Lining cover

Abstract

The invention relates to a backing board consisting of at least a front layer, a middle layer, and a back layer, wherein the front layer contains softwood kraft pulp, the percentage content of softwood kraft pulp in the front layer is not less than 80% by mass; the middle layer contains waste corrugated board pulp, and the percentage content of softwood kraft pulp in the middle layer is not more than 30% by mass; the back layer contains softwood kraft pulp, waste corrugated board pulp, and waste kraft pulp. Waste kraft pulp is waste pulp originating from kraft paper with a thin plastic film applied to at least one side of the backing. The percentage content of waste corrugated cardboard pulp in the backing layer is not less than 30% by weight and not more than 70% by weight, and the ratio of the fronting layer's weight to the total weight is not less than 20% and not more than 35%. The bursting index of the backing board in an environment of 60°C and relative humidity of 80% is better than 3.4 kPa m2 / g.