Bamboo pulp corrugated carton preparation process

Abstract

The invention provides a bamboo pulp corrugated carton preparation technology, and relates to the technical field of corrugated carton preparation, the bamboo pulp corrugated carton preparation technology comprises the following steps: S1, bamboo pulp paper preparation: S11, pulping, S12, paper pulp blending, and S13, papermaking; s2, corrugated board preparation: pressing the wood pulp paper into core paper by adopting a single-sided machine, coating an adhesive on a corrugated peak part on one side of the core paper by adopting the single-sided machine, so that the core paper and the inner paper are initially adhered to form a single-sided corrugated board, coating an adhesive on a corrugated peak part on the other side of the core paper by adopting a double-sided machine, and adhering the single-sided corrugated board and the surface paper to form double-sided corrugated paper; and S3, corrugated case preparation: forming lap joint grooves in the double-sided corrugated paper prepared in the S2 by adopting a grooving machine, pressing folding lines, and performing die cutting forming by adopting a die cutting machine to prepare the corrugated case. Bamboo pulp is used as surface paper and inner paper, the cost advantage is remarkable, the problems of moisture absorption and embrittlement of a corrugated carton are solved, and the performance defects caused by bamboo pulp fiber short boards are overcome.

Description

Technical Field

[0001] This application relates to the field of corrugated cardboard box production technology, specifically to a process for preparing corrugated cardboard boxes using bamboo pulp paper as the face paper. Background Technology

[0002] Currently, most corrugated cardboard uses wood pulp as the face paper raw material, resulting in high raw material procurement costs and strong resource dependence. Bamboo planting and harvesting costs are lower than wood, especially in southern provinces with abundant bamboo resources, where raw material procurement costs are 10-20 parts lower than wood pulp, reducing the overall production cost of corrugated boxes. However, bamboo pulp fibers are shorter than softwood pulp, posing challenges to folding endurance, abrasion resistance, and printing quality when used directly in corrugated paper, thus limiting the application of bamboo pulp in corrugated paper production.

[0003] In addition, the adhesives used in traditional corrugated paper have limited properties and are difficult to cope with environmental changes in different seasons: during the rainy season in spring and summer, the high humidity causes the paperboard to absorb moisture, resulting in a significant decrease in the edge crush and compressive strength of the finished corrugated boxes; while in the dry winter season, the low air humidity causes the paperboard to lose moisture, making it brittle and resulting in a high breakage rate. Summary of the Invention

[0004] The purpose of this application is to provide a corrugated cardboard box manufacturing process that solves the problems of moisture absorption and brittleness in corrugated cardboard boxes by using bamboo pulp as the face paper and liner paper, thereby addressing the performance defects caused by the shortness of bamboo pulp fibers.

[0005] The technical problem solved by this application is achieved by the following technical solution.

[0006] This application provides a process for manufacturing bamboo pulp corrugated cardboard boxes, including the following steps:

[0007] S1, Bamboo pulp paper preparation:

[0008] S11, pulping, select fresh bamboo materials, peel, slice, steam, wash, screen and then grind, control the pulping degree of freeness at 45-55°SR.

[0009] S12, pulp preparation: bamboo pulp fiber is mixed with water to form a suspension with a concentration of 3%-5%, and 0.1%-0.3% of polyamide epichlorohydrin resin by weight of oven-dried bamboo pulp fiber is added and stirred evenly;

[0010] S13, Papermaking: The refined bamboo pulp is fed into a paper machine and sequentially undergoes wire forming, pressing, and drying processes. The pressing process uses a boot press, and the drying temperature is controlled in stages. After drying, the pulp undergoes hard calendering, and the surface is sized on both sides at 4-6 g / m². 2 The final weight obtained was 90-120 g / m³. 2Bamboo pulp paper is used as the liner and face paper for corrugated cardboard.

[0011] S2, Corrugated Board Preparation: Wood pulp paper is pressed into core paper using a single-facer. Adhesive is applied to the corrugated peaks on one side of the core paper using a single-facer to initially bond the core paper to the linerboard, forming single-faced corrugated board. Adhesive is then applied to the corrugated peaks on the other side of the core paper using a double-facer to bond the single-faced corrugated board to the linerboard, forming double-faced corrugated board. The single-facer adhesive application rate is 25-30 g / m². 2 Double-sided machine-applied adhesive 27-32g / m 2 After bonding, the cardboard enters the wet end drying zone, where the temperature is 95-105℃, and then enters the dry end drying zone, where the temperature is 135-150℃, controlling the glue application rate to 18-22 g / m². 2 The gluing pressure is 0.3-0.5MPa to ensure a firm bond between the inner paper, outer paper, and core paper.

