WO2020143134A1 - Recycled paper and manufacturing method thereof - Google Patents

Abstract

A manufacturing method of recycled paper comprises: simultaneously shredding and de-inking waste paper, and forming de-inked dry flocculent fiber; spraying a liquid papermaking adhesive; and sequentially performing pressing and drying operations.

Description

Recycled paper and preparation method thereof Technical field

The invention belongs to the technical field of papermaking production, and relates to a papermaking method, in particular to a method of using waste to make paper.

Background technique

According to the investigation, it is learned that the traditional paper manufacturing industry is still crushing the recovered waste paper, and then adding a large amount of water and chemical reagents to soak the waste paper, re-pulp, deink, and finally make various paper products . According to the relevant information, the current waste paper recycling is still mainly to send the waste paper to the paper mill for reuse, and the current paper mill still has greater pollution to the surrounding environment. Even if reagents are added to the sewage to neutralize it, It will inevitably cause damage to the natural environment and cannot achieve or achieve "zero" pollution.

In the present invention, the waste paper crushing and deinking machine is crushed into flocculent dry fibers and the waste paper ink is removed at the same time, and no moisture and chemical reagents are added during the process of preparing the flocculent fibers. Due to the different morphology of the substance, in this form, the ink present in the waste paper exists at a very low content and is broken up. Only a certain proportion of starch glue needs to be added to bind, suppress, and dry the flocculent dry fiber In the process of drying, etc., the conventional paper that can be used can be made to avoid environmental pollution and achieve "zero" pollution and "zero" emissions.

Compared with the paper prepared by the traditional papermaking method, the recycled paper prepared by the present invention has better water retention, moldability and higher toughness, and the method of the present invention is a papermaking process without waste water generation. The papermaking method of the present invention is green, Environmental protection.

Summary of the invention

The purpose of the present invention is to provide a kind of recycled paper and its preparation method in view of the existing preparation method of using waste paper to prepare recycled paper and the technical problem of preparing recycled paper. The method of the present invention is a new type of anhydrous papermaking method to discard paper As raw materials, the ink of the waste paper is removed at the same time of crushing, and the flocculent dry fiber to remove the ink is prepared and mixed with the adhesive to make a new paper. The method of the present invention provides a new papermaking idea and solves the papermaking Due to the problems of water pollution and waste paper waste in the industry, the waste paper raw materials of the present invention have a wide range of sources, the prepared paper is cheap, the preparation time is less, the waste paper can be reused, the use of tree materials is reduced, and environmental protection is convenient. A small amount of water is used in the production of various paper products, which reduces the series of heavy pollution processes such as beating and waste disposal of traditional papermaking, and realizes the true green printing, clean papermaking, and pollution-free papermaking process and process effects.

In order to achieve the purpose of the present invention, one aspect of the present invention provides a papermaking method, including the following steps:

1) The waste paper is crushed and deinked at the same time to make flocculent dry fiber to remove printing ink;

2) Spray the papermaking adhesive solution into the flocculent dry fiber to make a paper fiber-adhesive mixture;

3) Pressing and drying the paper fiber-adhesive mixture in sequence, that's it.

Wherein, the length of the flocculent dry fiber in step 1) is ≥ 1.0 mm, preferably 1.0-1.2 mm.

Among them, the deinking treatment is carried out at the same time as the waste paper is crushed to prepare the flocculent dry fiber from which the ink is removed.

In particular, the pulverization and deinking treatment is to pulverize waste paper into flocculent dry fibers, and at the same time pulverize, remove the ink from the waste paper to produce flocculent dry fibers from which printing ink has been removed.

Among them, the crushing and deinking process is performed on the waste paper by using a crushing and deinking machine.

In particular, the crushing and deinking machine includes: a housing; a coarse crushing component installed on the housing for cutting waste paper into the housing; mounted on the housing and below the coarse crushing component A paper-washing assembly for preventing clogging of the coarse crushing device; a crushing and de-inking assembly installed on the casing and located below the paper-washing assembly for crushing the paper pieces into flocculent scraps and separating the scraps and the ink on the scraps ; The collecting assembly installed on the casing and located below the crushing and deinking device has a filter screen for filtering the flocculent paper dust and a screen for screening the flocculent paper dust located below the filter screen.

Wherein, the coarse crushing assembly includes: at least two rotating shafts which are rotatably mounted on the casing and extend in the horizontal direction; a plurality of paper cutting blades installed at intervals along the axial direction of the rotating shaft; wherein, two adjacent rotating shafts The cutting blades are misaligned.

In particular, the coarse crushing module crushes the waste paper into shredded paper pieces having a size of (1-5) mm×(1-5) mm, and the size of the shredded paper pieces is preferably 5 mm×5 mm.

Wherein, the punching assembly includes at least one pair of nozzles disposed on both sides of the casing.

Wherein, the crushing and deinking assembly includes: a pair of rotors installed side by side on the casing and having a central axis perpendicular to the central axis of the rotating shaft; a ring provided on the outer wall of each rotor for crushing the paper sheet Multiple rows of hammers formed into flocculent scraps; a rotary drive mechanism connected to a pair of rotors to drive a pair of rotors to rotate at a high speed in order to separate the flocculent scraps and the ink on the scraps.

