US2018490A - Method of producing paper pulp from fibrous material - Google Patents
Method of producing paper pulp from fibrous material Download PDFInfo
- Publication number
- US2018490A US2018490A US15620A US1562035A US2018490A US 2018490 A US2018490 A US 2018490A US 15620 A US15620 A US 15620A US 1562035 A US1562035 A US 1562035A US 2018490 A US2018490 A US 2018490A
- Authority
- US
- United States
- Prior art keywords
- conglomerate
- shives
- paper pulp
- washing
- fibrous material
- 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 - Lifetime
Links
- 238000000034 method Methods 0.000 title description 30
- 229920001131 Pulp (paper) Polymers 0.000 title description 11
- 239000002657 fibrous material Substances 0.000 title description 8
- 239000000835 fiber Substances 0.000 description 20
- 238000005406 washing Methods 0.000 description 16
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 14
- 239000000126 substance Substances 0.000 description 13
- 238000004061 bleaching Methods 0.000 description 12
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 11
- 239000000460 chlorine Substances 0.000 description 11
- 229910052801 chlorine Inorganic materials 0.000 description 11
- 238000010411 cooking Methods 0.000 description 11
- WQYVRQLZKVEZGA-UHFFFAOYSA-N hypochlorite Chemical compound Cl[O-] WQYVRQLZKVEZGA-UHFFFAOYSA-N 0.000 description 10
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 9
- 241000208202 Linaceae Species 0.000 description 8
- 235000004431 Linum usitatissimum Nutrition 0.000 description 8
- 239000012535 impurity Substances 0.000 description 7
- 239000000203 mixture Substances 0.000 description 7
- 239000000463 material Substances 0.000 description 6
- CDBYLPFSWZWCQE-UHFFFAOYSA-L sodium carbonate Substances [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 6
- GEHJYWRUCIMESM-UHFFFAOYSA-L sodium sulfite Chemical compound [Na+].[Na+].[O-]S([O-])=O GEHJYWRUCIMESM-UHFFFAOYSA-L 0.000 description 6
- 239000007844 bleaching agent Substances 0.000 description 5
- 244000025254 Cannabis sativa Species 0.000 description 4
- 235000012766 Cannabis sativa ssp. sativa var. sativa Nutrition 0.000 description 4
- 235000012765 Cannabis sativa ssp. sativa var. spontanea Nutrition 0.000 description 4
- 235000009120 camo Nutrition 0.000 description 4
- 235000005607 chanvre indien Nutrition 0.000 description 4
- 239000003153 chemical reaction reagent Substances 0.000 description 4
- 239000011487 hemp Substances 0.000 description 4
- 238000003801 milling Methods 0.000 description 4
- LSNNMFCWUKXFEE-UHFFFAOYSA-L sulfite Chemical compound [O-]S([O-])=O LSNNMFCWUKXFEE-UHFFFAOYSA-L 0.000 description 4
- 229910000029 sodium carbonate Inorganic materials 0.000 description 3
- 229940083608 sodium hydroxide Drugs 0.000 description 3
- 235000011121 sodium hydroxide Nutrition 0.000 description 3
- 235000010265 sodium sulphite Nutrition 0.000 description 3
- ZKQDCIXGCQPQNV-UHFFFAOYSA-N Calcium hypochlorite Chemical compound [Ca+2].Cl[O-].Cl[O-] ZKQDCIXGCQPQNV-UHFFFAOYSA-N 0.000 description 2
- 239000005708 Sodium hypochlorite Substances 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- SUKJFIGYRHOWBL-UHFFFAOYSA-N sodium hypochlorite Chemical compound [Na+].Cl[O-] SUKJFIGYRHOWBL-UHFFFAOYSA-N 0.000 description 2
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 1
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 238000013019 agitation Methods 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 239000011575 calcium Substances 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- AXCZMVOFGPJBDE-UHFFFAOYSA-L calcium dihydroxide Chemical compound [OH-].[OH-].[Ca+2] AXCZMVOFGPJBDE-UHFFFAOYSA-L 0.000 description 1
- 239000000920 calcium hydroxide Substances 0.000 description 1
- 229910001861 calcium hydroxide Inorganic materials 0.000 description 1
- 229920002678 cellulose Polymers 0.000 description 1
- 239000001913 cellulose Substances 0.000 description 1
- 235000019993 champagne Nutrition 0.000 description 1
- 150000001804 chlorine Chemical class 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 230000029087 digestion Effects 0.000 description 1
- QWPPOHNGKGFGJK-UHFFFAOYSA-N hypochlorous acid Chemical compound ClO QWPPOHNGKGFGJK-UHFFFAOYSA-N 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 229920005610 lignin Polymers 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
Classifications
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
- D21C1/00—Pretreatment of the finely-divided materials before digesting
- D21C1/02—Pretreatment of the finely-divided materials before digesting with water or steam
Definitions
- Patented Oct. 22, 1935 UNITED STATES unrnon or raonucmc PAPER PULP mom muons m'rnam Edwin P. Jones, Garden City, andJames M. Dempsey, New York, N. Y., assignors to Champagne Paper Corporation, New York, N. Y., a corporation of New York No Drawing. Application April 10, 1935,
- Our present invention relates to the manufacture of paper, and the like from. cellulose containing materials, and more particularly to an improved method of preparing pulp to be used in such manufacture.