[0012] S3, Corrugated Cardboard Box Preparation: The double-sided corrugated paper prepared in S2 is cut with a slotting machine to open the overlap groove and press the fold lines. Then, it is die-cut into shape using a die-cutting machine with a die-cutting pressure of 8-10MPa to obtain a corrugated cardboard box.

[0013] By adopting the above technical solution, the bamboo pulp corrugated cardboard box preparation process of this application has significant cost advantages, strong resource adaptability, overcomes the shortcomings of bamboo pulp fiber performance, has stable bonding strength, reliable performance throughout the seasons, and achieves the positive effects of balancing production efficiency and product quality.

[0014] In some embodiments of this application, the adhesive in S2 comprises the following raw materials in parts by weight: 68.0-72.0 parts water, 18.0-22.0 parts modified starch, 1.2-1.8 parts caustic soda solution, 0.8-1.2 parts borax, 1.5-2.0 parts water-soluble PVA, 0.3-0.5 parts polydimethylsiloxane, 0.6-1.0 parts carbomeramide, 0.5-0.8 parts sodium chloride, 0.4-0.6 parts nano silica, 0.3-0.5 parts hydroxypropyl methylcellulose, and 0.2-0.4 parts sodium alginate.

[0015] Using the above technical solutions, the nano-silica in this application forms a dense protective film, blocking moisture penetration and solving the problem of cardboard moisture absorption during the rainy season. Sodium alginate and hydroxypropyl methylcellulose synergistically improve the flexibility of the adhesive, alleviating the brittleness caused by moisture loss in winter cardboard, fundamentally solving the problem of all-season environmental adaptability of corrugated boxes, and synergistically improving moisture resistance and anti-brittleness performance. Modified starch is selected as the core adhesive component, combined with water-soluble PVA, whose molecular chains form strong hydrogen bonds with the hydroxyl groups on the surface of bamboo pulp fibers, improving the bonding strength. The optimized ratio of borax and caustic soda solution further enhances the adhesive's wetting and penetration ability on bamboo pulp paper, avoiding adhesive delamination, thereby enhancing the compatibility with bamboo pulp fibers. Polydimethylsiloxane improves the adhesive's anti-aging properties, and carbamate and sodium chloride synergistically optimize the curing speed of the adhesive layer, ensuring the stability of the adhesive performance under different temperatures and humidity. The formulation components are free of toxic and harmful substances, biodegradable, and the raw material costs are controllable, meeting the cost requirements of large-scale production and satisfying the needs of stable performance and environmental protection.

[0016] In some embodiments of this application, the adhesive is prepared as follows: water is added to a reaction vessel in proportion, the temperature is raised to 45-50°C, caustic soda solution is added while stirring, and after stirring evenly, it is allowed to stand for 10 minutes; modified starch is slowly added while stirring, the temperature is maintained at 50-55°C, and the mixture is stirred for 30 minutes until the starch is completely dissolved; borax, water-soluble PVA, and polydimethylsiloxane are added in sequence, the temperature is raised to 60-65°C, and the mixture is stirred continuously for 20 minutes; the temperature is lowered to 40-45°C, and carbodiamine, sodium chloride, nano silica, hydroxypropyl methylcellulose, and sodium alginate are added, the mixture is stirred for 40 minutes, cooled to room temperature, and then filtered to obtain the adhesive.

[0017] Using the above technical solution, this application ensures the complete gelatinization of modified starch and the uniform dispersion of functional components such as borax and nano-silica through step-by-step temperature control (adding caustic soda at 45-50℃, dissolving starch at 50-55℃, mixing functional additives at 60-65℃, and adding the remaining components at 40-45℃) and precise stirring time control. This avoids performance fluctuations caused by excessively high or low local concentrations and maximizes the synergistic effect of each component. During the preparation process, impurities are removed and bubble formation is avoided through steps such as settling, simultaneous addition and stirring, and filtration. The finished adhesive has uniform viscosity and stable storage; it can be directly used for coating on single-facer and double-facer machines without additional modification treatment, adapting to the continuous operation requirements of corrugated cardboard production lines and reducing the difficulty of production operations.

