Fiber blend having high yield and enhanced pulp performance and method for making same

Abstract

The present disclosure relates to producing paper or paperboard having improved stiffness and strength, compared to the conventional paperboard at the same basis weight. It also discloses a method of wood pulping having a significantly increased yield and providing fiber pulps with enhanced properties such as strength and stiffness. Wood chips are chemically pulped to a high kappa number, providing a rejects component and an accepts component. The rejects component is subjected to a substantially mechanical pulping process, optionally in a presence of bleaching agent, prior to blending back into the accepts component. The resulting fiber blend is washed, optionally bleached, and subjected to a papermaking process to provide paper or paperboard with enhanced strength and stiffness at low basis weight.

1 . A process for producing a fiber blend, comprising steps of:
 (a) chemically pulping wood chips to generate a first amount of pulp including a first accepts component and a first rejects component;   (b) separating the first accepts component from the first rejects component;   (c) performing a substantially high consistency mechanical pulping of the first rejects component to generate a second amount of pulp including a second accepts component; and   (d) combining the first and the second accepts components to produce the fiber blend.   
   
   
       2 . The process of  claim 1 , wherein the chemically pulping in step (a) comprises a step of chemically pulping the wood chips to a kappa number of at least 20. 
   
   
       3 . The process of  claim 2 , wherein the wood chips comprise hardwood. 
   
   
       4 . The process of  claim 1 , wherein the chemically pulping in step (a) comprises a step of chemically pulping the wood chips to a kappa number of at least 30. 
   
   
       5 . The process of  claim 4 , wherein the wood chips comprise softwood. 
   
   
       6 . The process of  claim 1 , wherein the chemically pulping in step (a) comprises a step of chemically pulping the wood chips to a kappa number of about 55. 
   
   
       7 . The process of  claim 1 , wherein the first amount of pulp includes a first weight associated therewith, wherein the first rejects component includes a first weight associated therewith, and wherein the ratio of the first weight of the first rejects component to the first weight of the first amount of pulp comprises about 6% to about 50%. 
   
   
       8 . The process of  claim 1 , wherein the first amount of pulp includes a first weight associated therewith, wherein the first rejects component includes a first weight associated therewith, and wherein the ratio of the first weight of the first rejects component to the first weight of the first amount of pulp comprises about 30% to about 35%. 
   
   
       9 . The process of  claim 1 , wherein the chemically pulping in step (a) comprises a chemical pulping process selected from the group consisting of kraft pulping, soda pulping, and sulfite pulping. 
   
   
       10 . The process of  claim 1 , wherein the chemically pulping in step (a) comprises a kraft pulping. 
   
   
       11 . The process of  claim 1 , wherein the chemically pulping in step (a) comprises a kraft pulping including a chemical additive selected from the group consisting of anthraquinone, polysulfide, penetrating aids, thiourea, and combinations thereof. 
   
   
       12 . The process of  claim 1 , wherein the separating step in step (b) comprises a step of passing the first amount of pulp through a screen to separate the first accepts component from the first rejects component. 
   
   
       13 . The process of  claim 1 , wherein the substantially high consistency mechanical pulping in step (c) comprises a pulping process selected from the group consisting of mechanical pulping, alkaline mechanical (APMP) pulping, alkaline thermomechanical pulping, thermomechanical pulping, and chemi-thermomechanical pulping. 
   
   
       14 . The process of  claim 1 , wherein the substantially high consistency mechanical pulping in step (c) comprises a step of refining the first rejects component. 
   
   
       15 . The process of  claim 1 , wherein the substantially high consistency mechanical pulping in step (c) comprises steps of:
 (c1) refining the first rejects component; and   (c2) pre-bleaching the first rejects component.   
   
   
       16 . The process of  claim 1 , wherein the substantially high consistency mechanical pulping in step (c) comprises steps of:
 (c1) refining the first rejects component;   (c2) pre-bleaching the first rejects component; and   (c3) retaining the first rejects component treated at steps (c1) and (c2) for a predetermined time period.   
   
