Process for producing decorative base paper by fourdrinier vat paper machine

Abstract

The invention relates to the technical field of decorative base paper production, in particular to a process for producing decorative base paper by a fourdrinier vat paper machine. Comprising the following steps: conveying a pulp board, a chain plate, a pulper, a discharging pool, a pulping machine, a pulp forming pool, a machine front pool, a white water tank outside the machine, a slushing pump, a pressure screen, a headbox, a net part, a squeezing part, a Yankee drying cylinder, a sizing machine, a group cylinder, a calender, a coiling part, rewinding, and packaging and warehousing. According to the invention, the decorative base paper is produced by selecting the full eucalyptus hardwood pulp, so that the finished paper is good in uniformity, high in smoothness and clear in printing.

Description

Technical Field

[0001] The present invention relates to the technical field of decorative base paper production, specifically to the process of producing decorative base paper by a fourdrinier Yankee machine. Background Art

[0002] Decorative base paper is a special industrial paper. After printing and impregnation with melamine resin, it is mainly used as the surface layer paper, surface layer paper and bottom layer paper for fiberboard, particleboard and other wood-based panels. This paper has excellent properties such as heat insulation, flame retardancy, non-warping, non-cracking, and easy cleaning. Moreover, it has a variety of colors and patterns, rich and beautiful patterns, bright and vivid colors, and is widely used in the manufacture of medium and high-grade building decoration, furniture, laminate flooring, and the interior decoration of transportation vehicles.

[0003] The general pulp board ratio of traditional decorative base paper is bleached sulfate softwood pulp + bleached sulfate hardwood pulp, which is produced by a fourdrinier multi-cylinder paper machine. Generally, it is not equipped with a film transfer sizing machine. During printing, printing white spots caused by powder dropping are likely to occur, and there is also a problem of cylinder sticking caused by rapid drying when producing decorative base paper with a Yankee machine. Summary of the Invention

[0004] According to the above deficiencies in the prior art, the purpose of the present invention is to provide a process for producing decorative base paper by a fourdrinier Yankee machine, which uses all eucalyptus hardwood pulp to produce decorative base paper, and the formed paper has good evenness, high smoothness, and clear printing.

[0005] The present invention is realized by adopting the following technical solutions:

[0006] The process for producing decorative base paper by a fourdrinier Yankee machine includes the following steps:

[0007] Pulp board → Chain plate conveyor → Pulper → Discharge tank → Refiner → Pulp pond → Chest before the machine → White water tank outside the machine → Headbox pump → Pressure screen → Headbox → Wire section → Press section → Yankee dryer → Sizing machine → Group cylinder → Calender → Rewinder → Re-reeling → Packaging and warehousing;

[0008] The pulp board ratio is 100% bleached sulfate softwood and hardwood pulp, and the fiber length is 1.0 - 1.2 mm;

[0009] Online full-width spraying is carried out at the Yankee dryer. When carrying out online full-width spraying, an online full-width spraying release agent needs to be added, and the online full-width spraying release agent is a silicone-based release agent.

[0010] The pulper uses three DD720 double-disc refiners in series for beating. All three disc refiners use defibrating type grinding plates. The refining power is: 330 - 350 kw + 330 - 350 kw + 330 - 350 kw, the flow rate is 280 - 300 m3 / h, the valve opening is 65 - 70%, the beating degree is 35 ± 1°SR, and the wet weight is 2 ± 0.2 g.

[0011] Cationic starch is added at the pulping pond, and the addition amount of cationic starch is 16 - 20 kg per ton of paper; wet strength agent is added at the pre - sizing pond, and the addition amount of wet strength agent is 60 - 80 kg per ton of paper; kaolin and titanium dioxide are added at the pulper. The addition amount of kaolin is 120 - 150 kg per ton of paper, and the addition amount of titanium dioxide is 80 - 100 kg per ton of paper. In kaolin: Al2O3 ≥ 36%, whiteness ≥ 85%, fineness ≥ 800 mesh; in titanium dioxide: TiO2 content ≥ 90%, whiteness ≥ 99%, fineness ≥ 900 mesh.

[0012] Silica sol is added after the pressure screen, and the addition amount of silica sol is 2 - 4 kg per ton of paper; at the Yankee dryer position, a peeling agent is added in front of a supporting roller, and the addition amount of the peeling agent is 2 - 3 kg per ton of paper; polyether defoamer is added at the external white water tank, and the addition amount of polyether defoamer is 150 - 200 g per ton of paper; organic bromine bactericide is added at the external white water tank, and the addition amount of organic bromine bactericide is 100 - 150 g per ton of paper.

