A method for manufacturing mechanical pulp
A pulp and mechanical technology, applied in papermaking, textile and papermaking, cellulose pulp post-processing, etc., can solve the problems of deterioration of processing equipment, lowering the pH value of pulp, etc., to prevent corrosion and be easy to bleach.
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
Method used
Image
Examples
example 0
[0044] A process that does not involve alkaline treatment prior to ozonation is used to treat mechanical pulp made from pine wood.
[0045] Points 1 and 2 correspond to the results obtained from normal TMP refining, where pine wood was used as raw material.
[0046] Figure 5 and point 5 in Figure 6 corresponds to the results obtained from a process in which ozonated pine rejects were mixed with non-ozonated pine accepts. No base is added.
[0047] Figure 5 and point 7 in Figure 6 correspond to the results obtained from a process in which ozonated pine rejects were mixed with ozonated pine acceptors. No base is added.
[0048] as from Figure 5 As can be seen in Figure 6, energy savings of +20% and better strength properties compared to normal pine treatment were achieved by ozonated pine rejection.
example 1
[0050] The first process option is described below by referring to FIG. 1 .
[0051] The raw material of mechanical pulp is first dewatered, for example in a thickener 1 such as a screw press, and then the raw material is sent to a refiner 2, where the raw material, for example pine chips, is refined in a first stage at elevated temperature and is refined under pressure to form mechanical pulp. The concentration during the refining process is approximately 30%. The preferred raw material is pine wood, since the method of the invention is most advantageous when the raw material is pine wood compared to other processes. The first stage of refining is quite gentle; the pulp is refined to a freeness of 600 to 700ml CSF. Freeness values can even be higher than 700ml CSF. The pulp is treated with an alkali such as sodium hydroxide in the alkali treatment reactor 3 . The pH of the first rejected stock was raised to a level between 9 and 11. There is a delay in caustic treatmen...
example 2
[0058] The second process is described below by referring to FIG. 2 .
[0059] The raw material of mechanical pulp is first dewatered, for example in a thickener 1 such as a screw press, and then the raw material is sent to a refiner 2, where the raw material, for example pine chips, is refined in a first stage at elevated temperature and is refined under pressure to form mechanical pulp. The consistency of the pulp is about 30%. The preferred raw material is pine wood, since the method of the invention is most advantageous when the raw material is pine wood compared to other processes. The first stage of refining is quite gentle; the pulp is refined to a freeness of 600 to 700ml CSF. The pulp is treated with an alkali such as sodium hydroxide in the alkali treatment reactor 3 . The pH of the first rejected stock was raised to a level between 9 and 11. There is a delay in caustic treatment reactor 3 such that the pulp remains in caustic treatment reactor for at least 0.5 h...
PUM
Login to View More Abstract
Description
Claims
Application Information
Login to View More