CA1138697A - Production of mechanical wood pulp - Google Patents
Production of mechanical wood pulpInfo
- Publication number
- CA1138697A CA1138697A CA000343955A CA343955A CA1138697A CA 1138697 A CA1138697 A CA 1138697A CA 000343955 A CA000343955 A CA 000343955A CA 343955 A CA343955 A CA 343955A CA 1138697 A CA1138697 A CA 1138697A
- Authority
- CA
- Canada
- Prior art keywords
- liquid
- water
- boiling point
- wood
- wood 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.)
- Expired
Links
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
- 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
- D21B1/16—Disintegrating in mills in the presence of chemical agents
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Wood Science & Technology (AREA)
- Mechanical Engineering (AREA)
- Paper (AREA)
- Manufacturing Of Electric Cables (AREA)
- Preparation Of Compounds By Using Micro-Organisms (AREA)
- Switches With Compound Operations (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
Wood is pulped by the action of a grinding member in the presence of a liquid. In order that the process can be carried out at a temperature above 100°C, either under pressure or at atmospheric pressure, a liquid is used which has a boiling point at atmospheric pressure above 100°C. Previous-ly, water has been employed as the liquid.
Wood is pulped by the action of a grinding member in the presence of a liquid. In order that the process can be carried out at a temperature above 100°C, either under pressure or at atmospheric pressure, a liquid is used which has a boiling point at atmospheric pressure above 100°C. Previous-ly, water has been employed as the liquid.
Description
- 1~3~6~
The invention relates to a process for the production of wood pulp in a pulp grinder having a grinding member against which wood is pressed, ~he grinding zone being supplied with liquid.
Hitherto, water has always been used as the liquid. The water serves as transport means, for the cooling of the grinding member - e.g.
grindstone - and also as a solvent for fibre-bonding substances. As a result of frictional heat, the grinding member becomes hot which can lead to local burning. Thus the supplied water brings about a cooling of the stone. More-over, the separated fibres are floated away with the water.
It has been shown that the grinding process is particularly bene-ficial to the fibres if water is used at elevated temperature. At high tem-peratures the lignin, which is the bonding agent of the wood, is softened.
Consequently, the fibres can be released from the bond much easier and with less damage. The wood pulp contains fewer fragments of fibre and much fewer splinters or groups of fibres. Furthermore, the percentage of long fibres and the strength properties of the wood pulp increase considerably. A liquid temperature of around approximately 120C or more in the grinding zone would be optimal. At this temperature the lignin softens readily, whereby a smaller outlay of energy is necessary for the production of the wood pulp. However, water boils at atmospheric pressure at 100C. For this reason it has already been proposed to provide the grinder with a pressure-tight housing and to grind under pressure. In this manner it is possible, e.g. at a superatmos-pheric pressure of from 1 to 3 bar, to achieve water temperatures of 120 to 130C. However, this process has the disadvantage that a considerable con-structional outlay is necessary and an arrangement of this type is thus very expensive.
According to the present invention there is provided a method of producing mechanical wood pulp in a wood grinder having a grinding member " 1~31~6!~7 against which the wood is pressed while a liquid is fed to the grinding zone, which comprises employing a liquid having a boiling point at atmospheric pressure above 100C.
The process in accordance with the invention thus allows elevated temperatures to be achieved in a simple manner and without special structural means. If the grinding process is carried out in the temperature range at which the lignin softens, a very good wood pulp can be obtained. Preferably the boiling point of the liquid which is used is above 115C.
There are numerous liquids which meet these requirements. For this purpose both organic and inorganic liquids or solids which are dissolved in a liquid, e.g. water, can be used. For example, an aqueous solution of sodium chloride (table salt) can be used, the boiling point of the liquid being determined by the concentration of the sodium chloride. It is also possible to use high boiling-point alcohols, e.g. butyl alcohol, heptyl alcohol or benzyl alcohol having boiling points of 118C, 176C and 205C, respectively.
Glycerol (boiling point 290C) or a mixture of water and glycerol can likewise be used. An aqueous solution of sodium sulphite (Na2S03) or sodium sulphate (Na2S04) is also possible. Obvisusly other liquids can be used provided that they do not impair the grinding action or, of course, corrode the apparatus used.
If desired, the liquid used can be recycled, to limit heat loss.
Although one aim of the invention is to permit the use of tempera-tures above 100C without the need for pressurized apparatus, it is also applicable to pulp grinders which are operated under pressure or in which water at super-atmospheric pressure is fed into the grinding zone. Thus, if required, a further increase in temperature can be achieved.
There is thus provided a process for the production of wood pulp by means of which a wood pulp of high quality can be produced, having a high ``` 113~697 percentage of long fibres and good strength whilst requiring relatively little energy yet not necessitating expensive apparatus.