[0013] Surface sizing agent solution is added at the sizing machine. In the surface sizing agent solution, the solid content is 15 ± 1%, the viscosity is 30 - 50 mPa·s, the pH is 7 - 8, and the temperature is 65 - 70 °C.

[0014] The mass parts of each raw material in the surface sizing agent are as follows: amphoteric surface cassava starch: 50 parts; polyvinyl alcohol: 10 parts; chitosan: 6 parts; CMC: 20 parts; titanium dioxide: 100 parts; clear water: 1096 parts.

[0015] The preparation method of the surface sizing agent is as follows: Mix the formulated amount of amphoteric surface cassava starch, titanium dioxide, polyvinyl alcohol, and CMC with 1 / 3 of the formulated amount of clear water in the surface sizing cooking tank, stir evenly, then steam, and heat up to 95 °C, keep warm for 20 min, transfer it to the surface sizing dilution tank and mix with the formulated amount of chitosan and 2 / 3 of the formulated amount of clear water to form a surface sizing agent with a solid content of 15%, and transfer it to the surface sizing storage tank for standby.

[0016] Back - side surface sizing agent for the finished paper is added at the sizing machine. The preparation method of the back - side surface sizing agent for the finished paper is as follows: Mix the formulated amount of surface cassava starch with 1 / 3 of the formulated amount of clear water evenly in the starch modulation tank, pump it into the starch cooking tank, heat up to 95 °C, keep warm for 20 min, pump it into the starch dilution tank, cool down to 65 - 70 °C, add 2 / 3 of the formulated amount of clear water to make a solution with a solid content of 7 ± 1%, and pump it into the starch storage tank for standby; among them, the mass parts of each raw material are amphoteric surface cassava starch: 10 parts; clear water 132 parts.

[0017] The operating parameters of the paper machine are as follows: basis weight 78 - 82 g / m 2; Lip opening 12 - 14 mm; Shaking: Amplitude 20 - 25 mm, vibration frequency 200 - 230 times / min; Wire concentration 0.8 - 1.0%; Machine speed 350 - 400 m / min; Dryness of the paper coming out of the couch roll 20 - 22%; Main press pressure 60 - 80 kN / M; Pressure of the carrying rolls: The first carrying roll 90 - 100 kN / M, the second carrying roll 110 - 120 kN / M; Steam pressure of the large cylinder 500 - 550 kPa; Pressure of the soft calender: The first press 130 kN / M, the second press 150 kN / M, temperature 150 - 180 °C; Moisture content of the finished paper 4 - 6%.

[0018] Among the operating parameters of the paper machine described above, the control parameters of the film transfer coater are as follows:

[0019] Model and pressure of the metering rod:

[0020] The front metering rod is V40, with a linear pressure of 20 kN / m, coating the surface sizing agent of the coating on the front side of the coated paper sheet;

[0021] The back metering rod is V30, with a linear pressure of 20 kN / m, coating the surface sizing agent of the coating on the back side of the finished paper on the back side of the coated paper sheet;

[0022] Pick-up amount of the surface coating on the finished paper: 2 - 2.2 g / m on the front side 2 , 0.3 - 0.5 g / m on the back side 2 ;

[0023] The dryness of the paper entering the film transfer coater is ≥ 90%, and the dryness of the paper coming out of the film transfer coater is ≥ 70%.

[0024] Product index: 80 g / m 2 Decorative base paper

[0025]

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0027] (1) Selecting all hardwood eucalyptus pulp to produce decorative base paper, the finished paper has good formation, high smoothness, and clear printing;

[0028] (2) Selecting a fourdrinier large cylinder paper machine to produce decorative base paper, the finished paper has good stiffness, high smoothness on the front side, bright, clear and vivid printed pattern colors, low shrinkage rate of the finished paper, and small wet deformation during printing.

[0029] (3) Using an online full-width spray release agent in the large cylinder, the release effect is good, improving the release of the paper sheet from the large cylinder, and solving the problem of difficult release of the paper sheet from the large cylinder when adding titanium dioxide to the decorative base paper.

[0030] (4) Adding titanium dioxide both in the pulp and on the surface sizing, reducing the problem of large loss of titanium dioxide when adding it only in the pulp, reducing the production cost, and at the same time improving the opacity and covering power of the finished paper.

