Longitudinal grinding of Norway spruce
Liu , Jie (2011)
Liu , Jie
Saimaan ammattikorkeakoulu
2011
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Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:amk-2011120817755
https://urn.fi/URN:NBN:fi:amk-2011120817755
Tiivistelmä
The purpose of this bachelor’s thesis was to analyze the paper properties of Norway spruce (softwood) pulp which was made in two grinding ways and different longitudinal grinding angle for the paper making process. In the theoretical part, the fundamentals of mechanical pulping and the properties of Norway Spruce was introduced by Saimaa University of Applied Sciences, Imatra.
In the experimental part, the Norway spruce pulps which were made by traditional grinding and longitudinal grinding were studied. These pulps were obtained from cutting the fresh Norway spruce wood at a different angle by mechanical pulping. Screened pulps were ground in angle 0°, 15°, 30°, 45°and angle 0°of reference type.
As a result, the grinding angle affected the properties of pulp and paper. For measuring the properties of the pulp, the bigger the grinding angle, the shorter the fiber length and less coarseness, the smaller the CSF freeness number, the bigger the water retention value. And for measuring the handmade paper, the paper which was made from a big grinding angle pulp had a smaller bulk, a higher tensile strength and burst strength, a lower tear strength, a worse air permeability and a better brightness.
In the experimental part, the Norway spruce pulps which were made by traditional grinding and longitudinal grinding were studied. These pulps were obtained from cutting the fresh Norway spruce wood at a different angle by mechanical pulping. Screened pulps were ground in angle 0°, 15°, 30°, 45°and angle 0°of reference type.
As a result, the grinding angle affected the properties of pulp and paper. For measuring the properties of the pulp, the bigger the grinding angle, the shorter the fiber length and less coarseness, the smaller the CSF freeness number, the bigger the water retention value. And for measuring the handmade paper, the paper which was made from a big grinding angle pulp had a smaller bulk, a higher tensile strength and burst strength, a lower tear strength, a worse air permeability and a better brightness.