EP0677122A1 - A method of producing mechanical and chemi-mechanical pulp - Google Patents

A method of producing mechanical and chemi-mechanical pulp

Info

Publication number
EP0677122A1
EP0677122A1 EP94904362A EP94904362A EP0677122A1 EP 0677122 A1 EP0677122 A1 EP 0677122A1 EP 94904362 A EP94904362 A EP 94904362A EP 94904362 A EP94904362 A EP 94904362A EP 0677122 A1 EP0677122 A1 EP 0677122A1
Authority
EP
European Patent Office
Prior art keywords
temperature
lignin
mechanical
feed
softening temperature
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.)
Granted
Application number
EP94904362A
Other languages
German (de)
French (fr)
Other versions
EP0677122B1 (en
Inventor
Hans HÖGLUND
Roland BÄCK
Ove Danielsson
Bo Falk
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Valmet AB
SCA Research AB
Original Assignee
Sunds Defibrator Industries AB
SCA Research AB
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Family has litigation
First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=20388282&utm_source=google_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=EP0677122(A1) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
Application filed by Sunds Defibrator Industries AB, SCA Research AB filed Critical Sunds Defibrator Industries AB
Publication of EP0677122A1 publication Critical patent/EP0677122A1/en
Application granted granted Critical
Publication of EP0677122B1 publication Critical patent/EP0677122B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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
    • 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
    • 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
    • D21B1/02—Pretreatment of the raw materials by chemical or physical means