[0031] (5) The present invention is equipped with a film transfer sizing machine, aiming to improve the surface strength of the decorative base paper, prevent the occurrence of linting and powdering problems. Detailed implementation manners

[0032] In order to make the purpose and technical solution of the present invention clearer and more understandable, the present invention will be further described in detail below.

[0033] The following are some of the raw materials used in the examples and comparative examples:

[0034] Cationic starch: degree of substitution 0.025 - 0.03, commercially available product from Shandong Fuyang Biotechnology Co., Ltd.

[0035] Wet strength agent: main component PAE, solid content 40 ± 1%, commercially available product from Kurita Water Treatment New Materials (Jiangyin) Co., Ltd.

[0036] Kaolin: commercially available product from Jinan Xinhong Chemical Industry Co., Ltd.

[0037] Titanium dioxide: commercially available product from Shandong Dongjia Group Co., Ltd.

[0038] Cationic polyacrylamide: commercially available product from Dongying Nuoer Chemical Co., Ltd., model N8412

[0039] Silica sol: composition SiO2, solid content 20 ± 1%, commercially available product from Zhejiang Chuanhua Huayang Chemical Industry Co., Ltd.

[0040] Release agent: model: RA - Z02, commercially available product from Zhejiang Chuanhua Huayang Chemical Industry Co., Ltd.

[0041] Polyether defoamer: commercially available product from Jining Nantian Agricultural Science and Technology Chemical Industry Co., Ltd.

[0042] Organic bromine bactericide: model WL - 20, commercially available product from Zhejiang Chuanhua Huayang Chemical Industry Co., Ltd.

[0043] Amphoteric surface cassava starch: LS - 2, commercially available product from Jiangxi Liuhe Chemical Industry Co., Ltd.

[0044] Polyvinyl alcohol: 1799, commercially available product from Anhui Wanwei Group Co., Ltd.

[0045] Chitosan: commercially available product from Linyi Sanshui Technology Co., Ltd.

[0046] Release agent: RA - 10, commercially available product from Zhejiang Chuanhua Huayang Chemical Industry Co., Ltd.

[0047] Example 1

[0048] The process for producing decorative base paper by a fourdrinier cylinder paper machine includes the following steps:

[0049] Pulping board → Chain plate conveyor → Pulper → Discharge tank → Refiner → Pulp pond → Chest before forming → White water tank outside the machine → Headbox pump → Pressure screen → Headbox → Wire section → Press section → Yankee dryer → Sizing machine → Group cylinder → Calender → Reeling section → Rewinding → Packaging and warehousing;

[0050] The pulping board ratio is 100% bleached sulfate softwood and hardwood pulp, and the fiber length is 1.0 mm;

[0051] Online full-width spraying is carried out at the Yankee dryer. When carrying out online full-width spraying, an online full-width spraying release agent needs to be added. The online full-width spraying release agent is a silicone-based release agent.

[0052] The pulper uses three DD720 double-disc refiners in series for beating. All three disc refiners use dispersing-type grinding plates. The refining power is: 330 kw + 330 kw + 330 kw, the flow rate is 280 m 3 / h, the valve opening is 65%, the beating degree is 34°SR, and the wet weight is 1.8 g.

[0053] Cationic starch is added at the pulp pond, and the addition amount of cationic starch is 16 kg / ton of paper; wet strength agent is added at the chest before forming, and the addition amount of wet strength agent is 60 kg / ton of paper; kaolin and titanium dioxide are added at the pulper, the addition amount of kaolin is 120 kg / ton of paper, and the addition amount of titanium dioxide is 80 kg / ton of paper; in kaolin: the content of Al2O3 is 36%, the whiteness is 85%, and the fineness is 800 mesh; in titanium dioxide: the content of TiO2 is 90%, the whiteness is 99%, and the fineness is 900 mesh.

[0054] Silica sol is added after the pressure screen, and the addition amount of silica sol is 2 kg / ton of paper; at the position of the Yankee dryer, a release agent is added in front of a support roller, and the addition amount of the release agent is 2 kg / ton of paper; polyether defoamer is added at the white water tank outside the machine, and the addition amount of polyether defoamer is 150 g / ton of paper; organic bromine bactericide is added at the white water tank outside the machine, and the addition amount of organic bromine bactericide is 100 g / ton of paper.

