Corrugating medium for fruit box and production process of corrugating medium

Abstract

The invention relates to corrugating base paper for a fruit box. The corrugating base paper comprises the following raw materials in percentage by weight: 65-75% of OCC pulp, 23-27% of broadleaf wood chemi-mechanical pulp and 5-8% of wood fibers. According to the invention, broadleaf wood chemi-mechanical pulp is added into OCC pulp to increase the fracture length of paper, wood fibers are added to increase the permeation of surface sizing starch, and the starch enhancer is introduced, so that in the starch gelatinization process, the starch enhancer can effectively weave a glucose chain of starch into a net-shaped structure, thereby remarkably improving the strength of the OCC pulp, optimizing the sizing effect of the starch, and improving the quality of the OCC pulp. The process of combining internal sizing and surface sizing is used, the moisture regain resistance of the paper on the end face and the surface is improved, the stiffness, bursting strength and ring crush compression resistance of the paper can be remarkably improved by using the production process, and the moisture regain resistance effect is good.

Description

Technical Field

[0001] The invention belongs to the technical field of corrugated paper production, and in particular relates to a production process of corrugated paper for fruit boxes. Background Art

[0002] Corrugated paper, also known as corrugated core paper, is used to manufacture the core layer of carton board. After being processed by corrugated rollers, corrugated paper is formed into corrugated paper, which is then bonded with linerboard to form a corrugated box. As an indispensable raw material for carton board, the market demand for corrugated paper continues to grow.

[0003] Fruits are picked in summer and autumn, put into cartons, transferred to cold storage for storage, and shipped out in winter or the spring of the following year. Therefore, the packaging boxes are required to have high water resistance and high pressure resistance. The corrugated paper in the packaging box plays a decisive role in supporting the strength of the box body. Therefore, high requirements are placed on the moisture regain resistance of the corrugated base paper to ensure that the carton remains stable when valuables are stored in a low temperature and high humidity environment for a long time, and avoid softening and collapse. In this way, the ring compression strength of the corrugated base paper becomes a key performance indicator in its practical application.

[0004] At present, the production of corrugated paper mainly relies on domestic waste as raw materials. However, after repeated use, the strength of waste paper fiber has significantly decreased, resulting in insufficient strength of the produced high-strength corrugated paper, which is difficult to meet the packaging industry's demand for high-quality materials. Summary of the invention

[0005] The object of the present invention is to provide a production process of corrugated paper for fruit boxes, which can solve the problems of low ring pressure and poor moisture resistance;

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] A production process of corrugated paper for fruit boxes. The corrugated paper comprises the following raw materials in percentage by weight: 65-75% of OCC pulp, 23-27% of broadleaf chemical-mechanical pulp and 5-8% of wood fiber.

[0008] In another aspect, the present invention provides a production process for preparing the corrugated paper for fruit boxes as described above, comprising the following steps:

[0009] S1, making OCC pulp from waste paper, and crushing hardwood chemimechanical pulp and wood fiber material with water to make hardwood chemimechanical pulp and wood fiber pulp;

[0010] S2, mixing OCC pulp, hardwood chemimechanical pulp and wood fiber pulp in proportion to obtain a mixed pulp;

[0011] S3. The mixed pulp is formed into slurry through the flow conveying system. The slurry is dispersed through the headbox and then sprayed onto the wire. After the paper is dehydrated and formed on the wire, it is pressed, pre-dried, surface-bonded, post-dried, and rolled up to obtain corrugated base paper.

[0012] Preferably, the concentration of the OCC pulp is 10%, the concentration of the hardwood chemimechanical pulp is 5%, and the concentration of the wood fiber pulp is 4%.

[0013] Preferably, the flow system includes a slurry pump and a pressure screen. After the mixed slurry passes through the slurry pump, 0.8-1 kg / ton of paper of ASA neutral sizing agent is added to the mixed slurry. After the pressure screen, 2-3 kg / ton of paper of bentonite is added.

[0014] Preferably, in step S3, the slurry concentration is 0.9%-0.95%.

[0015] Preferably, in step S3, corn starch, starch increasing agent and impedance agent are added during the surface bonding process.

[0016] Preferably, the amount of corn starch added is 100-110 kg / ton of paper, and the amount of starch increasing agent added is 3-3.5 kg / ton of paper.

[0017] Preferably, the impedance agent is silicone oil, and the added amount of the impedance agent is 8-15 kg / ton of paper.

[0018] The present invention adds poplar chemical-mechanical pulp to OCC pulp to increase the breaking length of paper, adds wood fiber to increase the penetration of surface starch, and introduces a starch enhancer. During the starch gelatinization process, the starch enhancer can effectively weave the glucose chains of starch into a network structure, thereby significantly improving its strength, optimizing the starch sizing effect, and enhancing the strength of starch film formation. Using this production process, the stiffness, bursting resistance and ring crush strength of paper can be significantly improved, ensuring the production of high-strength corrugated paper.

