METHOD OF PRODUCING THERMAL-RESISTANT NONWOVEN MATERIAL Russian patent published in 2018 - IPC D04H1/549 D06M11/05 B32B5/02 

FIELD: manufacturing technology.

SUBSTANCE: invention relates to the production of non-woven materials based on synthetic fibers, namely aramid heat resistant hard-to-burn and self-extinguishing, for example, for use as a basis for structural composite laminates and interlayer insulation in dry transformers. Method for producing a heat-resistant nonwoven fabric from a synthetic aromatic polyamide fiber by impregnating the fibrous flooring obtained on the sheet-pouring apparatus with a surface density of 60–90 g/m from cut chaotically located in the horizontal and vertical directions at different angles to each other high-strength aramid fibers with an oxygen index of 44±1 % aqueous solution containing 10–12 % zinc chloride, 2–3 % calcium chloride and an additional 1–2 % lithium chloride at a temperature of 85 °C, followed by a spin-out to weight gain of 450–500 % solution, drying to a humidity of 30–40 %, calendering at a temperature of 220 °C and at a pressure of 100–120 kgf/cm² and washing.

EFFECT: obtaining a high-strength non-woven fabric based on aramid fiber with a high oxygen index (44±1 %) by increasing the dissolving power of the impregnating solution, which causes adhesion between the fibers.

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