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
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B07—SEPARATING SOLIDS FROM SOLIDS; SORTING
  • B07C—POSTAL SORTING; SORTING INDIVIDUAL ARTICLES, OR BULK MATERIAL FIT TO BE SORTED PIECE-MEAL, e.g. BY PICKING
  • B07C5/00—Sorting according to a characteristic or feature of the articles or material being sorted, e.g. by control effected by devices which detect or measure such characteristic or feature; Sorting by manually actuated devices, e.g. switches
  • B07C5/04—Sorting according to size
  • B07C5/12—Sorting according to size characterised by the application to particular articles, not otherwise provided for
  • B07C5/14—Sorting timber or logs, e.g. tree trunks, beams, planks or the like
• • 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

Definitions

• the present invention relates to a method according to the preamble of claim 1 for adjusting the fibrous properties of pulp.
• the invention also relates to a method for manufacturing the pulp according to claim 17 and for manufacturing a fibrous product according to the preamble of claim 18.
• Paper mills use different wood materials in papermaking, depending on the type of end products, such as the paper or packaging products that are made of intermediary products, such as chemical and/or mechanical or chemi-mechanical pulps.
• end products such as the paper or packaging products that are made of intermediary products, such as chemical and/or mechanical or chemi-mechanical pulps.
• different paper grades are manufactured from both long and short fibres.
• Long-fibred raw material imparts strength to the paper
• short-fibred material in turn imparts smoothness and printing qualities to the paper.
• raw material is used with an average fibre length (weighted by the length) of about 2 mm.
• the average fibre length of the long-fibred portion of magazine paper material should preferably be over 2.2 mm.
• the average fibre length of the long- fibred chemical pulp of the raw material used in the manufacture of paper (or board) that has top-quality printing and other properties should preferably be 2.3 mm.
• a raw material is called armouring (reinforcement pulp) fibre and it can be used advantageously, for example, in the manufacture of top-quality LWC (light weight coated) paper with a low basis weight.
• the printing properties of such paper are good, but not a great deal of material is used. The strength of the paper thus comes from the armouring fibre and the printing properties from the mechanical pulp.
• the fibre length" of wood is not adjusted at all or the adjustment is carried out by classifying the wood, on arrival at a plant, according to the log di- ameter or the felling method.
• the mean value of the wood's fibre length can be set at the correct level.
• the wood from the first thinning is combined with older wood and, possibly, with sapwood.
• sapwood the problem arises that the greater the amount of young growing tim- ber that is used as raw material, the shorter the fibre.
• the international patent publication WO 00/72652 examines standing trees or the sectional planes of cut wood by scanning them by means of electromagnetic short-wave of microwave energy and by making an image of the scanned data. In this way, various wood properties such as knots, were discovered, which cannot be observed from the outside. On the basis of the observations, the wood material was selected for various purposes, such as turning lathes, sawmills, for chemical pulp or paper.
• the publication also mentions observations of annual rings but nothing about observing the number of annual rings or dividing the wood material into categories according to the number of annual rings.
• the fibrous properties of pulp such as chemical or paper pulp can be adjusted by using, in the manufacture of chemical or chemi-mechanical pulp, a wood material, which is selected on the basis of the number of the tree's annual rings. More specifically, the solution according to the invention is mainly characterized by what was stated in the characterising part of claim 1.
• the number of the tree's annual rings correlates with its fibre dimensions, such as the fibre length and the fibre coarseness. Classifying the wood material into categories on the basis of the number of annual rings results in a wood material with homogeneous fibre dimensions. If the categories are appropriately selected, the variation in dimensions within a category is also minor.
• the definition of the annual rings can be mechanized and carried out at any stage between wood harvesting and pulping, if talking about making chemical pulp, or the number of annual rings can be defined at any stage between wood harvesting and grinding or refining (a (C)TMP refiner), if mechanical or chemi-mechanical pulp is made.
• the wood material can be classified into categories on the basis of the number of annual rings in various ways. By now selecting the raw material from a certain category, a fibre with dimensions at the desired level can be obtained. On the other hand, combining and mixing the wood material that is divided into the different categories can result in a fibre with the desired, preselected fibre dimensions. To obtain the preselected fibre dimensions, it may be necessary to divide the annual ring categories in a different way depending on the sort of wood injguestipn.