[0055] Surface sizing agent solution is added at the sizing machine. In the surface sizing agent solution, the solid content is 14%, the viscosity is 30 mPa·s, the pH is 7, and the temperature is 65 °C.

[0056] The mass parts of each raw material in the surface sizing agent are: amphoteric surface cassava starch: 50 parts; polyvinyl alcohol: 10 parts; chitosan: 6 parts; CMC: 20 parts; titanium dioxide: 100 parts; clear water: 1096 parts.

[0057] The preparation method of the surface sizing agent is as follows: Mix the formula amount of amphoteric surface cassava starch, titanium dioxide, polyvinyl alcohol, and CMC with 1 / 3 of the formula amount of clear water in the surface sizing cooking tank, stir evenly, then steam, and heat up to 95°C, keep warm for 20 minutes, transfer it to the surface sizing dilution tank and mix with the formula amount of chitosan and 2 / 3 of the formula amount of clear water to form a surface sizing agent with a solid content of 15%, and transfer it to the surface sizing storage tank for standby.

[0058] Add the surface sizing agent for the back of the formed paper at the sizing machine. The preparation method of the surface sizing agent for the back of the formed paper is as follows: Mix the formula amount of surface cassava starch with 1 / 3 of the formula amount of clear water evenly in the starch modulation tank, pump it into the starch cooking tank, heat up to 95°C, keep warm for 20 minutes, pump it into the starch dilution tank, cool down to 65°C, add 2 / 3 of the formula amount of clear water to make a solution with a solid content of 6%, and transfer it to the starch storage tank for standby; among them, the mass parts of each raw material are: amphoteric surface cassava starch: 10 parts; clear water 132 parts.

[0059] The running parameters of the paper machine are as follows: basis weight 78 g / m 2 ; lip opening 12 mm; shaking: amplitude 20 mm, vibration frequency 200 times / min; forming consistency 0.8%; paper speed 350 m / min; dryness after leaving the couch roll 20%; main press pressure 60 kN / M; pressure of the carrying rolls: the first carrying roll 90 kN / M, the second carrying roll 110 kN / M; steam pressure of the large cylinder 500 kPa; pressure of the soft calender: the first press 130 kN / M, the second press 150 kN / M, temperature 150°C; moisture content of the formed paper 4%.

[0060] Among the running parameters of the paper machine, the control parameters of the film transfer coater are:

[0061] Model and pressure of the metering rod:

[0062] The front metering rod is V40, the linear pressure is 20 kN / m, coat the surface sizing agent of the coating on the front of the paper sheet;

[0063] The back metering rod is V30, the linear pressure is 20 kN / m, coat the surface sizing agent for the back of the formed paper of the coating on the back of the paper sheet;

[0064] Pick-up amount of the surface coating for the formed paper: 2 g / m on the front 2 , 0.3 g / m on the back 2 ;

[0065] The dryness of the paper entering the film transfer coater is 90%, and the dryness of the paper leaving the film transfer coater is 70%.

[0066] Example 2

[0067] The process for producing decorative base paper on a fourdrinier large cylinder paper machine includes the following steps:

[0068] Pulping board → Chain board conveyor → Pulper → Discharge tank → Refiner → Stock tank → Chest before the paper machine → White water tank outside the machine → Headbox pump → Pressure screen → Headbox → Wire section → Press section → Yankee dryer → Sizing machine → Group dryer → Calender → Reel section → Rewinding → Packaging and warehousing;

[0069] The pulping board ratio is 100% bleached sulfate softwood and hardwood pulp, and the fiber length is 1.2 mm;

[0070] Online full-width spraying is carried out at the Yankee dryer. When carrying out online full-width spraying, an online full-width spraying release agent needs to be added. The online full-width spraying release agent is a silicone-based release agent.

[0071] The pulper uses three DD720 double-disc refiners in series for beating. All three disc refiners use defibering type grinding plates. The refining power is: 350 kw + 350 kw + 350 kw, the flow rate is 300 m 3 / h, the valve opening is 70%, the beating degree is 36°SR, and the wet weight is 2.2 g.

[0072] Cationic starch is added at the stock tank, and the addition amount of cationic starch is 20 kg / ton of paper; wet strength agent is added at the chest before the paper machine, and the addition amount of wet strength agent is 80 kg / ton of paper; kaolin and titanium dioxide are added at the pulper, the addition amount of kaolin is 150 kg / ton of paper, and the addition amount of titanium dioxide is 100 kg / ton of paper; in kaolin: the content of Al2O3 is 36%, the whiteness is 85%, and the fineness is 800 mesh; in titanium dioxide: the content of TiO2 is 90%, the whiteness is 99%, and the fineness is 900 mesh.