   
       17 . The process of  claim 1 , wherein the substantially high consistency mechanical pulping of the first rejects component in step (c) generates the second amount of pulp including a second rejects component. 
   
   
       18 . The process of  claim 17 , further comprising a step of separating the second accepts component from the second rejects component. 
   
   
       19 . The process of  claim 1 , further comprising a step of bleaching the fiber blend. 
   
   
       20 . The process of  claim 1 , wherein the fiber blend includes a first weight associated therewith, wherein the first accepts component includes a first weight associated therewith, and wherein the ratio of the first weight of the first accepts component to the first weight of the fiber blend comprises about 50% to about 90%. 
   
   
       21 . The process of  claim 1 , wherein the fiber blend includes a first weight associated therewith, wherein the first accepts component includes a first weight associated therewith, and wherein the ratio of the first weight of the first accepts component to the first weight of the fiber blend comprises about 65% to about 75%. 
   
   
       22 . The process of  claim 1 , wherein the wood chips have a weight associated therewith, wherein the combined the fiber blend has a weight associated therewith, and wherein the weight of the combined the fiber blend is at least 45% of the weight of the wood chips. 
   
   
       23 . A process of for producing a fiber blend, comprising steps of:
 (a) chemically processing wood chips to a predetermined kappa number to produce a first amount of pulp including a first accepts component and a first rejects component, wherein the first rejects component comprises more than 30% of the first amount of pulp;   (b) separating the first accepts component from the first rejects component;   (c) substantially high consistency mechanically pulping the first rejects component to produce a second amount of pulp including a second accepts component and a second rejects component; and   (d) combining the first and the second accepts components to produce the fiber blend.   
   
   
       24 . The process of  claim 23 , wherein the wood chips comprise hardwood, and wherein the kappa number is at least 20. 
   
   
       25 . The process of  claim 23 , wherein the wood chips comprise softwood, and wherein the kappa number is at least 30. 
   
   
       26 . The process of  claim 23 , wherein the kappa number is about 55. 
   
   
       27 . The process of  claim 23 , wherein the chemically processing in step (a) comprises a chemical pulping process selected from the group consisting of kraft pulping, soda pulping, and sulfite pulping. 
   
   
       28 . The process of  claim 23 , wherein the chemically processing in step (a) comprises a kraft pulping. 
   
   
       29 . The process of  claim 23 , wherein the chemically pulping in step (a) comprises a kraft pulping including a chemical additive selected from the group consisting of anthraquinone, polysulfide, penetrating aids, thiourea, and combinations thereof. 
   
   
       30 . The process of  claim 23 , wherein the separating step (b) comprises a step of passing the first amount of pulp through a screen to separate the first accepts component from the first rejects component. 
   
   
       31 . The process of  claim 23 , wherein the substantially high consistency mechanically pulping in step (c) comprises a pulping process selected from the group consisting of mechanical pulping, alkaline mechanical (APMP) pulping, alkaline thermomechanical pulping, thermomechanical pulping, and chemi-thermomechanical pulping. 
   
   
       32 . The process of  claim 23 , wherein the substantially high consistency mechanically pulping in (c) comprises a step of refining the first rejects component. 
   
   
       33 . The process of  claim 23 , wherein the substantially high consistency mechanically pulping in (c) comprises steps of:
 (c1) refining the first rejects component; and   (c2) pre-bleaching the first rejects component.   
   
   
       34 . The process of  claim 23 , wherein the substantially high consistency mechanically pulping in (c) comprises steps of:
 (c1) refining the first rejects component;   (c2) pre-bleaching the first rejects component; and   (c3) retaining the first rejects component treated at steps (c1) and (c2) for a predetermined time period.   
   
   
       35 . The process of  claim 23 , further comprising a step of separating the second accepts component from the second rejects component. 
   
   
       36 . The process of  claim 23 , further comprising a step of bleaching the fiber blend. 
   