[0018] In some embodiments of this application, in S11, after the bamboo is peeled and sliced, it is steamed at 120°C for 2 hours, washed and screened, and then bleached using an oxygen bleaching process. The bleached bamboo pulp fibers are then subjected to a pulping treatment with a pulping pressure of 0.3 MPa and a pulping time of 25 minutes.

[0019] Using the above technical solution, this application can fully remove impurities such as lignin and hemicellulose from bamboo by cooking at 120℃ for 2 hours. The oxygen bleaching process further improves fiber whiteness (reaching 78%-82% ISO whiteness), enhancing the product's aesthetics. The synergistic treatment of cooking and oxygen bleaching softens the cell walls of bamboo pulp fibers, requiring only 0.3MPa pressure and 25 minutes during subsequent pulping to achieve the required beating degree of 45-55°SR. Compared to the unoptimized pulping process, pulping energy consumption is reduced by 15%-20%, while also reducing excessive fiber cutting and ensuring a balance between fiber length and strength.

[0020] In some embodiments of this application, in S13, the surface sizing agent includes the following raw materials in parts by weight: 70-80 parts of oxidized starch, 20-30 parts of polyvinyl alcohol, totaling 100 parts.

[0021] Using the above technical solution, this application combines oxidized starch and polyvinyl alcohol. Oxidized starch provides basic adhesion and cost advantages, while polyvinyl alcohol enhances the flexibility and surface strength of the adhesive film, making it suitable for the packaging needs of corrugated boxes. The continuous and uniform adhesive film formed by the sizing agent improves the ink acceptability of bamboo pulp paper and avoids powdering and smudging during printing. At the same time, the active groups such as hydroxyl, carboxyl, and ether bonds on the surface of the adhesive film form a secondary bond with the corrugated board adhesive through hydrogen bonding and polar adsorption, further enhancing the adhesion between the face paper / linerboard and the core paper, and improving the overall compressive strength of the carton.

[0022] In some embodiments of this application, the drying temperature segmented control method in S13 is as follows: a multi-segment drying cylinder group is adopted, and the drying temperature is set as follows: 100-110℃ for the first segment, 110-120℃ for the middle segment, and 90-100℃ for the last segment.

[0023] This application's multi-stage drying cylinder assembly employs a gradient temperature design: a first stage at 100-110℃ to remove free water, a middle stage at 110-120℃ to remove bound water, and a final stage at 90-100℃ for cooling and shaping. The first stage's low temperature ensures rapid dehydration and prevents paper wrinkling; the middle stage's high temperature enhances drying efficiency; and the final stage's cooling and shaping reduces paper shrinkage and deformation, stabilizing the bamboo pulp paper's moisture content at 8%-10%, making it suitable for subsequent sizing and bonding processes. Segmented temperature control avoids fiber carbonization or embrittlement caused by single high-temperature drying, ensuring the natural strength of the bamboo pulp fibers is not compromised. Simultaneously, uniform drying reduces the internal moisture gradient of the paper, preventing deformation and cracking due to uneven moisture distribution during subsequent use, thus improving product stability.

[0024] In summary, compared with the prior art, the embodiments of this application have at least the following advantages or beneficial effects:

[0025] 1. Using bamboo pulp paper instead of traditional wood pulp paper as the inner and outer paper reduces raw material procurement costs by 10%-20% compared to timber due to the lower costs of bamboo planting and harvesting. The density and strength properties of bamboo pulp fibers support the production of 90-120g / m² paper. 2 Low-grammage, high-strength paper reduces raw material usage and transportation costs, and can reduce logistics energy consumption by 10%-15%, making it particularly suitable for cost-sensitive industries such as e-commerce and logistics.

[0026] 2. By controlling the beating degree of the pulp at 45-55°SR, the bamboo pulp fibers are highly fibrillated, increasing the strength of hydrogen bonds between fibers and compensating for the shorter length of bamboo pulp fibers compared to softwood pulp; this is combined with boot pressing, hard calendering, and a 4-6 g / m²... 2 The double-sided sizing process enables bamboo pulp paper to achieve the same level of folding endurance, abrasion resistance, and surface smoothness as wood pulp paper, thus meeting the performance requirements of corrugated board linerboard and faceboard.