In particular, the multiple rows of hammers on the rotor respectively include a plurality of hammers arranged at intervals along the axial direction of the rotor, and the hammers on the pair of rotors are arranged in a misaligned manner.

In particular, the hammer is a T-shaped hammer.

In particular, the T-shaped hammer piece includes a radial segment extending in the radial direction of the rotor and a tangential segment extending in the tangential direction of the rotor, and the inner end of the radial segment is fixedly mounted on the outer wall of the rotor.

In particular, the radial section and the tangential section of the T-shaped hammer have the same shape and size.

In particular, the gap between two adjacent rows of T-shaped hammer pieces arranged on one rotor in the axial direction of the rotor is 0.8-1.2 cm, preferably 1.0 cm.

In particular, the width of the radial section of the T-shaped hammer piece in the axial direction of the rotor is 0.6-1.5 cm, preferably 1.2 cm.

In particular, there is a gap of 0.2-0.4cm, preferably 0.2mm, between the ends of the pair of rotors opposite the hammers, (usually the hammers are staggered, regardless of the gap, but the paper is flammable, the opposite hammers There is a certain gap between them), that is, the gap between the ends of the tangential section of the hammer is 0.2-0.4cm, preferably 0.2mm (usually the hammers are staggered, the gap is not considered, but the paper is flammable) , There is a certain gap between the opposite hammers).

In particular, the rotational speed of the control rotor during the crushing and deinking process is ≥3000 rpm, preferably ≥7000 rpm, and more preferably 7000-15000 rpm.

Wherein, the pore size of the filter screen of the collecting component is 14-16 mesh; the pore size of the screen is 16-20 mesh, preferably 16 mesh.

In particular, the collecting assembly further includes: a pipe located below the screen of the crushing and deinking assembly, and a blower connected to the viewpoint for discharging the filtered flocculent paper dust.

In particular, it also includes a material guide assembly mounted on the casing and located between the coarse crushing assembly and the crushing deinking assembly.

In particular, the material guide assembly includes a triangular plate or an inverted V-shaped flap with its top hinged to the casing, and a hinged edge of the triangular plate or inverted V-shaped flap for hinged with the casing The extending direction of is parallel to the direction of the central axis of the rotor of the crushing and deinking assembly.

In particular, the paper cutting blade of the coarse crushing assembly and the inner wall of the cabinet are respectively coated with an antistatic coating for preventing static electricity.

Wherein, the adhesive for papermaking mentioned in step 2) is starch glue, preferably glutinous rice glue.

In particular, the adhesive solution for papermaking is prepared according to the following method: starch glue is added to distilled water and stirred evenly, wherein the mass ratio of starch glue to distilled water is 1:14-20, preferably 1:16 .

In particular, the mass ratio of the flocculent dry fiber to the adhesive solution for papermaking is 100:0.5-1.2, preferably 100:1.

Wherein, the pressing process in step 3) is divided into two rollings, the first rolling is to produce a paper roughness 1.2-1.8 times thicker than the finished paper thickness, preferably a paper roughness 1.5 times thick; The second rolling is to roll the rough paper after the first rolling into a semi-finished paper with a moisture content of 10-15%.

In particular, two sets of rollers are used for the two rollings.

In particular, the gap between the first group of rollers during the first rolling process is 1.2-1.8 times the thickness of the resulting paper, preferably 1.5 times.

Wherein, the drying process is to dry the pressed paper semi-finished product to a moisture content of 7%-8%.

In particular, the drying process is selected to be a vacuum drying process, in which the drying temperature is controlled to be 40-50°C; the degree of vacuum is -0.0075 to -0.1 MPa.

In particular, the drying treatment selects atmospheric pressure drying, wherein the drying temperature is 110°C-150°C, preferably 120°C.

In particular, UV drying is selected for the drying process.

Compared with the prior art, the present invention has the following advantages and benefits:

1. The method for preparing recycled paper of the present invention breaks the tradition, directly crushes waste paper materials into flocculent form, and completes deinking treatment in the crushing process. It is an innovative application that has never been used in the field of recycled paper preparation. , So that no deinking of water is needed in the papermaking process, no pollution to the environment, and the waste papermaking process is simplified.

2. Compared with the waste paper in the prior art which is swollen with warm water and then re-beated into pulp, the method of the present invention eliminates the effect of the residual ink on the waste paper on the quality of the recycled paper, and no waste pulp waste will be generated in the papermaking process Liquid, and improve the quality of recycled paper, in line with China's green production road to protect the environment.

3. In the present invention, a crushing and deinking machine is used to crush the paper into flocculent paper dust, and the ink on the paper is detached from the paper fiber, so that there is no need to use warm water to soak the paper dust and add chemicals to perform the deinking process. No pollution to the environment due to waste liquid.

4. The present invention uses a deinking crusher to crush waste paper. Its T-shaped hammers ease the speed of air circulation in the casing, reduce the impact on light and fine flocculent paper scraps, and improve the crushing efficiency.

