The invention relates to the technical field of kraft linerboards, in particular to a
flame-retardant kraft linerboard and a surface treatment process thereof. An upper
transition layer is arranged below the upper
surface layer, a core layer located on a middle base layer of the kraft linerboard is arranged below the upper
transition layer, a
flame-retardant layer for inhibiting
combustion reaction and reducing
flame propagation speed through a flame retardant is arranged in the core layer, and a lower
transition layer is arranged below the core layer. A lower-layer
surface layer which is symmetrical with the upper-layer
surface layer and is positioned on the outermost layer of the bottom of the kraft linerboard is arranged below the According to the flame-retardant kraft linerboard, a layered
composite structure is adopted, the upper transition layer and the lower transition layer are additionally arranged, the
binding force between the
layers is enhanced, the layering phenomenon is effectively avoided, the overall strength and durability of the kraft linerboard are greatly improved, the flame-retardant layer adopts a multi-layer
composite structure and gradient flame-retardant design, and the flame-retardant efficiency is improved; according to the process, the flatness, glossiness and printing stability of the
paperboard are ensured, the quality of a finished product is stable, the defective rate is reduced, and the production efficiency and
economic benefits are improved.