[0027] 3. In the preparation of corrugated cardboard, precise control of the amount of glue applied, the glue application pressure, and the drying temperature gradient is achieved. Low temperature and rapid moisture removal in the wet end protect the fibers from brittleness, while high temperature in the dry end promotes cross-linking and curing of the glue layer, ensuring a strong bond between the inner liner, face paper, and core paper. Combined with subsequent die-cutting processes, the formed carton structure is stable, avoiding the problems of moisture absorption strength reduction during the rainy season and brittleness and breakage in winter.

[0028] 4. The process design of segmented drying, continuous gluing, and integrated grooving and die-cutting enables the production line from bamboo pulp to cardboard boxes; the precise matching of parameters for each process ensures both production efficiency and consistent product quality, adapting to the needs of large-scale industrial production. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0030] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present application will now be described in detail with reference to specific embodiments.

[0031] Preparation Example

[0032] Preparation Example 1: Preparation of Modified Starch

[0033] Take 100 parts of cassava starch, add 300 parts of deionized water, stir and disperse, then heat to 55℃, add 0.8 parts of sodium hydroxide, keep warm and stir for 20 min; then add 5 parts of propylene oxide, heat to 85℃ and react for 3 h; cool to room temperature, adjust pH to neutral, filter, dry and pulverize to obtain hydroxypropyl modified starch for later use.

[0034] Preparation Example 2: Preparation of Surface Sizing Agent

[0035] Weigh 75 parts of oxidized starch and 25 parts of polyvinyl alcohol by weight, add 800 parts of deionized water, heat to 90°C and stir for 40 minutes until completely dissolved, cool to 60°C for later use, and obtain a surface sizing agent with a solid content of about 9.1%.

[0036] Example

[0037] Example 1

[0038] The specific steps for preparing a bamboo pulp corrugated cardboard box are as follows:

[0039] S1, Bamboo pulp paper preparation:

[0040] S11, Pulping: Select fresh moso bamboo, peel it, and cut it into 3cm×5cm bamboo strips. Cook the strips at 120℃ for 2 hours. After cooking, wash the strips with water until the pH is neutral. Remove impurities by screening through a 40-mesh sieve. Bleach the strips using an oxygen bleaching process (oxygen pressure 0.6MPa, temperature 80℃, time 60min) to obtain bamboo pulp with a whiteness of 80% ISO. Feed the bamboo pulp into a double-disc refiner and refine it for 25min at a pressure of 0.3MPa, controlling the freeness to be 45°SR.

[0041] S12 Pulp Preparation: Mix the above-ground bamboo pulp with water to make a pulp suspension with a concentration of 3%-5%; add polyamide epichlorohydrin resin (solid content 10%) at 0.1%-0.3% of the oven-dry bamboo pulp fiber mass, and stir for 15 minutes until uniform.

[0042] S13 Papermaking: The pulp suspension is fed into a fourdrinier paper machine, and successively passes through the wire forming section and shoe press (pressure 0.4 MPa); a multi-stage drying cylinder group is used for drying, with the specific temperatures set as follows: 100-110℃ for the first stage, 110-120℃ for the middle stage, and 90-100℃ for the last stage; after drying, it undergoes hard calendering (pressure 8 MPa), and double-sided sizing is performed using the surface sizing agent from Preparation Example 2, with a dry sizing amount of 4 g / m³. 2 The final yield was 90 g / m³. 2 Bamboo pulp paper was used as both the inner and outer paper.

[0043] S2. Corrugated Cardboard Preparation

[0044] Preparation of S21 adhesive: Weigh out 68.0 parts by weight of water, 18.0 parts of modified starch from Preparation Example 1, 1.2 parts of caustic soda solution (concentration 30%), 0.8 parts of borax, 1.5 parts of water-soluble PVA (degree of polymerization 1700), 0.3 parts of polydimethylsiloxane, 0.6 parts of carbamate, 0.5 parts of sodium chloride, 0.4 parts of nano-silica (particle size 20-30nm), 0.3 parts of hydroxypropyl methylcellulose, and 0. 2 parts; add water to the reactor, heat to 45-50℃, add caustic soda solution and stir evenly, then let stand for 10 minutes; slowly add modified starch while stirring, and keep at 50-55℃ for 30 minutes until dissolved; add borax, water-soluble PVA and polydimethylsiloxane in sequence, heat to 60-65℃ and stir for 20 minutes; cool to 40-45℃, add the remaining components and stir for 40 minutes, cool to room temperature and filter to obtain the adhesive.

