EP0219643B1 - Carton double Kraft et procédé pour la production de carton double Kraft de pâte Kraft blanchie ou non blanchie, pâte TMP, pâte SCMP ou pâte de bisulfite - Google Patents

Carton double Kraft et procédé pour la production de carton double Kraft de pâte Kraft blanchie ou non blanchie, pâte TMP, pâte SCMP ou pâte de bisulfite Download PDF

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Publication number
EP0219643B1
EP0219643B1 EP86111513A EP86111513A EP0219643B1 EP 0219643 B1 EP0219643 B1 EP 0219643B1 EP 86111513 A EP86111513 A EP 86111513A EP 86111513 A EP86111513 A EP 86111513A EP 0219643 B1 EP0219643 B1 EP 0219643B1
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Prior art keywords
pulp
kraft
sheets
paperboard
paper
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EP86111513A
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German (de)
English (en)
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EP0219643A1 (fr
Inventor
Roy S. Swenson
Donald M. Macdonald
Michael Ring
Jasper H. Field
F. Keith Hall
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International Paper Co
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International Paper Co
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Priority claimed from US06/768,642 external-priority patent/US4718981A/en
Priority claimed from US06/768,598 external-priority patent/US4718982A/en
Priority claimed from US06/768,776 external-priority patent/US4692212A/en
Application filed by International Paper Co filed Critical International Paper Co
Publication of EP0219643A1 publication Critical patent/EP0219643A1/fr
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    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H25/00—After-treatment of paper not provided for in groups D21H17/00 - D21H23/00
    • D21H25/04—Physical treatment, e.g. heating, irradiating
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
    • D21F11/00—Processes for making continuous lengths of paper, or of cardboard, or of wet web for fibre board production, on paper-making machines
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H27/00—Special paper not otherwise provided for, e.g. made by multi-step processes
    • D21H27/18—Paper- or board-based structures for surface covering
    • D21H27/22—Structures being applied on the surface by special manufacturing processes, e.g. in presses

