CN108166307B - Preparation method of bobbin paper and boxboard paper - Google Patents

Abstract

The invention provides a preparation method of bobbin paper and boxboard paper. The preparation method of the bobbin paper and the boxboard paper comprises the following steps: step one, waste paper is crushed; step two, removing impurities; step three, screening; step four, treating pulp fibers; step five, pulping in a pulping tank; step six, screening before the net; step seven, forming, dehydrating and drying the slurry to obtain a semi-finished product; step eight, post-treatment: and carrying out post-treatment on the semi-finished paper. The preparation method of the bobbin paper and the cardboard paper provided by the invention has the advantages of cheap and easily available raw materials, simple process steps, good product quality, low production cost, environmental protection, safety, high efficiency and suitability for industrial production.

Description

Preparation method of bobbin paper and boxboard paper

Technical Field

The invention belongs to the field of paper, and particularly relates to a preparation method of bobbin paper and boxboard paper.

Background

Papermaking involves shredding plant fibers into a slurry and then treating the slurry with various processes to form paper. The existing papermaking process has the advantages of simple pulping process, simple water filtration and pressing process, low paper quality, high production cost, environmental pollution, insecurity, low efficiency and difficult industrial production.

Disclosure of Invention

In order to solve the technical problems, the invention provides the preparation method of the bobbin paper and the cardboard paper, which has the advantages of good quality, low production cost, environmental protection, safety, high efficiency and suitability for industrial production.

The preparation method of the bobbin paper and the boxboard paper provided by the invention comprises the following steps:

step one, waste paper fragmentation: conveying the waste paper to a hydrapulper for pulping;

step two, impurity removal: removing impurities such as metal, stones, paper pieces, hard plastic sheets, straw ropes and the like from the crushed slurry;

step three, screening: screening the coarsely screened slurry;

step four, treating pulp fibers: the screened pulp is treated by a multi-disc thickener by a mechanical method to ensure that the fiber tissue has uniform density and high strength;

step five, pulping in a pulping tank: the slurry enters a slurry forming pool, and the concentration ranges of bottom slurry and core slurry, the wet weight of the slurry, the concentration of surface slurry and the wet weight of the slurry are controlled;

step six, screening in front of a net: screening the treated slurry by a screen before a net;

step seven, forming, dehydrating and drying the slurry to obtain a semi-finished product: after the slurry is transversely and uniformly distributed through mechanical action, dehydrating and drying to obtain a semi-finished product; the method specifically comprises the following steps:

seventhly, transversely and uniformly distributing the slurry through mechanical action;

seventhly, surfing the web along the longitudinal direction of the paper machine;

seventhly, allowing the paper pulp to flow to the upper edge of the rotating dewatering net through the forming plate, and enabling the paper pulp to be uniformly distributed on the net through the vibration of the breast roll;

seventhly, entering a dewatering net and a dewatering plate: the back side of the dewatering net is a densely distributed dewatering plate, and water flows down along the dewatering plate in the running process;

seventhly, entering a watermark roller: entering a watermark roller to increase the uniformity of the paper;

seventhly, entering a vacuum couch roll, dewatering, and enabling paper pulp to flow out of the lip plate;

seventhly, squeezing and dehydrating: further dewatering by mechanical pressing in the press section;

seventhly, drying in a drying part: the finished paper enters a drying part to further shrink the paper;

step eight, post-treatment: and carrying out post-treatment on the semi-finished paper.

In a preferred embodiment of the method for preparing bobbin paper and carton board paper provided by the present invention, in the second step, the removing impurities includes the following steps:

step two, removing heavy impurities: heavy impurities such as metal, stone and the like are removed heavily in a high-concentration slag remover;

step two, removing large impurities: larger impurities such as paper sheets, hard plastic sheets, straw ropes and the like are removed through primary screening.

In a preferred embodiment of the method for preparing bobbin paper and carton board paper provided by the present invention, in the third step, the classifying and screening includes the following steps:

step three, screening by a grading screen: classifying and screening the coarsely screened slurry through a classifying screen;

step three, removing impurities by a low-concentration desander: removing impurities with different fiber sizes from the slurry through a low-concentration desander;

step three, fine screening: the slurry is further cleaned by fine screening.

In a preferred embodiment of the method for preparing bobbin paper and carton board paper provided by the invention, in the third step, the slurry inlet concentration of the low-concentration desander is controlled as follows: the pulp inlet concentration of the long and short fibers is less than or equal to 1.8 percent, the pulp inlet concentration of the medium fibers is less than or equal to 1.6 percent, and the pulp inlet pressure is controlled as follows: the long fiber pulp inlet pressure 260-.