5. The method for preparing recycled paper of the present invention can recycle and remanufacture waste paper in situ, which consumes less time and has a lower price. It can reuse waste paper and reduce the use of tree materials. It is environmentally friendly and convenient, and the process of manufacturing recycled paper For waterless recycled paper, a series of heavy pollution processes such as beating and waste disposal of traditional papermaking are reduced, green printing is achieved, papermaking is clean, it is beneficial to protect the ecological environment, and the papermaking process is reduced.

6. The papermaking process of the present invention eliminates the use of water, omits the beating process, and achieves zero pollution and zero emissions; and the prepared recycled paper can be used to manufacture cardboard and carton; packaging paper bags; newsprint and other products.

7. The recycled paper of the present invention is made from waste paper, in which 80% of the raw materials come from recycled waste paper. Since there is no need to add any whitening agent, fluorescent agent and other chemicals in the process of manufacturing recycled paper, it can more show the true color of the paper, and because the recycled paper produced is not reflective, it is more conducive to protecting eyesight. In addition, no deinking treatment is needed for water in the manufacturing process, reducing the generation of waste liquid, reducing environmental pollution, and reducing the consumption of trees, which is conducive to the protection of the ecological environment.

BRIEF DESCRIPTION

Figure 1 is a process flow diagram of the preparation of recycled paper of the present invention;

2 is a schematic structural view of a crushing and deinking machine of the present invention;

3 is a schematic diagram of the relative position of the cutting blades on the two rotating shafts of the crushing and deinking machine of the present invention;

4 is a schematic view of the nozzle of the crushing and deinking machine of the present invention installed on the casing;

5 is a schematic structural view of a pair of rotors of the crushing and deinking machine of the present invention and the rotors provided with hammers;

6 is another schematic structural view of the crushing and deinking machine of the present invention;

7 is a flow chart of the crushing and deinking process of waste paper by using the crushing and deinking machine of the present invention.

detailed description

The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments. The advantages and features of the present invention will become more clear as the description proceeds. However, these examples are only exemplary and do not limit the scope of the present invention. Those skilled in the art should understand that the embodiments of the present invention are not limited to this, and the details and forms of the technical solutions of the present invention can be modified or replaced without departing from the spirit and scope of the present invention, but these modifications and replacements all fall within Within the protection scope of the present invention.

Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

Unless otherwise specified, the materials, reagents, equipment, and instruments used in the following examples can be obtained from commercial sources. In the embodiment of the present invention, the waste paper comes from a waste paper recycling station.

As shown in Figure 1, the preparation process of recycled paper of the present invention: firstly, the collected waste paper is crushed and deinked by a crushing and deinking machine, and the flocculent dry fiber is prepared by filtration and sieving, and then the papermaking is sprayed into the flocculent dry fiber Using an adhesive, a flocculent fiber-adhesive mixture is prepared; then the flocculent fiber-adhesive mixture is sequentially rolled and dried to obtain a recycled paper.

As shown in FIG. 2, the crushing and deinking machine of the present invention includes: a casing; a coarse pulverizing assembly 1 installed on the casing for cutting waste paper into the casing; mounted on the casing and located in the coarse Punching assembly 4 below the crushing assembly 1 for preventing the clogging of the coarse crushing assembly 1; installed on the cabinet and below the punching assembly 4 for crushing the paper pieces into flocculent scraps and separating the scraps and scraps The crushing and deinking assembly 7 of the ink; the receiving assembly 10 installed on the casing and located below the crushing and deinking assembly 7, has a filter screen 9 for filtering the flocculent paper dust and a filter screen for filtering the floc under the filter screen状纸碎的Screen网 11.

Among them, the casing includes: a coarse crushing chamber casing, which is a cylindrical upper cylindrical casing 13, and a paper inlet for waste paper is opened at an upper portion thereof; a crushing and deinking chamber casing includes: The upper narrow, lower wide upper conical shell 14 connected to the bottom of the cylindrical shell 13, the lower cylindrical shell 15 whose top is connected to the bottom of the upper conical shell 14, the top thereof and the bottom of the lower cylindrical shell 15 Connected upper wide and lower narrow lower conical shell 16, wherein the pipe 12 of the receiving device 10 is connected to the bottom of the lower conical shell 16, in design, it can be set at the outlet of the lower cylindrical shell 15 Open or close the outlet baffle (not shown).

The coarse crushing assembly 1 is installed in the upper cylindrical casing 13 of the casing, which includes: at least two rotating shafts 2 which are rotatably installed in the upper cylindrical casing 13 and extend in the horizontal direction; A plurality of paper cutting blades 3 on the rotating shaft; among them, the paper cutting blades on the two adjacent rotating shafts are arranged in a misaligned manner. In addition, it also includes a driving mechanism installed in the upper cylindrical housing and connected to the rotating shaft for driving the rotating shaft to rotate. The driving mechanism may use a motor to drive a gear set mechanism or other mechanisms in the prior art, which is not correct here. Its structure is described.

In application, there may be two or more rotating shafts installed in the upper cylindrical housing 13. In the specific embodiment of the present invention, two parallel rotating shafts 2 that are parallel to each other are used as an example to describe the structure.