[0019] The present invention adds ASA neutral sizing agent into the slurry, reacts with the hydroxyl groups of the fibers in OCC pulp, poplar chemical mechanical pulp and wood fiber pulp to form esters, and at the same time, partially hydrolyzed dicarboxylic acid forms acid salts or esters with various metal ions and cationic polymer substances in the slurry to increase the waterproof performance of the paper on the cut surface. After the pressure screen, bentonite is added to absorb fine fibers through the bentonite, which is conducive to the retention of the ASA neutral sizing agent and ensures the sizing effect in the slurry. In addition, an impedance agent is added to the surface glue to form a water-resistant film on the surface of the paper. The water-resistant film can significantly reduce the moisture absorption of corrugated paper in a high-humidity environment and reduce the decrease in the ring compression strength of the corrugated paper due to moisture.

[0020] The present invention adds silicone oil during the surface adhesive process, and the hydrophobic groups in the silicone oil molecules extend toward the water surface to form a molecular film, which can effectively isolate water and other substances and achieve a moisture-proof effect. DETAILED DESCRIPTION

[0021] The present invention is further described below in conjunction with specific embodiments.

[0022] In the specific implementation, in the present invention, preferably, the broadleaf wood chemical-mechanical pulp is poplar wood chemical-mechanical pulp, and the poplar wood chemical-mechanical pulp is purchased from Jiaozuo Ruifeng, with the wet weight ≥1.0g and beating degree 25-35°SR; the wood fiber material is purchased from Bazhou Zhongya, with the wet weight ≥0.8g, beating degree 25-35°SR, and COD ≤5000mg / L; the ASA neutral sizing agent is Nalco ASA; the starch enhancer is Hongfa Technology starch cross-linking agent, the main component of which is polymer resin.

[0023] The present invention provides a production process of corrugated paper for fruit boxes, comprising the following steps:

[0024] S1, making OCC pulp from waste paper, and crushing hardwood chemimechanical pulp and wood fiber material with water to make hardwood chemimechanical pulp and wood fiber pulp;

[0025] Specifically, the process of making OCC pulp from waste paper includes the following steps: the waste paper is conveyed by a chain conveyor to a hydraulic pulper, and then an appropriate amount of water is added for stirring and crushing. During this process, light impurities such as plastics are effectively removed from the system through the synergistic effect of equipment such as hydraulic slag removers, drum screens and roller screens, while heavy residues such as gravel and iron sheets are separated by a high-concentration slag remover and discharged from the system. Finally, the treated pulp is sent to a discharge tower for subsequent use.

[0026] The pulp delivered from the pulping workshop must first be screened through a coarse screen for preliminary screening of the pulp. The tail pulp from the coarse screen is processed through an apple screen, and the separated fibers are re-transported to the hydraulic pulper for recycling, while the impurities are discharged from the system. For the good pulp after preliminary screening, the fibers in the pulp are divided into different grades according to the length and diameter of the fibers through a grading screen for fine grading to form long, medium and short fiber pulps. Subsequently, these pulps are processed by a low-concentration cleaner to remove the fine sand and gravel mixed in them.

[0027] In addition, long fiber pulp is screened more deeply through fine screening, and coarse fibers such as fiber bundles and impurities are discharged from the system to ensure the quality of the pulp. The long and short fiber pulp and medium fiber pulp will enter the long and short fiber multi-disc concentrator and the medium fiber multi-disc concentrator for concentration treatment respectively. After treatment, the pulp concentration reaches 10%, for subsequent use.

[0028] Specifically, the hardwood chemimechanical pulp is made into hardwood chemimechanical pulp comprising the following steps:

[0029] The bulk hardwood pulp is conveyed by a chain conveyor to a hydraulic pulper. After that, an appropriate amount of water is added for stirring and crushing. It is pumped to a high-concentration cleaner to remove heavy residues such as stones and iron sheets. It is then diluted to form a 5% concentration pulp and sent to a discharge tower for subsequent use.

[0030] Specifically, the process of making wood fiber pulp from wood fiber material includes the following steps: the wood fiber bulk material is conveyed by a chain conveyor to a hydraulic pulper, and then an appropriate amount of water is added for stirring and crushing treatment, and then the material is pumped to a high-concentration remover to remove heavy residues such as stones and iron sheets, and then enters a pre-beating tank, where it is beaten by a disc grinder to form a 4% concentration of pulp and enters a post-beating tank for subsequent use.

