Toughened water-washed kraft paper hangers and methods of making the same

Abstract

The application discloses a strong and tough water-washed kraft paper hook and a preparation method thereof. The hook comprises two hook plates outwardly extending from the top of a packaging box and two connecting plates fixedly connected with the inner wall of the top of the packaging box. The two hook plates are symmetrically and integrally connected with each other and are foldably arranged. Hook holes are formed in the two hook plates. The two hook plates are fixedly connected through a first adhesive layer after being folded. The two hook holes are in communication with each other. Each hook plate comprises a first outer layer and a first inner layer. The two connecting plates are symmetrically and integrally connected with the outer ends of the two hook plates. The two connecting plates are foldably arranged relative to the two hook plates. The hook is made of the water-washed kraft paper material of the application and the structure and the preparation method of the application. The hook has high toughness and high bearing capacity. The hook does not need to be laminated with multiple paper sheets, the material loss is small, the production efficiency is high, and the production operation is facilitated.

Description

Technical Field

[0001] The present invention relates to the field of packaging box accessories, and in particular to a strong and tough washed kraft paper hook and a preparation method thereof. Background Art

[0002] A box hook is a device designed to hang or secure items on a box. These hooks can be easily integrated into various boxes, such as gift boxes, express boxes, and storage boxes, providing added convenience when carrying, storing, or displaying items. Adding a hook to a gift box allows users to hang gifts on doorknobs, tree branches, or other fixed points, enhancing their presentation. Hooks on express boxes can be used to hang shopping bags and small items, making them easier to organize and carry. Hooks on storage boxes can be used to hang items such as clothing, hats, and scarves, saving space and improving storage efficiency. Hooks on display boxes can be used to hang small trinkets, keychains, and other items, increasing the appeal and visibility of the products.

[0003] To ensure the load-bearing capacity of hooks, plastic hooks were previously common. However, due to environmental protection requirements, paper hooks are now commonly used to replace plastic hooks. However, the load-bearing capacity of paper hooks is closely related to the thickness of the paper. To achieve high strength, multiple layers of paper must be laminated. This method not only results in high waste but also inefficient production. Therefore, it is necessary to develop a solution to this problem. Summary of the Invention

[0004] In view of this, the present invention aims to address the deficiencies in the prior art, and its main purpose is to provide a strong washed kraft paper hook and a preparation method thereof, which can effectively solve the problems of large loss and low efficiency in the production of existing paper hooks.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A strong and tough washed kraft paper hook, comprising two hook plates extending outward from the top of the packaging box and two connecting plates fixedly attached to the top inner wall of the packaging box;

[0007] The two hook plates are symmetrical and integrally connected to each other, and the two hook plates are foldably arranged. Both hook plates are provided with hook holes. After folding, the two hook plates are bonded and fixed by a first adhesive layer, and the two hook holes are directly connected to each other. Each hook plate includes a first outer layer and a first inner layer. The first outer layer is made of washed kraft paper. The first inner layer is inlaid and fixed in the first outer layer. The first inner layer is made of carbon fiber.

[0008] The two connecting plates are symmetrical to each other and are integrally connected to the outer ends of the two hook plates. The two connecting plates are bendably arranged relative to the two hook plates. A second adhesive layer is provided on the surface of each connecting plate. Each connecting plate includes a second outer layer and a second inner layer. The second outer layer is made of washed kraft paper and is integrally connected to the first outer layer. The second inner layer is inlaid and fixed in the second outer layer. The second inner layer is made of carbon fiber and is separated from the first inner layer.

[0009] The washed kraft paper material includes the following raw materials in parts by weight:

[0010] 55-70 parts of long fiber wood pulp; 35-45 parts of short fiber wood pulp; 15-18 parts of synthetic fiber; 20-25 parts of cotton pulp; 4-5 parts of wet strength agent; 2-3 parts of water repellent; 0.8-1.2 parts of dispersant; 25-30 parts of filler.

[0011] As a preferred solution, the long-fiber wood pulp is coniferous wood pulp, the short-fiber wood pulp is broadleaf wood pulp, and the synthetic fiber is aramid fiber or polyvinyl alcohol fiber.

[0012] As a preferred embodiment, the wet strength agent is polyamide polyamine epichlorohydrin.

[0013] As a preferred solution, the water repellent is an alkyl ketene dimer.

[0014] As a preferred solution, the dispersant is sodium polyacrylate.

[0015] As a preferred solution, the filler is calcium carbonate.

[0016] As a preferred solution, the inner sides of the two hook plates are coated with a first adhesive layer, and after folding, the two first adhesive layers are bonded and fixed together.

[0017] As a preferred solution, the width of the connecting plate is greater than the width of the hook plate, and the inner middle portion of the connecting plate is integrally connected to the outer end of the hook plate to form a T-shaped structure.