[0073] Silica sol is added after the pressure screen, and the addition amount of silica sol is 4 kg / ton of paper; at the position of the Yankee dryer, a release agent is added before a support roller, and the addition amount of the release agent is 3 kg / ton of paper; polyether defoamer is added at the white water tank outside the machine, and the addition amount of polyether defoamer is 200 g / ton of paper; organic bromine bactericide is added at the white water tank outside the machine, and the addition amount of organic bromine bactericide is 150 g / ton of paper.

[0074] Surface sizing agent solution is added at the sizing machine. In the surface sizing agent solution, the solid content is 16%, the viscosity is 50 mPa·s, the pH is 8, and the temperature is 70 °C.

[0075] The mass parts of each raw material in the surface sizing agent are: amphoteric surface cassava starch: 50 parts; polyvinyl alcohol: 10 parts; chitosan: 6 parts; CMC: 20 parts; titanium dioxide: 100 parts; clear water: 1096 parts.

[0076] The preparation method of the surface sizing agent is as follows: Mix the formula amount of amphoteric surface cassava starch, titanium dioxide, polyvinyl alcohol, and CMC with 1 / 3 of the formula amount of clear water in the surface sizing cooking tank, stir evenly, then steam, and heat up to 95°C, keep warm for 20 minutes. Transfer it to the surface sizing dilution tank and mix with the formula amount of chitosan and 2 / 3 of the formula amount of clear water to form a surface sizing agent with a solid content of 15%, and then transfer it to the surface sizing storage tank for standby.

[0077] Add the surface sizing agent for the back of the formed paper at the sizing machine. The preparation method of the surface sizing agent for the back of the formed paper is as follows: Mix the formula amount of surface cassava starch with 1 / 3 of the formula amount of clear water evenly in the starch modulation tank, pump it into the starch cooking tank, heat up to 95°C, keep warm for 20 minutes, then pump it into the starch dilution tank, cool down to 70°C, add 2 / 3 of the formula amount of clear water to make a solution with a solid content of 8%, and then transfer it to the starch storage tank for standby; among them, the mass parts of each raw material are: amphoteric surface cassava starch: 10 parts; clear water 132 parts.

[0078] The operating parameters of the paper machine are as follows: basis weight 82 g / m 2 ; lip opening 14 mm; shaking: amplitude 25 mm, vibration frequency 230 times / min; forming consistency 1.0%; paper machine speed 400 m / min; dryness after leaving the couch roll 22%; main press pressure 80 kN / M; pressure of the carrying rolls: the first carrying roll 100 kN / M, the second carrying roll 120 kN / M; steam pressure of the large cylinder 550 kPa; pressure of the soft calender: the first press 130 kN / M, the second press 150 kN / M, temperature 180°C; moisture content of the formed paper 6%.

[0079] Among the operating parameters of the paper machine, the control parameters of the film transfer coater are:

[0080] Model and pressure of the metering rod:

[0081] The front metering rod is V40, the linear pressure is 20 kN / m, coating the surface sizing agent on the coating, and coating the front side of the paper sheet;

[0082] The back metering rod is V30, the linear pressure is 20 kN / m, coating the surface sizing agent for the back of the formed paper on the coating, and coating the back side of the paper sheet;

[0083] Pick-up amount of the surface coating for the formed paper: 2.2 g / m on the front side 2 , 0.5 g / m on the back side 2 ;

[0084] The dryness of the formed paper entering the film transfer coater is 90%, and the dryness of the formed paper leaving the film transfer coater is 70%.

[0085] Example 3

[0086] The process for producing decorative base paper by a fourdrinier large cylinder paper machine includes the following steps:

[0087] Pulp board → Chain plate conveyor → Pulper → Discharge tank → Refiner → Stock chest → Chest before the paper machine → White water trough outside the machine → Approach flow pump → Pressure screen → Headbox → Wire section → Press section → Yankee dryer → Sizing machine → Group cylinder → Calender → Reel section → Rewinding → Packaging and warehousing;

[0088] The pulp board ratio is 100% bleached sulfate softwood and hardwood pulp, and the fiber length is 1.1 mm;

[0089] Online full-width spraying is carried out at the Yankee dryer. When carrying out online full-width spraying, an online full-width spraying release agent needs to be added. The online full-width spraying release agent is a silicone-based release agent.

