engleski

Durability of Coated and Uncoated Boards

In this chapter the study of durability of coated and uncoated boards is described. The aim of the study was to determine the influence of board raw materials, technological conditions of production and surface treatment on durability and permanence by accelerated ageing according to ISO 5630/3 which is proposed by EN/ISO 9706 for materials on board with permanent value. Eight coated and five uncoated boards of nominal grammage 250 g/m2 were produced as two and three layer boards, consisted of virgin cellulose, CTMP wood and recycled fibres. Laboratory prints (CMYK) were prepared by IGT equipment for all investigated boards. Basic, mechanical and surface properties of boards were studied, by standard methods for determination, as well as, their chemical and optical stability. Colour stability of laboratory prints was studied too. From the obtained results it can be concluded that the use of recycled fibres of undefined origin and of mechanical pulp fibres is adequate and recommendable for printing boards whose estimated lifetime does not exceed a few years. In the case of printed materials of durable value high-quality primary pulp fibres must be used in a neutral medium in the absence of optical bleaching agents and with calcium carbonate as alkaline buffer reserve.

Accelerated ageing; Boards, Degradation of Boards, Durability of Boards; Permanence of Boards; Optical and Colour Stability.

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