   
       37 . The process of  claim 23 , wherein the fiber blend includes a first weight associated therewith, wherein the first accepts component includes a first weight associated therewith, and wherein the ratio of the first weight of the first accepts component to the first weight of the fiber blend comprises about 50% to about 90%. 
   
   
       38 . The process of  claim 23 , wherein the fiber blend includes a first weight associated therewith, wherein the first accepts component includes a first weight associated therewith, and wherein the ratio of the first weight of the first accepts component to the first weight of the fiber blend comprises about 65% to about 75%. 
   
   
       39 . The process of  claim 23 , wherein the wood chips have a weight associated therewith, wherein the combined the fiber blend has a weight associated therewith, and wherein the weight of the combined the fiber blend is at least 45% of the weight of the wood chips. 
   
   
       40 . A process for producing a fiber blend, comprising steps of:
 (a) chemically processing wood chips in a digester to a predetermined kappa number to produce a first amount of pulp including a first accepts component and a first rejects component;   (b) separating the first accepts component from the first rejects component;   (c) refining the first rejects component to produce a second amount of pulp including a second accepts component and a second rejects component;   (d) retaining the second amount of pulp for a predetermined time period;   (e) separating the second accepts component from the second rejects component; and   (f) combining the first and the second accepts components to produce the fiber blend.   
   
   
       41 . The process of  claim 40 , wherein the wood chips comprise hardwood, and wherein the kappa number is at least 20. 
   
   
       42 . The process of  claim 40 , wherein the wood chips comprise hardwood, and wherein the kappa number is in a range of about 20 to about 70. 
   
   
       43 . The process of  claim 40 , wherein the wood chips comprise softwood, and wherein the kappa number is at least 30. 
   
   
       44 . The process of  claim 40 , wherein the wood chips comprise softwood, and wherein the kappa number is in a range of about 30 to about 95. 
   
   
       45 . The process of  claim 40 , wherein the chemically processing in step (a) comprises a pulping process selected from the group consisting of kraft pulping, soda pulping, and sulfite pulping. 
   
   
       46 . The process of  claim 40 , wherein the chemically processing in step (a) comprises a kraft pulping. 
   
   
       47 . The process of  claim 40 , wherein the chemically pulping in step (a) comprises a kraft pulping including a chemical additive selected from the group consisting of anthraquinone, polysulfide, penetrating aids, thiourea, and combinations thereof. 
   
   
       48 . The process of  claim 40 , wherein the separating in step (b) comprises a step of passing the first amount of pulp through a screen to separate the first accepts component from the first rejects component. 
   
   
       49 . The process of  claim 40 , wherein the refining in step (c) comprises a step of pulping selected from the group consisting of mechanical pulping, alkaline mechanical (APMP) pulping, alkaline thermomechanical pulping, thermomechanical pulping, and chemi-thermo mechanical pulping. 
   
   
       50 . The process of  claim 40 , wherein the refining in step (c) includes a step of pre-bleaching. 
   
   
       51 . The process of  claim 50 , wherein the pre-bleaching agent is selected from the group consisting of chlorine dioxide; elemental chlorine; sodium hypochlorite; sodium hydrosulfite; ozone; peroxide; oxygen delignification; a bleaching liquor consisting of peroxide, caustic, and sodium silicate; a bleaching liquor consisting of alkaline chemical and peroxide; and combinations thereof. 
   
   
       52 . The process of  claim 40 , further comprising a step of bleaching the fiber blend. 
   
   
       53 . The process of  claim 40 , wherein the fiber blend includes a first weight associated therewith, wherein the first accepts component includes a first weight associated therewith, and wherein the ratio of the first weight of the first accepts component to the first weight of the fiber blend comprises about 50% to about 90%. 
   
   
       54 . The process of  claim 40 , wherein the fiber blend includes a first weight associated therewith, wherein the first accepts component includes a first weight associated therewith, and wherein the ratio of the first weight of the first accepts component to the first weight of the fiber blend comprises about 65% to about 75%. 
   