In a preferred embodiment of the preparation method of the bobbin paper and the cardboard paper, in the fifth step, the concentration ranges of the bottom pulp and the core pulp are controlled to be 3 +/-0.2%, and the wet weight of the pulp is more than or equal to 5.5 g; the concentration range of the surface sizing agent is 2.8% +/-0.2%, and the wet weight of the sizing agent is more than or equal to 5.5 g.

In a preferred embodiment of the method for preparing bobbin paper and carton board paper provided by the invention, in the sixth step, a pressure screen in front of a screen or a stainless steel corrugated screen is used for screening, a light slag discharge port is arranged at the top of the screen, and part of light impurities and sticky substances are removed without passing through the screen.

In a preferred embodiment of the method for preparing bobbin paper and cardboard paper provided by the present invention, the eighth step is one or more of sizing, re-dewatering, calendering, curling and slitting.

In a preferred embodiment of the preparation method of the bobbin paper and the cardboard paper, the sizing is to add a water-resistant substance into a sizing machine so that the finished paper has the property of delaying the penetration of fluid; and the semi-finished paper is dehydrated again through the post-drying part.

In a preferred embodiment of the method for preparing bobbin paper and boxboard paper provided by the invention, the seventh step and the sixth step are specifically to control the uniform distribution of the speed, pressure, concentration and the like of the pulp at each point along the full width and full height directions of the paper machine, ensure the smooth flow of the paper material on the net without cross flow vortex and instantaneous speed fluctuation, so as to meet the requirement of consistent transverse width ration of the paper sheet and control the pulp retention rate range to be 60% +/-5%.

The preparation method of the bobbin paper and the cardboard paper has the following beneficial effects:

cheap and easily available raw materials, simple process steps, good product quality, low production cost, environmental protection, safety, high efficiency and suitability for industrial production. The processes of dehydration and the like are precise, and the dehydration quality is good. When reaching the vacuum suction roll, the dewatering plate and the vacuum couch roll remove 20% of water, the press part is required to further dewater by using mechanical pressing, the dryness is improved, simultaneously, the tightness and the strength of the paper are increased, the surface property of the paper sheet is improved, the dryness of the finished paper which can be obtained by pressing and dewatering is 25% -42%, the moisture of wet paper in the press part of the paper machine is reduced by 1%, the drying cylinder part is saved by 5%, and the cost is saved by 10%. The paper squeezed from the last press of the press part has the dryness of 30-45 percent generally, and the residual water in the paper is difficult to remove by a mechanical method, so the paper is further shrunk by the drying part, the fiber is more tightly combined, the strength of the paper and the paperboard is increased, the paper has certain smoothness, and the dryness of the paper passing through the drying part reaches 93-95 percent. After passing through the front drying part, the paper is added with a water-resistant substance at the glue applicator, so that the paper has the performance of delaying fluid permeability.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without inventive efforts, wherein:

FIG. 1 is a process flow diagram of the method for making bobbin paper and boxboard paper provided by the present invention;

FIG. 2 is a process flow diagram of step two of the method of making the bobbin paper and the boxboard paper shown in FIG. 1;

FIG. 3 is a process flow diagram of step three of the method of making the bobbin paper and the boxboard paper shown in FIG. 1;

fig. 4 is a process flow diagram of a seventh step of the method for preparing the bobbin paper and the cardboard paper shown in fig. 1.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1, fig. 1 is a process flow chart of a method for preparing bobbin paper and carton paper according to the present invention; FIG. 2 is a process flow diagram of step two of the method of making the bobbin paper and the boxboard paper shown in FIG. 1; FIG. 3 is a process flow diagram of step three of the method of making the bobbin paper and the boxboard paper shown in FIG. 1; fig. 4 is a process flow diagram of a seventh step of the method for preparing the bobbin paper and the cardboard paper shown in fig. 1.

The preparation method of the bobbin paper and the boxboard paper comprises the following steps:

step S1, waste paper disintegration: and conveying the waste paper to a hydrapulper for pulping.

Step S2, removing impurities: removing impurities such as metal, stones, paper pieces, hard plastic sheets, straw ropes and the like from the crushed slurry; the method comprises the following steps:

step S21, removing heavy impurities: heavy impurities such as metal, stone and the like are removed heavily in a high-concentration slag remover;

step S22, removing large impurities: larger impurities such as paper sheets, hard plastic sheets, straw ropes and the like are removed through primary screening.