A plurality of cutting blades 3 are installed on the two rotating shafts 2 at intervals (in FIG. 2, five cutting blades are installed on one rotating shaft and four cutting blades are installed on the other rotating shaft), and the cutting blades 3 are round Disc-shaped, the outer edges are provided with cutting teeth along the circumferential direction, as shown in Figure 3, and the center distance between the cutting blades on the two rotating shafts is smaller than the diameter of the outermost edges of the two cutting blades. When assembling, in order to avoid the interference of the paper cutting blades on the two rotating shafts, the paper cutting blades on the two rotating shafts are misaligned along the axial direction of the respective rotating shafts, that is, from the axial view of a pair of rotating shafts, the The cutting blade on one shaft is located between the two cutting blades on the other shaft.

A coarse crushing assembly 1 is provided below the feed opening of the upper cylindrical housing 13, and when waste paper (ie, waste paper) is thrown in through the feed opening, the waste paper will be shredded under the action of the cutting blade of the coarse crushing assembly The paper sheet ((1-5) mm×(1-5) mm, preferably 5 mm×5 mm) is advantageous for the next crushing of the paper sheet by the crushing and deinking device 7 to improve production efficiency.

After the waste paper is cut into pieces by the cutting blade, in order to prevent the cut pieces of paper from clogging the cutting blade, a punching assembly 4 for preventing clogging of the coarse crushing assembly is provided below the coarse crushing assembly. At least one pair of spray heads 42 on both sides of the inner wall of the upper cylindrical housing, and the air outlets of the pair of spray heads are arranged to face each other obliquely upward, and are respectively aligned with the two rotating shafts or the positions between the two rotating shafts, as shown in FIG. 2.

As shown in FIG. 4, the spray head 42 is made of a material with elasticity, and the spray head shell 41 is clamped on the outside, and the spray head shell is installed on the inner wall of the upper cylindrical shell by bolts, and the air inlet of the spray head is provided on the upper cylindrical shell The air outlet of the small hair dryer (including motor and fan blade) is connected. After the coarse crushing component cuts the waste paper into paper pieces, the blower is energized, and its motor drives the fan blades to generate a certain intensity of airflow. The airflow enters through the air inlet of the nozzle and is blown out diagonally upward from the air outlet, so that Cut into pieces of paper to prevent the cutting blade from clogging.

The paper sheet cut by the coarse crushing assembly falls down into the shell of the crushing and deinking assembly under the action of gravity, so that the crushing and deinking assembly 7 can perform secondary crushing treatment on the paper sheet And deinking treatment.

Among them, a part of the crushing and deinking assembly 7 is placed in the upper conical shell 14 and the other part is placed in the lower cylindrical shell 15 to facilitate the overall reception of the paper pieces falling down from the upper cylindrical shell to fully prevent paper The piece clogs the upper cylindrical housing.

As shown in FIG. 2, the crushing and deinking assembly 7 includes: a pair of rotors 8 installed side by side at a horizontal position where the upper conical housing 14 and the lower cylindrical housing 15 are connected, and the central axis of the rotor 8 is different from the central axis of the rotating shaft 2 The surface is vertical; the multiple rows of hammers 6 that are placed on the outer wall of each rotor to crush the paper into flocculent scraps; connected to a pair of rotors respectively to drive a pair of rotors to rotate at a high speed to separate the flocculent scraps and A rotary drive mechanism for ink on paper scraps (not shown in the figure). The rotary drive mechanism can use a prior-art rotary mechanism, such as a motor-driven mechanism, to transmit its output power to a pair of rotors, respectively. The rotors rotate toward each other, for example, the rotor on the left in FIG. 2 rotates clockwise, and the rotor on the right rotates counterclockwise, so that the hammer 6 crushes the paper into fluffy paper dust.

As shown in Figures 2 and 4, multiple rows of hammers are fixedly installed on the outer wall of the rotor in the embodiment of the present invention (four rows of hammers in this embodiment), each row of hammers includes a plurality of spaced apart along the axial direction of the rotor Hammer. The hammers on a pair of rotors are misaligned, and there is a gap between the ends of opposite rotors on a pair of rotors, as shown in Figure 5, that is, the sum of the distances from the end faces of the hammers of the two rotors to the axis is less than two The distance between the axes of the two rotors prevents the two rotors from vibrating during the high-speed rotation and crushing of the paper. The hammers on the pair of rotors will cause mechanical collisions, and the ends of the pair of rotors opposite the hammers There is a gap of 0.2-0.4cm, preferably 0.2mm, (usually the hammers are staggered, regardless of the hammer head gap, but the paper is flammable, and there is a certain gap between the hammer heads), that is, the relative hammer The gap between the ends of the tangential section is 0.2-0.4cm, preferably 0.2mm (usually the hammers are staggered, regardless of the gap, but the paper is flammable, and there is a certain gap between the hammers).

The hammer adopts T-shaped hammer, which includes a radial segment extending in the radial direction of the rotor and a tangential segment extending in the tangential direction of the rotor. The inner end of the radial segment is fixedly installed on the outer wall of the rotor. The center and diameter of the tangential segment Connect to the outer end of the segment. The use of T-shaped hammer blades can reduce the leakage of the formed flocculent scraps in the process of crushing the papers, thereby preventing the flocculent scraps from damaging the rotor and the motor. In addition, the use of a pair of rotors to drive the T-shaped hammer blades to rotate at high speed can crush the waste paper strips into deinked flocculent paper scraps, alleviating the speed of air circulation in the crushing and deinking chamber, and reducing the impact on light and fine paper scraps. Improving crushing efficiency, greatly improving production efficiency, improving product quality, and breaking the traditional waste paper recycling method are innovative applications that have never been used in the field of shredders or even waste paper recycling.

