Classifications

• • 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
  • D21H11/00—Pulp or paper, comprising cellulose or lignocellulose fibres of natural origin only
• • 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
  • D21C5/00—Other processes for obtaining cellulose, e.g. cooking cotton linters ; Processes characterised by the choice of cellulose-containing starting materials
• • 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
  • D21C9/00—After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; Treatment of dilute or dewatered pulp or process improvement taking place after obtaining the raw cellulosic material and not provided for elsewhere
  • D21C9/10—Bleaching ; Apparatus therefor
• • 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
• • 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
  • D21H27/002—Tissue paper; Absorbent paper

Definitions

• the present invention relates to semi-bleached or unbleached Eucalyptus globulus pulp and to its use for the production of tissue products. Additionally the present invention further relates to tissue papers sheets made by incorporating semi-bleached or unbleached Eucalyptus globulus pulp, and their use for the production of household and sanitary products.
• Tissue papers are those used both domestically and in public spaces for hygienic and sanitary use.
• a tissue paper product is characterized by different key properties, namely bulk, strength, absorption, softness and even visual appearance.
• the consumer of this type of product seeks a positive balance in terms of the overallity of these different properties.
• the current consumer also intends to purchase environmentally conscious products produced through raw materials and processes that lead, for example, to lower chemical and water consumptions.
• JP2005325493 discloses a tissue paper for kitchen applications produced with unbleached pulp of a coniferous wood, with improved whiteness. This is achieved through the use of ultraviolet light absorption compounds and an antioxidant compound.
• EP0416278B1 discloses a tissue paper produced using unbleached sulfate pulp. This solution only allows improvements in softness and tensile strength, without any mention of bulk characteristics and absorption capacity.
• CN102733225A relates to an ecological and environmentally friendly toilet paper making process which uses unbleached pulp and additionally includes fermentation processes.
• the characteristics of the paper produced are softness, fineness, durability and a natural fiber fragrance.
• tissue paper products with a globally improved consumer-appreciated paper properties such as bulk, absorbency, capillarity, strength, softness and consumer-friendly visual appearance of the use of an environmentally sustainable product, produced using existing processes in the industrial pulp and paper production units and with the raw materials commonly used therein, with lower environmental impact and production costs as, for example, on the consumption of chemical additives and water.
• a problem is solved by the invention described herein.
• the semi-bleached or unbleached Eucalyptus globulus pulps disclosed in this document unexpectedly enables the production of tissue paper products with a range of improved consumer-appreciated paper properties, such as bulk, absorbency, capillarity, strength, softness and consumer-identifying visual appearance of the use of an environmentally sustainable and friendly product.
• the invention here disclosed describes a cellulose pulp for the production of tissue paper products comprising semi-bleached or unbleached Eucalyptus globulus fibers.
• the semi-bleached or unbleached Eucalyptus globulus pulp comprises fibers having a length of not less than 0.8 mm, a width of not less than 19 ⁇ m and a coarseness of not less than 6 mg/100m.
• the semi-bleached or unbleached Eucalyptus globulus pulp presents a viscosity of not less than 1300 mL/g and a carboxyl content of not less than 10%.
• the present disclosure further includes tissue paper sheets incorporating at least 35% of the semi-bleached or unbleached Eucalyptus globulus pulp, and short and long cellulose bleached fiber pulps.
• the paper sheets have globally improved paper properties compared to tissue paper sheets that incorporate only bleached pulps into their composition.