[0045] S22 corrugated forming: A single-facer is used to form the wood pulp core paper (120g / m²). 2 Press into A-type corrugated paper, and apply 25g / m² of adhesive to the corrugated peaks on one side of the core paper. 2 The core paper is initially bonded to the inner liner to form a single-sided corrugated board; on the other side of the core paper, a double-sided machine-coated adhesive of 27g / m² is applied to the corrugated peaks. 2 It is bonded to the face paper to form double-sided corrugated cardboard; the gluing pressure is controlled at 0.3MPa, and the gluing amount is 18g / m². 2 .

[0046] S23 Drying and Curing: The double-sided corrugated cardboard is sequentially fed into the wet end drying zone (95℃) and the dry end drying zone (135℃) to ensure that the final moisture content of the cardboard is 8%.

[0047] S3. Corrugated Cardboard Box Preparation

[0048] The double-sided corrugated cardboard is slotted and folded using a slotting machine, then die-cut using a die-cutting machine (pressure 8MPa), and finally glued to produce a corrugated cardboard box.

[0049] Example 2

[0050] The difference between this embodiment and Embodiment 1 is that:

[0051] S11 grinding and beating degree control is 50°SR; S13 surface adhesive application dry amount is 5g / m². 2 Bamboo pulp paper weight 105g / m² 2 ;

[0052] S21 adhesive raw material dosage: water 70.0 parts, modified starch 20.0 parts, caustic soda solution 1.5 parts, borax 1.0 parts, water-soluble PVA 1.8 parts, polydimethylsiloxane 0.4 parts, carbodiamine 0.8 parts, sodium chloride 0.65 parts, nano silica 0.5 parts, hydroxypropyl methylcellulose 0.4 parts, sodium alginate 0.3 parts;

[0053] S22 single-sided machine adhesive application rate: 28g / m 2 Double-sided machine adhesive application rate: 30g / m 2 The adhesive application pressure is 0.4 MPa, and the adhesive application amount is 20 g / m. 2 ;

[0054] The temperature of the wet part drying zone of S23 is 100℃, and the temperature of the dry part drying zone is 140℃; the die-cutting pressure of S3 is 9MPa.

[0055] The remaining steps and parameters are the same as in Example 1.

[0056] Example 3

[0057] The difference between this embodiment and Embodiment 1 is that:

[0058] S11 grinding and slurry dissociation degree is controlled at 55°SR; S13 surface adhesive application dry amount is 6g / m². 2 Bamboo pulp paper, 120g / m² 2 ;

[0059] S21 adhesive raw material dosage: water 72.0 parts, modified starch 22.0 parts, caustic soda solution 1.8 parts, borax 1.2 parts, water-soluble PVA 2.0 parts, polydimethylsiloxane 0.5 parts, carbodiamine 1.0 part, sodium chloride 0.8 parts, nano silica 0.6 parts, hydroxypropyl methylcellulose 0.5 parts, sodium alginate 0.4 parts;

[0060] S22 single-sided machine adhesive application rate: 30g / m 2 Double-sided machine adhesive application rate: 32g / m 2 The adhesive application pressure is 0.5 MPa, and the adhesive application amount is 22 g / m. 2 ;

[0061] The temperature of the wet part drying zone of S23 is 105℃, and the temperature of the dry part drying zone is 150℃; the die-cutting pressure of S3 is 10MPa.

[0062] Comparative Example 1

[0063] The difference between this comparative example and Example 2 is that the S11 pulping degree of beating is controlled at 35°SR, and the oxygen bleaching process is not used; the remaining steps and parameters are the same as those in Example 2.

[0064] Comparative Example 2

[0065] The difference between this comparative example and Example 2 is that: S13 did not involve double-sided sizing treatment; the remaining steps and parameters are the same as in Example 2.

[0066] Comparative Example 3

[0067] The difference between this comparative example and Example 2 is that no nano-silica and sodium alginate were added to the S21 adhesive; the remaining steps and parameters are the same as in Example 2.

[0068] Comparative Example 4

[0069] The difference between this comparative example and Example 2 is that the drying in S13 uses a single temperature of 110°C without segmented control; the remaining steps and parameters are the same as in Example 2.

