The Properties And Printability Of Double Coated Recycled Linerboard

Corrugated boxes have long been used to pack and protect various goods. In the past, strength and durability were the major quality considerations. However, during the last three decades, the retail industry had set new demands for corrugated boxes. More and more goods were being left in the boxes in which they were shipped, to be sold directly from the shelf. To promote the product within, these boxes 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 linerboard. Increasing coat weight or adding expensive TiO2in coating color could increase the brightness of coated brown board. It was nesseary to study the application of cheaper pigments in coated brown linerboard.The effect of blending ratio of clay and GCC on the optical properties, mechanical properties and printability of pre-coated and doubled coated recycled linerboard were investigated. It was found that the brightness of pre-coated 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 recycled linerboard than100%GCC coating layer. The blending ratio of clay and GCC had synergy effect on the brightness of pre-coated linerboard. With the increasing of coarse GCC in pre-coat, gloss of pre-coated linerboard increased and the roughness decreased. Blending ratio of clay and fine GCC of top coat had little effect on the brightness and roughness of double coated linerboard. The gloss and printing surface strength of doubled coated linerboard decreased with the increasing of fine GCC, hydrophibic of double coated linerboard increased with the increasing of fine GCC. The K&N value increased with the increasing of fine GCC or coarse GCC.In this research, OBA was added in the top coating color. The effect of OBA carriers (PVA, CMC and starch) on the optical properties, mechanical properties and printability of doubled coated linerboard and the effect of carriers and fine GCC content on the OBA brightening efficiency were reasearched. It was found that carrier types and viscosity had little effect on the OBA brightening efficiency, but the doubled coated linerboard with CMC as OBA carrier had the best brightness stability. Fine GCC had a positive effect on the OBA brightening effieciency. The addition of PVA and CMC decreased the gloss of double coated linerboard. But the addition of starch in pre-coat had little effect on the gloss of double coated linerboard contrary with the result that starch was used in top coat. CMC and starch could improve the printing surface strength of doubled coated linerboard.