• the method described herein can be used to improve the quality of wood material and to obtain a wood material with homogeneous fibre dimensions for various processes.
• the method according to the invention can be used to adjust the fibrous properties of chemical pulp, mechanical pulp or chemi-mechanical pulp, to adjust the smoothness of the properties and to decrease any variation in quality.
• the method can be used to improve the quality of fibre products. As the fibrous properties can be affected since the felling of the tree, and not until after measuring the fibrous properties, the method is also advantageous in terms of economy and production.
• the invention is described more closely with the aid of a detailed specification and a few application examples.
• Fig. 1 shows the correlation between the annual rings and the fibre lengths and the fibre coarseness (with standard length deviations) of the top logs of spruce, which are obtained in regeneration cutting, when the material is classified into annual ring categories;
• Fig. 2 shows the correlation between the tops, which are classified according to the diameter, and the fibre length and the fibre coarseness (with standard length deviations) of spruce logs, which are obtained in regeneration cutting;
• Fig. 3 shows the correlation between the butt logs, which are classified according to the number of annual rings, and the fibre length and the fibre coarseness (with standard length deviations) of spruce, which are obtained in regeneration cutting;
• Fig. 4 shows the correlation between the butt logs, which are classified according to the diameter, and the fibre length and the fibre coarseness (with standard length deviations) of spruce, which are obtained in generation cutting;
• Fig. 5 shows the correlation between the top logs, which are classified according to the log's age/annual rings, and the fibre length and the fibre coarseness (with standard length deviations) of spruce;
• Fig. 6 shows the correlation between the top logs, which are classified according to the diameter in thinning, and the fibre length and the fibre coarseness (with standard length deviations) of spruce;
• Fig. 7 shows the correlation between the butt logs, which are classified according to the annual rings in thinning, and the- fibre length and the fibre coarseness (with standard length deviations) of spruce;
• Fig. 8 shows the correlation between the butt logs, which are classified according to the diameter in thinning, and the fibre length and the fibre coarseness (with standard length deviations) of spruce;
• Fig. 9 shows the correlation between the top logs, which are classified according to the annual rings in regeneration cutting, and the fibre length and the fibre coarseness (with standard length deviations) of pine;
• Fig. 10 shows the correlation between the top logs, which are classified according to the diameter in regeneration cutting, and the fibre length and the fibre coarseness (with standard length deviations) of pine.
• Pulp in the present invention refers to chemical pulp, mechanical pulp or chemi- mechanical pulp. Pulp, the fibre dimensions of which are at the preselected level, can be used in the manufacture of paper, board or packaging materials or in any other processes that utilize pulp.
• the wood material is classified according to the number of the log's annual rings.
• the annual rings of a tree are formed, when the tree grows peri- odically, and they can be distinguished from one another.
• the age of the log in years is obtained by counting the number of these concentric cycles.
• the periodic nature in turn is a conse- quence of the variation in the environmental conditions, such as light, heat and water supply.
• the alternation of seasons between a warm summer and a cold winter induces the formation of annual rings, as well as, for example, a dry summer and a rainy winter.
• the classification of wood "by log” means that the number of annual rings is determined for each tree harvested from a forest, the cut parts of which are called logs.
• logs are known to be close to one another in terms of the numbers of annual rings
• groups of logs correspondingly refers to the definition of the number of annual rings from a group of two or more logs.
• the classification is preferably carried out mechanically or by modelling.
• the division/sorting according to annual rings can be carried out at any processing stage of the wood, when making chemical pulp (after felling the tree and before pulping) or when making mechanical or chemi-mechanical pulp (after felling the tree and before grinding or before the refining process).
• the number of annual rings can be determined, for example, near the chopping machine, after which the logs are classified into their respective piles according to the number of annual rings. It is preferable to define the number of annual rings as early as at the chopping machine in the forest in connection with felling the wood.
• the chopping machine can have a device at its end, which reads the annual rings in the same manner as bar code readers read bar codes.
• the wood material can be directly classified according to the number of annual rings, when the tree is felled, decreasing the need to classify the logs at a later stage.
• the classification can pref- erably be carried out mechanically in the plant by counting the number of annual rings or by classifying in accordance with the markings that are based on the number of annual rings or modelling and obtained by means of the felling machine.
