Experimental thermal behavior of fibrous structures for high-performance heat resistant fire curtains

Fibrous materials are often used in the manufacturing of fire protection devices such as fire curtains. Their optimization and improved performance is still a topic of interest. The present work aims to develop and test a new combination of fibers arranged in various 2D and 3D patterns with coatings. For this purpose, basalt fibers were added into a glass fiber fabric, and wires of a shape memory material (SMM) were inserted into the fabric to create air pockets induced by temperature. In fire curtains, the base structure is a 2D basket pattern, and all combinations were tested with and without a waterborne polyurethane (WPU) coating with inorganic materials. Three different tests were selected to characterize the thermal behavior: fire resistance, ignitability, and smoke production. Fiberglass proved to be the best material to provide thermal resistance in fire curtains, with the outer surface temperature of the fabric below 650 °C at the end of the tests. The SMM wires provided good protection during the initial stages of the test, but a combination of excessive deformation and reduced strength of the fabric resulted in a sudden failure of the structure. Basalt fibers contribute to a reduction of smoke production. It was observed an improvement of up to 10% in the thermal capacity between 1MIX2 (glass fibers fabric with coating, MIX2) and the best commercial curtain evaluated, Commercial3 (glass and steel fibers fabric with coating). This work was co-financed by Compete 2020, Portugal 2020, and the European Union through the European Regional Development Fund—FEDER within the scope of the project ThermFire4Woven— Development of advanced fibrous structures with fibrous surface treatments and coatings with high thermal efficiency and flame resistance for high value-added applications (POCI-01-0247-FEDER-033637). This work was supported by FCT within the Projects Scope UIBD/EMS/04077/2020 (METRICS); UIDB/04436/2020 (CMEMS); UIDB/05256/2020 (IPC); UIDP/05256/2020 (IPC); UID/CTM/00264/2021 (2C2T) and UIDP/00264/2020 (2C2T).