Definitions

  • This invention relates to the production of mechanical and chemi-mechanical pulp with a yield of above 85% from ligno ⁇ cellulose-containing material for the making of paper or board products .
  • the first step normally is pressurized, i.e. the refining takes place at temperatures exceeding 100°C, usually immediately below or at the so-called softening temperature (Tg) of the lignin.
  • Tg softening temperature
  • the softening temperature of the lignin which has proved to be an important variable at the refining of chips in mechanical and chemi-mechanical pulp processes, has been determined in the most recent decades in a number of scientific investigations for a plurality of wood types concerned. At the investigations standard equipment and conventional measuring principles for the determination of viscoelastic parameters have been used. For wood, as for other viscoelastic materials, the softening temperature varies with the load frequency at the measurements. At a higher load frequency, the softening temperature increases. At the processing frequencies normally applied in refiners the softening temperature of coniferous wood was determined to be between 125°C and M 5°£ , while it proved to be somewhat lower for our most usual hardwood types. The softening temperature can be shifted by the addition of different chemicals. It can be lowered, for example, after impregnation by usual lignin softening chemicals, of the type sulphite.
  • the present invention relates to such a method, where the mechanical processing, for example refining, takes place in at least two steps.
  • the material at its feed into the first processing step has a temperature below the softening temperature of the lignin, and at its feed into at least one subsequent processing step has a temperature exceeding the softening temperature of the lignin.
  • refining takes place in at least two steps.
  • the chips are fed into the refiner at a temperature below the softening temperature of the lignin and then are processed under relatively intensive conditions, for example in a double-disc refiner with a speed of at least 1200 rpm or in a single-disc refiner with high relative speed between the refiner discs (at least 1800 rp ⁇ , preferably at least 2400 rpm).
  • the energy input in the first step is chosen to be on such a low level, that the long fiber content of the pulp which a.o. yields the potential for the later strength development at the refining, is not deteriorated appreciably.
  • the freenes (CSF) of the pulp after the first step therefore, shall be high, preferably
  • a subsequent refining step is carried out under conditions where the lignin of the fiber material is well softened.
  • the fiber material then is fed into the refiner at a temperature exceeding the softening temperature of the lignin.
  • the temperature should exceed 150°C, suitably 160°C and preferably 170°C.
  • the temperature should exceed 135°C, suitably 150°C and preferably 160°C.
  • temperatures over 200°C should be avoided, a.o. with regard to dark colouring of the fiber material.
  • the processing frequency preferably can be high (relative speed at least 24.00 rpm) at the processing of the well- ⁇ oftened fiber material, which has proved especially favourable from an energy point of view.
  • the temperature difference between the temperatures of the material at its feed into the first and, respectively, a subsequent processing step should be at least 15°C, suitably at least 25°C and preferably at least 35°C.
  • fractures and fracture indications in the material initially are guided to layers in the fiber wall- not rich in lignin.
  • the known fact then can be utilized, that the fiber material can be separated with low energy inputs in areas rich in lignin at temperatures above the softening temperature of the wood lignin.
  • the fractures initially having been guided to areas not rich in lignin, it is thereby avoided to obtain a fiber material with only lignin-jovered surfaces which are difficult to fibrillate. This has previously been the great problem when it was tried to utilize refining temperatures above the softening temperature of the lignin at the production of mechanical pulps for printing paper or board products.
  • Fine material from areas between the initial fracture zone and the middle lamina of the fiber rich in lignin also is easily released at temperatures above the softening temperature of the lignin in the later refining step, which can explain the low total energy consumption to a certain freeness (C. q F) in this process step and in the entire process according to the invention.
  • the production of fine material otherwise is the most energy requiring part of the mechanical pulp process using conventional technique.
  • Thermomechanical pulp from sprucechips was produced after refining in two steps in a 20" single-disc refiner of a well-equipped test plant.
  • the first refining step (defibering) was carried out after preheating the chips at 115°C for about 3 minutes, i.e. at a temperature below the softening temperature of the lignin.
  • the refiner was driven by a 3000 rpm motor, in order to ensure that the initial defibering should not take place under too mild conditions.
  • the effect input in the first step was 64.O kWh/t, which yielded a pulp with freeness (CSF) 518 ml.
  • the second refining step the conditions were varied according to the following Table:
  • Fi g - 1 shows freeness as a function of energy consumption. It appears that by carrying out the second refining step at temperatures above the softening temperature of the lignin the energy input at refining to a certain freeness can be reduced considerably compared to conventional second step refining at temperatures below the softening temperature of the lignin (compare Tests A and B).The energy reduction will be still greater when, in addition, the speed is increased from 1500 to 3000 rpm (compare Test B with Tests C and D) .
  • Fig. 2 shows the shives content as a function of ' the energy consumption. It appears that second step refining at temper ⁇ atures above the softening temperature of the lignin yields a clearly lower shives content at a certain energy input than refining at a temperature below the softening temper ⁇ ature of the lignin (compare Test A with Tests B-D) . Also in this case the higher speed yields the most favourable values. This proves to be a further advantage by using the conditions according to the invention.
  • Fig- 3 shows the long fiber content as a function of freeness.
  • Fig. 4 show,-; the tear index as a function of freeness. It appears that the tear index of the pulp can be maintained all the way down to the freeness range 150-200 ml, in spite of the iarge energy reduction at refining at the conditions of the invention.
  • Figs. 5 and 6 show the tensile index and, respectively, light scattering as a function of freeness. It appears that- all tested pulps develop tensile index and, respectively, light scattering coefficient in a similar way when they are valued conventionally against freeness.
  • thermomechanical pulp was made from spruce chips after refining in two steps by single-disc refiners.
  • the first refining step was carried out at temperatures above the softening temperature of the lignin in the same equipment which was used previously in the test.
  • the conditions in the first refining step and the freeness after refining with a certain energy input are described in the following Table:
  • Fig. 7 shows that the energy consumption is considerably higher when the TMP-process is initiated with a refining step at a temperature above the softening temperature of lignin than that obtained with conditions according to the invention (compare Fig. 1).
  • Fig. 8 shows that the light scattering coefficient is considerably lower when the TMP-process is initiated with a refining step at temperatures above the softening temperature of lignin than that obtained with conditions according to the invention (compare Fig. 6).
  • the pulps produced, according to the invention, there ore, are clearly most suitable for use as printing paper pulps, where just the light scattering coefficient must be sufficiently high for achieving the desired optical properties.
  • chemicals can be added advantageously after or during the first refining step, in order to avoid dark colouring at the high temperatures above the softening temperature of lignin in subsequent refining steps.
  • the chemicals also can have a bleaching effect. Examples of such chemicals are sodium sulphite, sodium bisulphite, sodium ditionite, peroxide etc.
  • the initial processing can be carried out, besides in refiners, also in grinders, compressing screws or other mechanical processing equipment.
  • this reject with a temperature above the softening temperature of lignin shall be fed into at least one subsequent processing step.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Wood Science & Technology (AREA)
  • Paper (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
  • Chemical And Physical Treatments For Wood And The Like (AREA)