   
       55 . The process of  claim 40 , wherein the wood chips have a weight associated therewith, wherein the combined the fiber blend has a weight associated therewith, and wherein the weight of the fiber blend is at least 45% of the weight of the wood chips. 
   
   
       56 . The process of wood pulping comprising steps of:
 (a) pulping of wood chips to generate a first amount of pulp including a first accepts component and a first rejects component; and   (b) pulping of the first rejects component, characterized by a pulp yield of at least 8% higher than a pulp yield of a chemical pulping using same wood chips.   
   
   
       57 . The process of  claim 56 , wherein the chemical pulping comprises a kraft pulping. 
   
   
       58 . The process of  claim 56 , wherein the chemically pulping in step (a) comprises a kraft pulping including a chemical additive selected from the group consisting of anthraquinone, polysulfide, penetrating aids, thiourea, and combinations thereof. 
   
   
       59 . The process of wood pulping comprising steps of:
 (a) pulping of wood chips to generate a first amount of pulp including a first accepts component and a first rejects component; and   (b) pulping of the first rejects component, characterized by a pulp yield of at least 10% higher than a pulp yield of a chemical pulping using the same wood chips.   
   
   
       60 . The process of  claim 59 , wherein the chemical pulping comprises a kraft pulping. 
   
   
       61 . The process of  claim 59 , wherein the chemically pulping in step (a) comprises a kraft pulping including a chemical additive selected from the group consisting of anthraquinone, polysulfide, penetrating aids, thiourea, and combinations thereof. 
   
   
       62 . The process of wood pulping comprising steps of:
 (a) pulping of wood chips to generate a first amount of pulp including a first accepts component and a first rejects component; and   (b) pulping of the first rejects component, characterized by a pulp yield of at least 15% higher than a pulp yield of a chemical pulping using the same wood chips.   
   
   
       63 . The process of  claim 62 , wherein the chemical pulping comprises a kraft pulping. 
   
   
       64 . The process of  claim 62 , wherein the chemically pulping in step (a) comprises a kraft pulping including a chemical additive selected from the group consisting of anthraquinone, polysulfide, penetrating aids, thiourea, and combinations thereof. 
   
   
       65 . A fiber blend, produced by a process comprising steps of:
 (a) providing wood chips;   (b) chemically pulping the wood chips to generate a first amount of pulp including a first accepts component and a first rejects component;   (c) separating the first accepts component from the first rejects component;   (d) performing a substantially high consistency mechanical pulping of the first rejects component to generate a second amount of pulp including a second accepts component; and   (e) combining the first and the second accepts components to produce the fiber blend.   
   
   
       66 . The fiber blend of  claim 65 , comprising from about 50% to about 90% of the first accepts component. 
   
   
       67 . The fiber blend of  claim 65 , comprising from about 65% to about 75% of the first accepts component. 
   
   
       68 . A fiber blend, produced by a process comprising steps of:
 (a) providing wood chips;   (b) chemically processing the wood chips to a predetermined kappa number to produce a first amount of pulp including a first accepts component and a first rejects component, wherein the first rejects component comprises more than 30% of the first amount of pulp;   (c) separating the first accepts component from the first rejects component;   (d) substantially high consistency mechanically pulping the first rejects component to produce a second amount of pulp including a second accepts component and a second rejects component; and   (e) combining the first and the second accepts components to produce the fiber blend.   
   
   
       69 . The fiber blend of  claim 68 , comprising from about 50% to about 90% of the first accepts component. 
   
   
       70 . The fiber blend of  claim 68 , comprising from about 65% to about 75% of the first accepts component. 
   