The distance between two adjacent hammers on the same rotor in the axial direction is 0.8-1.2 cm, preferably 1 cm. The radial section of the T-shaped hammer piece has the same shape and size as the tangential section; and the width of the radial section of the T-shaped hammer piece in the axial direction of the rotor is 0.6-1.5 cm, preferably 1.2 cm. The rotation speed of the rotor is ≥3000 rpm, preferably ≥7000 rpm, and more preferably 7000-15000 rpm.

After the waste paper fragments crushed by the coarse crushing component flow into the crushing and deinking component, the rotating mechanism of the crushing and deinking component 7 drives the rotor and the T-shaped hammer to rotate and cut the paper at high speed, and the paper is crushed by the high speed impact of the hammer and the paper The flakes are crushed into flocculent scraps (size range ≥ 1.0mm, preferably 1.1-1.2mm), at the same time, the ink on the waste paper strip is peeled off under the impact of the T-shaped hammer, and the rotor and T-shaped hammer are high-speed Under the action of rotating centrifugal force, the ink is separated from the paper (rotor speed ≥3000rpm). Because the mass of the ink itself is greater than the mass of the paper scraps, the centrifugal force is thrown on the inner wall of the upper conical shell, the lower cylindrical shell or remains on the T-shaped hammer, and the paper scraps fall down under the action of gravity. When the flocculent dry fiber material (ie, flocculent scraps) dropped into the lower cylindrical housing 15 accumulates a certain amount, the baffle plate is opened, and the scraps are collected and discharged through the collecting assembly 10, and thrown to the upper conical shell The ink on the inner wall of the body and the lower cylindrical shell can be periodically processed manually.

In the existing waste paper recycling process, paper beating is used for deinking. The present invention uses a crushing deinking section to directly process waste paper into deinked flocculent scraps, eliminating the need for paper beating, thereby reducing the use of waste paper The papermaking process steps are carried out, and because there is no paper beating process, a large amount of waste pulp and waste liquid will not be generated, thereby avoiding pollution to the environment.

Because the two rotors rotate to crush the paper at high speed, a crushing vacuum area without squeezing force will be formed between the opposing T-shaped hammers of a pair of rotors, and in order to prevent the paper falling from the coarse crushing chamber from falling into the crushing vacuum In the area, between the coarse crushing chamber and the crushing deinking chamber, a material guide assembly 5 for guiding the falling direction of the paper sheet is provided. The material guide assembly 5 includes its top and the upper cylindrical shell and/or upper cone The inverted V-shaped baffle of the reversed V-shaped baffle (as shown in FIG. 2) is hinged, and the extending direction of the hinged edge of the inverted V-shaped baffle used to be hinged with the housing and the rotor of the crushing deinking assembly The direction of the central axis is parallel.

The inverted V-shaped baffle is installed directly above the pair of rotors, and the paper after primary crushing by the coarse crushing assembly is guided along the slope of the inverted V-shaped plate into the crushing deinking chamber to avoid crushing falling between the pair of rotors Vacuum zone, which improves crushing efficiency.

The material guide assembly 5 of the present invention may also adopt a triangular plate. As shown in FIG. 6, the top of the triangular plate is hinged with the upper cylindrical shell and/or the upper conical shell. Similarly, the hinged edge of the triangular plate is used to hinge with the shell. The extending direction is parallel to the central axis direction of the rotor of the crushing deinking assembly.

The use of a triangular plate, in addition to guiding the paper to the direction of crushing and deinking chamber, the bottom plate opposite to the top can also destroy the annular throwing ring formed by the paper under the action of the rotor, preventing paper or paper scraps and hammers The pieces produce opposite movement, which improves the hammer's impact on the paper or paper scraps, and is more conducive to the separation of the ink on the paper or paper scraps.

The crushed and deinked paper dust from the crushing and deinking assembly 7 falls down and is collected and discharged by the collecting assembly 10. The receiving assembly includes: a screen 9 installed in the lower cylindrical housing 15 and below the pair of rotors 8; a screen 11 below the screen 9 for screening paper dust; and a paper dust for deinking Discharged duct 12; a blower (not shown in the figure) connected to the duct 12 for discharging the paper dust that has fallen out after screening.

The filter screen 9 is an arc filter screen with an arc shape adapted to the outer contours of the pair of rotors 8, the periphery of the filter screen is fixed to the inner wall of the lower cylindrical housing 15, and the filter 9 is filtered and crushed and deinked by the crushing and deinking assembly The resulting flocculent paper dust causes paper dust with a size smaller than or equal to the mesh diameter to fall through the filter onto the screen, and paper dust with a size larger than the diameter of the filter mesh is repeated by a pair of rotors and T-shaped hammers on the rotor Crushing, in the process of crushing the paper strip, the filter screen also plays the role of rubbing and shearing the paper strip, the pore size of the filter screen is 14-16 mesh; at the same time, it is necessary to control the tangential section of the hammer on the rotor and the filter screen The gap between them is ≤8mm, preferably 6-8mm, further preferably 8mm), the paper is lighter and not easy to fall during the crushing process.