Step S3, screening: screening the coarsely screened slurry; the classification screening comprises the following steps:

step S31, screening by a grading sieve: classifying and screening the coarsely screened slurry through a classifying screen;

step S32, removing impurities by a low-concentration desander: removing impurities with different fiber sizes from the slurry through a low-concentration desander; controlling the slurry inlet concentration of the low-concentration desander: the pulp inlet concentration of the long and short fibers is less than or equal to 1.8 percent, the pulp inlet concentration of the medium fibers is less than or equal to 1.6 percent, and the pulp inlet pressure is controlled as follows: the long fiber pulp inlet pressure 260-.

Step S33, fine screening: the slurry is further cleaned by fine screening.

Step S4, pulp fiber treatment: the screened pulp is treated by a multi-disc thickener by a mechanical method to ensure that the fiber tissue has uniform density and high strength;

step S5, pulping in a pulping pool: the slurry enters a slurry forming pool, and the concentration ranges of bottom slurry and core slurry, the wet weight of the slurry, the concentration of surface slurry and the wet weight of the slurry are controlled; controlling the concentration range of the bottom slurry and the core slurry to be 3 +/-0.2%, and controlling the wet weight of the slurry to be more than or equal to 5.5 g; the concentration range of the surface sizing agent is 2.8% +/-0.2%, and the wet weight of the sizing agent is more than or equal to 5.5 g.

Step S6, pre-network screening: screening the treated slurry by a screen before a net; the screen is screened by a pressure screen in front of a screen or a stainless steel corrugated screen, a light slag discharge port is arranged at the top of the screen, and part of light impurities and sticky matters are removed in advance without passing through the screen.

Step S7, forming, dehydrating and drying the slurry into a semi-finished product: after the slurry is transversely and uniformly distributed through mechanical action, dehydrating and drying to obtain a semi-finished product; the method specifically comprises the following steps:

step S71, transversely and uniformly distributing the slurry through mechanical action;

s72, feeding the pulp in the longitudinal direction of the paper machine, controlling the uniform distribution of the speed, pressure, concentration and the like of the pulp at each point along the full width and full height directions of the paper machine, ensuring the smooth flow of the paper material fed on the pulp, having no cross flow vortex and instantaneous speed fluctuation, meeting the requirement of consistent transverse width ration of paper sheets, and controlling the retention rate range of the pulp to be 60 +/-5%;

s73, allowing the paper pulp to flow to the upper edge of the rotating dewatering net through a forming plate, and allowing the paper pulp to be uniformly distributed on the net by the vibration of the breast roll;

step S74, entering a dewatering net and a dewatering plate: the back side of the dewatering net is a densely distributed dewatering plate, and water flows down along the dewatering plate in the running process;

step S75, entering a watermark roller: entering a watermark roller to increase the uniformity of the paper;

step S76, entering a vacuum couch roll, dewatering, and enabling paper pulp to flow out of the lip plate;

step S77, squeezing and dewatering: further dewatering by mechanical pressing in the press section;

step S78, drying section: the finished paper enters a drying part to further shrink the paper;

step S8, post-processing: carrying out post-treatment on the semi-finished paper; specifically one or more of sizing, re-dewatering, calendaring, curling and slitting; the sizing is to add water-resistant substances into a sizing machine so that the finished paper has the performance of delaying the penetration of fluid; and the semi-finished paper is dehydrated again through the post-drying part.

The preparation method of the bobbin paper and the cardboard paper has the following beneficial effects: cheap and easily available raw materials, simple process steps, good product quality, low production cost, environmental protection, safety, high efficiency and suitability for industrial production. The processes of dehydration and the like are precise, and the dehydration quality is good. When reaching the vacuum suction roll, the dewatering plate and the vacuum couch roll remove 20% of water, the press part is required to further dewater by using mechanical pressing, the dryness is improved, simultaneously, the tightness and the strength of the paper are increased, the surface property of the paper sheet is improved, the dryness of the finished paper which can be obtained by pressing and dewatering is 25% -42%, the moisture of wet paper in the press part of the paper machine is reduced by 1%, the drying cylinder part is saved by 5%, and the cost is saved by 10%. The paper squeezed from the last press of the press part has the dryness of 30-45 percent generally, and the residual water in the paper is difficult to remove by a mechanical method, so the paper is further shrunk by the drying part, the fiber is more tightly combined, the strength of the paper and the paperboard is increased, the paper has certain smoothness, and the dryness of the paper passing through the drying part reaches 93-95 percent. After passing through the front drying part, the paper is added with a water-resistant substance at the glue applicator, so that the paper has the performance of delaying fluid permeability.