- our present invention relates to'an improved method of producing a satisfactory pulp for paper making from crude decorticated bast fiber, such as flax or hemp, which either has or has not been first subjected to the usual and ordinary retting process.
- An object of our invention is an improved method 01' producing a better quality of paper pulp from decorticated flax or hemp than has been heretofore possible.
- Another object of our invention is an improved method of treating fibrous material, derived from fiax or hemp stalks, to produce a pulp having strength, color, and other characteristics superior tothat produced by previously known' methods.
- the first step in our improved process consistsin passing the mixture of mechanically decorticatedfiax through a continuously operated equipment (such as heaters, rod mills, etc.) which imparts a crushing, rather than a cutting action to the raw material.
- a continuously operated equipment such as heaters, rod mills, etc.
- the fibrous material After the fibrous 'material has beentreated as move the dissolved matter.
- the fibrous material is then placed in a rotary digester, where it is cooked at an appropriate temperature and pressure for a, predetermined length of time.
- the time, temperature, and pressure will vary according to the character of the material being worked upon, but we have obtained satisfactory results by cooking the material under a pressure of approximately 50 pounds per square inch'i'or a period of approximately two hours.
- concentration and combination of chemicals employed in this digesting step are of more importance than either the temperature, pressure or length of time of cooking.
- the next, and equally important, part of our improved process or method comprises bleachin the shives without at the same time sacrificing the strength of the bast fiber itself. It-is practically impossible to bleach the cooked conglomerate (that is, bast fiber and shives), using an alkaline hypochlorite in a single stage bleach, so as to produce a satisfactory pulp. Therefore, we have utilized as this part of the invention what may be termed a two-stage bleach.
- the digested conglomerate is treated with a predetermined quantity of either saturated chlorine water or hypochlorous acid or gaseous chlorine. It is ordinarily necessary to use approximately 23 grams of chlorine for each 100 grams of conglomerate. The amount actually used must of necessity depend upon both the quantity of shives present in the conglomerate, as well as the thoroughness of the previously described digestion. The shives absorb or react with either the chlorine water, gaseous chlorine or hypochlqrous acid, immediately upon exposure to the chemicals mentioned.
- the bast fiber is lightened in color irmnediately and the shivesturn a deep brownishred color, indicating that the chlorine reacts very quickly upon both the bast fiber andjthe shives.
- the mixture is now washed, either with water or with a mild solution of any of the common alkalies, such as. sodium hydroxide, sodium carbonate, or the like.
- the material is now ready for the second stage of the two-stage bleaching process, which consists in treatment with an alkaline hypochlorite.
- the mixture of reddish brown shives and comparatively white bast fiber is placed in'a solution of either sodium or calcium *hypochlorite.
- the former appears to work better than'the common bleaching solution of calcium hypochlorite and is to ,be preferred thereto, although good results may be obtained with the latter.
- the mixture is allowed to remain in the bleaching solution at room temperature for approximately seven hours, when it will be found that the heretofore small reddish-#brown shives have become practically white, and can hardly be found in the mass of bast fibers which have now reached a satisfactory color.
- the pulp is thoroughly washed to remove all of the bleaching liquor. and the pulp is then ready to be used in subsequent steps in the making of a high quality 989
- the various steps of our process may be varied to suit different conditions, depending largely on the nature of the material being worked upon.
- the process may be practiced with the use of apparatus which will permit of the continuous 5 treatment of the fibers from the decorticatin step to the passing ofthe completely prepared pulp to the paper making machine.
- the improved method of producing vpaper pulp from flax which consists in submitting mechanically decorticated flax to the action of water, washing the same, cooking the fibers in a digester in the presence of an alkaline chemical in combination with a-soluble sulphite andthen bleaching the fibers.