[0018] A method for preparing a strong, washed kraft paper hook comprises the following steps:

[0019] (1) Beating: Long-fiber wood pulp, short-fiber wood pulp, and cotton pulp are respectively put into respective beating equipment for beating treatment, and the beating degree of long-fiber wood pulp is controlled at 30-40°SR, and the beating degree of short-fiber wood pulp is controlled at 40-50°SR; and the synthetic fiber is separately opened to make it fully dispersed, and then uniformly mixed with the beaten long-fiber wood pulp, short-fiber wood pulp, and cotton pulp according to a proportion;

[0020] (2) Slurry preparation: Add an appropriate amount of water to the slurry preparation tank, turn on the stirring device, dissolve the dispersant in the water first to form a uniform dispersion, then add the mixed fiber slurry, wet strength agent, water repellent and filler in sequence, and continue stirring for 30-60 minutes to ensure that all ingredients are fully mixed and evenly formed to form a stable pulp suspension;

[0021] (3) Papermaking: The prepared pulp suspension is evenly sprayed onto the papermaking wire through the headbox. During the spraying process, multiple pieces of uncured carbon fiber cloth that have been cut are placed. Then, the forming device of the papermaking machine is used for preliminary dehydration and forming to form a wet paper sheet. Then, the wet paper sheet is passed through the pressing section to further remove moisture through mechanical pressure. During the pressing process, the pressure is controlled at 5-10 MPa.

[0022] (4) Drying: After being pressed, the paper sheet enters the drying section and is dried by steam heating or hot air drying. The drying temperature is controlled at 125-140°C. At the same time, the uncured carbon fiber cloth is cured by heat to form the first inner layer and the second inner layer.

[0023] (5) Post-processing: The dried paper is calendered as needed, and the calendering pressure is controlled at 10-20 MPa;

[0024] (6) Cutting: Cutting the paper to form two hook plates and two connecting plates connected in one piece;

[0025] (7) Gluing: applying glue on corresponding positions of the two hook plates and the two connecting plates to form a first glue layer and a second glue layer;

[0026] (8) Folding and forming: fold the two hook plates and fix them together through the first adhesive layer, and bend the two connecting plates relative to the two hook plates respectively, so that the two connecting plates extend horizontally and the two hook plates extend vertically.

[0027] Compared with the prior art, the present invention has obvious advantages and beneficial effects. Specifically, it can be seen from the above technical solution that:

[0028] By adopting the washed kraft paper material of the formula of the present invention and cooperating with the structure and preparation method of the present invention to produce a hook, the hook has strong toughness and effectively improved load-bearing capacity. There is no need to mount multiple layers of paper, the material loss is small, and the production efficiency is high, which brings convenience to production operations.

[0029] In order to more clearly illustrate the structural features and effects of the present invention, the present invention is described in detail below with reference to the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a three-dimensional diagram of a preferred embodiment of the present invention before it is folded;

[0031] Figure 2 It is a three-dimensional view from another angle of the preferred embodiment of the present invention before being folded;

[0032] Figure 3 It is a three-dimensional diagram of the folding process of the preferred embodiment of the present invention;

[0033] Figure 4 This is a three-dimensional diagram of the preferred embodiment of the present invention after folding;

[0034] Figure 5 It is a cross-sectional view of a preferred embodiment of the present invention after folding.

[0035] Description of the accompanying drawings:

[0036] 10. Hook plate 11. First outer layer

[0037] 12. First inner layer 101, hook hole

[0038] 20. Connecting plate 21. Second outer layer

[0039] 22. Second inner layer 31. First adhesive layer

[0040] 32. Second adhesive layer. DETAILED DESCRIPTION

[0041] Please refer to Figures 1 to 5 As shown, it shows the specific structure of a strong washed kraft paper hook of a preferred embodiment of the present invention, including two hook plates 10 extending outward from the top of the packaging box and two connecting plates 20 fixed to the top inner wall of the packaging box.

[0042] The two hook plates 10 are symmetrical and integrally connected, and are foldable. Each hook plate 10 is provided with a hook hole 101 in the shape of an isosceles triangle. When folded, the two hook plates 10 are bonded together by a first adhesive layer 31, with the two hook holes 31 facing each other and connected. Each hook plate 10 comprises a first outer layer 11 and a first inner layer 12. The first outer layer 11 is made of washed kraft paper, and the first inner layer 12 is embedded and fixed within the first outer layer 11. The first inner layer 12 is made of carbon fiber and serves to enhance structural strength and provide excellent support. The inner sides of the two hook plates 10 are coated with a first adhesive layer 31. When folded, the two first adhesive layers 31 are bonded together.

[0043] The two connecting plates 20 are symmetrical and integrally connected to the outer ends of the two hook plates 10. The two connecting plates 20 are bendably arranged relative to the two hook plates 10. A second adhesive layer 32 is provided on the surface of each connecting plate 20. Each connecting plate 20 includes a second outer layer 21 and a second inner layer 22. The second outer layer 21 is made of washed kraft paper and is integrally connected to the first outer layer 11. The second inner layer 22 is inlaid and fixed within the second outer layer 21. The second inner layer 22 is made of carbon fiber and serves to enhance structural strength and provide excellent support. The second inner layer 22 is separated from the first inner layer 12. The width of the connecting plate 20 is greater than that of the hook plate 10. The inner middle portion of the connecting plate 20 is integrally connected to the outer ends of the hook plate 10, forming a T-shaped structure.

