The Preparation And Properties Of High Performance Light Weight Coated Kraft Linerboard

With the development of commodity packaging technology, people require more and more. Corrugated boxes should have not only packing and protecting function, but also need graphics that were colorful and appealing with printing that was easy to read. Retailers also need clearly printed bar codes to make it more expedient to control inventory. Residual demand for better print quality at an economical cost in corrugated containers and continued growth of mass merchandising leading to less personal selling and more dependence on product informati-on provided on the package motivated the growth of visual appeal coated kraft linerboard. Increasing coat weight or adding expensive TiO2 in coating color could increase the brightness of coated kraft linerboard. It was nesseary to study the application of cheaper pigments in coated kraft linerboard.The preparation and the effect of blending ratio of clay and GCC on the optical properties, mechanical properties of pre-coated and coated kraft linerboard were investigated. It was found that the brightness of pre-coated kraft linerboard not only depend on the brightness of pigment but also on the base paper brightness.100% clay coating layer gave a higher brightness of the pre-coated kraft linerboard than 100%GCC coating layer. The blending ratio of clay and GCC had synergy effect on the brightness of pre-coated kraft linerboard. When the blending ratio of clay and GCC is 70/30, the brightness of coated kraft liner board can reach the highest relatively. With the increasing of coarse GCC in pre-coat, gloss of pre-coated kraft linerboard increased and the roughness decreased. In pre-coating and top coating process, the pre-coating formulation have a greater influence on the brightness of coated kraft liner board than the pre-coating formulation. The increase of GCC content in pre-coating and top coating can decrease the gloss of coated kraft liner board, but the top coating formulation have a greater influence on gloss than the pre-coating formulation.In this research, OBA was added in the top coating color to improve the brightness of coated kraft linerboard. The result showed the addition of OBA and CMC to coating colors can obviously improve the brightness of coated kraft liner board. Increase of GCC content can improve OBA brightening efficiency. The addition of CMC can improve the mechanical properties of coated kraft linerboard.In this research, natural polymer starch has been used to partially replace high-cost synthetic latex in the pre-coating or the top coating, and the effects of starch replacing latex on the optical properties of coated kraft linerboard were investigated. The result showed that the brightness of the coated kraft linerboard increased when using starch to replace latex partly in the pre-coating or the top coating and the brightness improved significantly when it used in the top coating. Using starch to replace latex also make the gloss change, which virtually do not change in pre-coating but decrease sharply in the top coating. So using starch to replace latex in the pre-coating is feasible in the actual production.