[0070] Comparative Example 5

[0071] The difference between this comparative example and Example 2 is that commercially available wood pulp paper (105 g / m²) was used. 2 The bamboo pulp paper was used as the inner and outer paper; the remaining steps and parameters were the same as in Example 2.

[0072] Blank example

[0073] Blank example: Commercially available ordinary corrugated cardboard boxes (inner and outer paper are wood pulp paper, no special sizing, and ordinary starch glue are used as adhesives) are selected, and the specifications are the same as those of the corrugated cardboard boxes prepared in Example 2.

[0074] Performance testing solution

[0075] Referring to comparative documents and corrugated cardboard box industry standards, performance tests were conducted on the corrugated cardboard boxes of Examples 1-3, Comparative Examples 1-5, and blank examples. The specific procedures are as follows:

[0076] Basic mechanical properties: Edge crush strength: tested according to GB / T 16717-2013 "Packaging Containers - Heavy Duty Corrugated Boxes" standard, unit kN / m;

[0077] Puncture strength: Tested according to GB / T 6544-2008 "Corrugated Board" standard, unit: J;

[0078] Bursting strength: Tested according to GB / T 6544-2008 "Corrugated Board" standard, unit kPa;

[0079] Folding endurance: Tested according to GB / T 2679.5-1995 "Determination of folding endurance of paper and paperboard", unit is fold (MIT method, longitudinal).

[0080] Environmental adaptability performance: Plum rain season simulation test: The sample was placed in a constant temperature and humidity chamber at 25℃ and 90% relative humidity for 48h. Immediately after removal, the edge crush strength was tested, and the strength retention rate was calculated (strength after treatment / strength before treatment × 100%).

[0081] Winter simulation test: Place the sample in a constant temperature and humidity chamber at 5℃ and 30% relative humidity for 48 hours. Immediately after removal, test the folding endurance and calculate the folding retention rate (folding after treatment / folding before treatment × 100%).

[0082] Printing compatibility: The standard pattern is printed on the surface of the paper using a flexographic printing press. The printing effect is visually observed and divided into three levels: excellent (clear pattern, no powdering, no blurring), good (relatively clear pattern, slight powdering), and poor (blurred pattern, severe powdering or blurring).

[0083] Cost accounting: Calculate the raw material costs and energy consumption costs during the production process of each sample, and calculate the production cost per unit area (yuan / m²). 2 The cost reduction rate is calculated based on the blank example.

[0084] Performance test comparison

[0085] Table 1 Comparison of Corrugated Cardboard Box Performance Tests

[0086]

[0087]

[0088] Note: 1. Cost reduction rate = (Unit cost of blank example - Unit cost of sample) / Unit cost of blank example × 100%; 2. Comparative Example 5 uses wood pulp paper, which has a higher raw material cost than bamboo pulp paper in this application, so the cost reduction rate is negative.

[0089] Test Result Analysis

[0090] 1. Mechanical performance advantages: The core mechanical indicators such as edge crush strength and puncture strength of Examples 1-3 are significantly better than those of the blank example and better than most comparative examples, indicating that the bamboo pulp processing technology (precision pulping and oxygen bleaching) and composite adhesive formulation of this application can effectively make up for the shortcomings of bamboo pulp fibers and improve the structural stability of the carton.

[0091] 2. Outstanding environmental adaptability: The edge compression retention rate (88%-93%) and flexural strength retention rate (90%-94%) of the examples during the rainy season were much higher than those of the blank examples (52%, 58%) and the comparative example 3 (68%, 75%) without the addition of nano silica and sodium alginate, proving that the functional components in the adhesive can effectively solve the problem of seasonal performance fluctuations.

[0092] 3. Printing and cost balance: All examples achieved "excellent" level of printability, which is better than Comparative Example 2 without sizing; at the same time, the unit cost was reduced by 9.8%-18.8%. Compared with Comparative Example 5 which uses wood pulp paper, the cost advantage is obvious under similar performance conditions, making it suitable for low-cost demand scenarios such as e-commerce logistics.

[0093] 4. Verification of process rationality: The performance of Comparative Example 1 (low solubility, no oxygen bleaching) and Comparative Example 4 (single drying temperature) was lower than that of the Example, proving that the process details such as the pulping parameters and drying method of this application are crucial to product quality, further highlighting the scientific nature of the process design.