[0044] The washed kraft paper material includes the following raw materials in parts by weight:

[0045] The paper comprises 55-70 parts long-fiber wood pulp, 35-45 parts short-fiber wood pulp, 15-18 parts synthetic fiber, 20-25 parts cotton pulp, 4-5 parts wet strength agent, 2-3 parts water repellent, 0.8-1.2 parts dispersant, and 25-30 parts filler. The long-fiber wood pulp is coniferous, providing the paper's basic strength and toughness. Its long fibers offer strong interweaving, enhancing the paper's tensile strength. The short-fiber wood pulp is broadleaf wood pulp, filling the gaps between the long fibers, making the paper's structure more compact. This helps improve the paper's evenness and smoothness, contributing to its overall strength. The synthetic fiber is aramid fiber or polyvinyl alcohol fiber, which has high strength and high modulus, significantly improving the toughness of washed kraft paper, particularly its strength retention in a wet state, and enhancing the paper's resistance to external forces. The cotton pulp can improve paper strength. Cotton pulp fibers are long, and when interwoven, they enhance the paper's tensile strength, making kraft paper tougher and less prone to tearing. This allows it to better withstand pressure and tension in packaging applications, among other applications. Cotton pulp also improves the paper's smoothness, making the surface smoother and flatter, facilitating subsequent processing such as printing. Furthermore, cotton pulp helps improve the durability of kraft paper, allowing it to withstand the adverse effects of time and environmental factors, extending its service life. The wet strength agent is a polyamide polyamine epichlorohydrin, which forms covalent bonds with the fibers. When the paper comes into contact with water, it effectively prevents the breakdown of hydrogen bonds between the fibers, thereby increasing the paper's wet strength and ensuring it resists deformation or damage during washing. The water repellent is an alkyl ketene dimer, which forms a hydrophobic film on the fiber surface, reducing the paper's water absorption. This minimizes water absorption during washing, maintaining the paper's dimensional stability and strength. The dispersant is sodium polyacrylate, which is used to evenly disperse the fibers and additives, preventing fiber agglomeration and ensuring uniform paper quality, thus improving the paper's overall performance. The filler is calcium carbonate, which can improve the opacity, whiteness and printability of paper, and at the same time improve the stiffness of paper to a certain extent. However, excessive addition may affect the strength of the paper and needs to be reasonably controlled.

[0046] The present invention also discloses a method for preparing the aforementioned strong and tough washed kraft paper hook, comprising the following steps:

[0047] (1) Beating: Long-fiber wood pulp, short-fiber wood pulp and cotton pulp are respectively put into respective beating equipment for beating treatment. The beating degree of long-fiber wood pulp is controlled at 30-40°SR, and the beating degree of short-fiber wood pulp is controlled at 40-50°SR, so that the fibers have an appropriate degree of fibrillation and improve the bonding force between the fibers; and the synthetic fibers are separately opened to make them fully dispersed, and then evenly mixed with the beaten long-fiber wood pulp, short-fiber wood pulp and cotton pulp according to the proportion.

[0048] (2) Preparing the pulp: In the pulp preparation tank, add appropriate amount of water, start the stirring device, first dissolve the dispersing agent in water to form a uniform dispersion, then add the mixed fiber pulp, wet strength agent, water resistance agent and filler in sequence, continue stirring for 30-60 minutes to ensure that all ingredients are fully mixed and uniform, forming a stable paper pulp suspension.

[0049] (3) Papermaking: The prepared paper pulp suspension is uniformly sprayed through the headbox to the papermaking net section. During the spraying process, multiple pieces of uncured carbon fiber cloth that have been cut are placed in. Then, the wet paper sheet is formed by using the forming device of the paper machine to perform preliminary dewatering and forming. Subsequently, the wet paper sheet passes through the press section to further remove water through mechanical pressure. During the pressing process, the pressure is controlled at 5-10 MPa, and the pressing time is adjusted according to the basis weight of the paper and the equipment performance.

[0050] (4) Drying: The paper sheet after pressing enters the drying section, which adopts steam heating or hot air drying method for drying treatment, and the drying temperature is controlled at 125-140℃. At the same time, the uncured carbon fiber cloth is solidified to form the first inner layer 12 and the second inner layer 22. During the drying process, attention should be paid to the uniformity of the temperature to avoid deformation or strength reduction of the paper due to local rapid drying.

[0051] (5) Post-treatment: The dried paper is subjected to calendering treatment as needed, and the calendering pressure is controlled at 10-20 MPa.

[0052] (6) Cutting: As shown in Figure 1 , the paper is cut to form two hook plates 10 and two connecting plates 20 that are integrally connected.

[0053] (7) Gluing: Glue is applied to the corresponding positions of the two hook plates 10 and the two connecting plates 20 to form the first glue layer 31 and the second glue layer 32.

[0054] (8) Folding and forming: The two hook plates 10 are folded and adhered and fixed together through the first glue layer 31 (as shown in Figure 3 ), and the two connecting plates 20 are bent relative to the two hook plates 10, respectively. The two connecting plates 20 extend horizontally, and the two hook plates 10 extend vertically (as shown in Figure 4 ).

[0055] In use, the two hook plates 10 are inserted from the bottom to the top of the slot hole in the packaging box and extend outward, and the second glue layer 32 on the two connecting plates 20 is adhered and fixed to the inner wall of the top of the packaging box.

[0056] The following examples further illustrate the present application:

[0057] Example 1:

[0058] A strong and tough washed kraft paper hook comprises two hook plates 10 extending outward from the top of a packaging box and two connecting plates 20 fixedly attached to the inner wall of the top of the packaging box.

