AU8233887A - Method of making mechanical pulp - Google Patents
Method of making mechanical pulpInfo
- Publication number
- AU8233887A AU8233887A AU82338/87A AU8233887A AU8233887A AU 8233887 A AU8233887 A AU 8233887A AU 82338/87 A AU82338/87 A AU 82338/87A AU 8233887 A AU8233887 A AU 8233887A AU 8233887 A AU8233887 A AU 8233887A
- Authority
- AU
- Australia
- Prior art keywords
- impregnation
- defibering
- pulp
- material pieces
- mechanical pulp
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 229920001131 Pulp (paper) Polymers 0.000 title claims description 11
- 238000004519 manufacturing process Methods 0.000 title claims description 4
- 238000005470 impregnation Methods 0.000 claims description 12
- 238000000034 method Methods 0.000 claims description 12
- 239000000463 material Substances 0.000 claims description 11
- 239000007788 liquid Substances 0.000 claims description 8
- 239000000835 fiber Substances 0.000 claims description 7
- 239000007791 liquid phase Substances 0.000 claims description 2
- 239000000126 substance Substances 0.000 description 11
- 238000007670 refining Methods 0.000 description 7
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 6
- 239000002994 raw material Substances 0.000 description 6
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 6
- 239000002023 wood Substances 0.000 description 6
- 238000010025 steaming Methods 0.000 description 5
- 230000029087 digestion Effects 0.000 description 4
- GEHJYWRUCIMESM-UHFFFAOYSA-L sodium sulfite Chemical compound [Na+].[Na+].[O-]S([O-])=O GEHJYWRUCIMESM-UHFFFAOYSA-L 0.000 description 4
- 238000005265 energy consumption Methods 0.000 description 3
- 230000003287 optical effect Effects 0.000 description 3
- XLYOFNOQVPJJNP-ZSJDYOACSA-N Heavy water Chemical compound [2H]O[2H] XLYOFNOQVPJJNP-ZSJDYOACSA-N 0.000 description 2
- 239000003513 alkali Substances 0.000 description 2
- 238000005520 cutting process Methods 0.000 description 2
- 238000007688 edging Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 150000002500 ions Chemical class 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 239000000123 paper Substances 0.000 description 2
- 150000002978 peroxides Chemical class 0.000 description 2
- 238000003825 pressing Methods 0.000 description 2
- 235000011121 sodium hydroxide Nutrition 0.000 description 2
- 235000010265 sodium sulphite Nutrition 0.000 description 2
- LSNNMFCWUKXFEE-UHFFFAOYSA-L sulfite Chemical compound [O-]S([O-])=O LSNNMFCWUKXFEE-UHFFFAOYSA-L 0.000 description 2
- 239000010876 untreated wood Substances 0.000 description 2
- 235000017166 Bambusa arundinacea Nutrition 0.000 description 1
- 235000017491 Bambusa tulda Nutrition 0.000 description 1
- 241001330002 Bambuseae Species 0.000 description 1
- LSNNMFCWUKXFEE-UHFFFAOYSA-M Bisulfite Chemical compound OS([O-])=O LSNNMFCWUKXFEE-UHFFFAOYSA-M 0.000 description 1
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 1
- 235000015334 Phyllostachys viridis Nutrition 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- 229910052783 alkali metal Inorganic materials 0.000 description 1
- 150000001340 alkali metals Chemical class 0.000 description 1
- AZDRQVAHHNSJOQ-UHFFFAOYSA-N alumane Chemical compound [AlH3] AZDRQVAHHNSJOQ-UHFFFAOYSA-N 0.000 description 1
- 239000011425 bamboo Substances 0.000 description 1
- 239000002585 base Substances 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 238000004061 bleaching Methods 0.000 description 1
- 239000007844 bleaching agent Substances 0.000 description 1
- 239000011111 cardboard Substances 0.000 description 1
- 229940106135 cellulose Drugs 0.000 description 1
- 239000001913 cellulose Substances 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 238000004040 coloring Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 239000011121 hardwood Substances 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 229920005610 lignin Polymers 0.000 description 1
- 239000011087 paperboard Substances 0.000 description 1
- 239000012071 phase Substances 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 239000004576 sand Substances 0.000 description 1
- 238000012216 screening Methods 0.000 description 1
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 description 1
- 229910010271 silicon carbide Inorganic materials 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 239000011122 softwood Substances 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 239000004575 stone Substances 0.000 description 1
- 230000008961 swelling Effects 0.000 description 1
- 230000000930 thermomechanical effect Effects 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
Classifications
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21B—FIBROUS RAW MATERIALS OR THEIR MECHANICAL TREATMENT
- D21B1/00—Fibrous raw materials or their mechanical treatment
- D21B1/04—Fibrous raw materials or their mechanical treatment by dividing raw materials into small particles, e.g. fibres
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21B—FIBROUS RAW MATERIALS OR THEIR MECHANICAL TREATMENT
- D21B1/00—Fibrous raw materials or their mechanical treatment
- D21B1/04—Fibrous raw materials or their mechanical treatment by dividing raw materials into small particles, e.g. fibres
- D21B1/12—Fibrous raw materials or their mechanical treatment by dividing raw materials into small particles, e.g. fibres by wet methods, by the use of steam
- D21B1/14—Disintegrating in mills
Landscapes
- Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Wood Science & Technology (AREA)
- Mechanical Engineering (AREA)
- Paper (AREA)
- Reinforced Plastic Materials (AREA)
- Chemical And Physical Treatments For Wood And The Like (AREA)
Description
Method of making mechanical pulp
This invention relates to a method of making mechanical, thermo echanical and chemi-mechanical pulp of ligno-cell- ulose containing material, such as softwood, hardwood or bamboo, with the puppose of being used in different paper and cardboard qualities etc.