[0094] The embodiments described above are some, but not all, of the embodiments of this application. The detailed description of the embodiments of this application is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

Claims

1. A process for the preparation of a bamboo pulp corrugated carton, characterized by, It comprises the following steps: S1, bamboo pulp paper preparation: S11, pulping, select fresh bamboo, after peeling, slicing, cooking, washing, screening, the pulp processing, the beating degree is controlled in 45-55 °SR; S12, paper pulp deployment, bamboo pulp fiber and water mixed into 3%-5% concentration of suspension, add 0.1%-0.3% of the dry bamboo pulp fiber quality of polyamide epoxy chloropropane resin, stir evenly; S13, papermaking, the bamboo pulp after refining is sent into a paper machine, sequentially through a net section forming, pressing, drying process, wherein the pressing process adopts a shoe type pressing technology, drying temperature is controlled in sections, after drying, hard calendering treatment is carried out, and surface double sizing is 4-6 g / m 2 The final bamboo pulp paper with a grammage of 90-120 g / m 2 is used as inner paper and surface paper of corrugated paperboard. S2, corrugated board preparation: using single-sided machine to press wood pulp paper into core paper, using single-sided machine to coat adhesive on one side of the corrugated peak of the core paper, so that the core paper and the inner paper are initially adhered to form single-sided corrugated paper, using double-sided machine to coat adhesive on the other side of the corrugated peak of the core paper, so that the single-sided corrugated paper and the surface paper are adhered to form double-sided corrugated paper, the single-sided machine coats adhesive 25-30 g / m 2 , the double-sided machine coats adhesive 27-32 g / m 2 ; after the adhesion is completed, the paperboard enters the wet part drying area, the temperature of the wet part drying area is 95-105℃, then enters the dry part drying area, the temperature of the dry part drying area is 135-150℃, the coating amount is controlled to be 18-22 g / m 2 , the coating pressure is 0.3-0.5 MPa, so that the inner paper, the surface paper and the core paper are firmly adhered; S3, corrugated box preparation: using slotting machine to open the double-sided corrugated paper prepared in S2 to lap joint slot, fold the line after pressing, using die cutting machine to die cut into shape, die cutting pressure is 8-10 MPa, the corrugated box is prepared.

2. The corrugated carton making process of claim 1 wherein, The adhesive in S2 comprises the following raw materials by weight: water 68.0-72.0 parts, modified starch 18.0-22.0 parts, caustic solution 1.2-1.8 parts, borax 0.8-1.2 parts, water-soluble PVA 1.5-2.0 parts, polydimethylsiloxane 0.3-0.5 parts, carbamide 0.6-1.0 parts, sodium chloride 0.5-0.8 parts, nano silicon dioxide 0.4-0.6 parts, hydroxypropyl methyl cellulose 0.3-0.5 parts, sodium alginate 0.2-0.4 parts.

3. The corrugated carton making process of claim 2, wherein, The preparation method of the adhesive is: according to the proportion, water is added to the reaction kettle, heated to 45-50℃, the caustic solution is added under stirring, stirred evenly and then placed for 10 minutes; slowly add modified starch, stirring while adding, keep the temperature at 50-55℃, stirring for 30 minutes until the starch is completely dissolved; add borax, water-soluble PVA, polydimethylsiloxane in turn, heat to 60-65℃, continue stirring for 20 minutes; cool to 40-45℃, add carbamide, sodium chloride, nano silicon dioxide, hydroxypropyl methyl cellulose and sodium alginate, stir for 40 minutes, cool to room temperature and then filter to obtain the adhesive.

4. The corrugated carton manufacturing process of claim 1, wherein, In S11, the bamboo is peeled, sliced, cooked at 120℃ for 2h, washed, screened and bleached by oxygen bleaching process. The bleached bamboo pulp fiber is subjected to pulp processing, the pulp pressure is 0.3MPa, and the pulp time is 25min.

5. The corrugated carton manufacturing process of claim 1 wherein, In S13, the surface sizing agent comprises the following raw materials by weight: oxidized starch 70-80 parts, polyvinyl alcohol 20-30 parts, total 100 parts.

6. The corrugated carton manufacturing process of claim 1, wherein, The dry temperature segmented control method in S13 is: using multi-section drying cylinder group, setting the drying temperature as front section 100-110℃, middle section 110-120℃, rear section 90-100℃.

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