Production process of pure bamboo pulp bleached instant paper

Abstract

The present invention relates to the technical field of instant paper production, and discloses a production process of pure bamboo pulp bleached instant paper, including raw material selection, selecting Neosinocalamus affinis as the raw material for production; pulping, after obtaining dry pulp through kraft method combined with elemental chlorine-free bleaching, performing pulping operation through a pulper; refining, increasing the cutting ratio of a refiners to improve the refining strength; sizing, adding white water to the pure bamboo pulp for dilution; papermaking, using wet strength-free circulating water to make a wet paper web; drying, sending the wet paper web into a dryer for drying to obtain paper; wrinkling, using a wrinkling knife to wrinkle the paper; embossing, performing embossing operation on the paper by means of curved surface full embossing. It is to solve the problems of complex existing instant paper production processes and raw materials used, and large pollution caused by the production process.

Description

Technical Field

[0001] The invention relates to the technical field of instant paper production, in particular to a production process of pure bamboo pulp bleached instant paper. Background Art

[0002] Bamboo pulp is primarily made from moso bamboo, nanmu bamboo, and tsaoko bamboo, produced through the sulfate and caustic soda processes. Its fiber morphology, length, and softness are intermediate between those of wood and grass fibers. Due to its slender fibers and hollow cross-section, bamboo pulp exhibits excellent air permeability, instantaneous water absorption, and strong abrasion resistance, while also possessing high mechanical strength.

[0003] Household paper produced from pure bamboo pulp has received widespread acclaim in the market for its high strength, toughness, smooth surface, and resistance to shedding and linting, thanks to the slender fibers of bamboo pulp, high firmness, and the fact that they are all medium-long fibers. However, while pure bamboo pulp household paper has received positive reviews from the market, some products have also received negative feedback. This feedback mainly concerns toilet paper rolls and toilet paper, which are usually used after going to the toilet. Due to their high strength, the paper retains a certain strength even after being wetted, making it difficult to break and disperse. If placed directly in the toilet or sanitary equipment after use, it can easily cause blockage of related equipment and even sewer pipes. If placed in a toilet paper basket in the bathroom, the air in the bathroom can easily become unfriendly.

[0004] Based on the demand for toilet paper's usage environment and easy disposal, pure bamboo pulp toilet paper that can dissolve instantly after being wetted, while ensuring its normal function, has broad market prospects. Currently, instant pure bamboo pulp toilet paper products are rare, and the existing instant paper production process and raw materials are relatively complex, using many chemical reagents, and causing significant environmental pollution. Summary of the Invention

[0005] The present invention aims to provide a pure bamboo pulp bleached instant paper production process to solve the problems of the existing instant paper production process, the complex raw materials used, and the large pollution caused by the production process.

[0006] To achieve the above object, the present invention adopts the following technical solution: a pure bamboo pulp bleached instant paper production process, comprising the following steps:

[0007] Material selection: use bamboo as the raw material for production;

[0008] Pulping, after the dry pulp is made by the sulfate process combined with elemental chlorine-free bleaching, it is pulped by a pulper;

[0009] Refining, by increasing the cutting ratio of the disc refiner to improve the refining intensity;

[0010] Sizing: add white water to the pure bamboo pulp to dilute it;

[0011] Papermaking: Use wet-strength-free recycled water for papermaking to obtain a wet paper web.

[0012] Drying: Feed the wet paper web into a drying cylinder for drying to obtain paper.

[0013] Wrinkling: Use a wrinkling knife to wrinkle the paper.

[0014] Embossing: Perform an embossing operation on the paper in a full-surface curved embossing manner.

[0015] The beneficial effects of this solution are as follows: Using low-cost pure Neosinocalamus affinis bamboo pulp as the production raw material, obtaining pure bamboo pulp raw materials through the kraft method combined with elemental chlorine-free bleaching, and using wet-strength-free recycled water for papermaking to obtain a wet paper web. That is, without adding wet-strength agents in the production process, while meeting the quality requirements of sanitary paper and achieving wet-water rapid-dissolving finished paper, the complexity of the production process and production costs are reduced, and the environmental pollution caused by papermaking is also reduced.

[0016] 1. Neosinocalamus affinis grows fast, has a high yield per unit area, and is relatively convenient for logging and transportation, which can greatly reduce production costs. Moreover, Neosinocalamus affinis can provide high-quality pure long-fiber bamboo pulp. Long fibers can not only ensure the paper strength and air permeability of rapid-dissolving paper, but also, due to the long fiber length, the arrangement will be more orderly, making the surface of the rapid-dissolving paper smoother, the quality of the paper product better, and it is easier to show high brightness.

[0017] 2. In the pulping step, beating enzymes are not used; thus, while avoiding excessive fibrillation of fibers, production costs can be reduced. And because beating enzymes are not used, the temperature control procedure in the pulping step can be omitted, thereby reducing the complexity of the rapid-dissolving paper production process.

[0018] 3. By increasing the cutting effect on bamboo fibers, while ensuring the refining effect, further reducing fiber fibrillation, and thus avoiding excessive internal fiber connection strength in the paper product, which affects the water solubility of the paper when it meets water.

[0019] 4. Through the full-surface curved embossing process, while not affecting the water solubility of the rapid-dissolving paper product when it meets water, the bulkiness of the paper is increased, improving the quality of the formed rapid-dissolving paper; moreover, the surface of the embossed rapid-dissolving paper becomes uneven, correspondingly increasing the surface area of the paper. The small grooves on the rapid-dissolving paper can better absorb and store water, thus further increasing the dissolution speed of the rapid-dissolving paper when it meets water.

[0020] Preferably, in the pulping step, without adding beating enzymes, control the pulping concentration to be 6.5 ± 0.5% and the pulping time to be 300 ± 100 s.

[0021] The beneficial effects of this solution are as follows: enabling bamboo fibers to mix better with water and be evenly distributed, ensuring the quality and effect of pulping, and further guaranteeing the durability of the finished paper product.

[0022] Preferably, in the pulping step, the pulping power of the disk refiner is controlled at 50 ± 10 Kwh / t, the slurry flow rate is 3800 ± 500 L / min, and the pulping concentration of pure bamboo pulp is 5.0 ± 0.2%.

[0023] The beneficial effects of this solution are as follows: enabling bamboo fibers to maintain a certain fiber length while being fully cut, split, and swollen, thus ensuring that the quality of the finished instant paper meets the standards of sanitary paper.

[0024] Preferably, in the sizing step, the lip opening is controlled at 8.20 ± 0.30, and the pulp-to-wire speed ratio is 0.93 ± 0.02.

[0025] The beneficial effects of this solution are as follows: controlling the pure bamboo fiber suspension to prevent flocculation and pulp channels, making the thickness of the paper uniform after the instant paper is formed, and further ensuring the quality.

[0026] Preferably, in the drying step, it also includes a high-efficiency hot air hood and a shoe press technology, and the shoe press pressure is 150 KN / m.

[0027] The beneficial effects of this solution are as follows: ensuring that the water content of the paper after drying is 7.0 ± 0.5%, meeting the standards of sanitary paper.

[0028] Preferably, in the wrinkling step, the angle between the cutting edge surface of the wrinkling knife and the paper outlet end of the dryer cylinder is controlled at 18 ± 0.5°.

[0029] The beneficial effects of this solution are as follows: not only ensuring the softness of the paper and the quality of the paper, but also avoiding excessive wrinkling rate and preventing the instant paper from being damaged during wrinkling.

[0030] Preferably, before the dryer cylinder drying step, it also includes the addition of chemical coatings, and the chemical coatings include a cylinder adhesive, a release agent, and a modifier.

[0031] The beneficial effects of this solution are as follows: ensuring the quality of the finished paper without adding other chemical coatings.

[0032] Preferably, in the pulping and refining steps, a deposit control agent and active alkali are added to the pure bamboo pulp, and the addition amount of active alkali is 0.7 ± 0.3 kg / T.

[0033] The beneficial effects of this solution are as follows: adjusting the pH value of water in the pulping and refining steps.

[0034] Preferably, the sediment control agent includes a fixing agent and a retention aid. The addition amount of the fixing agent is 0.15 ± 0.05 kg / T, and the addition amount of the retention aid is 0.20 ± 0.10 kg / T.

[0035] The beneficial effects of this solution are as follows: The type and amount of the added sediment control agent are both reduced compared with those in the existing papermaking process, which can reduce the production process of this instant paper and lighten the load of wastewater treatment. Description of the Drawings

[0036] Figure 1 It is the process flow chart in Embodiment 1 of the present invention. Detailed Embodiments

[0037] The following is a further detailed description through specific embodiments:

[0038] Embodiment 1

[0039] As Figure 1 shown in the production process of pure bamboo pulp bleached instant paper, which specifically includes the following steps:

[0040] Step 1: Material selection, using Neosinocalamus affinis as the raw material for production.

[0041] When selecting the production raw materials, considering that the obtained instant paper needs to meet the requirements of the sanitary paper standard regulations and instant solubility in water, finally pure Neosinocalamus affinis is selected as the production raw material for the instant paper.

[0042] The fiber content of Neosinocalamus affinis can reach up to 52%, and the fiber belongs to long fiber, with an average length of more than 2.0 mm. It is one of the high-quality bamboo species among bamboos; when using bamboo pulp to make paper, the higher the cellulose content of the bamboo, the higher the pulping rate and the quality of the paper finished product. By selecting pure Neosinocalamus affinis as the production raw material for the instant paper, the paper finished products are all long fibers. The long fibers can not only ensure the paper strength and air permeability of the instant paper, but also because of the long fiber length, the fiber arrangement will be more regular, so that the surface of the instant paper is smoother, the quality of the paper finished product is better, and it is easier to show high brightness.

[0043] In addition, Neosinocalamus affinis grows fast, is easy to reproduce, has a short cycle, and has a high single yield. It is an economic bamboo species. Compared with wood with a long growth cycle, selecting fast-growing pure Neosinocalamus affinis as the production raw material for the instant paper can not only reduce the impact on the environment, but also the raw material cost is relatively low; the felling and transportation of Neosinocalamus affinis are also more convenient, which can further help enterprises reduce production costs. At present, Sichuan has formed a bamboo pulp papermaking industrial chain with it as the leader, which can ensure the supply quantity and supply quality of raw materials and provide guarantee for the production process of pure bamboo pulp bleached instant paper.

[0044] Step 2: Pulping. After obtaining dry pulp through kraft pulping combined with elemental chlorine-free bleaching, pulping operation is carried out using a pulper.

[0045] After cooking the Neosinocalamus affinis raw material with a cooking liquor mainly composed of sodium hydroxide and sodium sulfide, chlorine dioxide is used to replace chlorine and hypochlorite as the bleaching agent to bleach the bamboo pulp, and pure bleached bamboo pulp is obtained. In this embodiment, the procedure of producing pure bamboo pulp by kraft pulping combined with elemental chlorine-free bleaching process is completed by the supplier of Neosinocalamus affinis raw material. The supplier transports the obtained pure bamboo pulp after drying it into dry pulp to reduce transportation costs.

[0046] After obtaining the dry pulp raw material of pure bamboo pulp, pulping operation is carried out using a pulper. In the pulping step, water is added to the dry pulp and it is cut and broken to form cellulose slurry. In order to ensure the instant water solubility of the obtained instant paper product, during pulping, it is not necessary to cause excessive fibrillation of the fibers in the pure bamboo pulp slurry. Excessive fibrillation at both ends of the fibers will increase the bonding points and bonding strength between the bamboo pulp fibers, thereby increasing the wet strength of the paper and making the paper product difficult to dissolve after being wetted. Based on this, in this embodiment, no beating enzyme is added during pulping, which can avoid excessive fibrillation of the fibers while reducing production costs. And because no beating enzyme is used, the control procedure for water temperature in this step can be omitted during water-added pulping, thereby reducing the complexity of the instant paper production process.

[0047] At the same time, in the case of not adding beating enzyme, in order to make the bamboo fibers better mix with water and the bamboo fibers be evenly distributed to ensure the pulping quality and effect, and further ensure the durability of the paper product and ensure that the quality of the instant paper meets the standards of sanitary paper, the pulping concentration is set to 6.5±0.5%, and the time for each pulping is 300±100s. In this embodiment, the pulping concentration is 7.0%, the pulping time is 400s, and the dilution concentration of the pure bamboo pulp slurry is 6.5%.

[0048] In addition, in order to further improve the quality of the instant paper product, after pulping is completed, a high-concentration slag remover is used to remove impurities from the pure bamboo pulp slurry in a suspension state, and the bamboo pulp is refined to further ensure the paper quality.

[0049] Step 3: Refining. By increasing the cutting ratio of the disc refiner, the refining intensity is improved.

[0050] In order to ensure the instant water solubility of the instant paper, in the refining step, a cutting tooth-shaped disc refiner is specially selected to carry out the cutting and refining operation on the pure bamboo pulp slurry. The cutting tooth-shaped disc refiner has a small grinding tooth gap and a large cutting ratio, which can increase the cutting effect on the bamboo fibers, and further reduce the fibrillation of the fibers while ensuring the refining effect, thereby avoiding excessive internal fiber connection strength of the paper product and affecting the instant water solubility.

[0051] Meanwhile, during the pulping process, to ensure the pulping effect, when the pulp slurry passes through the cutting tooth-shaped disc refiner, while increasing the pulp slurry throughput, the pulping consistency is reduced, thereby achieving the effect of reducing the tensile force between bamboo fibers during pulping. Excessive tensile force between fibers will reduce the solubility of the instant paper after wetting. Similarly, in this step, there is no need to add wet strength agents to improve the wet strength of the finished paper. While ensuring the solubility of the instant paper, it can further reduce the addition of chemical reagents in the process of producing instant paper, reduce the complexity of the production process, and reduce the pollution caused by production to the environment.

[0052] In the pulping step, to ensure the finished product quality of the instant paper, it is still necessary to further control the pulping effect. Furthermore, the pulping power of the cutting tooth-shaped disc refiner is set to 50 ± 10 Kwh / t, the pulp slurry flow rate is 3800 ± 500 L / min, and the pulping consistency of pure bamboo pulp is 5.0 ± 0.2%. Thus, after pulping, the wet weight of pure bamboo pulp is controlled to be 13.0 ± 1.0 g, and the beating degree of pure bamboo pulp is 21.0 ± 1.0 °SR. By setting the wet weight of pure bamboo pulp after pulping to 13.0 ± 1.0 g and the range of beating degree to 21.0 ± 1.0 °SR, while the bamboo fibers are fully cut, split, and swollen, a certain fiber length can still be ensured, thereby ensuring that the finished product quality of the instant paper meets the standards of sanitary paper. In this embodiment, the pulping power is 50 Kwh / t, the pulp slurry flow rate is 4300 L / min, and the pulping consistency is 5.2%; thus, after pulping, the wet weight of pure bamboo pulp is 14.0 g, and the beating degree is 22.0 °SR.

[0053] Step Four: Sizing, adding white water to the pure bamboo pulp for dilution.

[0054] In the sizing step, white water is added to the pure bamboo pulp for dilution, and then the diluted pure bamboo pulp slurry is transformed into a thin and uniform pulp flow covering the entire width of the paper machine through a headbox, and the pure bamboo fiber suspension is controlled not to produce flocculation and pulp channels, so that the thickness of the instant paper after forming is consistent, further ensuring the quality; furthermore, the lip opening is set to 8.20 ± 0.30, the pulp-to-wire speed ratio is 0.93 ± 0.02, both the sizing ratio and the white water addition ratio are 50%, and the concentration of pure bamboo pulp is controlled to be 2.9 ± 0.1% during sizing; and to ensure that the pure bamboo pulp is not affected and deteriorates during sizing, the pH value of the added white water is controlled to be 7.8 ± 0.3. In this embodiment, the lip opening is 8.50, the pulp-to-wire speed ratio is 0.95, the concentration of the diluted pure bamboo pulp is controlled to be 3.0%, and the pH value of the added white water is controlled to be 7.8.

[0055] Step Five: Sheet forming, using wet strength-free recycled water to form a wet paper web.

[0056] The pure bamboo pulp after sizing is sent into a crescent former using non-wet-strength recycled water. After operations such as pressing and dewatering by the crescent former, a wet paper web of instant dissolving paper is formed by papermaking.

[0057] Step Six: Drying. The wet paper web is sent into a dryer cylinder for drying to obtain paper.

[0058] The wet paper web obtained by papermaking is sent into a dryer cylinder for water removal and drying. Meanwhile, the temperature of the dryer cylinder is set at 150 °C, and the wet paper web is dried using high temperature to obtain instant dissolving paper. Additionally, in this embodiment, before sending the wet paper web into the dryer cylinder for drying operation, pre-pressing and dewatering are also carried out using a high-efficiency hot air hood and shoe press technology. The shoe press is beneficial for the solidification of the wet paper web, enabling the wet paper web to obtain better strength before drying, thus enabling the press section to have better operating performance; and the reduction of water content in the paper web can also save steam consumption in the dryer cylinder, thereby reducing production costs; while improving the drying efficiency, the hot air hood further improves the bulk of the paper and enhances the softness of the paper, further ensuring the quality of the instant dissolving paper.

[0059] The settings of the pressure value of the dryer cylinder, the temperature value of the hood, and the pressure value of the shoe press are shown in Table 1 below:

[0060]

[0061] Meanwhile, through the above drying parameter settings, it is ensured that the water content of the paper after drying is 7.0 ± 0.5%.

[0062] In this embodiment, the dryer cylinder pressure is set at 700 Kpa, and the steam speed is 78 m / s; the temperature of the hood is 150 °C, the temperature of the exhaust fan is 120 °C, and the rotational speed of the circulation fan is 1200 rpm. The water content of the finally obtained instant dissolving paper is 6.8%.

[0063] Step Seven: Wrinkling. The paper is wrinkled using a wrinkling knife.

[0064] The dried paper is wrinkled using a wrinkling knife to increase the bulk and elongation of the instant dissolving paper, and improve the comfort of using the paper product. The surface of the wrinkling knife in contact with the paper is the blade surface. In this embodiment, the angle of the blade surface is set at 78°, and the angle between the blade surface of the wrinkling knife and the paper outlet end of the dryer cylinder is 18 ± 0.5°; the larger the angle of the blade surface, the greater the wrinkling rate of the surface of the paper scraped on the dryer cylinder, and the greater the bulk and elongation of the obtained paper product. Since pure bamboo pulp is all long fibers, the wrinkling rate is controlled at 22 ± 2%, which can not only ensure the softness of the paper and guarantee the quality of the paper, but also avoid excessive wrinkling rate and prevent the instant dissolving paper from being damaged during wrinkling. In this embodiment, the angle between the blade surface and the paper outlet end of the dryer cylinder is 18.5°, and the wrinkling rate of the instant dissolving paper after wrinkling is 24%.

[0065] Step Eight: Embossing. The paper is embossed by means of full-surface curved embossing.

[0066] The embossing step is an important step in the production process of this instant dissolving paper. In this embodiment, the instant dissolving paper is subjected to full-surface curved embossing. Through double-sided embossing, the instant dissolving paper is multi-layer compounded, thereby optimizing the surface characteristics and structural characteristics of the instant dissolving paper. Without affecting the property of the instant dissolving paper product to dissolve quickly in water, the fluffiness of the paper is increased, the quality of the formed instant dissolving paper is improved, and the comfort of use is enhanced.

[0067] After embossing, the surface of the instant dissolving paper becomes uneven, which correspondingly increases the surface area of the paper. The small grooves on the instant dissolving paper can better absorb and store water, thereby further increasing the dissolving speed of the instant dissolving paper after it meets water.

[0068] Through the above eight steps, from the selection of production raw materials to the embossing and forming of the instant dissolving paper, while ensuring that the finished product meets the use standards of sanitary paper and guaranteeing the quality of the finished paper, through controlling the setting ranges of parameters in each step and rejecting the addition of beating enzymes and wet strength agents and other controls of the actual production process, the instant dissolving of the paper product is achieved, and while simplifying the complexity of the production process, the pollution caused by papermaking production is reduced.

[0069] According to the above parameter control, the quality specifications of the instant dissolving paper product are obtained, as well as the quality parameters of the instant dissolving paper product obtained in Example 1. See Table 2 below for details:

[0070] Main parameters Quality specifications Example 1 Dispersibility (s) ≤25 18 <![CDATA[Quantitative (g / m 2 )]]> 15.5(﹢0.5，-0.3) 15.5 Thickness (mm / 10ply) 0.97±0.04 0.97 ISO whiteness (%) ≥82.5 84 Longitudinal tensile index (N.m / g) 7.5(﹢1.5，-1.0) 7.8 Transverse tensile index (N.m / g) 3.0(﹢0.8，-0.5) 3.2 Moisture content (%) 7.0±0.5 6.8 Longitudinal elongation rate (%) 27.0±3.0 29.1 Texture / calendering (medium fine texture) No No Average softness in both longitudinal and transverse directions (three layers) 125.0(﹢10.0，-20.0) 128.0 Holes (Φ2 - 5mm) ＜16 ＜16 Dirt count (0.2 - 1.0 m㎡) ＜30 ＜30

[0071] In this embodiment, the quality parameters of the obtained instant dissolving paper all meet the specified range of the national sanitary paper standard. While ensuring the quality of the instant dissolving paper product, the dispersibility of the instant dissolving paper after it meets water is less than or equal to 25 s, that is, the instant dissolving paper can be completely dissolved in water within 25 s, so as to achieve the purpose of not causing blockage when directly thrown into the toilet after use.

[0072] Comparative Example 1

[0073] In Comparative Example 1, the difference from Example 1 is that: in the beating step of Step Three, 15.0 kg / T of wet strength agent is added to the pure bamboo pulp slurry, so that after the beating ends, the fibrillation rate of the ends of bamboo fibers in the slurry is greatly increased, and the connection strength between bamboo fibers is increased. The relevant parameters of the instant dissolving paper obtained in Comparative Example 1 are shown in Table 3 below for details.

[0074] Comparative Example 2

[0075] In Comparative Example 2, the difference from Example 1 is that in the pulping step of Step Two, 0.1 kg / T of beating enzyme was added to the pure bamboo pulp for pulping in the hydraulic pulper to improve the pulping efficiency and effect, so as to improve the tensile strength and burst strength of the paper after forming. The relevant parameters of the instant paper obtained in Comparative Example 2 are shown in Table 3 below.

[0076] Comparative Example 3

[0077] In Comparative Example 3, the difference from Example 1 is that in the sizing step of Step Four, the sizing concentration was set at 2.3%; that is, dilution treatment was performed compared to the sizing concentration in Example 1. The relevant parameters of the instant paper obtained in Comparative Example 3 are shown in Table 3 below:

[0078] Main parameters Example 1 Comparative example 3 Comparative example 2 Comparative example 3 Dispersibility (s) 18 Non-dispersible 26 18 <![CDATA[Quantitative (g / m 2 )]]> 15.5 15.5 15.5 15.5 Thickness (mm / 10ply) 0.97 0.97 0.96 0.96 ISO whiteness (%) 84 83 84 84.5 Longitudinal tensile index (N.m / g) 7.8 7.8 8.1 7.9 Transverse tensile index (N.m / g) 3.2 3.2 3.4 3.3 Moisture content (%) 6.8 6.8 6.8 6.8 Longitudinal elongation rate (%) 29.1 28 33 29 Texture / calendering (medium fine texture) 128 128 133 130 Average softness in both longitudinal and transverse directions (three layers) ＜16 ＜16 ＜16 ＞16 Holes (Φ2 - 5mm) ＜30 ＜30 ＜30 ＞30

[0079] In Comparative Example 1, because a wet strength agent was added to the pure bamboo pulp slurry, the fibrillation degree of bamboo fibers was improved, and the connection strength between bamboo fibers was increased, resulting in the obtained finished paper not dispersing after being wetted, that is, the paper was not soluble after being wetted with water. Thus, no instant paper was produced.

[0080] In Comparative Example 2, beating enzyme was added during the pulping operation of pure bamboo pulp, which greatly improved the beating efficiency. Therefore, the longitudinal tensile index, transverse tensile index, longitudinal elongation rate, and average softness parameters in both longitudinal and transverse directions of the obtained finished paper were greatly improved, the structural strength of the finished paper increased, and further the dispersible time of the finished paper after being wetted increased, that is, the dissolution time in water increased, and it could not meet the instant requirements.

[0081] In Comparative Example 3, in the sizing step, the sizing concentration was controlled to decrease. Although the parameters such as dispersibility, ISO whiteness, and paper strength of the obtained finished paper had little difference from those in Example 1, due to the too low concentration, the number of holes and dirtiness on the finished paper increased, greatly reducing the quality of the finished paper.

[0082] In summary, in this example, by using low-cost pure Neosinocalamus affinis pulp as the production raw material, controlling parameters such as concentrations, equipment selection, and operating power in each step, and without adding wet strength agent and beating enzyme, while obtaining a finished paper that meets the quality of sanitary paper and can achieve instant dissolution in water, the complexity of the production process and production cost are reduced, and at the same time, the pollution caused by papermaking to the environment is also reduced.

[0083] Example 2

[0084] A production process for pure bamboo pulp bleached instant paper, different from Example 1 in that before the drying step of the drying cylinder, the addition of chemical coatings is also included, and the coatings include a cylinder sticking agent, a peeling agent, and a modifier.

[0085] The cylinder sticking agent ensures that the wet paper web can closely adhere to the surface of the drying cylinder during the drying process, thereby improving the drying effect. At the same time, it ensures that during the wrinkling step, the paper closely adheres to the drying cylinder to achieve uniform wrinkling of the paper, thereby further improving the quality of the finished paper. The peeling agent enables the wet paper web to smoothly separate from the drying cylinder during the papermaking and drying cylinder drying steps, avoiding excessive holes and excessive felt hairs on the paper surface caused by adhesion. The modifier can reduce the surface wear of the drying cylinder and extend the service life of the wrinkling knife. When in use, first mix the cylinder sticking agent, peeling agent and modifier with water, and then evenly spray them on the surface of the drying cylinder by spraying. The pressure range during coating is 3.8 - 4.3 bar, and the water temperature range during coating is controlled between 35 - 50 °C. In this embodiment, the coating pressure is 4.4 bar and the water temperature is between 50 °C.

[0086] Example 3

[0087] A production process of pure bamboo pulp bleached instant paper, which is different from Example 2 in that: in the pulping and grinding steps, the addition of a sediment control agent and active alkali is also included, and the specific addition amounts of the sediment control agent and active alkali are shown in Table 4 below:

[0088]

[0089]

[0090] By adding active alkali, the pH value of the water in the pulping and grinding steps is adjusted, and bacteria and microorganisms in the water are killed by a bactericide to achieve the recycling of water, thereby further reducing the production cost of the enterprise. The purpose of using the retention and drainage aid is to enhance the water filtration performance, reduce the dehydration energy consumption during the forming, pressing and drying processes, thereby increasing the production of the finished instant paper, reducing energy consumption and lowering the production cost. Moreover, in this embodiment, the type and addition amount of the sediment control agent are both reduced compared with those in the existing papermaking process, so that the production process of this instant paper can also be reduced and the load of wastewater treatment can be lightened.

[0091] The above are only embodiments of the present invention. Specific technical solutions and / or common knowledge such as characteristics known in the solutions are not described in detail here. It should be noted that for those skilled in the art, without departing from the technical solutions of the present invention, several deformations and improvements can be made, which should also be regarded as the protection scope of the present invention, and these will not affect the implementation effect of the present invention and the practicability of the patent. The protection scope required by this application should be based on the content of its claims, and the specific implementation manners in the specification can be used to explain the content of the claims.

Claims

1. The production process of pure bamboo pulp bleached instant paper is characterized in that: The following steps are involved: Material selection: use bamboo as the raw material for production; Pulping, after preparing dry pulp by the sulfate process combined with elemental chlorine-free bleaching, pulping is performed by a pulper; in the pulping step, without adding a pulping enzyme, the pulping concentration is controlled to be 6.5±0.5%, and the pulping time is 300±100s; Refining: by increasing the cutting ratio of the disc refiner, the refining intensity is improved; in the refining step, the refining power of the disc refiner is controlled to be 50±10Kwh / t, the pulp flow rate is 3800±500L / min, and the refining concentration of pure bamboo pulp is 5.0±0.2%; Sizing: adding white water to the pure bamboo pulp to dilute it; Papermaking, using non-wet strength circulating water to make wet paper web; Drying: sending the wet paper web into the drying cylinder for drying to obtain paper; Crinkling: using a crinkling knife to crinkle the paper; Embossing: embossing paper using a curved full-surface embossing method.

2. The production process of pure bamboo pulp bleached instant paper according to claim 1, characterized in that: In the sizing step, the lip opening is controlled to be 8.20±0.30 and the slurry-to-web speed ratio is controlled to be 0.93±0.

02.

3. The production process of pure bamboo pulp bleached instant paper according to claim 2, characterized in that: The drying step also includes a high-efficiency hot air hood and shoe press technology, with a shoe press pressure of 150KN / m.

4. The production process of pure bamboo pulp bleached instant paper according to claim 3, characterized in that: During the creping step, the angle between the blade surface of the creping knife and the paper outlet end of the drying cylinder is controlled to be 18±0.5°.

5. The production process of pure bamboo pulp bleached instant paper according to claim 4, characterized in that: Before the drying step, chemical coatings are added, including adhesives, stripping agents and improvers.

6. The production process of pure bamboo pulp bleached instant paper according to claim 5, characterized in that: During the pulping and refining steps, a sediment control agent and alkali are added to the pure bamboo pulp, and the amount of alkali added is 0.7±0.3 kg / T.

7. The production process of pure bamboo pulp bleached instant paper according to claim 6, characterized in that: The sediment control agent includes a fixing agent and a retention agent. The addition amount of the fixing agent is 0.15±0.05kg / T, and the addition amount of the retention agent is 0.20±0.10kg / T.

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