The screen is fixed to the connection between the lower cylindrical shell 15 and the lower conical shell 16, and the screen aperture is 16-20 mesh. When selecting the aperture of the screen, it should be selected according to the actual situation to prevent the flocculent scraps of paper strips from clogging the screen. If a baffle plate is provided below the crushing and deinking chamber, the baffle plate can be placed above the screen, under the filter screen, or the baffle plate can be placed under the screen. After the paper pieces are crushed, the baffle is opened to allow the paper scraps to fall down into the lower conical shell 16, and the paper scraps are drawn away through the duct 12 under the action of a blower (not shown) To complete the layout.

During design, the cutting blade of the coarse crushing component and the inner wall of the cabinet can be coated with anti-static fluorine coating to prevent static electricity, so as to prevent paper pieces or paper scraps from sticking to the inner wall of the cabinet and minimize the paper Material sticky phenomenon. In addition, wear-resistant materials can also be coated on the inner wall of the cabinet to reduce the noise when the equipment is working.

It should be noted that in the papermaking process, spraying papermaking adhesive sizing treatment, rolling treatment, and drying treatment can be carried out by spraying, rolling, and drying methods in the prior art, so each treatment is not carried out here. Methods and steps are described in detail.

The process of using a crushing and deinking machine to crush and deinking waste paper to make recycled paper is as follows:

1. Waste paper crushing-deinking treatment

As shown in Figure 7, the recovered waste paper (such as waste office paper) is put between the two rotating shafts through the feed inlet, and the waste paper is cut into shredded paper pieces through a plurality of cutting blades arranged on a pair of rotating shafts, The size of the shredded paper is ((1-5) mm×(1-5) mm).

After the waste paper is cut into several small pieces of paper, the paper cutting blade is cleaned by the paper punching assembly located below the coarse crushing assembly to prevent the cutting blade from being blocked by the small pieces of paper.

The shredded paper pieces processed by the coarse crushing assembly drop into the crushing deinking assembly under the action of gravity, and then crushed and deinked again by the crushing deinking assembly. During the process, the rotor and the T-shaped hammer (the hammer is the blade) , T-shaped) high-speed rotation cutting paper, through the high-speed impact of the hammer and the paper to crush the paper into flocculent scraps (ie flocculent dry fiber material), while separating the ink from the paper.

The paper dust that has been crushed and deinked by the rotor and T-shaped hammer is filtered through a filter screen. After the screen is sieved, the flocculent dry fibers with a length of 1.0mm to 1.2mm are collected to prepare deinked flocculent dry fibers; crushed- When a certain amount of flocculent dry fiber material accumulates after deinking, it passes through the screen and enters the lower conical shell (that is, storage bin) under the action of the blower, and is discharged through the pipeline for further processing.

2. Sizing treatment

Spray the atomized paper-making adhesive on the de-flocked dry fibers and mix them evenly to make a fiber-adhesive mixture;

3. Suppression processing

The fiber-adhesive mixture is rolled twice, the first rolling process is rough pressing, so that it initially takes the form of paper and slightly removes water, and the rolling thickness during the first rolling process is the thickness of the paper 1.2-1.8 times (preferably 1.5 times); the second rolling treatment is squeezing to obtain semi-finished paper with a moisture content of 10-15%, at this time the semi-finished paper is dark white. During the rolling process, the surface of the roller is coated with tetrafluoroethylene coating to prevent sticking.

4. Drying treatment

Drying the semi-finished recycled paper, usually by high temperature drying, vacuum drying, UV photothermal drying, etc., to obtain finished recycled paper.

The paper rolling treatment methods known in the art are all applicable to the present invention; the methods used for drying the paper are all applicable to the present invention.

The raw material used in the recycled paper of the present invention is waste paper. After being crushed and deinked by the crushing and deinking machine of the present invention, a 16-20 mesh screen is also used to sieve the crushed paper scraps and collect 1.0mm-1.2 mm-length flocculent inkless dry fiber. It reduces the use of tree materials and helps protect the ecological environment. The formed flocculent dry fiber can be used in the manufacture of daily office paper: using related equipment to crush the waste paper into flocculent dry fiber, and spray-type glue to bond, and then realize anhydrous papermaking. This papermaking technology uses waste paper that has been used in the production process, which reduces the use of tree materials and is beneficial to the protection of the ecological environment.

Drying treatment of paper semi-finished products can remove three types of water from paper, one is free water, one is water in fiber tube, and the other is combined water. Rolling treatment can remove part of free water and fiber tube The remaining water is completed by drying.