Heretofore such pulps were made by two methods different in principle, viz. by refining chips or grinding logs.
At refining, the material is chipped to chips, which are refined to pulp, normally in a disc-refiner in one, two or sometimes three steps. Different types of pulp made according to this method normally are distinguished, viz. PIMP (refiner mechanical pulp), TMP (thermomechanical pulp), CMP (chemi-mechanical pulp) and CTMP (chemi-thermomechanic¬ al pulp), as listed below.
RMP refining of untreated chips at atmospheric pressure TMP refining of steam-heated chips at overpressure CMP refining of chemical-treated chips at atmospheric pressure CTMP refining of chemical-treated chips in steam atmosphere at overpressure.
The pulps have a high content of long fibres and good streng properties. The energy consumption, however, is high, about 2000 kWh/ton pulp. Owing to the high content of long, stiff fibres, the forming in the paper aking machine and the smoothness and optical properties of the paper at times can be unsatisfactory.
At grinding, which is the older method, blocks, i.e. logs cut to a definite length, are ground by being pressed against a rotating grindstone while simultaneously water is supplied. Variants corresponding to those listed above are as follows.
Groundwood grinding of untreated wood at atmospheric pressure
Pressurized grinding of untreated wood at overpressure groundwood
Chemigrund- grinding at atmospheric pressure of wood, wo° which had been digested with chemicals.
At the later variant the stock is impregnated with chemic¬ als and digested in an autoclave prior to grinding (US-PS 2 713 5^0).
Groundwood pulps have a lower content of long fibres than refined pulps. For this reason, the strength properties are inferior, but forming, smoothness and optical properties are better than at refining. The energy consumption is considerably lower, about 1000 kWh/ton pulp. One serious disadvantage is that roundtimberhas to be used.
Chemiground ood has good strength properties. Its disad¬ vantage, however, is that the heart of the log is not im¬ pregnated. The heart, therefore, remains dark at digestion, thereby reducing the ISO-brightness of the pulp and render¬ ing the pulp difficult to bleach. The method, therefore, among other reasons has not got a wide-spread use.
The present invention has the object to provide a method, which eliminates the disadvantages of high energy consumption and of inferior strength and dependency on round timber at grinding.
This and further objects are achieved by the method accord¬ ing to the present invention as defined in the attached claims.
The accompanying block diagram shows in principle an embod¬ iment of the invention.
The raw material enters the process at 1. The raw material can be in the form of logs, small pulpwood, slabs, edgings or other piece shape having the minimum length stated below.
The raw material is washed clean at 2 by heavy water sprays which remove sand and other impurities. The raw material then is cross-cut at 3» for example by cross-cutting saws, to lengths adapted for the defibering apparatus under 8 below. The minimum length in question is 200 mm, but pref¬ erably at least 500 mm. The cross-cut wood is cleaved at 4 to sticks, which have a minimum dimension across the fibre direction of at maximum 50 mm, preferably at maximum 25 mm. The sticks, thus, can have the form of ribs with a width, which may be of the same size as the dimension of the raw material in transverse direction, but the thickness of which does not exceed the dimension stated. The cleaving can be carried out by cleaving apparatuses of different type preferably of the type cleaving the wood along its fibre structure, so that the fibres to the greatest possible exten remain intact. The object of the cleaving is to facilitate the subsequent impregnation. When the raw material, for example, consists of thin slabs or edgings, the cleaving, of course, can be passed over.
