Heat-sealing tea filter paper with double-layer structure and high internal bonding strength as well as preparation method and application of heat-sealing tea filter paper

The invention belongs to the technical field of new materials of specialty paper, and particularly relates to heat-sealing tea filter paper with a double-layer structure and high internal bonding strength, a preparation method and application. A double-layer structured heat-seal tea filter paper with high internal bonding strength is formed by papermaking of a base layer and a heat-seal layer, the base layer is made of 100% first natural plant fiber, the heat-seal layer accounts for 60-80% by mass of a whole paper sheet, and the heat-seal layer is composed of the following fibers in percentage by mass: 40-60% of heat-seal fiber and 30-60% of viscose fiber. 0-20% of a second natural plant fiber; the viscose fibers are viscose fibers with the fiber width being less than 20 microns and the length being 1-10 mm. The tea filter paper with the structure has better internal bonding strength after being soaked in boiling water for a long time, and a tea bag made of the filter paper is not easy to break after being so