[0059] The two hook plates 10 are symmetrical and integrally connected, and are foldable. Each hook plate 10 is provided with a hook hole 101 in the shape of an isosceles triangle. When folded, the two hook plates 10 are bonded together by a first adhesive layer 31, with the two hook holes 31 facing each other. Each hook plate 10 comprises a first outer layer 11 and a first inner layer 12. The first outer layer 11 is made of washed kraft paper, and the first inner layer 12 is embedded and fixed within the first outer layer 11. The first inner layer 12 is made of carbon fiber and serves to enhance structural strength and provide excellent support. The inner sides of the two hook plates 10 are coated with a first adhesive layer 31. When folded, the two first adhesive layers 31 are bonded together.

[0060] The two connecting plates 20 are symmetrical and integrally connected to the outer ends of the two hook plates 10. The two connecting plates 20 are bendably arranged relative to the two hook plates 10. A second adhesive layer 32 is provided on the surface of each connecting plate 20. Each connecting plate 20 includes a second outer layer 21 and a second inner layer 22. The second outer layer 21 is made of washed kraft paper and is integrally connected to the first outer layer 11. The second inner layer 22 is inlaid and fixed within the second outer layer 21. The second inner layer 22 is made of carbon fiber and serves to enhance structural strength and provide excellent support. The second inner layer 22 is separated from the first inner layer 12. The width of the connecting plate 20 is greater than that of the hook plate 10. The inner middle portion of the connecting plate 20 is integrally connected to the outer ends of the hook plate 10, forming a T-shaped structure.

[0061] The washed kraft paper material includes the following raw materials in parts by weight:

[0062] 55 parts long-fiber wood pulp; 45 parts short-fiber wood pulp; 16 parts synthetic fiber; 23 parts cotton pulp; 4.5 parts wet strength agent; 2 parts water repellent; 0.9 parts dispersant; 27 parts filler. The long-fiber wood pulp is softwood pulp, which provides the paper's basic strength and toughness. Its long fibers have a strong interweaving ability, enhancing the paper's tensile strength. The short-fiber wood pulp is hardwood pulp, which fills the gaps between the long fibers, making the paper's structure more compact. It also helps improve the paper's evenness and smoothness, and also contributes to the paper's overall strength. The synthetic fiber is aramid fiber, which has high strength and high modulus, significantly improving the toughness of washed kraft paper, especially its strength retention in a wet state, and enhancing the paper's resistance to external forces. The cotton pulp can improve paper strength. Cotton pulp fibers are long, and when interwoven, they enhance the paper's tensile strength, making kraft paper tougher and less prone to tearing. This allows it to better withstand pressure and tension in packaging applications, among other applications. Cotton pulp also improves the paper's smoothness, making the surface smoother and flatter, facilitating subsequent processing such as printing. Furthermore, cotton pulp helps improve the durability of kraft paper, allowing it to withstand the adverse effects of time and environmental factors, extending its service life. The wet strength agent is a polyamide polyamine epichlorohydrin, which forms covalent bonds with the fibers. When the paper comes into contact with water, it effectively prevents the breakdown of hydrogen bonds between the fibers, thereby increasing the paper's wet strength and ensuring it resists deformation or damage during washing. The water repellent is an alkyl ketene dimer, which forms a hydrophobic film on the fiber surface, reducing the paper's water absorption. This minimizes water absorption during washing, maintaining the paper's dimensional stability and strength. The dispersant is sodium polyacrylate, which is used to evenly disperse the fibers and additives, preventing fiber agglomeration and ensuring uniform paper quality, thus improving the paper's overall performance. The filler is calcium carbonate, which can improve the opacity, whiteness and printability of paper, and at the same time improve the stiffness of paper to a certain extent. However, excessive addition may affect the strength of the paper and needs to be reasonably controlled.

[0063] This embodiment also discloses a method for preparing the aforementioned strong washed kraft paper hook, comprising the following steps:

[0064] (1) Beating: Long-fiber wood pulp, short-fiber wood pulp and cotton pulp are respectively put into respective beating equipment for beating treatment. The beating degree of long-fiber wood pulp is controlled at 35°SR, and the beating degree of short-fiber wood pulp is controlled at 45°SR, so that the fibers have an appropriate degree of fibrillation and improve the bonding force between the fibers; and the synthetic fibers are separately opened to make them fully dispersed, and then evenly mixed with the beaten long-fiber wood pulp, short-fiber wood pulp and cotton pulp according to the proportion.

[0065] (2) Slurry preparation: Add an appropriate amount of water to the slurry preparation tank, turn on the stirring device, dissolve the dispersant in the water first to form a uniform dispersion, then add the mixed fiber slurry, wet strength agent, water repellent and filler in turn, and continue stirring for 50 minutes to ensure that all ingredients are fully mixed and evenly mixed to form a stable pulp suspension.

[0066] (3) Papermaking: The prepared pulp suspension is evenly sprayed onto the papermaking mesh through the headbox. During the spraying process, multiple pieces of uncured carbon fiber cloth that have been cut are placed. Then, the forming device of the papermaking machine is used to perform preliminary dehydration and forming to form wet paper sheets. Then, the wet paper sheets are passed through the pressing section to further remove moisture through mechanical pressure. During the pressing process, the pressure is controlled at 5-10 MPa, and the pressing time is adjusted according to the paper quantity and equipment performance.

