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CN-121992679-A - Process for improving plastic suction fastness of plastic suction card

CN121992679ACN 121992679 ACN121992679 ACN 121992679ACN-121992679-A

Abstract

The invention belongs to the technical field of papermaking, and particularly relates to a process for improving the plastic suction fastness of a plastic suction card. The method comprises the steps of firstly treating needle and hardwood pulp by using compound enzyme, adding light magnesium oxide, pulping to obtain compound modified pulp, then preparing three-layer pulp, diluting, purifying, adding an auxiliary agent to a three-layer pulp pump before purifying, adding a core layer auxiliary agent containing methylol urea modified cationic polysaccharide and the like to the core layer pump, compounding the three-layer pulp into a wet paper web layer by using a headbox, drying the wet paper web before gradient after multiple pressing dehydration, and then sequentially carrying out surface sizing, post drying, hard calendering, front and back coating and soft calendering to obtain a finished product of the plastic suction card. The process effectively solves the problems of unstable plastic suction and shelling in the narrow-side plastic suction bulb shell processing, realizes the standardized control of slurry quality, greatly reduces the batch-to-batch difference of plastic suction effect, obviously improves the binding force of a narrow-side plastic suction area, optimizes the surface performance of paper, reduces the phenomenon of printing hair and powder, and improves the printing adaptability.

Inventors

  • LI BANGYUAN
  • LIU JINGUANG
  • WANG JUNMING
  • WANG ZENGJIAN
  • QUAN JIPING

Assignees

  • 山东博汇纸业股份有限公司

Dates

Publication Date
20260508
Application Date
20260304

Claims (10)