Abstract

A method of producing mechanical and chemi-mechanical pulp with a yield above 85 % from lignocellulose-containing material for the manufacture of paper or board products. The material is subjected to mechanical processing in at least two steps. The material at its feed into the first step has a temperature below the softening temperature of lignin. When the material is fed into at least one subsequent processing step, it shall have a temperature above the softening temperature of lignin.

Description

A method of producing mechanical and chemi-mechanica pulp
This invention relates to the production of mechanical and chemi-mechanical pulp with a yield of above 85% from ligno¬ cellulose-containing material for the making of paper or board products .
Mechanical pulp (e.g. TMP) or chemi-mechanical pulp (e.g. CTMP) is today produced in several different process vari¬ ations, where steamed chips are refined in disc refiners of various types. At the production of pulps for different printing papers or wrapping materials, of board type, the refining usually is carried out in one or more steps. The first step normally is pressurized, i.e. the refining takes place at temperatures exceeding 100°C, usually immediately below or at the so-called softening temperature (Tg) of the lignin. Heretofore, it was chosen to hold the pressure and temperature in subsequent refining steps on the same level as in the first refining step, or to carry out later refin¬ ing steps in systems not pressurized, i.e. at a temperature lower than in the initial step, usually at the softening temperature of the lignin or below the same.
The softening temperature of the lignin, which has proved to be an important variable at the refining of chips in mechanical and chemi-mechanical pulp processes, has been determined in the most recent decades in a number of scientific investigations for a plurality of wood types concerned. At the investigations standard equipment and conventional measuring principles for the determination of viscoelastic parameters have been used. For wood, as for other viscoelastic materials, the softening temperature varies with the load frequency at the measurements. At a higher load frequency, the softening temperature increases. At the processing frequencies normally applied in refiners the softening temperature of coniferous wood was determined to be between 125°C and M 5°£ , while it proved to be somewhat lower for our most usual hardwood types. The softening temperature can be shifted by the addition of different chemicals. It can be lowered, for example, after impregnation by usual lignin softening chemicals, of the type sulphite.
Relatively high total electric energy amounts are required for producing the aforementioned types of pulp. The production of pulp for newsprint from coniferous wood, for example, can require up to 2000kWh/ton pulp. In many studies carried out recently with the object of trying to lower the electric energy consumption in the TMP-process, it was found that the initial processing phase seemed to be quite essential for the total energy consumption in different process variants and for the character of the resulting pulp. This seems to apply in spite of the fact that only a small part of the total electric energy consumption in the refining process is used for the fiber separation proper, i.e. for the conversion from chips to free individual fibers (also called defibering).
A fiber separation energy-effective per se as a result of an effective thermal or chemical softening of the chip areas rich in lignin, however, does not prove to be a garanty that the total energy consumption will be low. On the contrary, it was proved that TMP-process variants, which were initiated with a mild fiber separation poor in energy, often require a high total energy input.
This circumstance seems to be caused by the fact, that mildly separated but unprocessed fibers, which were obtained by carrying out the defibering at temperatures above the soften¬ ing temperature of the wood lignin, are difficult to fibrillate during the continued working in the refining process. This fibrillation is necessary for increasing the flexibility of the fibers to a desired level and bringing about the fine material characterizing a good TwP-quaiity. An intensive processing below the softening temperature of the wood lignin initially and during the continued refining process, on the other hand, easily leads to a de erioration of the long fiber content and thereby of the strength properties of the pulp. This is in many cases unacceptable from a quality point of view. A decrease in the energy consumption from an established level in the TMP-process, as a rule, has been associated with a deterioration of certain quality properties of the resulting pulp, for example lower long fiber contant, lower tear strength, lower tensile strength and higher shives content. The present high energy consumption in the TMP- and CTMP- process, therefore, has been necessary for achieving the desired pulp properties.