The sticks then are steamed at 5 with steam of atmospheric pressure or low pressure for removing the air, which impedes the impregnation. The sticks then are impregnated at 6 with liquid, which may be water, possibly containing chemicals. The liquid is pressed into the fibre material by means of a high hydraulic pump pressure.
The chemicals may be bases, such as caustic soda, salts of alkali metals, for example sodium sulphite or sodium bi¬ sulphite or percompounds, for example peroxide. Mixtures of, for example, caustic soda and sodium sulphite or per¬ oxide may also be used. The impregnation also can be carried out in two or more steps with different chemicals, Λ in which case the excess or spent chemicals are removed between the steps.
By the liquid impregnation remaining air is removed from the wood and replaced by the liquid. The fibres swell
and are softened so that their-slushing at the defiberi'ng is facilitated. The fibres thereby are less subjected to damage, and a pulp with longer fibres and greater strengt is obtained. This effect can be varied in strength, depend¬ ing .on the composition of the liquid etc. The mildest effect is obtained by using only water, while alkali yields a stronger swelling of the he icellulose of the wood. By using sulphite or bisulphite a partial sulphonation and release of the lignin is obtained. The yellow colouring resulting from alkali can be counteracted with peroxide. A stronger release causes.a lower pulp yield and deterior¬ ated optical properties as .well as higher chemical consumpt¬ ion and greater environmental problems. It is, thus, a question requiring careful weighing-up.
The impregnated sticks react at 7 with the chemicals for a certain time and at a certain temperature. The reaction can take place at atmospheric pressure or:.overpressure and in liquid phase or steam phase. After completed react¬ ion time possible excess liquid is drained, and the sticks are defibered at 8, in such a manner, that the sticks, with the fibres oriented in a definite direction, are pressed against the surface of a rotating defibering device, while water is being supplied. The fibres thereby shall be oriented in the same plane as the tangent press surface, and the direction of movement of the surface preferably shall be perpendicular to the fibre direction. Normal grind¬ ers, possibly pressurized, can be used, comprising a grind¬ stone built-up of sharp, hard grains, for example of alumin¬ ium oxide or silicon carbide, held together by a ceramic binder. The grinder and its feed means must be adapted for the treatment of sticks instead of blocks. Of existing pressing devices, chains, screws and the like are less suitable. Devices of pocket type are to be preferred, at which the wood is pressed against the grinding surface by a pressing plate.
After defibering, the pulp produced is removed at 9 for continued processing, such as screening, possibly washing, bleaching etc.
Other embodiments, of course, can be imagined within the scope of the invention idea. For the different process steps different types of continuous and discontinuous apparatuses can be used. The cross-cutting at 3 can be made so that the resulting lengths are twice or several times longer than the final lengths adapted for the defibering apparatus, and the finishing cross-cut is made before the ldefibering.
The steaming at 5 can be passed over or replaced, for example, by vacuum evacuation. The reaction at 7 can be left out. Other types of defibering apparatuses can be used. The defibering, for example, can be carried out against the plane surface of a defibering disc. The de¬ fibering surface can be built-up of other materials, for example steel and cemented carbide.
Pulp types corresponding to the different refiner and groundwood pulps according to above can be manufactured of the sticks in the way as follows.
Mechanical pulp possibly steaming, impregnation with water, defibering at atmospheric press¬ ure Thermomechanical possibly steaming, impregnation with pulp water, possibly digestion, defibering at steam pressure Chemimechanical steaming, impregnation with chemicals, pulp possibly digestion, defibering at at¬ mospheric pressure Chemithermo- steaming, impregnation with chemicals, mechanical pulp possibly digestion, defibering at steam pressure.
Other variants can also be imagined within the scope of the invention idea.
Claims (5)
1. A method of making mechanical pulp of lignocellulose- -containing material in piece shape with a length in the fibre direction of at least 200 mm, at which the mater¬ ial is defibered by being pressed against a rotating defibering member, while ritjtEEd is being supplied, c h a r a c t e r i z e d i n that the thickness of the material pieces first is reduced to a minimum dimension across the fibre direction of at maximum 50 mm, that the material pieces thereafter are impregnated with liquid, and thereafter the defibering is carried out.
2. A method as defined in claim 1, c h a r a c t e r ¬ i z e d i n that the thickness of the material pieces is reduced by cleaving along the fibre structure of the material.
3. A method as defined in claim 1 or 2, c h a r a c t ¬ e r i z e d i n that the material pieces are steamed immediately prior to the impregnation.
4. A method as defined in any one of the preceding claims, c h a r a c t e r i z e d i n that the impregnation is carried out in several steps with different impregnation liquids.