- the improved method of producing paper pulp from decorticated fiax which consists in steeping the same in water to dissolve soluble matter contained therein, washing the same to remove the dissolved matter, cooking in a digester in the presence of an alkaline chemical in combination with a; soluble sulphite, and then bleaching the same.
- the improved method of producing paper pulp from a conglomerate of bast fiber and shives which consistsin steeping the conglomerate in water, to dissolve the soluble matter contained therein, washing the conglomerate to remove the dissolved matter, cooking the conglomerate in a digester in the presence of an alkaline chemical in combination with a soluble sulphite, washing the conglomerate, and then subjecting the conglomerate to a two-stage bleaching operation.
- the improved method of producing paper pulp from a conglomerate of best fiber, shives, and soluble impurities which consists 'in steeping the conglomerate, milling the conglomerate, cooking the conglomerate in a digester with a reagent composed of approximately 95% of sodiumhydroxide and approximately 5% of sodium sulphite under a pressure of'from 30-75-pounds per square inch: treating -the conglomerate with chlorine in the presence of water, and treatin being thoroughly washed between each step 01' the method.
- the improved method of producing paper pulp from a conglomerate of best fiber and shives which consists in steeping the conglomerate, to dissolve soluble matter contained therein, washing the conglomerate to remove the dissolved matter, cooking the conglomerate in a digester in the presence of an alkaline chemical in combination with a soluble sulphite, washing the conglomerate, milling the conglomerate to crush and soften the shives, treating the conglomerate with chlorine in the presence oi water, washing the conglomerate, and then treating the conglomerate with an alkaline hypochlorite.
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- Paper (AREA)
Description
Patented Oct. 22, 1935 UNITED STATES unrnon or raonucmc PAPER PULP mom muons m'rnam Edwin P. Jones, Garden City, andJames M. Dempsey, New York, N. Y., assignors to Champagne Paper Corporation, New York, N. Y., a corporation of New York No Drawing. Application April 10, 1935,
-- Serial No. 15,620 a 8 Claims. (01. 92-11) Our present invention relates to the manufacture of paper, and the like from. cellulose containing materials, and more particularly to an improved method of preparing pulp to be used in such manufacture.
Specifically, our present invention relates to'an improved method of producing a satisfactory pulp for paper making from crude decorticated bast fiber, such as flax or hemp, which either has or has not been first subjected to the usual and ordinary retting process.
An object of our invention is an improved method 01' producing a better quality of paper pulp from decorticated flax or hemp than has been heretofore possible.
Another object of our invention is an improved method of treating fibrous material, derived from fiax or hemp stalks, to produce a pulp having strength, color, and other characteristics superior tothat produced by previously known' methods.
In the previously known'methods of producing paper pulp from fibrous material, derived from flax or hemp stalks, it is the practice to subject the fibrous material to a chemical treatment for the P pose of loosening and removing, to a more or less degree, the lignins and incrustants which bind the fibers together, so that the fibers may be easily separated. After such chemical treatment the separated fibers, are ordinarily subjected to a I bleaching process to increase the whiteness of the fibers to the desired degree.
Because of the limitations imposed on this bleaching process, it has been necessary to sacri-r fice, to some degree, the'quality of the finished pulp. This has been true with respect to certain types of fibrous material, particularly flax, in
, which a very large proportion of the fibrous material must be destroyed during processing, if the hard fiber bundles or shives are sufiiciently treated to permit of securing a resulting final Pulp of satisfactory whiteness with known bleaching methods.
in our present invention we have departed,
mechanically decorticated flax contains between above described, it is thoroughly washed to re-.
10% and 20% of water-soluble substances, and as a first step in my improved process we steep the flax tor a short period of time in water. Such period of time mayvary from fifteen to- 30 minutes. I
We find that it is quite immaterial whether hot or cold water is employed, as the water-soluble substances are dissolved with equal facility, in either. Cold water is employed however, and we find that the same dissolves these water-soluble substancesin a. satisfactorily short period of time.
We find further that we can facilitate the subsequent steps of our improved method or process by allowing the above referred to steeping in 1 water to take place while the fibrous material is 5 being subjected to the action of a beater, a rod mill, or similar equipment.. Therefore, in practice, the first step in our improved process consistsin passing the mixture of mechanically decorticatedfiax through a continuously operated equipment (such as heaters, rod mills, etc.) which imparts a crushing, rather than a cutting action to the raw material. 7
After the fibrous 'material has beentreated as move the dissolved matter. The fibrous material is then placed in a rotary digester, where it is cooked at an appropriate temperature and pressure for a, predetermined length of time. The time, temperature, and pressure will vary according to the character of the material being worked upon, but we have obtained satisfactory results by cooking the material under a pressure of approximately 50 pounds per square inch'i'or a period of approximately two hours. However, we are of the opinion that the concentration and combination of chemicals employed in this digesting step are of more importance than either the temperature, pressure or length of time of cooking.