   
       71 . A fiber blend, produced by a process comprising steps of:
 (a) providing wood chips;   (b) chemically processing the wood chips in a digester to a predetermined kappa number to produce a first amount of pulp including a first accepts component and a first rejects component;   (c) separating the first accepts component from the first rejects component;   (d) refining the first rejects component to produce a second amount of pulp including a second accepts component and a second rejects component;   (e) retaining the second amount of pulp for a predetermined time period;   (f) separating the second accepts component from the second rejects component; and   (g) combining the first and the second accepts components to produce the fiber blend.   
   
   
       72 . The fiber blend of  claim 71 , comprising from about 50% to about 90% of the first accepts component. 
   
   
       73 . The fiber blend of  claim 71 , comprising from about 65% to about 75% of the first accepts component. 
   
   
       74 . A fiber blend, characterized by a fiber length distribution containing at least 2 weight percent of long fibers as defined by a 14 mesh-size screen of a Bauer-McNett classifier and at least 15 weight percent of short fibers as defined by a 200 mesh-size screen of a Bauer-McNett classifier. 
   
   
       75 . A paper-based product, including a fiber blend produced by a process comprising steps of:
 (a) providing wood chips;   (b) chemically pulping the wood chips to generate a first amount of pulp including a first accepts component and a first rejects component;   (c) separating the first accepts component from the first rejects component;   (d) performing a substantially high consistency mechanical pulping of the first rejects component to generate a second amount of pulp including a second accepts component; and   (e) combining the first and the second accepts components to produce the fiber blend.   
   
   
       76 . The product of  claim 75 , wherein the fiber blend comprises from about 50% to about 90% of the first accepts component. 
   
   
       77 . The product of  claim 75 , wherein the fiber blend comprises from about 65% to about 75% of the first accepts component. 
   
   
       78 . A paper-based product, including a fiber blend produced by a process comprising steps of:
 (a) providing wood chips;   (b) chemically processing the wood chips to a predetermined kappa number to produce a first amount of pulp including a first accepts component and a first rejects component, wherein the first rejects component comprises more than 30% of the first amount of pulp;   (c) separating the first accepts component from the first rejects component;   (d) substantially high consistency mechanically pulping the first rejects component to produce a second amount of pulp including a second accepts component and a second rejects component; and   (e) combining the first and the second accepts components to produce the fiber blend.   
   
   
       79 . The product of  claim 78 , wherein the fiber blend comprises from about 50% to about 90% of the first accepts component. 
   
   
       80 . The product of  claim 78 , wherein the fiber blend comprises from about 65% to about 75% of the first accepts component. 
   
   
       81 . A paper-based product, including a fiber blend produced by a process comprising steps of:
 (a) providing wood chips;   (b) chemically processing the wood chips in a digester to a predetermined kappa number to produce a first amount of pulp including a first accepts component and a first rejects component;   (c) separating the first accepts component from the first rejects component;   (d) refining the first rejects component to produce a second amount of pulp including a second accepts component and a second rejects component;   (e) retaining the second amount of pulp for a predetermined time period;   (f) separating the second accepts component from the second rejects component; and   (g) combining the first and the second accepts components to produce the fiber blend.   
   
   
       82 . The product of  claim 81 , wherein the fiber blend comprises from about 50% to about 90% of the first accepts component. 
   
   
       83 . The product of  claim 81 , wherein the fiber blend comprises from about 65% to about 75% of the first accepts component. 
   
   
       84 . A paper-based product including a fiber blend, wherein a fiber length distribution of the fiber blend contains at least 2 weight percent of long fibers as defined by a 14 mesh-size screen of a Bauer-McNett classifier and at least 15 weight percent of short fibers as defined by a 200 mesh-size screen of a Bauer-McNett classifier. 
   
   
       85 . A paper-based product, characterized by a stiffness of at least 8% higher than a stiffness of a single ply paper-based product made of kraft pulp at the same basis weight, and wherein the stiffness is determined according to a TAPPI standard procedure Lorentzen & Wettre No. T-556. 
   
   
       86 . The product of  claim 85 , characterized by a stiffness of at least 10% higher than a stiffness of a single ply paper-based product made of kraft pulp at the same basis weight, and wherein the stiffness is determined according to a TAPPI standard procedure Lorentzen & Wettre No. T-556. 
   
