contain forward-looking statements based on current assumptions and forecasts made by Covestro AG. Various known and unknown risks, uncertainties and other factors could lead to material differences between the actual future results, financial situation, development or performance of the company and the estimates given here. These factors include those discussed in Covestro’s public reports which are available at The company assumes no liability whatsoever to update these forward-looking statements or to conform them to future events or developments.