It was now found by surprise, that it is possible to combine low energy consumption in a mechanical or chemi-mechanical pulp making process with maintained quality properties. The present invention relates to such a method, where the mechanical processing, for example refining, takes place in at least two steps. According to the invention, the material at its feed into the first processing step has a temperature below the softening temperature of the lignin, and at its feed into at least one subsequent processing step has a temperature exceeding the softening temperature of the lignin. The invention is described in greater detail in the following, with reference to some expedient embodiments and examples with associated Figures 1-8.
In a TMP-process according to the invention, refining takes place in at least two steps. In the first step the chips are fed into the refiner at a temperature below the softening temperature of the lignin and then are processed under relatively intensive conditions, for example in a double-disc refiner with a speed of at least 1200 rpm or in a single-disc refiner with high relative speed between the refiner discs (at least 1800 rpπ, preferably at least 2400 rpm). The energy input in the first step is chosen to be on such a low level, that the long fiber content of the pulp which a.o. yields the potential for the later strength development at the refining, is not deteriorated appreciably. The freenes (CSF) of the pulp after the first step, therefore, shall be high, preferably
^ 500 ml. A subsequent refining step is carried out under conditions where the lignin of the fiber material is well softened. The fiber material then is fed into the refiner at a temperature exceeding the softening temperature of the lignin. In cases when the material consists of coniferous wood not treated with chemicals, the temperature should exceed 150°C, suitably 160°C and preferably 170°C. When the material is treated with chemicals, the temperature should exceed 135°C, suitably 150°C and preferably 160°C. As regards an upper temperature limit, temperatures over 200°C should be avoided, a.o. with regard to dark colouring of the fiber material. The processing frequency preferably can be high (relative speed at least 24.00 rpm) at the processing of the well-βoftened fiber material, which has proved especially favourable from an energy point of view.
The temperature difference between the temperatures of the material at its feed into the first and, respectively, a subsequent processing step should be at least 15°C, suitably at least 25°C and preferably at least 35°C.
In a process according to the invention fractures and fracture indications in the material initially are guided to layers in the fiber wall- not rich in lignin. During the final refining the known fact then can be utilized, that the fiber material can be separated with low energy inputs in areas rich in lignin at temperatures above the softening temperature of the wood lignin. The fractures initially having been guided to areas not rich in lignin, it is thereby avoided to obtain a fiber material with only lignin-jovered surfaces which are difficult to fibrillate. This has previously been the great problem when it was tried to utilize refining temperatures above the softening temperature of the lignin at the production of mechanical pulps for printing paper or board products. Fine material from areas between the initial fracture zone and the middle lamina of the fiber rich in lignin also is easily released at temperatures above the softening temperature of the lignin in the later refining step, which can explain the low total energy consumption to a certain freeness (C.qF) in this process step and in the entire process according to the invention. The production of fine material otherwise is the most energy requiring part of the mechanical pulp process using conventional technique.
EXAMPLE
Thermomechanical pulp from sprucechips was produced after refining in two steps in a 20" single-disc refiner of a well-equipped test plant. The first refining step (defibering) was carried out after preheating the chips at 115°C for about 3 minutes, i.e. at a temperature below the softening temperature of the lignin. The refiner was driven by a 3000 rpm motor, in order to ensure that the initial defibering should not take place under too mild conditions. The effect input in the first step was 64.O kWh/t, which yielded a pulp with freeness (CSF) 518 ml. In the second refining step the conditions were varied according to the following Table:
Test Preheating time Refining temperature Motor speed min °C X^ τ_m
A about 1 115 ( < Tg) 1500
B II 1 160 ( > Tg) 1500
C II 1 160 ( > Tg) 3000
D II 1 170 ( Tg) 3000
x) Temperature at preheating and at feed into the refiner
The effect of the varying conditions is shown in Figs. 1-6 where the most essential pulp properties have been valued, and are commented on as oiiows : Fi g - 1 shows freeness as a function of energy consumption. It appears that by carrying out the second refining step at temperatures above the softening temperature of the lignin the energy input at refining to a certain freeness can be reduced considerably compared to conventional second step refining at temperatures below the softening temperature of the lignin (compare Tests A and B).The energy reduction will be still greater when, in addition, the speed is increased from 1500 to 3000 rpm (compare Test B with Tests C and D) .