   
       87 . The product of  claim 85 , characterized by a stiffness of at least 15% higher than a stiffness of a single ply paper-based product made of kraft pulp at the same basis weight, and wherein the stiffness is determined according to a TAPPI standard procedure Lorentzen & Wettre No. T-556. 
   
   
       88 . A packaging, including a fiber blend produced by a process comprising steps of:
 (a) providing wood chips;   (b) chemically pulping the wood chips to generate a first amount of pulp including a first accepts component and a first rejects component;   (c) separating the first accepts component from the first rejects component;   (d) performing a substantially high consistency mechanical pulping of the first rejects component to generate a second amount of pulp including a second accepts component; and   (e) combining the first and the second accepts components to produce the fiber blend.   
   
   
       89 . The packaging of  claim 88 , wherein the fiber blend comprises from about 50% to about 90% of the first accepts component. 
   
   
       90 . The packaging of  claim 88 , wherein the fiber blend comprises from about 65% to about 75% of the first accepts component. 
   
   
       91 . A packaging, including a fiber blend produced by a process comprising steps of:
 (a) providing wood chips;   (b) chemically processing the wood chips to a predetermined kappa number to produce a first amount of pulp including a first accepts component and a first rejects component, wherein the first rejects component comprises more than 30% of the first amount of pulp;   (c) separating the first accepts component from the first rejects component;   (d) substantially high consistency mechanically pulping the first rejects component to produce a second amount of pulp including a second accepts component and a second rejects component; and   (e) combining the first and the second accepts components to produce the fiber blend.   
   
   
       92 . The packaging of  claim 91 , wherein the fiber blend comprises from about 50% to about 90% of the first accepts component. 
   
   
       93 . The packaging of  claim 91 , wherein the fiber blend comprises from about 65% to about 75% of the first accepts component. 
   
   
       94 . A packaging, including a fiber blend produced by a process comprising steps of:
 (a) providing wood chips;   (b) chemically processing the wood chips in a digester to a predetermined kappa number to produce a first amount of pulp including a first accepts component and a first rejects component;   (c) separating the first accepts component from the first rejects component;   (d) refining the first rejects component to produce a second amount of pulp including a second accepts component and a second rejects component;   (e) retaining the second amount of pulp for a predetermined time period;   (f) separating the second accepts component from the second rejects component; and   (g) combining the first and the second accepts components to produce the fiber blend.   
   
   
       95 . The packaging of  claim 94 , wherein the fiber blend comprises from about 50% to about 90% of the first accepts component. 
   
   
       96 . The packaging of  claim 94 , wherein the fiber blend comprises from about 65% to about 75% of the first accepts component. 
   
   
       97 . A packaging including a fiber blend, wherein a fiber length distribution of the fiber blend contains at least 2 weight percent of long fibers as defined by a 14 mesh-size screen of a Bauer-McNett classifier and at least 15 weight percent of short fibers as defined by a 200 mesh-size screen of a Bauer-McNett classifier. 
   
   
       98 . A packaging, including a paper-based product characterized by a stiffness of at least 8% higher than a stiffness of a single ply paper-based product made of kraft pulp at the same basis weight, and wherein the stiffness is determined according to a TAPPI standard procedure Lorentzen & Wettre No. T-556. 
   
   
       99 . The packaging of  claim 98 , wherein the paper-based product has a stiffness of at least 10% higher than a stiffness of a single ply paper-based product made of kraft pulp at the same basis weight, and wherein the stiffness is determined according to a TAPPI standard procedure Lorentzen & Wettre No. T-556. 
   
   
       100 . The packaging of  claim 98 , wherein the paper-based product has a stiffness of at least 15% higher than a stiffness of a single ply paper-based product made of kraft pulp at the same basis weight, and wherein the stiffness is determined according to a TAPPI standard procedure Lorentzen & Wettre No. T-556.