Influence of Drying Temperature on Paper Properties Made of Sulfate-Bleached Softwood and Hardwood Pulps

Abstract

Most paper mills in the Russian Federation consume around 40 % more electrical power than they actually require. The reasons are a low level of technical, scientific, and proficient assistance. Moreover, the produced goods have non-competitive consumption characteristics. The urgent current measures in this matter contain constructional and technological optimization, including drying temperature modes. The drying section of a paper machine is the most energy-consuming, while it significantly affects the mechanical strength and supplementary properties of the resulting paper goods with their structural and dimensional characteristics. Drying the paper web takes 72–77 % of the total energy of the paper machine. Therefore, the purpose of this study is to analyze the influence of the temperatures of the drying process on the strength and structural-dimensional properties of the paper, with the perspective for further application of the results in the practice of industrial companies and additional scientific investigation. The presented results show the influence of pulp type, beating degree, mass of 1 m2, and drying temperature on the strength and structural-dimensional properties of laboratory samples. Within the investigational process, laboratory samples from sulphate-bleached softwood and hardwood pulp were created and tested. The weights of the samples varied from 60 to 120 g/m2, and the beating degrees ranged from 20 to 50 °SR. The drying temperature extended from 80 to 140 °C. The analysis of the acquired paper samples revealed that the drying temperatures had a considerable impact on the strength, structure, and dimensional qualities of the material. Namely, while sulfate-bleached softwood and hardwood pulp types were used as a raw material, increasing the drying temperature from 80 to 140 °C had the greatest effect on the structural-dimensional properties of the paper made from a pulp with a higher beating degree and the greatest effect on the strength properties of the paper made from a pulp with a lower beating degree. For citation: Prokhorov D.A., Dubovy V.K. Influence of Drying Temperature on Paper Properties Made of Sulfate-Bleached Softwood and Hardwood Pulps. Lesnoy Zhurnal = Russian Forestry Journal, 2023, no. 3, pp. 173–184. (In Russ.). https://doi.org/10.37482/0536-1036-2023-3-173-184