Fig. 2 shows the shives content as a function of' the energy consumption. It appears that second step refining at temper¬ atures above the softening temperature of the lignin yields a clearly lower shives content at a certain energy input than refining at a temperature below the softening temper¬ ature of the lignin (compare Test A with Tests B-D) . Also in this case the higher speed yields the most favourable values. This proves to be a further advantage by using the conditions according to the invention.
Fig- 3 shows the long fiber content as a function of freeness.
It appears that the long fiber content of the pulp generally can be maintained all the way down to the freeness range
150-200 ml, in spite of the heavy energy reduction at refining according to the conditions of the invention.
Fig. 4 show,-; the tear index as a function of freeness. It appears that the tear index of the pulp can be maintained all the way down to the freeness range 150-200 ml, in spite of the iarge energy reduction at refining at the conditions of the invention. Figs. 5 and 6 show the tensile index and, respectively, light scattering as a function of freeness. It appears that- all tested pulps develop tensile index and, respectively, light scattering coefficient in a similar way when they are valued conventionally against freeness.
In parallel with the tests described and with reference thereto it also was investigated, how energy consumption and pulp quality are affected when a refining process contrary to the conditions of the invention was started with a refining step where the temperature at the feed to the first step refiner is higher than the softening temperature of the lignin. Also in this case the thermomechanical pulp was made from spruce chips after refining in two steps by single-disc refiners. The first refining step was carried out at temperatures above the softening temperature of the lignin in the same equipment which was used previously in the test. The conditions in the first refining step and the freeness after refining with a certain energy input are described in the following Table:
Test Preheating Refining Motor Energy Freeness o χ) time, min temp. C speed rpm input kWh/t ml
E about 1 1 0 (> Tg) 3000 940 450
F II -i 160 (>Tg) 1500 900 580
G II -, 160 C>Tg) 3000 790 415
x) Temperature at preheating and feed into the refiner
In a second refining step which was carried out under atmospheric conditions in a 20" refiner, i.e. at temperatures below the softening temperature of lignin, the freeness was lowered to an interesting range for printing paper pulps. The refiner speed in this case was 1500 rpm. The effect of the varying conditions on energy consumption and light scattering capacity appears from Figs. 7 and *? , which show freeness as a function of energy consumption and, respectively, light scattering as a function of freeness.
Fig. 7 shows that the energy consumption is considerably higher when the TMP-process is initiated with a refining step at a temperature above the softening temperature of lignin than that obtained with conditions according to the invention (compare Fig. 1).
Fig. 8 shows that the light scattering coefficient is considerably lower when the TMP-process is initiated with a refining step at temperatures above the softening temperature of lignin than that obtained with conditions according to the invention (compare Fig. 6). The pulps produced, according to the invention, there ore, are clearly most suitable for use as printing paper pulps, where just the light scattering coefficient must be sufficiently high for achieving the desired optical properties.
The example described proves clearly, that mechanical pulp can ".be produced with the conditions of the invention at low energy consumption, at the same time as essential properties like shives content, long fiber content,tear strength, tensile strength and light scattering meet high requirements on this type of pulps. The energy consumption at the production of newsprint, for example, can be reduced by about 40% compared with conventional manufacturing methods.
In the process according to the invention, chemicals can be added advantageously after or during the first refining step, in order to avoid dark colouring at the high temperatures above the softening temperature of lignin in subsequent refining steps. The chemicals also can have a bleaching effect. Examples of such chemicals are sodium sulphite, sodium bisulphite, sodium ditionite, peroxide etc.
According to the invention, the initial processing can be carried out, besides in refiners, also in grinders, compressing screws or other mechanical processing equipment.
In cases when a reject fraction separated from the processed material is subjected to additional mechanical processing, this reject with a temperature above the softening temperature of lignin shall be fed into at least one subsequent processing step.
The invention, of course, is not restricted to the examples shown, but can be varied within the scope of the invention idea.