Definitions

  • This invention relates to the art of papermaking, particularly to treating paper products with pressure and heat to improve their wet strength while preserving their folding endurance.
  • This invention more specifically, relates to kraft paper products, bleached or unbleached paper products produced from SCMP and sulfite pulps, TMP paperboard.
  • TMP paperboard means thermomechanical pulp paperboard.
  • SCMP semichemical mechanical pulping process.
  • the kraft process is a method of preparation of an aqueous slurry of fibers by treatment of a suitable renewable raw material.
  • a considerable portion of the natural lignin in wood, grass or other vegetative matter is rendered soluble by chemical reaction with one or more nucleophilic reagents.
  • the nucleophilic reagents are sulfide and hydroxide ions, which are used under highly alkaline conditions.
  • Variations of the kraft process include the earlier practiced soda process, using hydroxyl ions derived from metals in Group IA of the periodic table, namely lithium, sodium, potassium, rubidinium and cesium.
  • a second variation involves the use of anthraquinone (AQ) or substituted anthraquinones as additional nucleophiles.
  • Anthraquinone can be used in the soda process, in which case the process is known as the soda-AQ process, or in the kraft process which is then known as the kraft-AQ process.
  • Such variations in the kraft process are well known in the industry and pulps prepared by any of these variations can be used in practicing the present invention.
  • the soda-AQ, kraft and kraft AQ pulps can be rendered white by application of suitable bleaching agents.
  • suitable bleaching agents are usually electrophilic in nature and may include chlorine, chlorine dioxide, sodium hypochlorite, hydrogen peroxide, sodium chlorite, oxygen and ozone. Use is often in sequential stages and a suitable nucleophilic agent, customarily hydroxyl ion, may be used in intermediate stages.
  • "Kraft paner” is paper made from pulp produced by the kraft process. Bleached kraft paper, because of its low lignin content, has low wet strength; hence it is desirable to develop this quality of bleached kraft products.
  • Linerboard is a medium-weight paper product used as the facing material in corrugated carton construction.
  • "Kraft linerboard” is linerboard made from pulp produced by the kraft process.
  • thermomechanical pulping process is a method of producing an aqueous slurry of fibers by mechanical treatment of a suitable renewable raw material.
  • a considerable portion of the natural lignin in wood, grass or other vegetative matter is rendered soluble by chemical reaction with one or more nucleophilic reagents.
  • nucleophilic reagents are not used in thermo­mechanical pulp production. Instead, fibers are liberated from a thermally softened source material, usually wood , chips, by passage through a suitable shredder or disc refiner operating under ambient steam pressure at a temperature of 120-150°C or more.
  • Such fibers are usually brittle and sheets prepared from them are brittle and have little or no wet strength.
  • TMP pulp is pulp produced as described above, by a thermomechanical process. Despite the fiber brittleness, TMP pulp has the advantage of avoiding the odor, disposal problems, and other drawbacks of chemical pulp production.
  • TMP paperboard is a medium-weight paper product made from TMP pulp. It is notoriously weak when wet, and inflexible, compared with products identically made from more flexible pulps such as kraft pulps. Hence, a process for improving both the wet strength and flexibility of TMP paper products is desirable.
  • Fig. 1 shows in simplified diagramatic form a typical papermaking machine, including a web former and three representative pairs of wet press rolls. Also shown are drying rolls whose purpose is to dry the paper to a desired final moisture content, and a calender stack to produce a smooth finish. At least some of the rolls are ordinarily heated to hasten drying. (The drawing is simplified - there are many more drying rolls in actual practice.)
  • the semichemical mechanical pulping process is a method of production of an aqueous slurry of fibers by treatment of a suitable renewable raw material.
  • a considerable portion of the natural natural lignin in wood, grass or other vegetative matter is rendered soluble by chemical reaction with one or more nucleophilic reagents.
  • Minimization of the lignin portion solubilized and removed whilst so altering the lignin as to permit recovery of fibers by the mechanical action of a disk or other refiner or shredder in a condition of little damage is the goal of the SCMP process.
  • CMP chemimechanical process
  • CT-MP chemithermomechanical process
  • NSC neutral sulfite semichemical
  • Such pulps are normally considered to be more brittle and of inferior strength when compared to lower lignin pulps produced by the kraft, sulfite, kraft-anthraquinone (AQ), soda-AQ or alkaline sulfite AQ processes.
  • properties are adequate for many end-uses, including corrugated medium and even as a linerboard component.
  • sulfite or bisulfite ion is the nucleophilic agent.
  • the sulfite or bisulfite ions cause the lignin molecules to break into small fragments. During this chemical reaction, the sulfite or bisulfite ions become chemically bonded to the lignin fragments thereby providing water solubility.
  • a variation of the sulfite process involves the use of anthraquinone (AQ) or substituted anthraquinones as a second nucleophile. AQ is reduced in situ during the earliest stages of the cook to anthrahydro­quinone (AHQ).