• the method according to the present invention can be applied to the manufacture of chemical or paper pulp, when using wood that has a periodic growth habit as raw material. Trees that have periods of quick and slow growth have such a growth habit, the periods resulting from fluctuations in heat, light and/or water supply, as described above.
• the wood material can either be softwood or hardwood.
• Softwood for example, comprises the spruce and the pine.
• Hardwood comprises birch, aspen, hybrid aspen, poplar, beech tree, red beech, hornbeam, oak, alder, maple, acacia and eucalyptus.
• the fibre dimension property refers to the fibre length and the fibre coarseness, for example.
• the fibre length refers to the arithmetic mean value of the fibre length distribution, the mean value of the fibre length distribution weighted by the fibre length or the mean value weighted by the weight. Of these, the mean value weighted by the length is generally used to provide the best description of the technical potential of fibre.
• the fibre coarseness refers to the weight of a fibre sequence of chemical or paper pulp, for example, the weight of a meter of the fibre sequence in milligrams.
• the above can be measured using equipment especially developed for this purpose, such as the FS-200 and Fibrelab instruments.
• the devices are based on measuring the fibre dimensions by optical measuring methods in a medium that flows in suitable filter troughs. The results obtained by means of the devices are device-specific and, therefore, not absolutely accurate. Good laboratories have developed in-house standards and calibrations for the measuring.
• the number of categories can be 2 to 60; preferably the number of categories is 2 to 6, typically 3 to 4 or 3 to 5.
• the classification can comprise the following categories, for example: less than 20 annual rings, 21 to 30 annual rings, 31 to 40 annual rings, over 40 annual rings. If the wood material is classified, for example, into the following categories: less than 20 annual rings, 21 to 30 annual rings, 31 to 40 annual rings, over 40 annual rings, the following correlations are obtained: Number of annual rings Fibre length less than 20 2
• the annual rings are classified into the following categories: less than 10 annual rings, less than 20 annual rings, less than 30 annual rings, less than 40 annual rings, less than 50 annual rings, over 50 annual rings.
• the desired fibre dimension property such as the fibre length
• the wood material is selected by selecting the wood material separately from a certain category or by combining the raw material obtained from different categories in the right proportions.
• the present method can be used to manufacture mechanical, chemical or chemi- mechanical pulp from the selected raw material.
• the fibre length (the mean value weighted by the length) of the product being less than 2.0 mm, typically, a wood material with less than 20 annual rings at the butt of the log should be selected.
• a wood material is selected, which has 21 to 30 annual rings at the butt of the log.
• a wood material is selected, which has 31 to 40 annual rings at the butt of the log, and to obtain a fibre length in the range of 2.5...3.5, a wood material is selected, " wherein the number of the log's annual rings " at the butt of The log is over 40 annual rings.
• the butt is measured but, alternatively, measuring can be carried out at the log's top end, and the annual ring can be changed, e.g., with the aid of a model, so that it corresponds to the number of the butt's annual rings as a function of the log's length.
• the method according to the invention for manufacturing pulp that has preselected fibre dimension properties typically comprises the following processing stages:
• the wood material is classified by log or group of logs into categories that represent a certain fibre dimension, e.g., the fibre length and or the coarseness,
• the raw material is selected separately from a certain category or by combining the raw materials of different categories partly or fully so that the preselected fibre dimensions are achieved, and - mechanical, chemical or chemi-mechanical pulp is manufactured of the wood material.
• Different coniferous or broad-leaved trees can be classified according to the annual ring categories of a log or a group of logs, and an improvement in quality can be achieved in the adjustment of the fibre dimensions and/or the smoothness tolerance of chemical, me- chanical or chemi-mechanical pulp and utilized in improving the quality of the manufactured products.
• a method according to the invention for manufacturing a fibre product that has preselected fibre dimension properties typically comprises the following processing stages:
• the wood material is selected ff ⁇ f the category of annual rings, which provides the preselected fibre dimension properties
• the fibre product is made of the pulp.
• the trees felled in connection with the regeneration felling of spruce were classified by top log, according to the number of annual rings, into the categories of ⁇ 20 annual rings, 21 to 30 annual rings, 31 to 40 annual rings and >40 annual rings. The results are shown in Fig. 1.
