This paper experimentally examined the impact of four different drying methods (free drying, press drying, vacuum drying and impingement drying) on paper physical properties including roughness, elongation, air permeance, tearing resistance, tensile index and bursting strength. The handsheets materials are HWBKP (Hardwood Bleached Chemical Pulp), SWBKP (Softwood Bleached Chemical Pulp), CTMP (Chemical Thermo mechanical Pulp) and ATMP (Advanced Thermo Mechanical Pulp). Good experimental data were obtained for the four pulps under different drying conditions. The results of our investigation indicate that press drying have lower surface roughness, elongation and air permeance but higher tearing resistance; the vacuum drying have higher roughness, tensile index and bursting strength; the impingement drying have lower tearing resistance, tensile index and bursting strength but higher elongation and air permeance. Selection of different drying conditions for effective productivity and quality improvement potential is proposed as a direction for the future dryer design.
Using hydrocyclone fractionation to improve chemical pulp quality