  • compression strength is edgewise linear compression strength as measured by a standard STFI (Swedish Forest Research Institute) Tester.
  • the method according to the invention comprise steps of 1) subjecting paper or linerboard, produced from bleached or unbleached kraft pulp or paperboard produced from thermo­mechanically produced pulp or SCMP paper pulp, to high pressure densification to achieve a density of at least 600 kg/m3 and 2) heating the product to an internal temperature of at least 420°F (216°C) for a period of time sufficient to increase the wet strength of the product.
  • the heating rate depends on method of heat transfer chosen. Furthermore, it is desirable to raise the web temperature as rapidly as possible to the chosen treating temperature. Improved heating rates can be achieved by using high roll temperatures and/or by applying high nip forces to the press roll against the sheet on the hot rolls. That high pressure dramatically improves heat transfer rates has previously been disclosed. One worker has attributed this to the prevention of vapor formation at the web-roll interface.
  • While the invention may be practiced over a range of temperatures, pressures and durations, these factors are interrelated. For example, the use of higher temperatures requires a heating step of shorter duration, and vice-versa.
  • 550° F (288°C) in the case of linerboard, a duration of 2 seconds has been found sufficient to obtain the desired improvements, while at 420°F, (216°C), considerably longer time is required.
  • AT 465°F (240°C) a duration of 60 seconds has been found sufficient to obtain the desired improvements, while at 420°F (216°C), considerably longer time is required.
  • SCMP board at 450°F (232°C), a duration of 5 seconds has been found sufficient to obtain substantial improvement.
  • the roll temperature be not greater than the web ignition temperature (572°F, 300°C); however, even higher roll tempe­ratures may be used if suitable precautions, such as the provision of an inert atmosphere, or rapid removal of paper from the hot environment, are taken.
  • Figure 1 shows, in greatly simplified diagrammatic form, a conventional apparatus for producing linerboard
  • FIG. 2 shows, in like diagrammatic form, an apparatus for practicing the present invention.
  • Figure 2 illustrates a preferred apparatus for carrying out the inventive process, although it should be understood that other devices, such as platen presses, can be used and in fact the data below was obtained from platen press tests.
  • bleached or unbleached kraft paper fibers or unbleached TMP pulp fibers or SCMP or sulfite pulp fibers in aqueous suspension are deposited on a web former screen 10, producing a wet mat or fibers.
  • the mat is then passed through a series of wet press nip rolls 12, 13, 14, 15, 16 and 17 which develop a consolidated web.
  • Suitable wet presses known today include long nip presses and shoe-type presses capable of developing high unit press pressures on the wet fiber web. This step is known as "high pressure wet pressing".
  • the web is then passed over pre-drying rolls 18, 19 to remove water from the wet web. Once the moisture content of the web has been reduced to less than 70% by weight, steps of the high pressure densification and high temperature treatment are applied according to the invention.
  • a series of drying rolls 20, 21, 22, 23 are provided with respective pressure rollers 25, 26, 27, 28 which are loaded sufficiently to be able to produce a web density of at least 700 kg/m3.
  • This step we define this step as “press drying” or “high pressure densification”.
  • the high pressure densification step of the invention is carried out both at normal drying temperatures (substantially below 400°F (204°C) in the press drying section, and also in the high temperature heat treatment section described below. It should be understood, however, that the two steps may be performed sequentially or simultaneously.
  • one or more drying rolls are heated to or slightly above the desired maximum internal web temperature.
  • Pressure rolls 35, 36, 37, 38 are used to improve heat transfer between the drying rolls and the web, and preferably, these pressure rolls are also highly loaded to continue the high pressure densification step during heat treatment.
  • the drying roll temperature necessary to achieve target web temperature is a function of several factors including web thickness, web moisture, web entering temperature, web speed, nip pressure, and roll diameter; its calculation is within the skill of the art.
  • the web may be passed over final rolls 50, 51 having air caps 60, 61 to condition the web, which is then calendered and reeled in a conventional manner.
  • Pine wood chips from the southeastern United states were cooked by the kraft process to an extent typical of pulp used in linerboard production.
  • the cooked chips were converted to a pulp by passage through a disk refiner.
  • the pulp was thoroughly washed with water to remove residual black liquor and was stored in the wet state at 38-42°F (3°-6°C) in a refrigerator until sheets were prepared.
  • the cooked, washed pulp had a kappa number of 98, indicating presence of 15% residual lignin and had a freeness of 720 ml by the Canadian Standard Freeness test, which values are typical of a pine linerboard pulp prior to beating.
  • a dispersion of the pulp in distilled water was converted to handsheets using a TAPPI sheet mold.
  • the quantity of fiber in the dispersion was adjusted to give a TAPPI sheet weight of 3.6 g in the oven dried state, said weight being close to that of an air dried, 42 lb/1000 ft2 (205 g/m2) commercial linerboard sheet.
  • the sheets were wet pressed with blotters at 60 psi (415 kPa) prior to drying.