The above description is only an embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes, which are made by using the contents of the present specification and the accompanying drawings, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims (2)

1. A preparation method of bobbin paper and carton paper is characterized by comprising the following steps:

step one, waste paper fragmentation: conveying the waste paper to a hydrapulper for pulping;

step two, impurity removal: removing impurities such as metal, stone, paper, hard plastic sheets and straw ropes from the crushed slurry;

step three, screening: screening the coarsely screened slurry; the screening comprises the following steps:

step three, screening by a grading screen: classifying and screening the coarsely screened slurry through a classifying screen;

step three, removing impurities by a low-concentration desander: removing impurities with different fiber sizes from the slurry through a low-concentration desander; the method specifically comprises the following steps: controlling the slurry inlet concentration of the low-concentration desander: the pulp inlet concentration of the long and short fibers is less than or equal to 1.8 percent, the pulp inlet concentration of the medium fibers is less than or equal to 1.6 percent, and the pulp inlet pressure is controlled as follows: the long fiber pulp inlet pressure is 260-320MPa, the medium fiber pulp inlet pressure is 240-300MPa, and the short fiber pulp inlet pressure is 150-240 MPa;

step three, fine screening: further removing impurities from the slurry through a fine screen;

step four, treating pulp fibers: the screened pulp is treated by a multi-disc thickener by a mechanical method to ensure that the fiber tissue has uniform density and high strength;

step five, pulping in a pulping tank: feeding the slurry into a slurry forming pool, controlling the concentration range of bottom slurry and core slurry to be 3 +/-0.2%, and controlling the wet weight of the slurry to be more than or equal to 5.5 g; the concentration range of the surface sizing agent is 2.8% +/-0.2%, and the wet weight of the sizing agent is more than or equal to 5.5;

step six, screening in front of a net: screening the treated slurry by a screen before a net, specifically adopting a pressure screen before the net or a stainless steel corrugated screen, wherein the top of the screen is provided with a light slag discharge port, and part of light impurities and sticky matters are removed before passing through the screen;

step seven, forming, dehydrating and drying the slurry to obtain a semi-finished product: after the slurry is transversely and uniformly distributed through mechanical action, dehydrating and drying to obtain a semi-finished product; the method specifically comprises the following steps:

seventhly, transversely and uniformly distributing the slurry through mechanical action;

seventhly, surfing the web along the longitudinal direction of the paper machine: the speed, pressure and concentration distribution of the pulp at each point in the full-width and full-height directions of the paper machine are controlled to be uniform, the paper material on the net is ensured to flow stably, cross flow vortex and instantaneous speed fluctuation do not exist, so that the paper sheet banner quantification is consistent, and the pulp retention rate range is controlled to be 60% +/-5%;

seventhly, allowing the paper pulp to flow to the upper edge of the rotating dewatering net through the forming plate, and enabling the paper pulp to be uniformly distributed on the net through the vibration of the breast roll;

seventhly, entering a dewatering net and a dewatering plate: the back side of the dewatering net is a densely distributed dewatering plate, and water flows down along the dewatering plate in the running process;

seventhly, entering a watermark roller: entering a watermark roller to increase the uniformity of the paper;

seventhly, entering a vacuum couch roll, dewatering, and enabling paper pulp to flow out of the lip plate;

seventhly, squeezing and dehydrating: further dewatering by mechanical pressing in the press section;

seventhly, drying in a drying part: the finished paper enters a drying part to further shrink the paper;

step eight, post-treatment: carrying out post-treatment on the semi-finished paper; the sizing is one or more of sizing, re-dewatering, calendaring, curling and slitting, and the sizing is to add a water-resistant substance into a sizing machine so that the finished paper has the performance of delaying fluid permeability; and the semi-finished paper is dehydrated again through the post-drying part.

2. The method for preparing bobbin paper and carton board paper according to claim 1, wherein in the second step, the removing impurities comprises the following steps:

step two, removing heavy impurities: heavy impurities of metal and stone are removed heavily in a high-concentration slag remover;

step two, removing large impurities: paper sheets, hard plastic sheets and straw ropes with larger impurities are removed through primary screening.

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