Maple HT-CTMP
AssigneeBillerud Aktiebolag (publ)
InventorsThomas Lindstedt, Thomas Granfeldt, Per Engstrand
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Abstract
There is provided a method of producing a high temperature chemithermomechanical pulp (HT-CTMP), said method comprising the steps of: —impregnating maple wood chips with an impregnation liquid comprising sulfite and NaOH to obtain impregnated chips; —heating the impregnated chips from the impregnation step by applying steam having a temperature of at least 150° C., such as at least 160° C. to obtain pre-treated chips; and—defibration of the pre-treated chips from the heating step to obtain a pulp, wherein the amount of NaOH supplied to the impregnation step is less than 10.0 kg per dry tonne of chips, such as less than 5 kg per dry tonne of chips. A HT-CTMP formed from maple wood is also provided.
Claims15
A method of producing a high temperature chemithermomechanical pulp (HT-CTMP), said method comprising the steps of:
- impregnating maple wood chips with an impregnation liquid comprising sulfite and NaOH to obtain impregnated chips;
- heating the impregnated chips from the impregnation step by applying steam having a temperature of at least 150° C. to obtain pre-treated chips;
- and
- defibration of the pre-treated chips from the heating step to obtain a pulp,
- wherein the amount of NaOH supplied to the impregnation step is less than 10.0 kg per dry ton of chips.
A high temperature chemithermomechanical pulp (HT-CTMP) formed from maple wood, said HT-CTMP having a shives content measured according to TAPPI T275 of below 0.5% and a bulk measured according to ISO 534:2011 after sheet forming according to ISO 5269-1:2005 of above 5.0 cm3/g.
The HT-CTMP of claim 11 having a Canadian Standard Freeness (CSF) of above 640 ml, which CSF is measured according to ISO 5267-2:2001 after disintegration according to ISO 5263-3:2004.
Dependencies are inferred from the claim text.