  • Sheets from the first set were dried on TAPPI rings at room temperature according to TAPPI standard T205 om-81. This is a conventional (C) drying procedure. Sheets from the second set were also dried by the conventional procedure but this procedure was followed by a heat treatment (HT).
  • the paper sheet was placed between two 150 mesh stainless steel screens, which assembly was placed in the platen press. Heat treatment was in accordance with the conditions found optimum for this invention, namely 2 seconds at 550°F (289°C) sheet internal temperature. To do this, single sheets were placed in a 550°F (289°C) Carver platen press for 4 seconds with 15 psi (105 kPa) as applied pressure.
  • Hardwood chips from the southeastern United States were cooked by the kraft process to yield, after disk refining and washing, a 98 kappa pulp of 618 ml Canadian Standard Freeness. This pulp was mixed with the softwood of example 1 to give a mixture containing 60% softwood and 40% hardwoodfiber. Sheets were prepared and tested following the procedure in Example 1. The superior fold and strength properties that were obtained are given in Table II.
  • Pine wood chips were processed into a pulp as in Example 1, first paragraph. A dispersion of the pulp in distilled water was converted to handsheets using a Noble & Wood sheet mold. The quantity of fiber in the dispersion was adjusted to give a sheet weight of 7.9 g in the oven dried state. The sheets were wet pressed with blotters at 50 psi (346 kPa) prior to drying.
  • Sheets from the first set were dried on a rotary drum dryer in a conventional (C) manner.
  • Sheets from the second set were heat treated (HT) as in Example 1
  • sheets from the third set were densified and then heat treated (PD & HT) as in Example 1.
  • One sample from each set was conditioned at 73°F (23°C), 50% relative humidity ("dry”); another sample was conditionned at 90°F (32°C), 90% relative humidity ("moist”).
  • Folding endurance, wet tensile strength and compressive strength tests were then carried out as in Example 1. The results, summarized below, show a marked improvement in both folding endurance and in tensile and compressive strength in high moisture conditions.
  • Example 1 The pine pulp used in Example 1 was subjected to three levels of beating by multiple passes through an Escher Wyss refiner to decrease the freeness of the pulp. Sheets were prepared and tested at each process level following the procedure in Example 1. The results in Table 3 again clearly demonstrate the lack of brittleness of the PD+HT sheets in comparison with sheets treated by the C+HT procedure. These values may be compared to those shown in Table I, for unbeaten pulp (720 Canadian Standard Freeness).
  • the densified board was then heat treated at 464°F for 20 seconds. The following results were obtained.
  • handsheets were prepared from a 60% softwood, 40% hardwood high yield pulp blend of the linerboard type.
  • the sheets were divided into two main groups. The first group of sheets were wet pressed at an intensity level approximating that in a conven­tionally equipped production machine wet press (CWP). The second group were pressed at an intensity level approximating that of a modern production machine equipped with a shoe press (SP).
  • CWP conven­tionally equipped production machine wet press
  • SP shoe press
  • Each group of sheets was further subdivided into individual sheets which were retained for testing after drying on a steam-heated rotating drum, or press drying by passage through the nip between a press roll and the rotating drum, or by static press drying between 150 mesh stainless steem screens at 465°F (240°C) for 30 seconds with 15 psi (104 kPa) pressure applied by means of a suitable press.
  • Pine wood chips from the southeastern United States were cooked by the kraft process to an extent typical of pulp used in linerboard production.
  • the cooked chips were converted to a pulp by passage through a disk refiner.
  • the pulp was bleached and washed with water to remove residual black liquor and was stored in the wet state at 38-42°F (3°-6°C) in a refrigerator until sheets were prepared.
  • the cooked, bleached pulp contained substantially no lignin and had a freeness of 720 ml by the Canadian Standard Freeness test, which values are typical of a bleached pine pulp prior to beating.
  • a dispersion of the pulp in distilled water was converted to handsheets using a TAPPI sheet mold.
  • the quantity of fiber in the dispersion was adjusted to give a TAPPI sheet weight of 3.6 g in the oven dried state, said weight being close to that of an air dried, 42 lb/1000 ft2 (205 g/m2) commercial sheet.
  • the sheets were wet pressed with blotters at 60 psi (415 KPa) prior to drying
  • Sheets from the first set were dried on TAPPI rings at room temperature according to TAPPI standard T205 om-81. This is a conventional (C) drying procedure. Sheets from the second set were also dried by the conventional procedure but this procedure was followed by a heat treatment (HT).
  • the paper sheet was placed between two 150 mesh stainless steel screens, which assembly was placed in the platen press. Heat treatment was in accordance with the conditions found optimum for this invention, namely 60 seconds at 465°F (240°C) sheet internal temperature. To do this, single sheets were placed in a 465°F (240°C) Carver platen press for 60 seconds with 15 psi (105 kPa) as applied pressure.
  • Example 6 A southern hardwood bleached kraft pulp in the never-dried state was processed in accordance with the procedure in Example 6.