[0067] (4) Drying: After being pressed, the paper sheets enter the drying section and are dried by steam heating or hot air drying. The drying temperature is controlled at 130°C. At the same time, the uncured carbon fiber cloth is cured by heat to form the first inner layer 12 and the second inner layer 22. During the drying process, attention should be paid to the uniformity of temperature to avoid deformation or loss of strength of the paper due to excessive local drying.

[0068] (5) Post-processing: The dried paper is calendered as needed, and the calendering pressure is controlled at 15 MPa.

[0069] (6) Cutting: Figure 1 As shown, paper is cut to form two hook plates 10 and two connecting plates 20 that are integrally connected.

[0070] (7) Gluing: Glue is applied to corresponding positions on the two hook plates 10 and the two connecting plates 20 to form a first adhesive layer 31 and a second adhesive layer 32 .

[0071] (8) Folding and forming: Fold the two hook plates 10 and fix them together through the first adhesive layer 31 (as shown in FIG. Figure 3 ), and the two connecting plates 20 are bent relative to the two hook plates 10, the two connecting plates 20 extend horizontally, and the two hook plates 10 extend vertically (such as Figure 4 ).

[0072] When in use, the two hook plates 10 are extended outward from the bottom of the packaging box through the slots on the top, and the second adhesive layers 32 on the two connecting plates 20 are bonded and fixed to the inner wall of the top of the packaging box.

[0073] After use tests, it was found that the hook in this embodiment, which has the same thickness as ordinary paper, has a tensile strength of 1200 grams of tension per centimeter of width and is not easily torn.

[0074] Example 2:

[0075] A strong and tough washed kraft paper hook comprises two hook plates 10 extending outward from the top of a packaging box and two connecting plates 20 fixed to the top inner wall of the packaging box.

[0076] The two hook plates 10 are symmetrical and integrally connected, and are foldable. Each hook plate 10 is provided with a hook hole 101 in the shape of an isosceles triangle. When folded, the two hook plates 10 are bonded together by a first adhesive layer 31, with the two hook holes 31 facing each other and connected. Each hook plate 10 comprises a first outer layer 11 and a first inner layer 12. The first outer layer 11 is made of washed kraft paper, and the first inner layer 12 is embedded and fixed within the first outer layer 11. The first inner layer 12 is made of carbon fiber and serves to enhance structural strength and provide excellent support. The inner sides of the two hook plates 10 are coated with a first adhesive layer 31. When folded, the two first adhesive layers 31 are bonded together.

[0077] The two connecting plates 20 are symmetrical and integrally connected to the outer ends of the two hook plates 10. The two connecting plates 20 are bendably arranged relative to the two hook plates 10. A second adhesive layer 32 is provided on the surface of each connecting plate 20. Each connecting plate 20 includes a second outer layer 21 and a second inner layer 22. The second outer layer 21 is made of washed kraft paper and is integrally connected to the first outer layer 11. The second inner layer 22 is inlaid and fixed within the second outer layer 21. The second inner layer 22 is made of carbon fiber and serves to enhance structural strength and provide excellent support. The second inner layer 22 is separated from the first inner layer 12. The width of the connecting plate 20 is greater than that of the hook plate 10. The inner middle portion of the connecting plate 20 is integrally connected to the outer ends of the hook plate 10, forming a T-shaped structure.

[0078] The washed kraft paper material includes the following raw materials in parts by weight:

[0079] Long-fiber wood pulp: 70 parts; short-fiber wood pulp: 35 parts; synthetic fiber: 15 parts; cotton pulp: 25 parts; wet-strength agent: 4 parts; water repellent: 2.5 parts; dispersant: 0.8 parts; filler: 2.5 parts. The long-fiber wood pulp is coniferous, providing the paper's basic strength and toughness. Its long fibers offer strong interweaving, enhancing the paper's tensile strength. The short-fiber wood pulp is hardwood, filling the gaps between the long fibers, making the paper's structure more compact. This helps improve the paper's evenness and smoothness, contributing to its overall strength. The synthetic fiber is polyvinyl alcohol, which boasts high strength and modulus, significantly improving the toughness of washed kraft paper, particularly its strength retention in a wet state, and enhancing the paper's resistance to external forces. The cotton pulp can improve paper strength. Cotton pulp fibers are long, and when interwoven, they enhance the paper's tensile strength, making kraft paper tougher and less prone to tearing. This allows it to better withstand pressure and tension in packaging applications, among other applications. Cotton pulp also improves the paper's smoothness, making the surface smoother and flatter, facilitating subsequent processing such as printing. Furthermore, cotton pulp helps improve the durability of kraft paper, allowing it to withstand the adverse effects of time and environmental factors, extending its service life. The wet strength agent is a polyamide polyamine epichlorohydrin, which forms covalent bonds with the fibers. When the paper comes into contact with water, it effectively prevents the breakdown of hydrogen bonds between the fibers, thereby increasing the paper's wet strength and ensuring it resists deformation or damage during washing. The water repellent is an alkyl ketene dimer, which forms a hydrophobic film on the fiber surface, reducing the paper's water absorption. This minimizes water absorption during washing, maintaining the paper's dimensional stability and strength. The dispersant is sodium polyacrylate, which is used to evenly disperse the fibers and additives, preventing fiber agglomeration and ensuring uniform paper quality, thus improving the paper's overall performance. The filler is calcium carbonate, which can improve the opacity, whiteness and printability of paper, and at the same time improve the stiffness of paper to a certain extent. However, excessive addition may affect the strength of the paper and needs to be reasonably controlled.