  1. 1. The process for improving the plastic suction fastness of the plastic suction card is characterized by comprising the following steps of: s1, pulping, namely using white water generated by a forming part of a paper machine as pulping water; S2, pulping, namely respectively carrying out enzyme treatment on softwood pulp and hardwood pulp by adopting compound enzyme of cellulase and laccase, mixing to obtain compound modified pulp, adding light magnesium oxide into the compound modified pulp, adjusting the concentration, and then delivering the mixture into a disc mill for pulping treatment; S3, preparing sizing agents, namely respectively preparing surface sizing agents, bottom sizing agents and core sizing agents; S4, diluting, namely respectively diluting the surface layer slurry, the bottom layer slurry and the core layer slurry after slurry preparation, correspondingly conveying the surface layer slurry, the bottom layer slurry and the core layer slurry by a three-layer slurry pump, and then feeding the surface layer slurry, the bottom layer slurry and the core layer slurry into a pressure screen for purification treatment; S5, net surfing molding, namely respectively conveying the purified surface layer slurry, the purified bottom layer slurry and the purified core layer slurry to a three-layer headbox for slurry distribution, sequentially spraying all layers of slurry flows on the surface of a molding net through the lip of the headbox, and compositing the layers of slurry flows layer by layer to form a wet paper web; S6, squeezing, namely conveying the wet paper web into a squeezing part, sequentially carrying out one-shoe squeezing and two-shoe squeezing to finish dehydration, and eliminating net marks and blanket marks through three-gloss squeezing; s7, pre-drying, namely, squeezing and dehydrating the wet paper web, then entering a pre-drying section, and performing pre-drying in a gradient heating mode; S8, surface sizing, namely performing surface sizing on the paper web dried before; s9, post-drying, namely post-drying the paper web subjected to surface sizing to enable the surface sizing liquid to be cured; S10, hard calendering, namely hard calendering the paper web after the post drying; S11, coating, namely performing front coating and back coating on the paper web subjected to hard calendering; s12, soft calendering, namely respectively carrying out soft calendering treatment on the front surface and the back surface of the coated paper web, and obtaining a finished product of the plastic suction card after the treatment.
  2. 2. The process for improving the plastic suction fastness of the plastic suction card according to claim 1, wherein in the step S1, the pulp crushing concentration is 5%; In the step S2, the softwood pulp is silver star bleached sulfate softwood pulp, and the hardwood pulp is Chilean star bleached sulfate hardwood pulp; in the enzyme treatment process, the softwood pulp is treated by a compound enzyme for 20-30min, the adding amount of the compound enzyme is 0.08-0.12wt.% of the softwood pulp, the enzymolysis temperature is 55-60 ℃, the pH value is 4.8-5.2, the hardwood pulp is treated by the compound enzyme for 15-20min, the adding amount of the compound enzyme is 0.05-0.08wt.% of the hardwood pulp, the enzymolysis temperature is 50-55 ℃, the pH value is 5.0-5.4, the softwood pulp and the hardwood pulp after the enzyme treatment are mixed according to the mass ratio (28-32) of (68-72) to obtain a compound modified pulp, light magnesium oxide is added into the compound modified pulp, the adding amount of the light magnesium oxide is 1.5-2.5wt.% of the compound modified pulp, the light magnesium oxide is adjusted to 3.0-3.5%, the mixture is sent into a disc mill for milling treatment, the specific energy consumption of the hardwood pulp is controlled to be more than or equal to 90kWh/t, the gap is 0.12-0.16mm, the milling current is 300-340A, the reflux ratio is 10-15 DEG, and the wet milling pulp is 6-38 g.
  3. 3. The process for improving the plastic suction fastness of the plastic suction card according to claim 1, wherein in the step S3, surface layer pulp consists of 70-75% of bleached sulfate hardwood pulp and 25-30% of bleached sulfate softwood pulp, bottom layer pulp consists of 70-75% of bleached sulfate hardwood pulp and 25-30% of bleached sulfate softwood pulp, core layer pulp consists of 57-65% of bleached chemical thermomechanical pulp and 35-43% of damaged pulp, the damaged pulp is unqualified paper produced in the production process, pulp obtained after being crushed by a pulper is prepared by taking poplar and pine as raw materials through NaOH pre-soaking, primary pulping, bleaching, secondary pulping and concentration in sequence.
  4. 4. The process for improving the plastic sucking fastness of the plastic sucking card according to claim 1, wherein in the step S4, the concentration of the diluted back layer slurry and the bottom layer slurry is 0.25-0.35%, the concentration of the core layer slurry is 0.8-1.2%, and the addition amount of the dry powder auxiliary agent is 200-500ppm of the total amount of each layer of slurry respectively; The dosage of AKD in the core layer auxiliary agent is 4.5-7kg/t pulp, the dosage of GCC 60 is 20-60kg/t pulp, the dosage of silica sol is 2-7kg/t pulp, the dosage of methylol urea modified cationic polysaccharide is 4-8kg/t pulp, and the dosage of cationic starch-PAE composite dry strength agent is 6-9kg/t pulp; The preparation method of the methylol urea modified cationic polysaccharide comprises the steps of adding cationic starch into deionized water to prepare a polysaccharide suspension, heating to 60-65 ℃, stirring until the polysaccharide suspension is completely gelatinized, adopting a hydrochloric acid solution to adjust the pH of a system to 4.8-5.2, then adding ammonium chloride and methylol urea, heating to 75-80 ℃, stirring at constant temperature for reacting for 40-60min, adopting a hydrochloric acid solution to maintain the pH value of the system to 4.8-5.2 during the period, and adopting a sodium hydroxide solution to adjust the pH of the system to 6.8-7.2 after the reaction is finished, and drying for later use, wherein the concentration of the polysaccharide suspension is 8-12wt.%, the addition amount of ammonium chloride is 0.05-0.1wt.% of the total amount of the polysaccharide suspension, and the mass ratio of the polysaccharide suspension to the methylol urea is (4-6): 1; The preparation method of the cationic starch-PAE composite dry strength agent comprises the steps of mixing cationic starch and PAE according to the mass ratio of (3-5): 1, adding the mixture into water to prepare a mixed solution with the concentration of 10-15wt.%, stirring and reacting for 30-40min at 70-75 ℃, and cooling to obtain the cationic starch-PAE composite dry strength agent.
  5. 5. The process for improving the plastic suction fastness of the plastic suction card according to claim 1, wherein in the step S5, the core layer is firstly compounded with the surface layer, and the tapioca starch is sprayed on the bonding surface of the surface layer before the compounding, and then the tapioca starch is compounded with the bottom layer.
  6. 6. The process for improving the plastic suction fastness of the plastic suction card according to claim 1, wherein in the step S6, the dryness of the pressed base paper is 45-48%.
  7. 7. The process for improving the plastic suction fastness of the plastic suction card according to claim 1, wherein in the step S7, the gradient heating mode is specifically that the drying temperature is divided into three sections, namely 100 ℃, 110 ℃ and 105 ℃, the corresponding drying completion degrees are 30%, 70% and 100%, and in the step S9, the post-drying temperature is 100-120 ℃.
  8. 8. The process for improving the plastic sucking fastness of the plastic sucking card according to claim 1, wherein in the step S8, a mixed solution of tapioca starch and AKD is used as a sizing solution, wherein the using amount of the AKD is 0.9-1.3wt.% of tapioca starch, the preparation viscosity of the sizing solution is 200-220cps, the preparation solid content is 27-29%, the upper machine temperature is 72-78 ℃, the upper machine viscosity is 30-40cps, the upper machine solid content is 10-14%, the front sizing amount is 0.8-1.2g/m 2 , and the back sizing amount is 3-4g/m 2 .
  9. 9. The process for improving the plastic sucking fastness of the plastic sucking card according to claim 1, wherein in the step S10, the temperature of hard calendering is 110-130 ℃ and the pressure is 5-20kN/m, in the step S12, the temperature of front soft calendering is 110-130 ℃, the pressure is 15-25kN/m, the temperature of back soft calendering is less than or equal to 55 ℃ and the pressure is 0kN/m.
  10. 10. The process for improving the plastic suction fastness of the plastic suction card according to claim 1, wherein in the step S11, a hard scraper is used for front coating, the coating weight is 24.5-26.5g/m 2 , a soft scraper is used for back coating, and the coating weight is 21-23g/m 2 .