[0090] The pulper uses three DD720 double-disc refiners in series for beating. All three disc refiners use defibering type grinding plates. The refining power is: 340 kw + 340 kw + 340 kw, the flow rate is 290 m3 / h, the valve opening is 68%, the beating degree is 35°SR, and the wet weight is 2 g.

[0091] Cationic starch is added at the stock chest, and the addition amount of cationic starch is 18 kg / ton of paper; wet strength agent is added at the chest before the paper machine, and the addition amount of wet strength agent is 70 kg / ton of paper; kaolin and titanium dioxide are added at the pulper. The addition amount of kaolin is 130 kg / ton of paper, and the addition amount of titanium dioxide is 90 kg / ton of paper; in kaolin: the content of Al2O3 is 36%, the whiteness is 85%, and the fineness is 800 mesh; in titanium dioxide: the content of TiO2 is 90%, the whiteness is 99%, and the fineness is 900 mesh.

[0092] Silica sol is added after the pressure screen, and the addition amount of silica sol is 3 kg / ton of paper; at the position of the Yankee dryer, a release agent is added in front of a supporting roller, and the addition amount of the release agent is 3 kg / ton of paper; polyether defoamer is added at the white water trough outside the machine, and the addition amount of polyether defoamer is 180 g / ton of paper; organic bromine bactericide is added at the white water trough outside the machine, and the addition amount of organic bromine bactericide is 120 g / ton of paper.

[0093] Surface sizing agent solution is added at the sizing machine. In the surface sizing agent solution, the solid content is 15%, the viscosity is 40 mPa·s, the pH is 8, and the temperature is 68 °C.

[0094] The mass parts of each raw material in the surface sizing agent are: amphoteric surface cassava starch: 50 parts; polyvinyl alcohol: 10 parts; chitosan: 6 parts; CMC: 20 parts; titanium dioxide: 100 parts; clear water: 1096 parts.

[0095] The preparation method of the surface sizing agent is as follows: Mix the formulated amounts of amphoteric surface cassava starch, titanium dioxide, polyvinyl alcohol, and CMC with 1 / 3 of the formulated amount of clear water in the surface sizing cooking tank, stir evenly, then steam, and raise the temperature to 95°C. Keep warm for 20 minutes, then transfer it to the surface sizing dilution tank and mix it with the formulated amount of chitosan and 2 / 3 of the formulated amount of clear water to form a surface sizing agent with a solid content of 15%. Transfer it to the surface sizing storage tank for standby.

[0096] Add the surface sizing agent for the back of the formed paper at the sizing machine. The preparation method of the surface sizing agent for the back of the formed paper is as follows: Mix the formulated amount of surface cassava starch with 1 / 3 of the formulated amount of clear water evenly in the starch modulation tank, pump it into the starch cooking tank, raise the temperature to 95°C, keep warm for 20 minutes, then pump it into the starch dilution tank, cool down to 68°C, add 2 / 3 of the formulated amount of clear water to make a solution with a solid content of 7%, and transfer it to the starch storage tank for standby; among them, the mass parts of each raw material are: amphoteric surface cassava starch: 10 parts; clear water 132 parts.

[0097] The operating parameters of the paper machine are as follows: basis weight 80 g / m 2 ; lip opening 13 mm; shaking: amplitude 23 mm, vibration frequency 220 times / min; approach concentration 0.9%; machine speed 380 m / min; dryness after leaving the couch roll 21%; main press pressure 70 kN / M; idler roll pressure: the first idler 95 kN / M, the second idler 115 kN / M; large cylinder steam pressure 530 kPa; soft calender pressure: the first press 130 kN / M, the second press 150 kN / M, temperature 170°C; moisture content of the formed paper 5%.

[0098] Among the operating parameters of the paper machine, the control parameters of the film transfer coater are:

[0099] Model and pressure of the metering rod:

[0100] The front metering rod is V40, the linear pressure is 20 kn / m, coat the surface sizing agent on the coating, and coat the front side of the paper sheet;

[0101] The back metering rod is V30, the linear pressure is 20 kn / m, coat the surface sizing agent for the back of the formed paper on the coating, and coat the back side of the paper sheet;

[0102] Pickup amount of the surface coating for the formed paper: 2.1 g / m on the front side 2 , 0.4 g / m on the back side 2 ;

[0103] The dryness of the paper entering the film transfer coater is 90%, and the dryness of the paper leaving the film transfer coater is 70%.