Claims

Claims
1. A method of producing mechanical and chemi-mechanical pulp with a yield above 85% from lignocellulose-containing fiber material for the manufacture of paper or board .products , which method comprises mechanical processing in at least two steps, c h a r a c t e r i z e d i n that the material at its feed into the first processing step has a temperature below the softening temperature of lignin, and at its feed into at least one subsequent processing step has a temperature above the softening temperature of lignin.
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 temperature difference between the temperatures of the material at its feed into the first step and at its feed into at least one subsequent step is at least 15°C, suitably at least 25°C and preferably at least 35°C.
3. A method as defined in claim 1 or 2, where the material consists of coniferous wood not treatedwith chemicals, c h a r a c t e r i z e d i n that the temperature of the material at its feed into at least one subsequent step exceeds 150°C, suitably 160°C and preferably 170°c.
4. A method as defined in claim 1 or 2 , where the material is treated with chemicals, c h a r a c t e r i z e d i n that the temperature of the material at its feed into at least one subsequent step exceeds 35°C, suitably 150°C and preferably 160°C.
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 mechanical processing in at least one subsequent step is carried out by a refiner .
6. 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 all processing steps are carried out by refiners.
7. 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 a reject fraction separated from the mechanically, processed material with a temperature above the softening temperature of lignin is fed into at least one subsequent processing step.
8. 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 -first processing step is carried out in a double-disc refiner with a speed of at least 1200 rpm or in a single-disc refiner with a speed of at least 1800 rpm, preferably at least 2400 rpm.
9. 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 at least one subsequent step is carried out in a refiner with a relative speed of at least 2400 rpm.
10. 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 chemicals maintaining brightness or bleaching chemicals", such as sodium sulphite, sodium bisulphite, sodium ditionite, peroxide etc. are added after or during the first processing step.
EP94904362A 1992-12-30 1993-12-08 A method of producing mechanical and chemi-mechanical pulp Expired - Lifetime EP0677122B1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
SE9203943A SE470555B (en) 1992-12-30 1992-12-30 Process for the manufacture of mechanical and chemical mechanical pulp with a yield of more than 85% from lignocellulosic fibrous material
SE9203943 1992-12-30
PCT/SE1993/001058 WO1994016139A1 (en) 1992-12-30 1993-12-08 A method of producing mechanical and chemi-mechanical pulp

Publications (2)

Publication Number Publication Date
EP0677122A1 true EP0677122A1 (en) 1995-10-18
EP0677122B1 EP0677122B1 (en) 1998-09-09

Family

ID=20388282

Family Applications (1)

Application Number Title Priority Date Filing Date
EP94904362A Expired - Lifetime EP0677122B1 (en) 1992-12-30 1993-12-08 A method of producing mechanical and chemi-mechanical pulp

Country Status (17)

Country Link
EP (1) EP0677122B1 (en)
JP (1) JP3258019B2 (en)
KR (1) KR950704567A (en)
CN (1) CN1052049C (en)
AT (1) ATE170940T1 (en)
AU (1) AU678802B2 (en)
BR (1) BR9307748A (en)
CA (1) CA2151364C (en)
DE (1) DE69320989T2 (en)
FI (1) FI115844B (en)
NO (1) NO312206B1 (en)
NZ (1) NZ259595A (en)
PL (1) PL309195A1 (en)
RU (1) RU95113478A (en)
SE (1) SE470555B (en)
WO (1) WO1994016139A1 (en)
ZA (1) ZA939370B (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR3117123A1 (en) 2020-12-09 2022-06-10 Compagnie Generale Des Etablissements Michelin RUBBER COMPOSITION WITH IMPROVED RESISTANCE TO MECHANICAL AGGRESSIONS
FR3117122A1 (en) 2020-12-09 2022-06-10 Compagnie Generale Des Etablissements Michelin OFF-ROAD VEHICLE TIRE