We have found that a cooking reagent composed,
-of practically any alkaline chemical in combina- ,actual concentration of the chemicals expressed Q as pounds of total chemicals in relation to the total number of pounds of water present yin the' cooking medium is not critically important, but
is dependent rather upon the ,shape-of the diish cast. An inspection of the shives discloses that they have lost a large part of their strength and have become much softer.
The next, and equally important, part of our improved process or method comprises bleachin the shives without at the same time sacrificing the strength of the bast fiber itself. It-is practically impossible to bleach the cooked conglomerate (that is, bast fiber and shives), using an alkaline hypochlorite in a single stage bleach, so as to produce a satisfactory pulp. Therefore, we have utilized as this part of the invention what may be termed a two-stage bleach.
In the first stage bleach the digested conglomerate is treated with a predetermined quantity of either saturated chlorine water or hypochlorous acid or gaseous chlorine. It is ordinarily necessary to use approximately 23 grams of chlorine for each 100 grams of conglomerate. The amount actually used must of necessity depend upon both the quantity of shives present in the conglomerate, as well as the thoroughness of the previously described digestion. The shives absorb or react with either the chlorine water, gaseous chlorine or hypochlqrous acid, immediately upon exposure to the chemicals mentioned.
In any event, the bast fiber is lightened in color irmnediately and the shivesturn a deep brownishred color, indicating that the chlorine reacts very quickly upon both the bast fiber andjthe shives.
At the end of about 15 to 30 minutes, depending upon whether or not agitation of the mixture .is employed, practically all of the available chlorine has been consumed.
The mixture is now washed, either with water or with a mild solution of any of the common alkalies, such as. sodium hydroxide, sodium carbonate, or the like.
The material is now ready for the second stage of the two-stage bleaching process, which consists in treatment with an alkaline hypochlorite.
The mixture of reddish brown shives and comparatively white bast fiber is placed in'a solution of either sodium or calcium *hypochlorite. The former appears to work better than'the common bleaching solution of calcium hypochlorite and is to ,be preferred thereto, although good results may be obtained with the latter.
The mixture is allowed to remain in the bleaching solution at room temperature for approximately seven hours, when it will be found that the heretofore small reddish-#brown shives have become practically white, and can hardly be found in the mass of bast fibers which have now reached a satisfactory color.
To bring about satisfactory bleaching in this stage or the process, we find it advantageous to use the equivalent of approximately 2-4 pounds of ordinary bleaching powder per 100 pounds of conglomerate. I
After this secondstep of the two-stage bleaching process, the pulp is thoroughly washed to remove all of the bleaching liquor. and the pulp is then ready to be used in subsequent steps in the making of a high quality 989 The various steps of our process may be varied to suit different conditions, depending largely on the nature of the material being worked upon.
The process may be practiced with the use of apparatus which will permit of the continuous 5 treatment of the fibers from the decorticatin step to the passing ofthe completely prepared pulp to the paper making machine. i
We claim.
1. The improved method of producing vpaper pulp from flax, which consists in submitting mechanically decorticated flax to the action of water, washing the same, cooking the fibers in a digester in the presence of an alkaline chemical in combination with a-soluble sulphite andthen bleaching the fibers. I w
'2. The improved method of producing paper pulp from decorticated fiax which consists in steeping the same in water to dissolve soluble matter contained therein, washing the same to remove the dissolved matter, cooking in a digester in the presence of an alkaline chemical in combination with a; soluble sulphite, and then bleaching the same.
3. The improved method of producing paper pulp from a conglomerate of bast fiber and shives, which consistsin steeping the conglomerate in water, to dissolve the soluble matter contained therein, washing the conglomerate to remove the dissolved matter, cooking the conglomerate in a digester in the presence of an alkaline chemical in combination with a soluble sulphite, washing the conglomerate, and then subjecting the conglomerate to a two-stage bleaching operation.
4. The improved method of 'oducing paper pulp from a conglomerate of rlber and shives.
chlorine in the presence of water, washing the conglomerate, and then treating the conglomerate with an alkaline hypochlorite.