The invention relates to a process for the production of wood pulp in a pulp grinder having a grinding member against which wood is pressed, ~he grinding zone being supplied with liquid.
Hitherto, water has always been used as the liquid. The water serves as transport means, for the cooling of the grinding member - e.g.
grindstone - and also as a solvent for fibre-bonding substances. As a result of frictional heat, the grinding member becomes hot which can lead to local burning. Thus the supplied water brings about a cooling of the stone. More-over, the separated fibres are floated away with the water.
It has been shown that the grinding process is particularly bene-ficial to the fibres if water is used at elevated temperature. At high tem-peratures the lignin, which is the bonding agent of the wood, is softened.
Consequently, the fibres can be released from the bond much easier and with less damage. The wood pulp contains fewer fragments of fibre and much fewer splinters or groups of fibres. Furthermore, the percentage of long fibres and the strength properties of the wood pulp increase considerably. A liquid temperature of around approximately 120C or more in the grinding zone would be optimal. At this temperature the lignin softens readily, whereby a smaller outlay of energy is necessary for the production of the wood pulp. However, water boils at atmospheric pressure at 100C. For this reason it has already been proposed to provide the grinder with a pressure-tight housing and to grind under pressure. In this manner it is possible, e.g. at a superatmos-pheric pressure of from 1 to 3 bar, to achieve water temperatures of 120 to 130C. However, this process has the disadvantage that a considerable con-structional outlay is necessary and an arrangement of this type is thus very expensive.
According to the present invention there is provided a method of producing mechanical wood pulp in a wood grinder having a grinding member " 1~31~6!~7 against which the wood is pressed while a liquid is fed to the grinding zone, which comprises employing a liquid having a boiling point at atmospheric pressure above 100C.
The process in accordance with the invention thus allows elevated temperatures to be achieved in a simple manner and without special structural means. If the grinding process is carried out in the temperature range at which the lignin softens, a very good wood pulp can be obtained. Preferably the boiling point of the liquid which is used is above 115C.
There are numerous liquids which meet these requirements. For this purpose both organic and inorganic liquids or solids which are dissolved in a liquid, e.g. water, can be used. For example, an aqueous solution of sodium chloride (table salt) can be used, the boiling point of the liquid being determined by the concentration of the sodium chloride. It is also possible to use high boiling-point alcohols, e.g. butyl alcohol, heptyl alcohol or benzyl alcohol having boiling points of 118C, 176C and 205C, respectively.
Glycerol (boiling point 290C) or a mixture of water and glycerol can likewise be used. An aqueous solution of sodium sulphite (Na2S03) or sodium sulphate (Na2S04) is also possible. Obvisusly other liquids can be used provided that they do not impair the grinding action or, of course, corrode the apparatus used.
If desired, the liquid used can be recycled, to limit heat loss.
Although one aim of the invention is to permit the use of tempera-tures above 100C without the need for pressurized apparatus, it is also applicable to pulp grinders which are operated under pressure or in which water at super-atmospheric pressure is fed into the grinding zone. Thus, if required, a further increase in temperature can be achieved.
There is thus provided a process for the production of wood pulp by means of which a wood pulp of high quality can be produced, having a high ``` 113~697 percentage of long fibres and good strength whilst requiring relatively little energy yet not necessitating expensive apparatus.
Claims (9)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. In a method of producing mechanical wood pulp in a wood grinder having a grinding member against which the wood is pressed while a liquid is fed to the grinding zone, for the purpose of carrying out the mechanical wood pulping at temperatures consider-ably above 100°C the step of employing a grinding liquid having a corresponding boiling point at atmospheric pressure.