[0080] This embodiment also discloses a method for preparing the aforementioned strong washed kraft paper hook, comprising the following steps:

[0081] (1) Beating: Long-fiber wood pulp, short-fiber wood pulp and cotton pulp are respectively put into respective beating equipment for beating treatment. The beating degree of long-fiber wood pulp is controlled at 30°SR, and the beating degree of short-fiber wood pulp is controlled at 40°SR, so that the fibers have an appropriate degree of fibrillation and improve the bonding force between the fibers; and the synthetic fibers are separately opened to make them fully dispersed, and then evenly mixed with the beaten long-fiber wood pulp, short-fiber wood pulp and cotton pulp according to the proportion.

[0082] (2) Slurry preparation: Add an appropriate amount of water to the slurry preparation tank, turn on the stirring device, dissolve the dispersant in the water first to form a uniform dispersion, then add the mixed fiber slurry, wet strength agent, water repellent and filler in turn, and continue stirring for 60 minutes to ensure that all ingredients are fully mixed and evenly mixed to form a stable pulp suspension.

[0083] (3) Papermaking: The prepared pulp suspension is evenly sprayed onto the papermaking mesh through the headbox. During the spraying process, multiple pieces of uncured carbon fiber cloth that have been cut are placed. Then, the forming device of the papermaking machine is used to perform preliminary dehydration and forming to form wet paper sheets. Then, the wet paper sheets are passed through the pressing section to further remove moisture through mechanical pressure. During the pressing process, the pressure is controlled at 5-10 MPa, and the pressing time is adjusted according to the paper quantity and equipment performance.

[0084] (4) Drying: After being pressed, the paper sheets enter the drying section and are dried by steam heating or hot air drying. The drying temperature is controlled at 125°C. At the same time, the uncured carbon fiber cloth is cured by heat to form the first inner layer 12 and the second inner layer 22. During the drying process, attention should be paid to the uniformity of temperature to avoid deformation or strength loss of the paper due to excessive local drying.

[0085] (5) Post-processing: The dried paper is calendered as needed, and the calendering pressure is controlled at 20 MPa.

[0086] (6) Cutting: Figure 1 As shown, paper is cut to form two hook plates 10 and two connecting plates 20 that are integrally connected.

[0087] (7) Gluing: Glue is applied to corresponding positions on the two hook plates 10 and the two connecting plates 20 to form a first adhesive layer 31 and a second adhesive layer 32 .

[0088] (8) Folding and forming: Fold the two hook plates 10 and fix them together through the first adhesive layer 31 (as shown in FIG. Figure 3 ), and the two connecting plates 20 are bent relative to the two hook plates 10, the two connecting plates 20 extend horizontally, and the two hook plates 10 extend vertically (such as Figure 4 ).

[0089] When in use, the two hook plates 10 are extended outward from the bottom of the packaging box through the slots on the top, and the second adhesive layers 32 on the two connecting plates 20 are bonded and fixed to the inner wall of the top of the packaging box.

[0090] After use tests, it was found that the hook in this embodiment, which has the same thickness as ordinary paper, has a tensile strength of 1250 grams of tension per centimeter of width and is not easily torn.

[0091] Example 3:

[0092] A strong and tough washed kraft paper hook comprises two hook plates 10 extending outward from the top of a packaging box and two connecting plates 20 fixed to the top inner wall of the packaging box.

[0093] The two hook plates 10 are symmetrical and integrally connected, and are foldable. Each hook plate 10 is provided with a hook hole 101 in the shape of an isosceles triangle. When folded, the two hook plates 10 are bonded together by a first adhesive layer 31, with the two hook holes 31 facing each other and connected. Each hook plate 10 comprises a first outer layer 11 and a first inner layer 12. The first outer layer 11 is made of washed kraft paper, and the first inner layer 12 is embedded and fixed within the first outer layer 11. The first inner layer 12 is made of carbon fiber and serves to enhance structural strength and provide excellent support. The inner sides of the two hook plates 10 are coated with a first adhesive layer 31. When folded, the two first adhesive layers 31 are bonded together.

[0094] The two connecting plates 20 are symmetrical and integrally connected to the outer ends of the two hook plates 10. The two connecting plates 20 are bendably arranged relative to the two hook plates 10. A second adhesive layer 32 is provided on the surface of each connecting plate 20. Each connecting plate 20 includes a second outer layer 21 and a second inner layer 22. The second outer layer 21 is made of washed kraft paper and is integrally connected to the first outer layer 11. The second inner layer 22 is inlaid and fixed within the second outer layer 21. The second inner layer 22 is made of carbon fiber and serves to enhance structural strength and provide excellent support. The second inner layer 22 is separated from the first inner layer 12. The width of the connecting plate 20 is greater than that of the hook plate 10. The inner middle portion of the connecting plate 20 is integrally connected to the outer ends of the hook plate 10, forming a T-shaped structure.