Example 1

1. Preparation of flocculent dry fiber

Put the waste paper from the feed port of the recycled paper crushing and deinking machine, and carry out preliminary crushing in the coarse crushing unit of the crushing and deinking machine to make the size 5mm×5mm (usually (1-5)mm×(1- 5) mm) shredded paper, then enter the crushing and deinking assembly under the action of gravity, cut the shredded paper under the high-speed rotation of the rotor and T-shaped hammer, and crush the paper into a high-speed impact of the hammer and the paper Flocculent paper dust (i.e., flocculent dry fiber material), at the same time, the ink is separated from the paper sheet, and deinking treatment is carried out, in which the rotor speed is controlled to 8000rpm (usually ≥7000rpm, preferably 7000-15000rpm); The gap between two adjacent rows of T-shaped hammer pieces in the axial direction is 1.0cm (usually 0.8-1.2cm); the radial section of the T-shaped hammer piece has the same shape and size as the radial section, and the radial section is along The width of the rotor in the axial direction is 1.2cm (usually 0.6-1.5cm); the gap between the ends of the pair of rotors on the opposite hammers is 0.2cm (usually 0.2-0.4cm, usually because the hammers are staggered) , The gap is not considered, but the paper is flammable, and there is a certain gap between the opposite hammers), that is, the gap between the ends of the tangential segments of the opposite hammers is 0.2cm (usually 0.2-0.4cm, usually because of The hammers are staggered and the gap is not considered, but the paper is flammable, and there is a certain gap between the hammers. At the same time, the gap between the tangential section of the hammers on the rotor and the filter screen needs to be controlled to 8mm (usually (Less than 8mm, preferably 6-8mm), the paper is light and not easy to fall, in the crushing process.

It is then filtered through a filter screen (the filter screen has a pore size of 14-16 mesh), then passes through a screen with a pore size of 16 mesh (usually 16-20 mesh), and the flocculent paper dust is sieved to obtain a length of 1.0-1.2 mm (usually the length of the flocculent dry fiber ≥ 1.0mm, preferably 1.0-1.2mm), the flocculent dry fiber of the waste paper, used;

The advantage of flocculent dry fiber is that it has a good capture of the water-starch glue mist system used in the anhydrous papermaking process. 1.0mm is the lower limit of the waste paper fiber bonding length, because the focus of the flocculent dry fiber is on the flocculent, that is, there are many soft hairs on the main fiber, which can capture the misty tiny colloidal particles, based on the principle of surface area effect (The more the same volume of material is dispersed, the greater the surface area), the smaller the flocculent dry fiber, the better the capture of colloidal particles, so 1.0mm-1.2mm length of fiber is used.

2. Preparation of adhesive solution

Add glutinous rice glue to distilled water and stir until the final formation of a stable and stable paper-making adhesive solution (ie glutinous rice glue-water mixture) without obvious lumps, in which the quality of glutinous rice glue and water The ratio is 1:16 (usually 1:14-20) and then the paper-made adhesive solution is poured into the atomization bottle and set aside.

Glutinous rice glue belongs to starch glue, and starch is divided into two types, amylose and amylopectin. For a certain type of starch glue, the higher the content of amylopectin, the stronger the viscosity, and the stickiness in glutinous rice glue The amylose content is above 90%, the highest content in natural starch-like gums, and environmentally friendly.

In the embodiment of the present invention, only glutinous rice glue is used as an example for description, and other starch adhesives such as corn glue and other solid glues are suitable for the present invention.

3. Sizing treatment

The flocculent waste paper dry fiber sieved through the screen of the crushing and deinking section is transported to the atomizing chamber through a conveyor belt, and the atomized papermaking adhesive solution (glutinous rice glue) is sprayed into the flocculent dry fiber in the atomizing chamber -Water mixture), spray sizing, the mass ratio of flocculent dry fiber to glutinous rice glue-water mixture is 100:1 (usually 100:0.5-1.2), the paper will be lifted by misty glutinous rice glue-water mixture The fiber tape falls and mixes with the paper dry fiber until a paste-like paper fiber-adhesive mixture is formed.

4. Suppression processing

The paste paper fiber-adhesive mixture is transported between two sets of rollers through a conveyor belt, and is subjected to two rolling treatments. After the two rollers are rolled, the first roller is used for preliminary paste Press to make it take the form of paper and remove water slightly. The gap of the first set of rollers is 1.5 (usually 1.2-1.8 times) the thickness of the resulting paper, and the thickness of the paper is 1.5 (usually 1.2-1.8) times thick. The second group of rolling rollers is precision pressing, that is, the second group of rolling rollers is used for the second rolling of the rough pressed paper blanks to obtain paper semi-finished products with a moisture content of 10-15%.

The pressing process is divided into two rolling processes. The first rolling process is rough pressing, which means that the paste is initially pressed to make it take the form of paper and remove water slightly, and the gap between the rollers is 1.5 of the thickness of the resulting paper (usually (1.2-1.8 times) times; two times of rolling and compacting to obtain semi-finished paper with a moisture content of 10-15%, at this time the semi-finished paper is dark white. The surface of the conveyor belt and roller is coated with tetrafluoroethylene coating to prevent sticking.

5. Drying treatment

The dark white semi-finished paper is transported to the drying section through the conveyor belt of the conveying section for vacuum drying, the drying temperature is 40-50°C, the vacuum degree is controlled to -0.0075～-0.1MPa during the drying process, and the drying time is 15s-20s.

It is continuous drying during operation, with an operating cycle of 5-7min and a cycle of 15-20 sheets of recycled paper until the paper color is bright white. Turn off the dryer and the paper preparation is completed.