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0775232B2 (en) * 1995-06-12 2003-05-02 Andritz Sprout-Bauer, Inc. Low-resident, high-temperature, high-speed chip refining
US6364998B1 (en) * 1995-06-12 2002-04-02 Andritz Inc. Method of high pressure high-speed primary and secondary refining using a preheating above the glass transition temperature
US6899791B2 (en) 1997-08-08 2005-05-31 Andritz Inc. Method of pretreating lignocellulose fiber-containing material in a pulp refining process
US7300541B2 (en) * 2002-07-19 2007-11-27 Andritz Inc. High defiberization chip pretreatment
DE102007057580A1 (en) * 2007-11-28 2009-06-04 Bühler AG Method for fractionation of lignocellulose containing raw material, involves breaking lignocellulose containing raw material into raw material particles
SE540115C2 (en) 2016-09-21 2018-04-03 A paper or paperboard product comprising at least one ply containing high yield pulp and its production method
US11624153B2 (en) * 2017-06-20 2023-04-11 Basf Se Method of increasing the throughput and/or decreasing energy usage of a pulping process

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE303088B (en) * 1963-05-31 1968-08-12 Defibrator Ab
SE466060C (en) * 1990-02-13 1995-07-11 Moelnlycke Ab Absorbent chemitermomechanical mass and preparation thereof

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO9416139A1 *

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR3117123A1 (en) 2020-12-09 2022-06-10 Compagnie Generale Des Etablissements Michelin RUBBER COMPOSITION WITH IMPROVED RESISTANCE TO MECHANICAL AGGRESSIONS
FR3117122A1 (en) 2020-12-09 2022-06-10 Compagnie Generale Des Etablissements Michelin OFF-ROAD VEHICLE TIRE
WO2022123154A1 (en) 2020-12-09 2022-06-16 Compagnie Generale Des Etablissements Michelin Tyre for an off-road vehicle
WO2022123155A1 (en) 2020-12-09 2022-06-16 Compagnie Generale Des Etablissements Michelin Rubber composition with improved resistance to mechanical stress

Also Published As

Publication number Publication date
KR950704567A (en) 1995-11-20
CN1092832A (en) 1994-09-28
SE9203943L (en) 1994-07-01
NZ259595A (en) 1997-10-24
CN1052049C (en) 2000-05-03
EP0677122B1 (en) 1998-09-09
AU5844594A (en) 1994-08-15
SE9203943D0 (en) 1992-12-30
WO1994016139A1 (en) 1994-07-21
BR9307748A (en) 1994-11-14
RU95113478A (en) 1997-05-27
NO312206B1 (en) 2002-04-08
NO952613D0 (en) 1995-06-29
PL309195A1 (en) 1995-09-18
FI953229A0 (en) 1995-06-29
JP3258019B2 (en) 2002-02-18
CA2151364C (en) 1999-02-09
FI115844B (en) 2005-07-29
AU678802B2 (en) 1997-06-12
DE69320989D1 (en) 1998-10-15
JPH08504894A (en) 1996-05-28
CA2151364A1 (en) 1994-07-21
ZA939370B (en) 1994-08-08
DE69320989T2 (en) 1999-01-28
SE470555B (en) 1994-08-22
ATE170940T1 (en) 1998-09-15
NO952613L (en) 1995-06-29
FI953229A (en) 1995-06-29