' 5. The improved methodof producing paper pulp from a conglomerate of bast fiber, shives,
' and soluble impurities, which consists in steep.-
ing the conglomerate, to dissolve the soluble impurities, washing the conglomerate to remove the dissolved impurities, milling the conglomerate to crush and soften the shives, cooking the conglomerate in a digester with a reagent composed of approximately 95% sodium carbonate and approximately 5% sodium sulphite, under pressure, washing the conglomerate, treating the conglomerate with a solution of chlorine, washing the conglomerate, then treating the conglomerate with a solution of sodium hypochlorite for approximately seven hours at room temperature, and then washing the conglomerate.
6. The improved method of producing paper pulp from a conglomerate of best fiber, shives, and soluble impurities. which consists 'in steeping the conglomerate, milling the conglomerate, cooking the conglomerate in a digester with a reagent composed of approximately 95% of sodiumhydroxide and approximately 5% of sodium sulphite under a pressure of'from 30-75-pounds per square inch: treating -the conglomerate with chlorine in the presence of water, and treatin being thoroughly washed between each step 01' the method.
'7. The improved method of producing paper pulp from a conglomerate of best fiber and shives, which consists in steeping the conglomerate, to dissolve soluble matter contained therein, washing the conglomerate to remove the dissolved matter, cooking the conglomerate in a digester in the presence of an alkaline chemical in combination with a soluble sulphite, washing the conglomerate, milling the conglomerate to crush and soften the shives, treating the conglomerate with chlorine in the presence oi water, washing the conglomerate, and then treating the conglomerate with an alkaline hypochlorite.
8. The improved method of producing paper pulp from a conglomerate of bast fiber, shlves, and soluble impurities, which consists in steeping the conglomerate, to dissolve the soluble impurities, washing the conglomerate to remove the dissolved impurities, milling the conglomerate to crush and soften the shives, cooking the conglomerate in a. digester under pressure with a reagent composed 0i? a mixture of calcium hydroxide, sodium carbonate and sodium hydroxide in combination with sodium sulphite, and-with the mixture constituting approximately 95% of the combination, washing the conglomerate, treating 10 the conglomerate with a solution of chlorine,
washing the conglomerate, then treating the conglomerate with a solution of sodium hypochlorite for approximately seven hours at room temperature, and then washing the conglomerate. l6
nnwm 1 JONES. JAMES M. DEMPSEY.
Priority Applications (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US15620A US2018490A (en) | 1935-04-10 | 1935-04-10 | Method of producing paper pulp from fibrous material |
| GB499/36A GB460812A (en) | 1935-04-10 | 1936-01-06 | Improvement in methods of producing paper pulp from fibrous materials |
| FR800563D FR800563A (en) | 1935-04-10 | 1936-01-13 | Improvements in papermaking |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US15620A US2018490A (en) | 1935-04-10 | 1935-04-10 | Method of producing paper pulp from fibrous material |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US2018490A true US2018490A (en) | 1935-10-22 |
Family
ID=21772490
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US15620A Expired - Lifetime US2018490A (en) | 1935-04-10 | 1935-04-10 | Method of producing paper pulp from fibrous material |
Country Status (3)
| Country | Link |
|---|---|
| US (1) | US2018490A (en) |
| FR (1) | FR800563A (en) |
| GB (1) | GB460812A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2706159A (en) * | 1951-03-09 | 1955-04-12 | American Enka Corp | Manufacture of artificial sponges |
| US2823121A (en) * | 1952-05-27 | 1958-02-11 | Rayonier Inc | Wood pulp preparation |
| US2924547A (en) * | 1954-11-08 | 1960-02-09 | Hawaiian Dev Company Ltd | Rapid neutral sulfite process for pulping bagasse and other non-woody plant lignocellulose |
-
1935
- 1935-04-10 US US15620A patent/US2018490A/en not_active Expired - Lifetime
-
1936
- 1936-01-06 GB GB499/36A patent/GB460812A/en not_active Expired
- 1936-01-13 FR FR800563D patent/FR800563A/en not_active Expired
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2706159A (en) * | 1951-03-09 | 1955-04-12 | American Enka Corp | Manufacture of artificial sponges |
| US2823121A (en) * | 1952-05-27 | 1958-02-11 | Rayonier Inc | Wood pulp preparation |
| US2924547A (en) * | 1954-11-08 | 1960-02-09 | Hawaiian Dev Company Ltd | Rapid neutral sulfite process for pulping bagasse and other non-woody plant lignocellulose |
Also Published As
| Publication number | Publication date |
|---|---|
| GB460812A (en) | 1937-02-04 |
| FR800563A (en) | 1936-07-08 |
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