Drying treatment In addition to vacuum drying treatment, other conventional drying methods, such as atmospheric high temperature drying, UV photothermal drying, etc., are suitable for the present invention.

The sizing treatment, pressing treatment and drying treatment of the present invention can adopt the methods of sizing, pressing and drying treatment currently known in the art, respectively, which are all applicable to the present invention.

The brightness, smoothness and transverse folding resistance of the prepared recycled paper were measured according to the national standard method. The measurement results are shown in Table 1, where:

The brightness of the recycled paper is measured according to the national standard "Determination of the Blue Light Diffuse Reflectance Factor D65 for Paper, Paperboard and Pulp (GB/T 7974-2013) (Diffuse/Vertical Method, Outdoor Daylight Conditions)" method;

The smoothness of recycled paper is measured according to the national standard "Determination of Smoothness of Paper and Paperboard (GB/T 456-2002) (Buick Method)";

The horizontal folding endurance of recycled paper is measured according to the national standard "Determination of folding endurance of paper and paperboard GB/T 457-2008";

The tightness of recycled paper usually refers to the quality of 1 cubic meter of paper or cardboard, also known as the apparent density; the specific measurement method is as follows: randomly select ten papers from the prepared paper and use an electric thickness gauge to measure the thickness of each paper Record with numbers; measure the corresponding mass of each paper with an electronic balance; then. According to the standard surface area of the prepared paper, divide the mass of the paper by the product of the thickness of the corresponding paper and the surface area and obtain the average of the tightness of the paper. Value, the measurement results are shown in Table 1;

The tensile strength of the recycled paper is measured by a tensile strength testing machine. The tensile strength tester stretches the specimen of the specified size to break under the condition of constant speed loading and measures its tensile strength. Record the maximum elongation at break and calculate the tensile (tensile) strength. The measurement results are shown in Table 1;

The surface strength of the recycled paper is determined by the IGT printing suitability tester and wax stick, according to the drawing speed measurement method and the wax stick method.

The thickness of the recycled paper was measured using an electric thickness gauge, and the measurement results are shown in Table 1.

Table 1 Performance test results of prepared recycled paper

Indicator name	standard regulation	The measurement results
Whiteness (%) ≥	70.0	71.2
Smoothness (both positive and negative) (S) ≥	20	21.62
Tightness (g/cm 3 )	0.80±0.10	0.802
Thickness (mm)	0.09±0.005	0.093

Claims (10)

1. A method for preparing recycled paper is characterized by the following steps:

   1) The waste paper is crushed and deinked at the same time to make flocculent dry fiber to remove printing ink;

   2) Spray the papermaking adhesive solution into the flocculent dry fiber to make a paper fiber-adhesive mixture;

   3) Pressing and drying the paper fiber-adhesive mixture in sequence, that's it.
2. The preparation method according to claim 1, wherein the length of the flocculent dry fiber in step 1) is ≥ 1.0 mm.
3. The preparation method according to claim 1 or 2, wherein the crushing and deinking treatment is performed on the waste paper by using a crushing and deinking machine, wherein the crushing and deinking machine includes: a casing; Coarse crushing assembly on the casing for cutting waste paper into the casing; paper punching assembly installed on the casing and located below the coarse crushing assembly to prevent clogging of the coarse crushing device; installed on the casing A crushing and deinking assembly on the lower part of the punching assembly for crushing the paper into flocculent scraps and separating the scraps and the ink on the scraps; a collecting assembly installed on the cabinet and below the crushing and deinking device It has a filter screen for filtering the flocculent paper dust and a screen for screening the flocculent paper dust under the filter screen.
4. The preparation method according to claim 3, wherein the crushing and deinking assembly comprises: a pair of rotors mounted side by side on the casing with a center axis perpendicular to the center axis of the rotating shaft; A plurality of rows of hammers on the outer wall of each rotor for crushing the paper into flocculent scraps; connected to a pair of rotors for driving a pair of rotors to rotate at a high speed to separate the flocculent scraps and the ink on the scraps Rotary drive mechanism.
5. The preparation method according to claim 3 or 4, characterized in that the multiple rows of hammers on the rotor respectively include a plurality of hammers arranged at intervals along the axial direction of the rotor, and the hammers on a pair of rotors are arranged out of position .
6. The preparation method according to claim 5, wherein the distance between two adjacent rows of hammers arranged on the axis of the rotor is 2-5 cm.
7. The preparation method according to claim 3 or 4, wherein the rotation speed of the rotor is controlled to be ≥3000 rpm during the crushing and deinking process.
8. The preparation method according to claim 1 or 2, wherein the adhesive for papermaking in step 2) is starch glue.
9. The preparation method according to claim 1 or 2, wherein the mass ratio of the flocculent dry fiber to the adhesive solution for papermaking in step 2) is 100: 0.5-1.2.
10. The preparation method according to claim 1 or 2, characterized in that, in step 3), the pressing process is divided into two rollings, and the first rolling is made into paper with a thickness 1.2-1.8 times the thickness of the finished paper Rough blank; The second rolling is to roll the rough blank of the paper after the first rolling into a semi-finished paper with a moisture content of 10-15%.

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