[0095] The washed kraft paper material includes the following raw materials in parts by weight:

[0096] Long-fiber wood pulp (65 parts); short-fiber wood pulp (40 parts); synthetic fiber (18 parts); cotton pulp (20 parts); wet strength agent (5 parts); water repellent (3 parts); dispersant (1.2 parts); and filler (30 parts). The long-fiber wood pulp is coniferous, providing the paper's basic strength and toughness. Its long fibers offer strong interweaving, enhancing the paper's tensile strength. The short-fiber wood pulp is hardwood, filling the gaps between the long fibers for a tighter paper structure. This improves the paper's evenness and smoothness, contributing to its overall strength. The synthetic fiber is aramid, boasting high strength and modulus, significantly enhancing the toughness of washed kraft paper, particularly its strength retention in a wet state, and strengthening the paper's resistance to external forces. The cotton pulp can improve paper strength. Cotton pulp fibers are long, and when interwoven, they enhance the paper's tensile strength, making kraft paper tougher and less prone to tearing. This allows it to better withstand pressure and tension in packaging applications, among other applications. Cotton pulp also improves the paper's smoothness, making the surface smoother and flatter, facilitating subsequent processing such as printing. Furthermore, cotton pulp helps improve the durability of kraft paper, allowing it to withstand the adverse effects of time and environmental factors, extending its service life. The wet strength agent is a polyamide polyamine epichlorohydrin, which forms covalent bonds with the fibers. When the paper comes into contact with water, it effectively prevents the breakdown of hydrogen bonds between the fibers, thereby increasing the paper's wet strength and ensuring it resists deformation or damage during washing. The water repellent is an alkyl ketene dimer, which forms a hydrophobic film on the fiber surface, reducing the paper's water absorption. This minimizes water absorption during washing, maintaining the paper's dimensional stability and strength. The dispersant is sodium polyacrylate, which is used to evenly disperse the fibers and additives, preventing fiber agglomeration and ensuring uniform paper quality, thus improving the paper's overall performance. The filler is calcium carbonate, which can improve the opacity, whiteness and printability of paper, and at the same time improve the stiffness of paper to a certain extent. However, excessive addition may affect the strength of the paper and needs to be reasonably controlled.

[0097] This embodiment also discloses a method for preparing the aforementioned strong washed kraft paper hook, comprising the following steps:

[0098] (1) Beating: Long-fiber wood pulp, short-fiber wood pulp and cotton pulp are respectively put into respective beating equipment for beating treatment. The beating degree of long-fiber wood pulp is controlled at 40°SR, and the beating degree of short-fiber wood pulp is controlled at 50°SR, so that the fibers have an appropriate degree of fibrillation and improve the bonding force between the fibers; and the synthetic fibers are separately opened to make them fully dispersed, and then evenly mixed with the beaten long-fiber wood pulp, short-fiber wood pulp and cotton pulp according to the proportion.

[0099] (2) Slurry preparation: Add an appropriate amount of water to the slurry preparation tank, turn on the stirring device, first dissolve the dispersant in the water to form a uniform dispersion, then add the mixed fiber slurry, wet strength agent, water repellent and filler in turn, and continue stirring for 30 minutes to ensure that all ingredients are fully mixed and evenly formed to form a stable pulp suspension.

[0100] (3) Papermaking: The prepared pulp suspension is evenly sprayed onto the papermaking mesh through the headbox. During the spraying process, multiple pieces of uncured carbon fiber cloth that have been cut are placed. Then, the forming device of the papermaking machine is used to perform preliminary dehydration and forming to form wet paper sheets. Then, the wet paper sheets are passed through the pressing section to further remove moisture through mechanical pressure. During the pressing process, the pressure is controlled at 5-10 MPa, and the pressing time is adjusted according to the paper quantity and equipment performance.

[0101] (4) Drying: After being pressed, the paper sheets enter the drying section and are dried by steam heating or hot air drying. The drying temperature is controlled at 140°C. At the same time, the uncured carbon fiber cloth is cured by heat to form the first inner layer 12 and the second inner layer 22. During the drying process, attention should be paid to the uniformity of temperature to avoid deformation or strength loss of the paper due to excessive local drying.

[0102] (5) Post-processing: The dried paper is calendered as needed, and the calendering pressure is controlled at 10 MPa.

[0103] (6) Cutting: Figure 1 As shown, paper is cut to form two hook plates 10 and two connecting plates 20 that are integrally connected.

[0104] (7) Gluing: Glue is applied to corresponding positions on the two hook plates 10 and the two connecting plates 20 to form a first adhesive layer 31 and a second adhesive layer 32 .

[0105] (8) Folding and forming: Fold the two hook plates 10 and fix them together through the first adhesive layer 31 (as shown in FIG. Figure 3 ), and the two connecting plates 20 are bent relative to the two hook plates 10, the two connecting plates 20 extend horizontally, and the two hook plates 10 extend vertically (such as Figure 4 ).

[0106] When in use, the two hook plates 10 are extended outward from the bottom to the top through the slots on the top of the packaging box, and the second adhesive layers 32 on the two connecting plates 20 are bonded and fixed to the inner wall of the top of the packaging box.

[0107] After use tests, it was found that the hook in this embodiment, which has the same thickness as ordinary paper, has a tensile strength of 1300 grams of tension per centimeter of width and is not easily torn.