Description

Process for improving plastic suction fastness of plastic suction card Technical Field The invention belongs to the technical field of papermaking, and particularly relates to a process for improving the plastic suction fastness of a plastic suction card. Background The plastic suction card is used as an environment-friendly paper-based packaging material, has been widely applied to packaging scenes of a plurality of industries such as food, medicine, electronics, toys, cosmetics, mechanical hardware and the like by virtue of good forming performance and environment-friendly characteristics, is especially suitable for forming and processing of narrow-side plastic suction blisters, can be used for preparing various non-thermal forming plastic suction products such as folded edges, cylinders, top and bottom boxes and the like, and takes an important place in the packaging field. The product belongs to the technical field of paper-based packaging material preparation, and has the core requirements of considering printing performance and plastic uptake fastness so as to meet the packaging use requirements in different scenes. At present, PVC, PP, PET, recyclable paper and the like are used as base materials in the existing preparation process of the plastic suction card, and cationic starch, a dry strength agent and other reinforcing chemicals are added into the pulp to improve the strength of the paper, and the plastic suction forming is realized by matching with a plastic suction oil coating process. However, the prior art still has a plurality of defects and shortcomings to be solved in practical application, which seriously affect the product quality and application expansion of the plastic suction card: First, there is a core contradiction between paper strength and plastic uptake. In the prior art, in order to improve the strength of paper, a mode of increasing the dosage of a reinforcing chemical and improving the degree of fine fiber of slurry is generally adopted, but excessive fiber hydrogen bonding can lead to compact paper structure and prevent the adequate penetration of plastic-absorbing oil. In particular to a narrow-side plastic foam shell (the processing area is limited), plastic oil cannot be effectively combined with paper fibers, the problems of infirm plastic suction, unshelling and the like are very easy to occur, and the processing requirements of special plastic suction products are difficult to meet. Secondly, the poor control of the stability of the raw materials leads to poor consistency of the products. Part of the prior art does not fix specific products and proportions of needle leaf pulp and broadleaf pulp, and also lacks specific technical modification treatment, so that pulp quality is easy to fluctuate, and the strength of finished paper is unstable. The instability indirectly aggravates the fluctuation of the plastic sucking effect, so that the difference between product batches is larger, the large-scale production requirement is difficult to adapt, and the productivity improvement and market expansion of enterprises are limited. Thirdly, the suitability for narrow-side plastic suction is poor. The existing plastic suction card technology is designed based on the requirements of wide-edge conventional plastic suction products, and the paper structure and chemical formula are not optimized aiming at the characteristic that the narrow-edge plastic suction blister processing area is limited. This leads to the plastic uptake card when the narrow limit plastic uptake scene of adaptation, and the problem that plastic uptake fastness is not enough is especially outstanding, can't satisfy the user demand of high-end precision packaging scene, has restricted the application popularization of plastic uptake card in high-end market. Therefore, developing a plastic suction card preparation process which can break the contradiction between strength and plastic suction fastness, ensure the consistency of products and adapt to narrow-side plastic suction becomes a technical problem to be solved urgently in the field of current paper-based packaging materials. Disclosure of Invention Aiming at the defects of the prior art, the invention aims to provide a process for improving the plastic suction fastness of a plastic suction card, which can cooperatively improve the strength and the plastic suction fastness of paper, effectively solve the problem of unstable plastic suction and shelling in the processing of narrow-side plastic suction foam shells, realize standardized control of slurry quality, greatly reduce the batch-to-batch difference of plastic suction effect, adapt to the large-scale production requirement, obviously improve the binding force of a narrow-side plastic suction area, adapt to high-end precise packaging scenes of the plastic suction card, optimize the surface performance of paper, reduce the phenomenon of printing and hair and powder dropping, and improve the printing adap