5. A method as defined in any one of the preceding claims, c h a r a c t e r i z e d i n that the material pieces between the impregnation and defibering are digested at overpressure in steam or liquid phase.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
SE8604769A SE458690B (en) | 1986-11-06 | 1986-11-06 | MAKE MANUFACTURING MECHANICAL MASS FROM LIGNOCELLULOSALLY MATERIAL IN PIECE FORM WITH A LENGTH IN THE FIBER DIRECTION OF AT LEAST 200 MM |
SE8604769 | 1986-11-06 |
Publications (1)
Publication Number | Publication Date |
---|---|
AU8233887A true AU8233887A (en) | 1988-06-01 |
Family
ID=20366212
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
AU82338/87A Abandoned AU8233887A (en) | 1986-11-06 | 1987-10-27 | Method of making mechanical pulp |
Country Status (7)
Country | Link |
---|---|
EP (1) | EP0329694A1 (en) |
JP (1) | JPH02501394A (en) |
AU (1) | AU8233887A (en) |
FI (1) | FI892152A0 (en) |
NZ (1) | NZ222448A (en) |
SE (1) | SE458690B (en) |
WO (1) | WO1988003581A1 (en) |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FI103418B1 (en) * | 1996-01-31 | 1999-06-30 | Sunds Defibrator Woodhandling | Method and apparatus for pretreating fibrous material for the production of cellulosic pulp |
SE0203594D0 (en) * | 2002-12-04 | 2002-12-04 | Skogsind Tekn Foskningsinst | Method of treatment of wood chips |
FI126694B (en) * | 2005-12-02 | 2017-04-13 | Metsä Board Oyj | Chemical-mechanical pulp and process for producing chemical-mechanical pulp |
Family Cites Families (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2075023A (en) * | 1934-12-12 | 1937-03-30 | Lester W David | Method of preparing wood for grinding |
US3130116A (en) * | 1960-08-24 | 1964-04-21 | Fmc Corp | Process for grinding or pulping wood |
CA662818A (en) * | 1961-06-23 | 1963-05-07 | Atack Douglas | Profiled tool and apparatus for the production of paper making pulp |
SE327886B (en) * | 1967-12-07 | 1970-08-31 | Svenska Cellulosa Ab | |
DE1951816A1 (en) * | 1969-06-12 | 1970-12-23 | Mosca Moscon & Cia | Process for the production of mechanical-chemical, semi-chemical or chemical wood pulp or pulp for the manufacture of paper, cardboard, etc. |
US3808090A (en) * | 1970-10-01 | 1974-04-30 | F Luhde | Mechanical abrasion of wood particles in the presence of water and in an inert gaseous atmosphere |
CA1240456A (en) * | 1983-10-20 | 1988-08-16 | Kamyr, Inc. | Mechanical pulping |
SE8501246L (en) * | 1985-03-13 | 1986-09-14 | Eka Ab | SET TO MANUFACTURE IN BLEACH, CHEMICAL MECHANICAL AND SEMI-CHEMICAL FIBER MASS USING ONE-STEP IMAGRATION |
BR8606875A (en) * | 1985-09-20 | 1987-11-03 | Scott Paper Co | HIGH PERFORMANCE PULPPING PROCESS FOR LIGNOCELLULOSIC MATERIAL IN THE FORM OF HORSES; NON-SULPHONATED PULP; NON-SULPHONED PULP BEACH; NON-SULPHONED EUCALYPTUS PULP; |
-
1986
- 1986-11-06 SE SE8604769A patent/SE458690B/en not_active IP Right Cessation
-
1987
- 1987-10-27 JP JP50683987A patent/JPH02501394A/en active Pending
- 1987-10-27 WO PCT/SE1987/000498 patent/WO1988003581A1/en not_active Application Discontinuation
- 1987-10-27 AU AU82338/87A patent/AU8233887A/en not_active Abandoned
- 1987-10-27 EP EP19870907450 patent/EP0329694A1/en not_active Withdrawn
- 1987-11-04 NZ NZ22244887A patent/NZ222448A/en unknown
-
1989
- 1989-05-04 FI FI892152A patent/FI892152A0/en not_active IP Right Cessation
Also Published As
Publication number | Publication date |
---|---|
NZ222448A (en) | 1989-02-24 |
JPH02501394A (en) | 1990-05-17 |
EP0329694A1 (en) | 1989-08-30 |
SE8604769D0 (en) | 1986-11-06 |
SE458690B (en) | 1989-04-24 |
FI892152A (en) | 1989-05-04 |
FI892152A0 (en) | 1989-05-04 |
SE8604769L (en) | 1988-05-07 |
WO1988003581A1 (en) | 1988-05-19 |
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