  • the test results illustrate the lack of wet pulp strength and the somewhat brittle nature of conventionally dried hardwood pulp sheets. Heat treatment of the conventionally dried sheets produced rather mediocre wet strength accompanied by increased brittleness. However, sheets processed in accordance with this invention gave fold values improved by a factor of almost four, thereby demonstrating a pronounced lowering of brittleness in the sheets, which also had significantly improved wet strength.
  • Example 8 illustrates the process of this invention when applied to TMP board.
  • Pine wood chips from the southeastern United States were converted to a pulp by passage through a 250°F (121°C) disk refiner.
  • the pulp was stored in the wet state at 38-42°F (3°-6°C) in a refrigerator until sheets were prepared.
  • a dispersion of the pulp in distilled water was converted to handsheets using a TAPPI sheet-mold.
  • the quantity of fiber in the dispersion was adjusted to give a TAPPI sheet weight of 3.6 g in the oven dried state, said weight being close to that of an air dried, 42 lb/1000 ft2 (205 g/m2) commercial linerboard sheet.
  • the sheets were wet pressed with blotters at 60 psi (415 kPa) prior to drying.
  • Sheets from the first set were dried on TAPPI rings at room temperature according to TAPPI standard T205 om-81. This is a conventional (C) drying procedure. Sheets from the second set were also dried by the conventional procedure but this procedure was followed by a heat treatment (HT). The paper sheet was placed in a 465°F (240°C) Carver platen press for 60 seconds with 15 psi (105 kPa) as applied pressure. Individual sheets from the third set were inserted in the wet state in a different platen press at 280°F (138°C).
  • PD densification process
  • sheet moisture was about 10%.
  • Each sheet was removed from the PD press and immediately placed in the other, HT press for 60 seconds at 465°F (240°C). All three sets of sheets were conditioned at 73°F (23°C) and 50% humidity for at least 24 hours before testing.
  • Table X show superior folding endurance and wet strength for the densified and heat treated sheets.
  • surface fibers after which the pressure was increased to 790 psi (5450 kPa) for 20 seconds.
  • PD densification process
  • sheet moisture was about 10%.
  • Each sheet was removed from the PD press and immediately placed in the other, HT press for 60 seconds at 465°F (240°C). All three sets of sheets were conditioned at 73°F (23°C) and 50% humidity for at least 24 hours before testing.
  • a mixture of spruce and fir wood chips was cooked by the SCMP process to a yield of 92% by weight of dry chips.
  • the cooked chips were converted to a pulp by passage through a disk refiner.
  • the pulp was washed with water to remove residual cooking chemical and solubilized material. Latency removal was accomplished by stirring at 4% consistency for 20 minutes at 85-90°C. Pulp freeness was 705 ml by the Canadian Standard Freeness Test.
  • a dispersion of the pulp in distilled water was converted to handsheets using a TAPPI sheet mold.
  • the quantity of fiber in the slurry fed to the mold was adjusted to give a basis weight of 42 lb/1000 ft2 (205 g/m2) in the oven dried state.
  • Sheets from the first set were dried on TAPPI rings at room temperature after wet pressing. Wet pressing and drying were in accordance with the procedure in TAPPI T-205 om-81. Sheets from the second set were placed between two 150 mesh stainless steel screens and pressed in a platen press at 300 psi (2067 kPa) and 450°F (232°C) platen temperature for different times between 5 and 60 seconds. This drying procedure effectively combines the densification and heat treatment stages and is known as high temperature press drying (HTPD). All sheets were conditioned at 73°F (22,5°C) and 50% humidity for at least 48 hours before testing.
  • HTPD high temperature press drying
  • the quantity of fiber in the slurry fed to the mold was adjusted to give a basis weight of 42 lbs/1000ft2 (2.05,5 kg/M2) in the oven dried state.
  • Four sets of sheets were prepared and wet pressed as specified in accordance with the procedure in TAPPI T-205 om-81. Two of the four sets of sheet were dried on rings as required by the procedure. These sheets were considered to be dried by a conventional (C) method. One of the two sets of dry sheets was then subjected to heat treatment.
  • each sheet was placed between two 150 mesh stainless steel screens and inserted between the platens of a preheated platen press. Press temperatures of 392, 428, 454°F (200, 220 and 240°C) were studied. The platens were immediately closed and 15 psi (103.4 kPa) pressure was applied for 5 seconds. Sheets were immediately removed from screens and allowed to cool after pressing.
  • thermocouple wire buried in the sheet showed the sheet internal temperature after 2 seconds is only 1-2°C lower than the platens temperature.
  • the third and fourth sets of sheets were placed between the 150 mesh screens and densified by a press densi­fication (PD) procedure during the process of drying.
  • PD press densi­fication
  • the wet sheets and the screens were placed between the platens of a second press and subjected to 15 psi (103.4 kPa) pressure at 138°C for 5 seconds to dry surface fibers, after which the pressure was increased to 790 psi (5443 kPa) for 20 seconds.
  • sheet moisture was about 10%.
  • One set of sheets was retained for testing.
  • Each individual sheet and screens from the second set were removed from the PD press and immediately placed in the other, HT press for 5 seconds.
  • HT press temperatures of 200, 220 and 240°C were studied.
  • HT pressure was 15 psi (103.4 kPa). All sheets were conditioned at 22.5°C for at least 48 hours before testing.