• the paper sheets have bulk values greater than 1 cm 3 /g, preferably from 2 to 7 cm 3 /g and a tensile index greater than 4 kN.m/kg, preferably from 6 to 60 kN.m/kg, an absorption capacity greater than 7 gH 2 O/g paper , preferably from 7 to 10 gH 2 O/g paper , an air permeability greater than 450 L/m 2 /s, preferably from 500 to 1090 L /m 2 /s, and a softness greater than 50 HF, more preferably from 55 to 80 HF.
• the tissue paper sheets disclosed have a tear index greater than 6 mN.m 2 /g, more preferably from 6 to 10 mN.m 2 /g, a burst index greater than 1 kPa.m 2 /g, preferably from 1 to 4 kPa.m 2 /g, a capillarity of not less than 60 mm/10min, and an opacity greater than 70%, preferably greater than 90%.
• the invention disclosed herein thus includes the use of the semi-bleached or unbleached Eucalyptus globulus pulp for the production of tissue products and the use of tissue papers sheets, incorporating the semi-bleached or unbleached Eucalyptus globulus pulp, for the production of household and sanitary products, such as toilet paper, napkins, kitchen paper rolls and tissues.
• the described pulp can be used in different forms, such as in the form of dried pulp bales and in the form of a slush, the later feed to the industrial process through pipeline systems.
• the biometric analysis of the fibers was performed in a Fiber Tester equipment (Lorentzen & Wettre), which is an instrument for advanced fiber analysis.
• the equipment measures, by 2D image analysis, a wide variety of properties such as length, width, fines content, coarseness, among others. Coarseness is defined as the weight per unit length of fiber expressed in milligrams per 100 meters. For that, 1 g (dry basis) of pulp was dispersed in 1 L of distilled water. Subsequently, all the suspensions were positioned for analysis by the equipment using available software. For each pulp three measurements were made, the final value of each parameter resulting from the arithmetic mean of the values obtained at the three measurements.
• Extractable compounds are hydrophobic (lipophilic) components present in wood and extracted by organic solvents.
• the extractable compounds content was determined using ethanol/toluene in quantities enough for samples analysis preparation, as it requires a pulp pre-extraction.
• the extraction was carried out during approximately 4 hours (24 extraction cycles) of 2 g (dry basis) of pulp in a 100 mL capacity Soxhlet extraction apparatus, using 250 mL of a 1:2 (v/v) ethanol/toluene solution.
• the insoluble residue was filtered and washed with hot absolute ethanol, for removing any remaining toluene, and dried at room temperature, contrary to what is indicated at the standard TAPPI T 204 om-88, since washing with water, as described, could lead to the loss of pentosans and other polysaccharides of low molecular weight.
• the obtained extract was dried at a rotary evaporator equipment and the extractable content was determined gravimetrically.
• Pentosans content was determined according to the Tappi Test Method T 223 cm-10. This method is based on the action of hydrochloric acid on the pulp hemicelluloses, hydrolyzing them and, consequently, converting the xylose and other pentoses to furfural, which is collected with the distillate and, reacting with orcinol, forms a colored complex making therefore possible the content quantification by spectrophotometry.
• the content of carboxyl groups was determined according to the TAPPI T 237 om-93 standard method. About 2.5 ⁇ 0.1 g of disintegrated pulp was first weighed and 250 mL of a diluted hydrochloric acid solution (approximately 0.1 M) was added during 12 hours, ensuring that all existing carboxylic groups are in their protonated form. Subsequently, the pulp was filtered and washed with distilled water until the pH of the filtrate equaled the pH of the distilled water.
• a is the volume, in mL, of hydrochloric acid (0,01 M) spent during titration
• b is the volume, in mL, of hydrochloric acid (0,01 M) consumed during the blank titration
• C w is the mass, in g, of the water in the pulp after filtration
• w is the weight, in g, of the dry pulp.
• the viscosity was determined according to the SCAN-test standards SCAN-CM 15:88, which consists on the determination of the viscosity of pulps by solubilization in a dilute copper-ethylenediamine (CED) solution.
• SCAN-CM 15:88 which consists on the determination of the viscosity of pulps by solubilization in a dilute copper-ethylenediamine (CED) solution.