[0104] Comparative Example 1: Compared with Example 3, 30% softwood pulp is used to replace hardwood pulp.

[0105] Comparative Example 2: Compared with Example 3, a fourdrinier multi-cylinder paper machine is used for production instead of a large cylinder paper machine.

[0106] Comparative Example 3: Compared with Example 3, the full-width spray release agent in the large vat was stopped.

[0107] Comparative Example 4: Compared with Example 3, the titanium dioxide used in surface sizing was removed, and titanium dioxide was used in the pulp to ensure that the ash content of the final paper met the requirements.

[0108] Comparative Example 5: Compared with Example 3, the surface sizing was separated into pressure zones, surface sizing was not used, and titanium dioxide was used in the pulp to ensure that the ash content of the final paper met the requirements, but the surface strength was low, resulting in linting and dusting during customer printing.

[0109] The test data of Examples 1-3 and Comparative Examples 1-5 are shown in Table 1.

[0110] Table 1: Test data of Examples 1-3 and Comparative Examples 1-5

[0111]

[0112] From the data of the above examples and comparative examples, it can be seen that:

[0113] Comparative Example 1: Compared with Example 3, when 30% softwood pulp was used to replace hardwood pulp, the smoothness of the paper sheet was lower and the formation was poorer, resulting in the opacity not meeting the requirements either;

[0114] Comparative Example 2: Compared with Example 3, when a fourdrinier multi-cylinder paper machine was used for production instead of a large vat paper machine, the smoothness was too low to meet the requirements of the customer's printing leveling property;

[0115] Comparative Example 3: Compared with Example 3, when the full-width spray release agent in the large vat was stopped, the smoothness of the formed paper was on the low side, and there was serious paper dust on the surface of the large vat, making it impossible to maintain production;

[0116] Comparative Example 4: Compared with Example 3, the titanium dioxide used in surface sizing was removed, and titanium dioxide was used in the pulp to ensure that the ash content of the final paper met the requirements, but the opacity was lower than the requirements;

[0117] Comparative Example 5: Compared with Example 3, the surface sizing was separated into pressure zones, surface sizing was not used, and titanium dioxide was used in the pulp to ensure that the ash content of the final paper met the requirements, but the surface strength was on the low side, resulting in linting and dusting during customer printing.

Claims

1. A process for producing decorative base paper on a fourdrinier cylinder paper machine, characterized in that It includes the following steps: Pulp board → Chain plate conveyor → Pulper → Discharge tank → Refiner → Stock chest → Chest before forming → White water trough outside the machine → Fill pump → Pressure screen → Headbox → Wire section → Press section → Yankee dryer → Sizing machine → Calender stack → Calender → Reel section → Rewinding → Packaging and warehousing; The pulp board ratio is 100% bleached sulfate softwood and hardwood pulp, and the fiber length is 1.0 - 1.2 mm; Online full-width spraying is carried out at the Yankee dryer. When carrying out online full-width spraying, an online full-width spraying release agent needs to be added, and the online full-width spraying release agent is a silicone-based release agent.

2. The process for producing decorative base paper by a Fourdrinier large cylinder paper machine according to claim 1, characterized in that, The pulper uses three DD720 double-disc refiners in series for beating. All three disc refiners use defibering type grinding plates. The refining power is: 330 - 350 kw + 330 - 350 kw + 330 - 350 kw, the flow rate is 280 - 300 m 3 / h, the valve opening is 65 - 70%, the beating degree is 35 ± 1°SR, and the wet weight is 2 ± 0.2 g.

3. The process for producing decorative base paper by a fourdrinier large cylinder paper machine according to claim 1, characterized in that, Cationic starch is added at the stock chest, and the addition amount of cationic starch is 16 - 20 kg / ton of paper; wet strength agent is added at the chest before forming, and the addition amount of wet strength agent is 60 - 80 kg / ton of paper; kaolin and titanium dioxide are added at the pulper, the addition amount of kaolin is 120 - 150 kg / ton of paper, and the addition amount of titanium dioxide is 80 - 100 kg / ton of paper; in kaolin: Al2O3 ≥ 36%, whiteness ≥ 85%, fineness ≥ 800 mesh; in titanium dioxide: TiO2 content ≥ 90%, whiteness ≥ 99%, fineness ≥ 900 mesh.