• the portion of wood in the category of ⁇ 20 annual rings was 12%, the fibre length ranged between 1.98 and 2.16 (standard deviation), the average fibre length weighted by the length was 2.07 mm.
• the fibre coarseness in this category ranged between 0.149 and 0.160 mg/m (st.dev.).
• the portion of wood in the category of 21 to 30 annual rings was 38%, the fibre length ranged between 2.20 and 2.38 (stdev.), and the average fibre length was 2.29 mm.
• the fibre coarseness in this category ranged between 0.163 and 0.172 (stdev.) mg/m.
• the portion of wood in the category of 31 to 40 annual rings was 25%, the fibre length ranged between 2.36 and 2.48 mm (stdev.), the average fibre length was 2.42 mm.
• the fibre coarseness in this category ranged between 0.171 and 0.178 mg/mm (stdev.).
• the portion of wood in the category of >40 annual rings was 25%, the fibre length ranged between 2.46 and 2.59 mm (stdev.), the average fibre length was 2.52 mm.
• the fibre coarseness in this category ranged between 0.184 and 0.178 mg/mm (stdev.).
• Example 2 The tops of the trees felled in connection with the regeneration cutting of spruce were classified according to the diameter into the categories of ⁇ 80 mm, ⁇ 100 mm, ⁇ 120 mm, ⁇ 140 mm, ⁇ 160 mm, >160 mm.
• the fibre length and the fibre coarseness of the categories were measured, it was observed that the fibre lengths and the fibre coarsnesses were partly or fully overlapping, as shown in Fig. 2.
• the fibre lengths are fully overlapping and, thus, the classification by diameter hardly has any significance in practice.
• the trees felled in connection with the regeneration cutting of spruce were classified by butt log, according to the number of annual rings, into the categories of ⁇ 30 annual rings, ⁇ 40 annual rings and >40 annual rings.
• the results are shown in Fig. 3.
• the portion of wood in the category of ⁇ 30 annual rings was 10%, the fibre length ranged between 2.21 and 2.44 mm (calculated stdev.), the average fibre length weighted by the length was 2.32 mm.
• the fibre coarseness in this category ranged between 0.163 and 0.175 mg/m (st.dev.).
• the portion of wood in the category of ⁇ 40 annual rings was 21%, the fibre length ranged between 2.40 and 2.56 mm, the average fibre length was 2.48 mm.
• the fibre coarseness in this category ranged between 0.173 and 0.182 mg/m (stdev.).
• the wood felled in connection with the regeneration cutting of spruce was classified by log, according to the diameter, into the categories of ⁇ 100 mm, ⁇ 120 mm and >120 mm.
• the fibre lengths and the fibre coarsenesses are partly over- lapping, as shown in Fig.4.
• the to Tparts of the trees felled in connection with the thihnihg of spruce were classified according to the age or the number of annual rings into the categories of ⁇ 20 annual rings, 21 to 30 annual rings, 31 to 40 annual rings and >40 annual rings. The results are shown in Fig. 5.
• the portion of wood in the category of ⁇ 20 annual rings was 20%, the fibre length ranged between 1.99 and 2.19 mm (st.dev.), the average fibre length weighted by the length was 2.09 mm.
• the fibre coarseness in this category ranged between 0.150 and 0.162 mg/m (st.dev.).
• the portion of wood in the category of 21 to 30 annual rings was 47%, the fibre length ranged between 2.23 and 2.46 mm (st.dev.), the average fibre length weighted by the length was 2.35 mm.
• the fibre coarseness in this category ranged between 0.164 and 0.177 mg/m (st.dev.).
• the portion of wood in the category of 31 to 40 annual rings was 21%, the fibre length ranged between 2.36 and 2.50 mm (stdev.), the average fibre length weighted by the length was 2.43 mm.
• the fibre coarseness in this category ranged between 0.172 and 0.179 mg/m (st.dev.).
• the portion of wood in the category of >40 annual rings was 21%, the fibre length ranged between 2.43 and 2.60 mm (stdev.), the average fibre length weighted by the length was 2.51 mm.
• the fibre coarseness in this category ranged between 0.174 and 0.185 mg/m (stdev.).