2. A method according to claim 1, in which the liquid has a boiling point at atmospheric pressure above 115°C.
3. A method according to claim 1, in which the liquid is water to which boiling point-raising agents have been added.
4. A method according to claim 3, in which the liquid is water having a salt dissolved therein.
5. A method according to claim 4, in which the salt is sodium chloride.
6. A method according to claim 4, in which the salt is sodium sulphite.
7. A method according to claim 4, in which the salt is sodium sulphate.
8. A method according to claim 1, in which the liquid is an alcohol or a mixture of an alcohol and water.
9. A method according to claim 8, in which the liquid is glycerol or a mixture of glycerol and water.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE2901943A DE2901943C3 (en) | 1979-01-19 | 1979-01-19 | Process for the production of wood pulp |
| DEP2901943.0 | 1979-01-19 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1138697A true CA1138697A (en) | 1983-01-04 |
Family
ID=6060895
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000343955A Expired CA1138697A (en) | 1979-01-19 | 1980-01-18 | Production of mechanical wood pulp |
Country Status (15)
| Country | Link |
|---|---|
| JP (1) | JPS5598986A (en) |
| AT (1) | AT371164B (en) |
| BE (1) | BE881180A (en) |
| BR (1) | BR5901751U (en) |
| CA (1) | CA1138697A (en) |
| CH (1) | CH645145A5 (en) |
| DE (1) | DE2901943C3 (en) |
| ES (1) | ES8102236A1 (en) |
| FI (1) | FI800123A (en) |
| FR (1) | FR2446885A1 (en) |
| GB (1) | GB2040727A (en) |
| IT (1) | IT1119612B (en) |
| NL (1) | NL7909076A (en) |
| NO (1) | NO150728C (en) |
| SE (1) | SE8000440L (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109112872B (en) * | 2018-10-25 | 2023-12-05 | 厦门中乾机械有限公司 | Multifunctional pulping machine |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE211047C (en) * | ||||
| DE397183C (en) * | 1923-06-19 | 1924-06-16 | Leopold Enge | Process for the production of pulp for paper manufacture |
| DE504705C (en) * | 1928-06-24 | 1930-08-07 | Chemische Werke Koholyt A G | Process for the production and processing of wood pulp and other fiber products |
| US1813988A (en) * | 1929-01-16 | 1931-07-14 | Allison R Chambers | Process for the manufacture of ground wood pulp |
| DE682070C (en) * | 1937-04-01 | 1939-10-07 | Werner Lange | Method and device for the production of wood pulp from pine wood |
| DE677504C (en) * | 1937-06-29 | 1939-06-27 | Chem Fab Coswig Anhalt Hans Sc | Process for the production of wood pulp from wood rich in resin, in particular pine wood |
| DE707894C (en) * | 1937-09-21 | 1941-07-07 | Tschimmer & Schwarz Chem Fab D | Process for the production of wood pulp, in particular from wood rich in resin |
| US2388592A (en) * | 1940-03-21 | 1945-11-06 | Defibrator Ab | Process of making ligno-cellulose pulps from straw |
| GB765690A (en) * | 1954-01-27 | 1957-01-09 | Powell River Company Ltd | Improvements in or relating to a process of producing groundwood pulp |
| FR1401560A (en) * | 1964-05-29 | 1965-06-04 | Defibrator Ab | Process for manufacturing cellulose pulp from chips in a shredder device |
-
1979
- 1979-01-19 DE DE2901943A patent/DE2901943C3/en not_active Expired
- 1979-12-03 AT AT0762679A patent/AT371164B/en not_active IP Right Cessation
- 1979-12-17 NL NL7909076A patent/NL7909076A/en not_active Application Discontinuation
- 1979-12-18 BR BR5901751U patent/BR5901751U/en unknown
- 1979-12-21 IT IT69466/79A patent/IT1119612B/en active
-
1980
- 1980-01-09 GB GB8000646A patent/GB2040727A/en not_active Withdrawn
- 1980-01-10 CH CH15180A patent/CH645145A5/en not_active IP Right Cessation
- 1980-01-14 FR FR8000948A patent/FR2446885A1/en not_active Withdrawn
- 1980-01-15 FI FI800123A patent/FI800123A/en not_active Application Discontinuation
- 1980-01-16 BE BE0/198988A patent/BE881180A/en not_active IP Right Cessation
- 1980-01-18 NO NO800125A patent/NO150728C/en unknown
- 1980-01-18 SE SE8000440A patent/SE8000440L/en unknown
- 1980-01-18 CA CA000343955A patent/CA1138697A/en not_active Expired
- 1980-01-18 JP JP375480A patent/JPS5598986A/en active Pending
- 1980-01-18 ES ES487815A patent/ES8102236A1/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5598986A (en) | 1980-07-28 |
| AT371164B (en) | 1983-06-10 |
| ES487815A0 (en) | 1980-12-16 |
| CH645145A5 (en) | 1984-09-14 |
| FR2446885A1 (en) | 1980-08-14 |
| BR5901751U (en) | 1981-06-16 |
| NO150728C (en) | 1984-12-05 |
| DE2901943B2 (en) | 1981-06-25 |
| ES8102236A1 (en) | 1980-12-16 |
| NO150728B (en) | 1984-08-27 |
| FI800123A (en) | 1980-07-20 |
| NO800125L (en) | 1980-07-21 |
| GB2040727A (en) | 1980-09-03 |
| IT1119612B (en) | 1986-03-10 |
| ATA762679A (en) | 1982-10-15 |
| NL7909076A (en) | 1980-07-22 |
| DE2901943A1 (en) | 1980-07-24 |
| BE881180A (en) | 1980-05-16 |
| IT7969466A0 (en) | 1979-12-21 |
| SE8000440L (en) | 1980-07-20 |
| DE2901943C3 (en) | 1982-02-25 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |