CN111472197B

CN111472197B - Pulping production of OCC high-consistency pulping, papermaking method thereof and recycled paper

Info

Publication number: CN111472197B
Application number: CN202010289372.6A
Authority: CN
Inventors: 陈光军; 赵恺; 张永春; 朱琦; 朱应鹏; 刘贵宽; 庄卫鹏; 周志强; 张维连; 程新坤
Original assignee: Liansheng Paper Industry Longhai Co ltd
Current assignee: Liansheng Paper Industry Longhai Co ltd
Priority date: 2020-04-14
Filing date: 2020-04-14
Publication date: 2022-05-13
Anticipated expiration: 2040-04-14
Also published as: CN111472197A

Abstract

The invention belongs to the technical field of pulping and papermaking, and particularly relates to pulping production of OCC high-consistency beating, a papermaking method of the OCC high-consistency beating and recycled paper. Carrying out disintegration, deslagging, screening and purification on 100% of domestic waste OCC, and concentrating until the concentration of the slurry is 26-30%; and (2) performing heat dispersion high-consistency refining, wherein the temperature of the heat dispersion high-consistency refining is 90-105 ℃, the operation gap of a heat dispersion grinding disc is 0.1-2.0 mm, the power consumption is 35-45 kwh/t, the back pressure is 1.0-1.5 bar, a heat dispersion outlet is used for diluting the pulp with water until the pulp concentration reaches 3.5-4.5%, the heat dispersion high-consistency refining is stopped, and the pulp is discharged, wherein the heat dispersion high-consistency refining adopts the heat dispersion grinding disc with the functions of heat dispersion and high-consistency refining, and the heat dispersion grinding disc is respectively a feeding area, a heat dispersion area and a high-consistency refining area from inside to outside. The paper breaking strength and folding strength of the paper prepared by the pulping production with the functions of heat dispersion and high-concentration pulping and the papermaking method thereof are improved, and the production cost can be saved by 3200 ten thousand yuan each year.

Description

Pulping production of OCC high-consistency pulping, papermaking method thereof and recycled paper

Technical Field

The invention belongs to the technical field of pulping and papermaking, and particularly relates to OCC high-consistency beating pulping production, a papermaking method and recycled paper thereof, and a paper product obtained by the papermaking method.

Background

The typical production process of domestic industrial packing paper such as corrugated base paper, kraft liner board paper, bobbin paper and the like uses recycled liner board paper as a raw material, prepares pulp by OCC waste paper pulp line and then delivers the pulp to a paper machine for papermaking. With the implementation of the restriction of import of waste paper, the proportion of domestic waste OCC in raw materials is increased, and the production of medium-high grade kraft liner board paper and high-strength corrugated base paper by using the domestic waste OCC as a main raw material becomes a main process of various large paper mills at present.

However, the domestic waste OCC paper pulp has the following characteristics: the recycling frequency is high, the long fiber proportion is low, the content of fine components in the slurry is high, and the strength is low. Due to the characteristics, the production practice shows that the strength (such as bursting strength) of the finished paper can be improved to a certain extent by using low-consistency beating, but the indexes such as folding strength and the like are greatly influenced because the average length of OCC pulp fibers is low and the long fiber ratio is low and the average length of the fibers is lower after beating. If low-consistency beating is not used, the devillicate brooming degree of fibers in the OCC pulp is low, which is not beneficial to the combination of the fibers and has great influence on the strength of finished paper, such as bursting strength, tightness and the like.

The working principle of the existing heat dispersion system is similar to that of a pulping machine, pulp is usually strongly kneaded at high concentration (25-30%) and high temperature (80-120 ℃), but the pulping effect is only equal to that of mild refining. Currently, because the strength of the OCC slurry subjected to low-consistency pulping is deficient, if the conventional low-consistency pulping process is changed into high-consistency pulping, longer time and large capital investment are required.

As the import of the American waste is increasingly difficult, domestic paper-making enterprises have to increase the usage amount of the national waste. But compared with the domestic waste, the domestic waste has the characteristics of short fiber, more recovery times and low strength. How to improve the strength of national wastes becomes a challenge subject in the industry. Compared with low-consistency refining, high-consistency refining can keep more fiber length and strength, and meanwhile, the components of fine fibers are increased very little, so that the high-consistency refining process is a more appropriate refining process, but the existing pulping process does not have high-consistency refining equipment, and if a set of high-consistency refining equipment is added, the equipment cost is high, the power consumption is high, and the technical improvement period is long. Therefore, it is necessary to develop a pulping production method with heat dispersion and high consistency pulping functions, which can achieve the high consistency pulping function under the condition of satisfying the removal rate of heat dispersion stickies, and effectively improve the fiber strength, improve the pulping effect and improve the paper-forming index under the conditions of keeping the fiber length, improving the fiber coiling degree and the fiber kinking index and improving the fiber fibrillation degree.

Disclosure of Invention

In view of the above technical problems in the prior art, it is desirable to provide a pulping process of OCC high consistency beating, a papermaking method thereof and recycled paper, so as to solve the problem of poor performance of pulp and paper products caused by short fiber and low strength in domestic OCC pulp when 100% domestic OCC is used as a raw material to produce high-grade kraft liner board paper and high-strength corrugated base paper.

In order to achieve the above object, a first aspect of the present invention provides a production method for high consistency pulping of OCC, comprising the steps of:

the method comprises the steps of crushing, deslagging, screening, purifying and concentrating 100% domestic waste OCC until the concentration of pulp is 26-30%, thermally dispersing high-consistency pulp grinding, wherein the temperature of the thermally dispersing high-consistency pulp grinding is 90-105 ℃, the operating gap of a thermally dispersing grinding disc is 0.1-2.0 mm, the power consumption is 35-45 kwh/t, the back pressure is 1.0-1.5 bar, adding water to dilute the pulp until the concentration of the pulp is 3.5-4.5%, stopping thermally dispersing high-consistency pulp grinding, and discharging the pulp.

The second aspect of the invention provides a papermaking method for improving brooming degree of domestic waste OCC pulp, which comprises pulping, charge balancing, pulp strengthening in a fore-stock pool, sheet making, surface sizing, calendaring and slitting, wherein the pulping is prepared by adopting the pulping production method of the first aspect of the invention.

In a third aspect of the invention, recycled paper produced by using 100% of domestic waste OCC is produced by the papermaking method of the second aspect of the invention.

Different from the prior art, the technical scheme at least has the following beneficial effects:

the high-consistency beating is relatively low-consistency beating, which is more favorable for fibrillating and improving the coiling degree and kinking index of the fiber, and the paper breaking strength and folding strength of the paper obtained by the pulping production of the OCC high-consistency beating and the papermaking method thereof provided by the invention are improved. Meanwhile, the double disc mill (installed power 1800kwh) for low consistency beating in the original production line is stopped, the power is saved by 1000kwh, the power is saved by 20kwh/t of paper, and the electricity can be saved by 800 ten thousand DEG per year. The beating degree of the formed pulp is stable, the wet weight is stable, the net part dehydration forming is stable, the wet paper strength is improved, and the paper breaking frequency of the paper machine at the wet part is obviously reduced.

Detailed Description

The pulp production method according to the first aspect of the present invention, the papermaking method according to the second aspect, and the recycled paper according to the third aspect are explained in detail below.

The pulp production process according to the first aspect of the invention will first be described. A pulping production method of OCC high consistency beating comprises the following steps:

the method comprises the steps of carrying out disintegration, deslagging, screening and purification on 100% of domestic waste OCC, concentrating until the pulp concentration is 26-30%, carrying out heat dispersion high-consistency grinding, wherein the temperature of the heat dispersion high-consistency grinding is 90-105 ℃, the operation gap of the heat dispersion grinding disc is 0.1-2.0 mm, the power consumption is 35-45 kwh/t, the back pressure is 1.0-1.5 bar, adding water to dilute until the pulp concentration is 3.5-4.5%, stopping the heat dispersion high-consistency grinding, and discharging pulp.

The internal binding force of the paper mainly comes from the hydrogen bond binding force formed by hydroxyl between paper fibers and fibers, and the hydrogen bond binding force formed by the auxiliary agent and the fibers after the auxiliary agent is retained and adsorbed on the fibers and the fine fibers is enhanced. The main area of the heat dispersion grinding plate adopted by the invention is still in the form of heat dispersion grinding teeth, but the periphery is improved into a high consistency grinding area in the form of low consistency grinding teeth. The treatment concentration of the pulp is 26-32%, the heat dispersion and the removal of the pulp are carried out in the main area, the sticky matters are well dispersed, the pulp with the concentration of 26-32% is beaten in a high-consistency pulping area with low-consistency grinding teeth at the periphery, and the high-consistency pulping is relatively carried out at low consistency, so that the fiber brooming is more prone to be carried out, and the fiber coiling degree and the fiber kinking index are improved.

In a preferable scheme of the invention, the tooth height of the heat dispersion area is 16-17 mm, and the tooth height of the high-consistency refining area is 8-8.5 mm. More preferably the heat spreading zone teeth are 16.5mm high, about 2 times as high as conventional heat spreading disks; the tooth height of the high consistency refining area is 8.2 mm.

In a preferable embodiment of the present invention, when the concentration of the slurry is 4 to 15%, the thermal dispersion high consistency refining step is stopped to discharge the slurry.

Next, a method for producing a paper by improving the brooming degree of domestic OCC pulp according to the second aspect of the present invention will be described. The domestic waste OCC with more recycling times, less long fiber proportion, high content of fine components in the pulp and low strength is completely adopted as the papermaking raw material, and in order to enhance the binding force between pulp fibers, improve the fibrillation rate and enhance the strength, a pulping production method of OCC high-concentration pulping is needed during pulping. The papermaking method for improving the brooming degree of the domestic waste OCC pulp comprises pulping, charge balancing, pulp strengthening in a fore-stock pool, sheet making, surface sizing, calendaring and slitting, wherein the pulping is prepared by adopting the pulping production method of the second aspect of the invention.

Finally, a recycled paper produced from 100% of domestic OCC is described as a third aspect of the present invention. Recycled paper produced by using 100% of domestic waste OCC is manufactured by adopting the papermaking method of the second aspect of the invention.

In order to explain technical contents, structural features, and objects and effects of the technical means in detail, the following detailed description is given with reference to specific embodiments. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present application.

Example 1 comparison of specific index tests of national, American and European waste materials

The national waste, the American waste and the European waste adopted in the specific embodiment of the invention are purchased from the market. The invention adopts a disintegrator which is a common disintegrating device in the pulping and papermaking field.

And (3) carrying out disintegration, deslagging, screening and purification on 100% of domestic waste OCC, and concentrating until the concentration of the slurry is 26-30%.

Soaking the slurry for 24h, then using a fluffer to fluff the slurry to be uniform, and after the slurry is made into sheets, balancing moisture and then measuring the strength index of the sheets. The quantitative of the sheets is 100g/cm²On the left and right, the rest data are averaged after multiple measurements. Specific indexes of thickness, folding times, burst index, ring crush index and the like of various raw materials are shown in table 1.

TABLE 1 indexes of national, American and European waste materials

As can be seen from Table 1, the strength of the domestic OCC raw material sheet is slightly higher than that of the American waste except for the ring pressure of the domestic OCC grade A, and the other strength indexes are lower than those of the American waste and the European waste (the American waste No. 11 raw material has high long fiber content, is difficult to disperse due to insufficient defibering, and causes uneven sheet formation, so that the sheet strength index is lower).

The folding endurance represents the number of times that the paper can withstand 180 ° reciprocal folding under a certain tension. Factors that affect the degree of folding resistance are the average length of the fibers, the bonding strength of the fibers, the arrangement of the fibers in the paper, the strength and elasticity of the fibers themselves, and the like. But the average length of the fibers is the greatest of the effects on the folding endurance. Therefore, the average fiber length of the domestic OCC pulp raw material is relatively lower than that of the American waste 11# and the European waste.

Burst indicates the maximum pressure that the paper can withstand. The burst index is obtained by dividing the burst by the quantification. The main factors affecting the burst strength are the fiber bonding force and the average fiber length, and secondly the fiber strength and the fiber interlacing condition. From the above table, it can be found that the fiber binding force, the fiber strength and the fiber interweaving condition of the domestic waste OCC raw material are not as good as those of the American waste 11# and the European waste.

The ring pressure strength is the maximum compressive force which can be borne by the edge of the ring-shaped test sample until the ring-shaped test sample is crushed. The factors influencing the fiber binding force and the paper thickness are mainly influenced by the raw material characteristics, so that the binding force of the domestic OCC raw material fiber is considered to be lower than that of the American waste 11# and the European waste.

In conclusion, compared with the domestic OCC raw material, the domestic OCC raw material is relatively American waste 11# and European waste, the average length of the fiber is low, the bonding force of the fiber is poor, and the strength of the fiber is low.

Example 2 morphological characteristics analysis of waste OCC fiber

The fiber analyzer used in this example is a fiber analyzer commonly used in pulp and paper making in the art.

The domestic waste OCC slurry with the concentration of 26-30% in example 1 was analyzed by a fiber analyzer, and morphological characteristic parameters of the fiber were measured. The properties of the fibers of the domestic OCC pulp are shown in Table 2.

TABLE 2 fibre characteristic parameters of domestic OCC pulp

As can be seen from the above table, the weight average length of the long fibers is the highest and is slightly higher than that of the short fibers by 0.2-2 mm; the width of the fiber is basically kept about 18-20 mu m; the twisting number of the fibers is about 1200 l/m; the proportion of the fine fibers is 35-43%; the brooming degree is about 2%.

Example 3 the domestic OCC slurry of example 2 was subjected to conventional thermal dispersion treatment

The slurry with the concentration of 26-30% in the above example 1 was subjected to a conventional thermal dispersion treatment, and the data before and after thermal dispersion are shown in table 3.

TABLE 3 OCC slurries Pre-and post-thermal Dispersion data

As can be seen from the comparison of the morphological characteristics of the fibers before and after the thermal dispersion of the slurry in Table 3, the weight average length and width of the fibers after the thermal dispersion treatment were reduced by about 0.1mm and 1 μm, respectively, indicating that the fiber had a certain cutting and extruding effect during the thermal dispersion treatment; in the aspects of curling, kinking, proportion of fine fibers and brooming degree, the pulp subjected to thermal dispersion treatment is improved compared with the pulp which is not treated, and the index lifting amplitude is only about 2% except for the lifting amplitude of 20% of the curling degree, which shows that the kneading and shearing action of the thermal dispersion on the pulp plays a certain role in improving the physical property of the pulp.

Example 4 the OCC slurry of example 3 after thermal dispersion treatment was subjected to low consistency disc milling

The OCC slurry obtained in example 3 after thermal dispersion was subjected to low consistency disc milling to obtain fiber characteristics as shown in Table 4.

TABLE 4 OCC pulp Low consistency disc milled fiber Property parameters

The comparison and analysis of the pulp data of the inlet and the outlet of the low-concentration disc mill can obtain that the weight-average length of the fiber is only reduced by 0.019mm and 0.052mm, and the width is reduced by 0.4 mu m and 0.1 mu m, which indicates that the fiber is cut less; the curling degree, the twisting number and the proportion of the fine fibers are improved after the low-concentration disc grinding treatment, but the lifting amplitude is not large, which indicates that the shape of the fibers of the low-concentration beating is not greatly changed; the brooming degree is respectively improved by 0.08 percent and 0.07 percent, and the change ranges are very similar, which indicates that the brooming of the pulp is improved less by the existing low-consistency refining.

Example 5 the OCC slurry of example 3 after thermal dispersion treatment was subjected to high consistency disc milling

The OCC slurry obtained in example 3 after heat dispersion was subjected to high-consistency disc milling, and the fiber property parameters obtained are shown in Table 5.

TABLE 5 OCC sizing high consistency disc milled fiber property parameters

From the comparison of the data obtained in examples 4 and 5, it can be seen that the uniformity of the fiber treatment is poor in low consistency refining, while the pulp concentration is high in high consistency refining, the gap between the refining discs is large, and the fibers are subjected to refining by the mutual friction, extrusion, kneading, twisting and other actions of the pulp, and simultaneously, a large amount of frictional heat is generated, so that the pulp is softened, and the pulp is favorably dissociated.

As can be seen from the data in Table 5, the long fibers at the heat dispersion inlet and the heat dispersion outlet are subjected to high concentration beating, the fiber cutting is less, the beating degree is respectively improved by 19 degrees SR and 12 degrees SR, and the weight-average length of the fiber is only reduced by about 10%. In addition, the curling and the kinking of the fibers are obviously improved along with the improvement of high-consistency beating degree, and the flexibility of the fibers is improved. The fibrillation rate of the fibers is improved along with the increase of the pulping degree, and meanwhile, the fine fibers are not changed greatly. Therefore, the characteristics of the fibers can improve the physical indexes of the paper to different degrees in the high-consistency beating process.

The comparative analysis of the thermal dispersion, low-concentration pulping and high-concentration pulping processes is as follows:

the heat dispersion process comprises the following steps: the thermal dispersion system is mainly used for concentrating slurry to a concentration of 26-35%, heating, and dissolving and dispersing hot melt impurities and ink particles into fine particles under the strong shearing and kneading of dispersion teeth in a thermal dispersion machine and mixing the fine particles with fibers. The detection and analysis of the previous steps show that the thermal dispersion treatment has a certain fiber pulping effect and can improve the fibrillation degree of the fibers to a certain degree, but the inventor discovers from multiple production practice observation that the pulping effect in the thermal dispersion treatment process does not obviously contribute to the improvement of the paper strength index.

And (3) low-concentration pulping process: the PM5 and PM9OCC pulping processes are both provided with 1800kwh double-disc refiners. In the actual production process, the low-concentration disc mill mainly depends on the direct action of the grinding discs on the fibers to enable the fibers to generate the effects of deformation, swelling, fibrillation, cutting and the like, if the disc mill is opened for pulping, the breaking strength index of finished paper is improved, but the folding strength is reduced more, and the index requirement of finished paper cannot be met, which indicates that the existing 100% of domestic OCC waste paper raw materials are short in fibers, and the cutting action of low-concentration pulping enables the fibers to be shorter, so that the folding strength of the finished paper is unqualified, and therefore, the production by adopting the low-concentration pulping process is not suitable.

The high-consistency pulping process comprises the following steps: the high-consistency pulping test shows that the high-consistency pulping cuts off the fibers very little, the beating degree is respectively improved by 19 degrees SR and 12 degrees SR, and the weight-average length of the fibers is only reduced by about 10 percent. In addition, the curling and kinking of the fibers are obviously improved along with the improvement of high concentration beating degree. The fibrillation rate of the fibers is improved along with the increase of the beating degree, and meanwhile, the small fibers are not changed greatly. Therefore, the characteristics of the fibers can improve the physical indexes of the paper to different degrees in the high-consistency beating process.

Example 6 production method of OCC high consistency beating

Adopts a heat dispersion grinding plate with heat dispersion and high-concentration pulping effects. The heat dispersion grinding disc with the heat dispersion and high-consistency pulping effects is respectively a feeding area, a heat dispersion area and a high-consistency pulping area from inside to outside. The main area of the grinding sheet is still in a conventional heat dispersion grinding tooth form, the grinding sheet has a good hot melt adhesive dispersion effect and a slight fiber brooming effect, the beating degree is slightly improved, and the quality requirements of the beating degree and the wet weight cannot be met. The above problems can be solved by modifying the periphery to a high consistency refining zone in the form of low consistency grinding teeth. The inlet pulp treatment concentration is 26-30%, the temperature is 90-105 ℃, the operation gap of a heat dispersion grinding disc is 0.1-2.0 mm, the power consumption is 35-45 kwh/t, the back pressure is 1.0-1.5 bar, the pulp heat dispersion treatment is carried out in the main area, the sticky matters are well dispersed, the pulp with the concentration of 26-30% is beaten in the high-concentration pulping area of the peripheral low-concentration grinding teeth, and the high-concentration beating is relatively low-concentration beating, so that the fiber brooming is more tended to be realized, and the fiber reeling degree and the kinking index are improved. The tooth height of the heat dispersion area is 16.5mm, which is about 2 times of the tooth height of the conventional heat dispersion disc; the tooth height of the high consistency refining area is 8.2 mm. And adding water into the pulp from the thermal dispersion outlet to dilute the pulp until the concentration of the pulp reaches 3.5-4.5%, stopping thermally dispersing the high-concentration pulp, and discharging.

The conventional heat dispersion under the selected operating conditions with similar power consumption is compared with the OCC high consistency beating heat dispersion provided by the invention, as shown in Table 6.

TABLE 6 working conditions of conventional heat dispersion and high consistency beating heat dispersion of OCC in the invention

According to the beating result, the following four analysis tests are carried out on the conventional heat dispersion and the OCC high-consistency beating heat dispersion with the heat dispersion and high-consistency beating effects: the method comprises the following steps of slurry pulping effect testing, fiber brooming degree testing, fiber strength testing and sticky matter removal rate testing. The test results are shown in table 7.

TABLE 7 test results of production of conventional thermally dispersed and highly concentrated OCC beaten thermally dispersed slurries of the present invention

As can be seen from the data in Table 7, the OCC high-consistency beating thermal dispersion process of the invention has stronger beating action than the conventional thermal dispersion process, and the beating index change percentages (freeness and beating degree) before and after thermal dispersion are greatly changed. Especially, the beating degree is improved, and compared with the conventional heat dispersion process, the OCC high-concentration beating heat dispersion process has the improvement value increased from 28.6% to 63.4% and is improved by 2.2 times. Furthermore, the side surface reflects the 'wet weight' index of partial cutting or brooming of the beating action, the reduction value before and after beating is not so large, and the reduction value is reversely improved from original-12.1% to only-7.2%, which is enough to indicate that the cutting action is small and the brooming action is large. This is also demonstrated by the following analysis of brooming. Further, the refining blade operation gap of OCC high concentration beating heat dispersion in the invention is adjusted to any value of 0.1-2.0 mm, and the beating effect is also presented.

The brooming degree analysis was conducted for the conventional heat-dispersing and the high consistency beating heat-dispersing of OCC of the present invention, and the results are shown in Table 8.

TABLE 8 results of analysis of degree of brooming by conventional thermal dispersion and high concentration beating of OCC in the present invention

As is apparent from the data in Table 8, the change range of the fibrillation degree of the fiber is very small and is only 6% in the conventional thermal dispersion process, and the fibrillation degree is improved by 39.7% and is 6.6 times of that of the process by the high-consistency beating thermal dispersion process. Especially, the medium brooming is improved by 92.8 percent after the high-consistency beating thermal dispersion treatment. The improvement of the fibrillation degree of the fibers is very important for the strength index.

As is apparent from the data in Table 8, both the burst index and the tensile index are greatly improved. Wherein the burst index is improved from 35.5% to 43.1% and is improved by 7.6%. The tensile index increase increased from 33.3% to 38.1%, which was a 4.8% improvement. The improvement of the strength index is due to the good beating (brooming) effect of the high-concentration beating on the fiber. Further, the operational clearance of the refining plate with high consistency refining heat dispersion of the invention is adjusted to any value of 0.1-2.0 mm, and the fiber brooming effect is also shown.

From the big stickies quantity, the big stickies area contrastive analysis of thermal dispersion import, thermal dispersion export, new technology stickies clearance receives the influence and does not take place, and on the contrary, the clearance still has the promotion of certain extent. The removal rate of stickies/dust in the new process meets the requirement. Can improve the beating degree, wet weight, evenness, brooming rate, binding force index and paper quality of paper pulp and can reduce energy consumption in the beating process.

Example 7 production of high grade Kraft liner Using the pulp obtained in example 6

The present embodiment is practiced using the PM9 production line. The paper machine of the PM9 production line is a wire paper machine, the width of the paper is 6660mm, the head box is a double-layer head box, high-grade kraft liner board paper is produced, and the gram weight is 75-140 g/m²The vehicle speed is 1200-1400 m/min, and the annual output is 40 ten thousand tons. After the process with high-concentration pulping heat dispersion is applied, the pulp solution degree, the wet weight index, the paper forming strength, the power consumption, the paper machine speed, the paper machine operation efficiency and the yield all reach the expected research and development indexes. Different from the prior art, the application of the high-consistency refining heat dispersion process has at least the following benefits:

1) the heat dispersion effect is good, and the requirement of the removal rate of sizing material stickies is met.

2) The bursting strength of the finished paper is improved, and the bursting index is 1.8-1.9 kpa.m²The/g is increased to 1.9-2.1 kpa²Per g, about 0.1kpa.m²And g, the lifting amplitude is 5.5-12%.

3) The folding resistance of the finished paper is improved from 10-13 times to 13-17 times, the folding resistance is improved for 3-4 times, and the lifting amplitude is 30-40%.

4) The double disc mill (installed power 1800kwh) for low consistency pulping is stopped, the power is saved by 1000kwh, 20kwh/t of paper is saved, and 800 ten thousand DEG of electricity can be saved each year.

5) Due to the improvement of the strength index, the using amount of the surface sizing starch is reduced from 50-52 kg/t to 44-46 kg/t, and about 6kg/t of starch is saved.

6) The beating degree of the formed pulp is stable, the wet weight is stable, the net part dehydration forming is stable, the wet paper strength is improved, the paper breaking frequency of the paper machine at the wet part is obviously reduced, the operation efficiency is improved, the speed of the paper machine is improved, the yield is improved (the design working speed of the paper machine is 1300m/min, and the actual working speed is 1350-1400 m/min), and the power consumption per ton of paper is reduced by 18-25 kwh/t of paper due to the improvement of the speed of the paper machine, the yield and the operation efficiency. Through calculation, the energy-saving and consumption-reducing benefits are about 40-45 yuan/ton of paper.

At present, the project has realized the achievement conversion, and the PM5 production line can be applied to produce the corrugated medium paper, kraft liner board paper, bobbin paper and other industrial packing paper in the actual production, the annual output of the two machines of PM5 and PM9 is total 80 ten thousand tons, and the production cost can be saved by 3200 ten thousand yuan each year.

It should be noted that, although the above embodiments have been described herein, the invention is not limited thereto. Therefore, based on the innovative concepts of the present invention, the technical solutions of the present invention can be directly or indirectly applied to other related technical fields by changing and modifying the embodiments described herein or by using the equivalent structure or equivalent flow chart of the content of the present invention, and are included in the scope of the patent protection of the present invention.

Claims

1. The production method for OCC high-consistency pulping is characterized by comprising the following steps:

disintegrating, deslagging, screening and purifying 100% domestic waste OCC, concentrating until the pulp concentration is 26-30%, thermally dispersing high-consistency pulp grinding, wherein the temperature of the thermally dispersing high-consistency pulp grinding is 90-105 ℃, the power consumption is 35-45 kwh/t, the back pressure is 1.0-1.5 bar, adding water to dilute until the pulp concentration is 3.5-4.5%, stopping thermally dispersing high-consistency pulp grinding, discharging pulp,

the heat dispersion high-consistency grinding adopts a heat dispersion grinding disc with heat dispersion and high-consistency beating functions, the operating clearance of the heat dispersion grinding disc is 0.1-2.0 mm, the heat dispersion grinding disc is respectively a feeding area, a heat dispersion area and a high-consistency grinding area from inside to outside, the tooth height of the heat dispersion area is 16-17 mm, and the tooth height of the high-consistency grinding area is 8-8.5 mm.

2. The pulping production method according to claim 1, wherein the thermally dispersed high consistency refining step is stopped when the pulp concentration is 4-15%, and the pulp is discharged.

3. A papermaking method for improving the brooming degree of domestic waste OCC pulp is characterized by comprising pulping, charge balancing, pulp strengthening in a fore-stock pool, sheet making, surface sizing, calendaring and slitting, wherein the pulping is prepared by adopting the pulping production method as claimed in claim 1 or 2.

4. Recycled paper produced from 100% domestic OCC, produced by the method of claim 3.