Claims (16)

1. Une méthode de production des produits de papier ayant une résistance à l'état humide améliorée à partir de pâtes kraft blanchies ou non blanchies, de pâtes thermomécaniques, de pâtes SCMP ou de pâtes au sulfite, tout en préservant leur endurance au pliage, comprenant les étapes suivantes :
on soumet le papier à une densification sous pression élevée durant sa production pour obtenir une densité d'au moins 600 kg/m³ et
on chauffe le papier afin d'augmenter sa température interne à au moins 420°F, (216°C) pendant une période de temps suffisante pour augmenter sa résistance à l'état humide.
2. La méthode selon la revendication 1, selon laquelle les étapes de densification et de chauffage sont conduites simul­tanément.
3. La méthode selon la revendication 1, selon laquelle l'étape de densification précède ladite étape de chauffage.
4. La méthode selon les revendications 1 à 3, selon laquelle ladite température interne est comprise dans l'intervalle de 420°F (216°C) )à 572°F (300°C).
5. La méthode selon les revendications 1 à 4, selon laquelle la pâte kraft n'est pas blanchie, et la température interne est environ 550°F (289°C) et ensuite la pâte est blanchie ou bien, lorsque la pâte est une pâte thermomécanique, la température interne est d'environ 465°F (240°C) et lorsque la pâte est une pâte SCMP ou une pâte au sulfite, la température interne est d'environ 450°F (232°C).
6. La méthode selon les revendications 1 à 5, selon laquelle, dans cette étape de densification, le carton est comprimé à une densité de 600 à 1 200 kg/m³.
7. La méthode selon les revendications 1 et 3 à 6, selon laquelle ladite densification inclut l'application d'une pression suffisante au papier pour produire une densité comprise dans l'intervalle de 700-900 kg/m³avant ladite étape de chauffage.
8. La méthode selon les revendications 1 à 7, selon laquelle ledit papier, avant ladite étape de densification, a une teneur en humidité comprise dans l'intervalle de 10% à 70% en poids.
9. La méthode selon les revendications 1 à 8, selon laquelle ledit produit de papier est le carton doublé ou le carton ordinaire.
10. La méthode selon la revendication 9, selon laquelle ledit produit de papier est le carton doublé et a un poids de base compris dans l'intervalle de 125 à 464 g/m².
11. La méthode selon les revendications 1 à 9, selon laquelle ledit produit de papier est du carton ordinaire et a un poids de base compris dans l'intervalle de 30 à 464 g/m² et lorsque le carton est produit à partir d'une pâte thermomécanique, le poids de base est de 60-464 g/m².
12. Un carton doublé ayant une résistance à l'état humide d'au moins 2,63 kN/m (15 lb/in) et satisfaisant à un test d'endurance au pliage d'au moins 300 cycles, de préférence d'au moins 1 000 cycles.
13. Un carton doublé provenant d'une pâte SCMP ou d'une pâte au sulfite, ayant une résistance à l'état humide d'au moins 1,05 kN/m (6 Ib/in) et satisfaisant au test d'endurance au pliage d'au moins 10 cycles.
14. Un carton kraft blanchi ayant une résistance à l'état humide d'au moins 0,88 kN/m (5 lb/in) et satisfaisant au test d'endurance au pliage d'au moins 50 cycles.
15. Un carton kraft blanchi selon la revendication 14 ayant une résistance à l'état humide d'au moins 2,63 kN/m (15 Ib/in) et satisfaisant au test d'endurance au pliage d'au moins 300 cycles.
16. Un carton provenant d'une pâte thermomécanique ayant une résistance à l'état humide d'au moins 1,75 kN/m (10 lb/in) et satisfaisant à un test d'endurance au pliage d'au moins un cycle.
EP86111513A 1985-08-23 1986-08-20 Carton double Kraft et procédé pour la production de carton double Kraft de pâte Kraft blanchie ou non blanchie, pâte TMP, pâte SCMP ou pâte de bisulfite Expired - Lifetime EP0219643B1 (fr)