[0031] S2, the pulp delivered from the pulping workshop is put into a mixing pulp tank according to the ratio of 70% OCC pulp, 25% hardwood chemical mechanical pulp and 5% wood fiber pulp to obtain a mixed pulp;

[0032] S3, the mixed pulp is formed into slurry through the flow conveying system, the slurry is dispersed through the headbox and then sprayed onto the wire part, the paper is dehydrated and formed on the wire part, and then pressed, pre-dried, surface glued, post-dried, and rolled to obtain corrugated base paper;

[0033] Specifically, after the mixed slurry is processed by the slurry tank, the slurry pump and the pressure screen, a slurry with a concentration between 0.9% and 0.95% is formed, and then the slurry is sprayed onto the net through the headbox;

[0034] More specifically, after the mixed slurry passes through the slurry pump, 5 kg / ton of aluminum sulfate and 0.8 kg / ton of ASA neutral sizing agent are added to the mixed slurry, 0.3 kg / ton of dry powder retention aid is added before the pressure screen, and 2 kg / ton of bentonite is added after the pressure screen.

[0035] More specifically, the neutral sizing agent is ASA neutral sizing agent, which undergoes an esterification reaction with the hydroxyl group of the fiber, and the surface of the fiber changes from hydrophilic to water-resistant. The sizing can be completed before surface sizing, does not require aging, and has good hot water resistance.

[0036] Specifically, the paper is dehydrated through a single-layer fourdrinier wire in the wire section, and the dehydration element is used to increase the dryness of the paper to 20-21%. Then, the paper enters the pressing section, which consists of four rollers and three presses. After the pressing process, the dryness of the paper is increased to about 52%. The paper goes through the processes of pre-drying, surface gluing, post-drying, winding, rewinding, packaging and storage in sequence.

[0037] More specifically, in the process of surface sizing of paper, corn starch and starch enhancer are used to improve the quality of paper. The amount of corn starch used is 110kg / ton of paper, and the amount of starch enhancer used is 3kg / ton of paper. The starch enhancer can bind the hydrogen bonds formed between starch molecules together, make the starch molecules cross each other, and form new chemical bonds, thereby increasing the stability of the starch molecules and allowing the starch to form a tighter structure during the heating process.

[0038] More specifically, during the process of sizing the surface of paper, an impedance agent is used to improve the waterproof performance of the product. The impedance agent is silicone oil, and the amount of the impedance agent added is 15kg / ton of paper. The water absorption of the finished paper is less than 40g / m 2 , water resistance time>30min, 180g / m 2 The transverse ring crush index of corrugated paper reaches 12N.m / g.

[0039] Table 1 shows the performance parameters of Comparative Examples 1 to 5 and Examples 1 to 2 obtained by using the above production method.

[0040] Table 1 Production weight 180g / m 2 , indicators under different addition conditions:

[0041]

[0042] From the above table, we can see that after adding starch enhancer, the ring compression strength index increased by 8%, from about 11.5 to about 12.5. By adding impedance agent, the water absorption value of the front and back sides decreased greatly, and the moisture regain ring pressure attenuation ratio dropped to less than 20%, achieving a good anti-moisture regain effect.

Claims

1. A corrugated paper for fruit boxes, characterized in that: The corrugated base paper comprises the following raw materials in percentage by weight: 65-75% of OCC pulp, 23-27% of broadleaf chemical mechanical pulp and 5-8% of wood fiber.

2. A production process for preparing the corrugated paper for fruit boxes as claimed in claim 1, characterized in that: The steps include: S1, making OCC pulp from waste paper, and crushing hardwood chemimechanical pulp and wood fiber material with water to make hardwood chemimechanical pulp and wood fiber pulp; S2, mixing OCC pulp, hardwood chemimechanical pulp and wood fiber pulp in proportion to obtain a mixed pulp; S3, the mixed pulp is formed into slurry through the flow conveying system, the slurry is dispersed through the headbox and then sprayed onto the wire part, the paper is dehydrated and formed on the wire part, and then pressed, pre-dried, surface glued, post-dried, and rolled to obtain corrugated base paper; Among them, corn starch, starch increasing agent and impedance agent are added during the surface bonding process.

3. The production process according to claim 2, characterized in that: The concentration of the OCC pulp is 10%, the concentration of the hardwood chemimechanical pulp is 5%, and the concentration of the wood fiber pulp is 4%.

4. The production process according to claim 2, characterized in that: The flow system includes a slurry pump and a pressure screen. After the mixed slurry passes through the slurry pump, 0.8-1 kg / ton of ASA neutral sizing agent is added to the mixed slurry. After the pressure screen, 2-3 kg / ton of bentonite is added.

5. The production process according to claim 2, characterized in that: In step S3, the slurry concentration is 0.9%-0.95%.

6. The production process according to claim 2, characterized in that: The added amount of corn starch is 100-110 kg / ton of paper, and the added amount of starch increasing agent is 3-3.5 kg / ton of paper.

7. The production process according to claim 2, characterized in that: The impedance agent is silicone oil; the added amount of the impedance agent is 8-15kg / ton of paper.

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