Similar Documents

Publication Publication Date Title
JP3856466B2 (en) Easily drainable, bulky chemimechanical pulp with low fiber content and low fines content
US6267841B1 (en) Low energy thermomechanical pulping process using an enzyme treatment between refining zones
US4502918A (en) Two-stage chemical treatment of mechanical wood pulp with sodium sulfite
CA2067129A1 (en) Process for manufacturing chemo-mechanical and/or chemo-thermal-mechanical wood pulps
AU678802B2 (en) A method of producing mechanical and chemi-mechanical pulp
CA1275760C (en) Method of manufacturing bleached chemimechanical and semichemical fibre pulp by means of a two-stage impregnation process
CA2633800C (en) A method for manufacturing mechanical pulp
US5853534A (en) Method of producing pulp with high yield using a two-stage refining system operating at different temperatures
US7306698B2 (en) Method for producing pulp
US4789429A (en) Method of making mechanical pulp
AU2002244309A1 (en) Method for producing pulp
Perssona et al. Very Low Energy High Yield Pulping
CA1230709A (en) Procedure for producing refined groundwood pulp
CA2243228A1 (en) Preparation of mechanical wood pulps with reduced energy
NO872775L (en) PROCEDURE FOR MAKING MECHANICAL MASS.
CA2285148A1 (en) Chemimechanical or mechanical pulp manufacture with reduced energy consumption

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 19950502

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT CH DE ES FR GB GR IT LI SE

TPAD Observations filed by third parties

Free format text: ORIGINAL CODE: EPIDOS TIPA

17Q First examination report despatched

Effective date: 19970127

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AT CH DE ES FR GB GR IT LI SE

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT;WARNING: LAPSES OF ITALIAN PATENTS WITH EFFECTIVE DATE BEFORE 2007 MAY HAVE OCCURRED AT ANY TIME BEFORE 2007. THE CORRECT EFFECTIVE DATE MAY BE DIFFERENT FROM THE ONE RECORDED.

Effective date: 19980909

Ref country code: GR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19980909

Ref country code: ES

Free format text: THE PATENT HAS BEEN ANNULLED BY A DECISION OF A NATIONAL AUTHORITY

Effective date: 19980909

REF Corresponds to:

Ref document number: 170940

Country of ref document: AT

Date of ref document: 19980915

Kind code of ref document: T

REG Reference to a national code

Ref country code: CH

Ref legal event code: EP

REF Corresponds to:

Ref document number: 69320989

Country of ref document: DE

Date of ref document: 19981015

ET Fr: translation filed
REG Reference to a national code

Ref country code: CH

Ref legal event code: NV

Representative=s name: BOVARD AG PATENTANWAELTE

PLBQ Unpublished change to opponent data

Free format text: ORIGINAL CODE: EPIDOS OPPO

PLBI Opposition filed

Free format text: ORIGINAL CODE: 0009260

PLBF Reply of patent proprietor to notice(s) of opposition

Free format text: ORIGINAL CODE: EPIDOS OBSO

26 Opposition filed

Opponent name: ANDRITZ-PATENTVERWALTUNGS-GESELLSCHAFT M.B.H.

Effective date: 19990608

PLBF Reply of patent proprietor to notice(s) of opposition

Free format text: ORIGINAL CODE: EPIDOS OBSO

PLBF Reply of patent proprietor to notice(s) of opposition

Free format text: ORIGINAL CODE: EPIDOS OBSO

RAP2 Party data changed (patent owner data changed or rights of a patent transferred)

Owner name: SCA RESEARCH AB

Owner name: VALMET FIBERTECH AKTIEBOLAG

PLBL Opposition procedure terminated

Free format text: ORIGINAL CODE: EPIDOS OPPC

PLBM Termination of opposition procedure: date of legal effect published

Free format text: ORIGINAL CODE: 0009276

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: OPPOSITION PROCEDURE CLOSED

27C Opposition proceedings terminated

Effective date: 20001209

REG Reference to a national code

Ref country code: GB

Ref legal event code: IF02

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: CH

Payment date: 20021212

Year of fee payment: 10

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LI

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20031231

Ref country code: CH

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20031231

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: SE

Payment date: 20081219

Year of fee payment: 16

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20081218

Year of fee payment: 16

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20081219

Year of fee payment: 16

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20081231

Year of fee payment: 16

EUG Se: european patent has lapsed
GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20091208

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

Effective date: 20100831

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20091231

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20100701

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20091208

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20091209

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: AT

Payment date: 20121227

Year of fee payment: 20

REG Reference to a national code

Ref country code: AT

Ref legal event code: MK07

Ref document number: 170940

Country of ref document: AT

Kind code of ref document: T

Effective date: 20131208