• the pulp sample was reduced to small fragments in the amount indicated at the table provided by the method (Table 7, Annex C.1.) - 150 mg of pulp were weighed. Each sample was placed into a glass vial along with 25 mL of distilled water and some copper wires. The vials were then placed on a shaker for as long as necessary to ensure that the pulp was completely disintegrated. The procedure continued with adding 25 mL of 1 M CED solution, expelling all existing air and stirring until the sample is completely dissolved. Finally, the temperature of the viscometer bath and the sample's were adjusted to 25.0 ⁇ 0.1 °C and, with the aid of a syringe, a portion of the solution was aspirated and allowed to flow unobstructed. The time it takes to travel the distance between the two viscometer marks was measured to within ⁇ 0.2 s. At least 5 readings were taken for each sample.
• Tissue paper sheets with a weight of 20 g/m 2 were prepared following an adaptation of the standard method ISO 5269-1:2005. Additionally, 60 g/m 2 tissue paper sheets were prepared according to the same ISO.
• Reference formulations consist on formulations used in the production of tissue paper sheets. The other formulations were based on the replacement of short fibers content by unbleached pulp ( UBP 1 to UBP 4 ). Table 1. Formulations used in sheet preparation Percentages (%) (w/w) References Formulations with UBP Formulations REF 1 REF 2 UBP 1 UBP 2 UBP 3 UBP 4 SF 70 100 35 20 - - LF 30 - 30 30 30 - UBP - - 35 50 70 100
• the prepared sheets were stored according to the standard ISO 187:1990 for further analysis.
• the softness was analyzed on an Emtec TSA - Tissue Softness Analyzer. This device combines data from the three parameters that have the greatest influence on the human feel to the touch: fibers softness, smoothness and sheet stiffness.
• the calculation method used by the device is an algorithm that calculates the hand feel (HF).
• the water absorption of the tissue papers was determined according to the standard ISO 12625-8:2010, by the immersion absorption method. Approximately 2 g of paper was placed in a basket of certain dimensions, contrary to what is mentioned at the standard, which indicates the use of 5 g of paper.
• the Scott Test is related to the internal fibers bonding strength of the paper when subjected to delamination. It allows the determination of the energy (or force) required to delaminate a sheet of paper in the z-direction.
• TAPPI T 569 standard the paper sheet is delaminated under the action of a pendulum of controlled mass and velocity.
• the internal strength of the fibers is affected by the paper sheets formation (bonding between layers) and also by the process of pulp refining.
• Gurley's air resistance is a structural property that quantifies the time required for a certain volume of air (100 mL) to pass through a given area of paper under constant pressure, ISO 5636-5:2013 standard. It is an indirect measure of the porosity of the fibrous matrix.
• the fibers UBP have larger width values than the other short fibers.
• the fibers UBP also present higher values than the other short fibers with regard to coarseness. Comparing unrefined pulps and after refining pulps, it is verified that the biometric properties of the fibers did not change significantly.
• a good degree of cellulose polymerization is maintained for the fibers of the UBP pulp, as inferred by its higher viscosity value than that of SF .
• the pulp UBP also has a higher percentage of carboxyl content than the other pulps.
• the pentosans content (measured by the xylan content, the majority of hemicelluloses in short fiber pulps) is within the typical range for this type of short fiber Eucalyptus globulus pulp.
• Paper sheets were produced with the refined pulps with a °SR of 25, considering the reference formulations REF 1 and REF 2 and with unbleached Eucalyptus Globulus kraft pulp fibers UBP 1 , UBP 2 , UBP 3 and UBP 4 .
• the main results from the analysis of their paper properties are shown in Table 8.
• Table 8. Results obtained for the properties of paper sheets of 20 g/m 2 with unbleached Eucalyptus globulus pulp, refined to a 25 °SR (formulation % SF : % LF : % UBP ).

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• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Wood Science & Technology (AREA)
• Paper (AREA)
• Sanitary Thin Papers (AREA)

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Citations (13)

• 2019
  • 2019-06-03 PT PT115563A patent/PT115563B/pt active IP Right Grant
  • 2019-12-05 EP EP19020675.5A patent/EP3748073A1/en active Pending
• 2020
  • 2020-06-01 WO PCT/EP2020/065124 patent/WO2020245072A1/en active Application Filing

Patent Citations (13)

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