[0108] The design focus of the present invention is: by adopting the washed kraft paper material of the formula of the present invention and cooperating with the structure and preparation method of the present invention to produce the hook, the hook has strong toughness and the load-bearing capacity is effectively improved. There is no need to mount multiple layers of paper, the material loss is small, and the production efficiency is high, which brings convenience to production operations.

[0109] The above description is merely a preferred embodiment of the present invention and does not limit the technical scope of the present invention. Therefore, any minor modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A strong and tough washed kraft paper hook, characterized by: It includes two hook plates extending outward from the top of the packaging box and two connecting plates fixed to the top inner wall of the packaging box; The two hook plates are symmetrical and integrally connected to each other, and the two hook plates are foldably arranged. Both hook plates are provided with hook holes. After folding, the two hook plates are bonded and fixed by a first adhesive layer, and the two hook holes are directly connected to each other. Each hook plate includes a first outer layer and a first inner layer. The first outer layer is made of washed kraft paper. The first inner layer is inlaid and fixed in the first outer layer. The first inner layer is made of carbon fiber. The two connecting plates are symmetrical to each other and are integrally connected to the outer ends of the two hook plates. The two connecting plates are bendably arranged relative to the two hook plates. A second adhesive layer is provided on the surface of each connecting plate. Each connecting plate includes a second outer layer and a second inner layer. The second outer layer is made of washed kraft paper and is integrally connected to the first outer layer. The second inner layer is inlaid and fixed in the second outer layer. The second inner layer is made of carbon fiber and is separated from the first inner layer. The washed kraft paper material includes the following raw materials in parts by weight: 55-70 parts of long fiber wood pulp; 35-45 parts of short fiber wood pulp; 15-18 parts of synthetic fiber; 20-25 parts of cotton pulp; 4-5 parts of wet strength agent; 2-3 parts of water repellent; 0.8-1.2 parts of dispersant; 25-30 parts of filler.

2. The strong and tough washed kraft paper hook according to claim 1, characterized in that: The long-fiber wood pulp is coniferous wood pulp, the short-fiber wood pulp is broad-leaved wood pulp, and the synthetic fiber is aramid fiber or polyvinyl alcohol fiber.

3. The strong and tough washed kraft paper hook according to claim 1, characterized in that: The wet strength agent is polyamide polyamine epichlorohydrin.

4. The strong and tough washed kraft paper hook according to claim 1, characterized in that: The water repellent is an alkyl ketene dimer.

5. The strong and tough washed kraft paper hook according to claim 1, characterized in that: The dispersant is sodium polyacrylate.

6. The strong and tough washed kraft paper hook according to claim 1, characterized in that: The filler is calcium carbonate.

7. The strong and tough washed kraft paper hook according to claim 1, characterized in that: The inner sides of the two hook plates are both coated with a first adhesive layer. After folding, the two first adhesive layers are bonded and fixed together.

8. The strong and tough washed kraft paper hook according to claim 1, characterized in that: The width of the connecting plate is greater than that of the hook plate, and the inner middle portion of the connecting plate is integrally connected with the outer end of the hook plate to form a T-shaped structure.

9. A method for preparing the tough washed kraft paper hook according to any one of claims 1 to 8, characterized in that: The following steps are included: (1) Beating: Long-fiber wood pulp, short-fiber wood pulp, and cotton pulp are respectively put into respective beating equipment for beating treatment, and the beating degree of long-fiber wood pulp is controlled at 30-40°SR, and the beating degree of short-fiber wood pulp is controlled at 40-50°SR; and the synthetic fiber is separately opened to make it fully dispersed, and then uniformly mixed with the beaten long-fiber wood pulp, short-fiber wood pulp, and cotton pulp according to a proportion; (2) Slurry preparation: Add an appropriate amount of water to the slurry preparation tank, turn on the stirring device, dissolve the dispersant in the water first to form a uniform dispersion, then add the mixed fiber slurry, wet strength agent, water repellent and filler in sequence, and continue stirring for 30-60 minutes to ensure that all ingredients are fully mixed and evenly formed to form a stable pulp suspension; (3) Papermaking: The prepared pulp suspension is evenly sprayed onto the papermaking wire through the headbox. During the spraying process, multiple pieces of uncured carbon fiber cloth that have been cut are placed. Then, the forming device of the papermaking machine is used for preliminary dehydration and forming to form a wet paper sheet. Then, the wet paper sheet is passed through the pressing section to further remove moisture through mechanical pressure. During the pressing process, the pressure is controlled at 5-10 MPa. (4) Drying: After being pressed, the paper sheet enters the drying section and is dried by steam heating or hot air drying. The drying temperature is controlled at 125-140°C. At the same time, the uncured carbon fiber cloth is cured by heat to form the first inner layer and the second inner layer. (5) Post-processing: The dried paper is calendered as needed, and the calendering pressure is controlled at 10-20 MPa; (6) Cutting: Cutting the paper to form two hook plates and two connecting plates connected in one piece; (7) Gluing: applying glue on corresponding positions of the two hook plates and the two connecting plates to form a first glue layer and a second glue layer; (8) Folding and forming: fold the two hook plates and fix them together through the first adhesive layer, and bend the two connecting plates relative to the two hook plates respectively, so that the two connecting plates extend horizontally and the two hook plates extend vertically.

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