• the top parts of the trees felled in connection with the thinning of spruce were classified according to the diameter into the categories of ⁇ 100 mm, ⁇ 140 mm, ⁇ 120 mm, ⁇ 160 mm and >160 mm.
• the fibre lengths and the fibre coarsenesses are partly or fully overlapping, as shown in Fig. 6.
• the portion of wood in the category of ⁇ 20 annual rings was 4%, the fibre length ranged between 1.97 and 2.16 mm (st.dev.), the average fibre length weighted by the length was 2.06 mm.
• the fibre coarseness in this category ranged between 0.149 and 0.160 mg/m (stdev.).
• the portion of wood in the category of ⁇ 30 annual rings was 27%, the fibre length ranged between 2.28 and 2.46 mm (stdev.), the average fibre length weighted by the length was 2.37 mm.
• the fibre coarseness in this category ranged between 0.167 and 0.176 mg/m (stdev.).
• the portion of wood in the category of ⁇ 40 annual rings was 33%, the fibre length ranged between 2.45 and 2.57 mm (st.dev.), the average fibre length weighted by the length was 2.51 mm.
• the fibre coarseness in this category ranged between 0.176 and 0.183 mg/m
• the portion of wood in the category of >40 annual rings was 21%, the fibre length ranged between 2.55 and 2.64 mm (st.dev.), the average fibre length weighted by the length was 2.60 mm.
• the fibre coarseness in this category ranged between 0.182 and 0.188 mg/m (stdev.).
• the top logs of the trees felled in connection with the regeneration cutting of pine were classified according to the number of annual rings into the categories of ⁇ 20 annual rings, 21 to 30 annual rings, 31 to 40 annual rings, 41 to 50 annual rings and >50 annual rings. The results are shown in Fig. 9.
• the portion of wood in the category of ⁇ 20 annual rings was 2%, the fibre length ranged between 1.57 and 1.79 mm (stdev.), the average fibre length weighted by the length was 1.68 mm.
• the fibre coarseness in this category ranged between 0.197 and 0.206 mg/m (stdev.).
• the portion of wood in the category of 21 to 30 annual rings was 13%, the fibre length- ranged between 1.85 and 2.07 mm (st.dev.), the average fibre length weighted by the length was 1.96 mm.
• the fibre coarseness in this category ranged between 0.207 and 0.214 mg/m (stdev.).
• the portion of wood in the category of 31 to 40 annual rings was 14%, the fibre length ranged between 1.99 and 2.16 mm (stdev.), the average fibre length weighted by the length was 2.08 mm.
• the fibre coarseness in this category ranged between 0.212 and 0.216 mg/m (st.dev.).
• the portion of wood in the category of 41 to 50 annual rings was 24%, the fibre length ranged between 2.12 and 2.22 mm (st.dev.), the average fibre length weighted by the length was 2.17 mm.
• the fibre coarseness in this category ranged between 0.215 and 0.218 mg/m (stdev.).
• the portion of wood in the category of >50 annual rings was 47%, the fibre length ranged between 2.19 and 2.28 mm (stdev.), the average fibre length weighted by the length was 2.24 mm.
• the fibre coarseness in this category ranged between 0.217 and 0.221 mg/m (stdev.).
• the tops of the trees felled in connection with the regeneration cutting of pine were classified according to the diameter into the categories of ⁇ 100 mm, ⁇ 120 mm, ⁇ 140 mm, ⁇ 160 mm and >160 mm.
• the fibre lengths and the fibre coarsenesses are partly or fully overlapping, as shown in Fig. 10.

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• 2002
  • 2002-03-22 FI FI20020561A patent/FI116534B/sv active IP Right Review Request
• 2003
  • 2003-03-21 US US10/507,423 patent/US20050109474A1/en not_active Abandoned
  • 2003-03-21 CA CA002478363A patent/CA2478363A1/en not_active Abandoned
  • 2003-03-21 JP JP2003578638A patent/JP2005520945A/ja active Pending
  • 2003-03-21 NZ NZ535204A patent/NZ535204A/en unknown
  • 2003-03-21 EP EP03712162A patent/EP1488037A1/en not_active Withdrawn
  • 2003-03-21 WO PCT/FI2003/000219 patent/WO2003080922A1/en active Application Filing
  • 2003-03-21 AU AU2003216942A patent/AU2003216942A1/en not_active Abandoned
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