Applications Claiming Priority (8)

Application Number Priority Date Filing Date Title
US76877885A 1985-08-23 1985-08-23
US06/768,642 US4718981A (en) 1985-08-23 1985-08-23 Bleached kraft paperboard by densification and heat treatment
US768776 1985-08-23
US768598 1985-08-23
US06/768,598 US4718982A (en) 1985-08-23 1985-08-23 Densification and heat treatment of paperboard produced from SCMP and other sulfite pulps
US768642 1985-08-23
US768778 1985-08-23
US06/768,776 US4692212A (en) 1985-08-23 1985-08-23 Kraft linerboard by densification and heat treatment

Publications (2)

Publication Number Publication Date
EP0219643A1 EP0219643A1 (fr) 1987-04-29
EP0219643B1 true EP0219643B1 (fr) 1991-01-09

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EP86111513A Expired - Lifetime EP0219643B1 (fr) 1985-08-23 1986-08-20 Carton double Kraft et procédé pour la production de carton double Kraft de pâte Kraft blanchie ou non blanchie, pâte TMP, pâte SCMP ou pâte de bisulfite

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CN109715882A (zh) * 2016-09-21 2019-05-03 H·霍格隆德 包含至少一含有高得率纸浆的层的纸或纸板产品及其生产方法
US10850901B2 (en) 2014-11-26 2020-12-01 Billerudkorsnas Ab High-strength fluting from NSSC pulp

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JP2002544403A (ja) * 1999-05-06 2002-12-24 ノボザイムス アクティーゼルスカブ 改良された湿潤強さを有する紙材料の製造方法
US6610172B1 (en) 1999-05-06 2003-08-26 Novozymes A/S Process for treating pulp with laccase and a mediator to increase paper wet strength
CN100447334C (zh) * 2006-12-08 2008-12-31 姜在胜 一种牛卡白板纸
CN101397765B (zh) * 2007-09-28 2010-08-25 中国制浆造纸研究院 一种涂布牛皮卡纸

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AT221923B (de) * 1957-12-23 1962-06-25 Paul Ing Lippke Maschine zur Herstellung von Faserstoffbahnen

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10850901B2 (en) 2014-11-26 2020-12-01 Billerudkorsnas Ab High-strength fluting from NSSC pulp
EP3026173B2 (fr) † 2014-11-26 2022-12-07 BillerudKorsnäs AB Procédé de production d'un carton à partir de pulpe à papier comprenant NSSC pulpe
US11814227B2 (en) 2014-11-26 2023-11-14 Billerudkorsnas Ab High-strength fluting from NSSC pulp
CN109715882A (zh) * 2016-09-21 2019-05-03 H·霍格隆德 包含至少一含有高得率纸浆的层的纸或纸板产品及其生产方法
US11299853B2 (en) * 2016-09-21 2022-04-12 Hans Hoglund Paper or paperboard product comprising at least one ply containing high yield pulp and its production method
CN109715882B (zh) * 2016-09-21 2022-07-15 H·霍格隆德 包含至少一含有高得率纸浆的层的纸或纸板产品及其生产方法

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FI863420A (fi) 1987-02-24
KR870002332A (ko) 1987-03-30
DE3676782D1 (de) 1991-02-14
FI863420A0 (fi) 1986-08-22
BR8604011A (pt) 1987-06-30

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