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A flame-shielding paper using polyphenylene sulfide fiber

News International-French

22 Dec 2015

Toray Industries announces that the company succeeded in developing a high-performance flame-shielding paper using polyphenylene sulfide fiber Torcon and polyacrylonitrile-base flame resistant yarn manufactured by its subsidiary Zoltek Companies.

The developed high-performance flame-shielding paper combines flexible thin film with outstanding fire resistance and high flame-shielding performance of more than 10 minutes (measured using Toray’s proprietary evaluation method). Using this flame-shielding paper in products that require fire resistance will improve the fire resistance properties of those products making them even safer. Replacing the existing thick and solid fire retardant materials with this paper will help in saving space and reducing the size of the final products.

Polyphenylene sulfide fiber Torcon is a thermoplastic fiber with fire retardation, heat resistant and chemical resistant properties and is mainly used widely in bag filter for coal-fired thermal power generation boilers. In addition, the flame resistant yarn produced by Zoltek, a large-tow carbon fiber production company that became a Toray subsidiary in February 2014, is oxidized polyacrylonitrile yarn fired in the air and is used in various industrial fields led by brake pads for aircraft and spatter sheet by leveraging its outstanding fire retardation and heat resistance.

The high-performance flame-shielding paper, which Toray succeeded in developing, is the fruit of fiber composite structuring technology, the research and development of which the company has been focusing its capabilities on for the past few years as an innovative elemental technology required for creating novel advanced fiber materials.

Existing fire retardant papers required a certain thickness to shield flame (flame-shielding property) and it was hard to make thin film from existing inorganic material-based flame-shielding sheets, and they lacked flexibility. Leveraging its fiber composite structuring technology, Toray combined and mixed polyphenylene sulfide fiber Torcon and the fire retardant yarn using a special paper making technology and developed fire-shielding paper that has both functions possessed individually by the two fibers and is thin with adequate strength and flexible with outstanding workability.

When the flame-shielding paper is exposed to flame and heated to 300 degree Celsius or higher, the polyphenylene sulfide fiber Torcon, which is thermal plastic resin, melts and spreads in the netlike gap in the paper and carbonizes as the temperature rises further and its structure changes into a fire retardant sheet that shields flame. With this feature, it exhibits the performance equivalent to UL-94 standard VTM-0 class and shields flame, though it is only a 60 micron thin film.

Moreover, this flame-shielding paper has high permeability and reduces heat retention and exhibits outstanding anchoring effect when applying adhesive in three-dimensional processing. For this reason, it has the characteristics of being thin, light, moldable and flame-shielding, and it is expected be used in a wide range of fields as it not only improves fire proof property of final products and reduce the risk of catching fire but also contributes to reducing space and weight of the products.

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