4. The process for producing decorative base paper on a fourdrinier large cylinder paper machine according to claim 1, characterized in that, Silica sol is added after the pressure screen, and the addition amount of silica sol is 2 - 4 kg / ton of paper; at the position of the Yankee dryer, a release agent is added in front of a support roller, and the addition amount of the release agent is 2 - 3 kg / ton of paper; polyether defoamer is added at the white water trough outside the machine, and the addition amount of polyether defoamer is 150 - 200 g / ton of paper; organic bromine bactericide is added at the white water trough outside the machine, and the addition amount of organic bromine bactericide is 100 - 150 g / ton of paper.

5. The process for producing decorative base paper by a Fourdrinier large cylinder paper machine according to claim 1, characterized in that, Surface sizing agent solution is added at the sizing machine. In the surface sizing agent solution, the solid content is 15 ± 1%, the viscosity is 30 - 50 mPa·s, the pH is 7 - 8, and the temperature is 65 - 70 °C.

6. The process for producing decorative base paper by a Fourdrinier cylinder paper machine according to claim 5, characterized in that, The mass parts of each raw material in the surface sizing agent are: Amphoteric surface cassava starch: 50 parts; Polyvinyl alcohol: 10 parts; Chitosan: 6 parts; CMC: 20 parts; Titanium dioxide: 100 parts; Clear water: 1096 parts.

7. The process for producing decorative base paper on a fourdrinier cylinder paper machine according to claim 6, characterized in that, The preparation method of the surface sizing agent is: Mix the formulated amounts of amphoteric surface cassava starch, titanium dioxide, polyvinyl alcohol, and CMC with 1 / 3 of the formulated amount of clear water in the surface sizing cooking tank, stir evenly, then steam, and raise the temperature to 95 °C, keep warm for 20 min, transfer it to the surface sizing dilution tank and mix it with the formulated amount of chitosan and 2 / 3 of the formulated amount of clear water to form a surface sizing agent with a solid content of 15%, and transfer it to the surface sizing storage tank for standby.

8. The process for producing decorative base paper by a Fourdrinier cylinder paper machine according to claim 7, characterized in that, Back side surface sizing agent for the formed paper is added at the sizing machine. The preparation method of the back side surface sizing agent for the formed paper is: Mix the formulated amount of surface cassava starch with 1 / 3 of the formulated amount of clear water in the starch modulation tank, pump it into the starch cooking tank, raise the temperature to 95 °C, keep warm for 20 min, pump it into the starch dilution tank, cool it to 65 - 70 °C, add 2 / 3 of the formulated amount of clear water to make a solution with a solid content of 7 ± 1%, and pump it into the starch storage tank for standby; among them, the mass parts of each raw material are amphoteric surface cassava starch: 10 parts; clear water 132 parts.

9. The process for producing decorative base paper on a Fourdrinier cylinder paper machine according to claim 8, characterized in that, The operating parameters of the paper machine are as follows: basis weight 78 - 82 g / m 2 ; lip opening 12 - 14 mm; shaking: amplitude 20 - 25 mm, vibration frequency 200 - 230 times / min; approach flow consistency 0.8 - 1.0%; paper machine speed 350 - 400 m / min; dryness of the paper leaving the couch roll 20 - 22%; main press pressure 60 - 80 kN / M; pressure of the carrying rolls: the first carrying roll 90 - 100 kN / M, the second carrying roll 110 - 120 kN / M; steam pressure of the large cylinder 500 - 550 kPa; pressure of the soft calender: the first nip 130 kN / M, the second nip 150 kN / M, temperature 150 - 180 °C; moisture content of the finished paper 4 - 6%.

10. The process for producing decorative base paper on a Fourdrinier cylinder paper machine according to claim 9, characterized in that, Among the operating parameters of the paper machine, the control parameters of the film transfer coating sizing machine are: Metering rod model and pressure: Positive metering rod V40, line pressure 20 kN / m, coating material is surface sizing agent, coating the front side of the paper sheet; Negative metering rod V30, line pressure 20 kN / m, coating material is surface sizing agent for the back side of the formed paper, coating the back side of the paper sheet; Surface coating paper picking quantity: 2 - 2.2 g / m on the front side 2 , 0.3 - 0.5 g / m on the back side 2 ; The dryness of the formed paper entering the film transfer sizing machine is ≥90%, and the dryness of the formed paper leaving the film transfer sizing machine is ≥70%.

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