Quick printing paper and preparation process thereof

Abstract

The invention provides quick printing paper and a preparation process thereof, and relates to the technical field of printing paper. According to the parameters of the quick printing paper, the weight is larger than or equal to 65 g / m < 2 >, the thickness is larger than or equal to 0.08 mm, the D65 brightness is larger than or equal to 55.0% and smaller than or equal to 85.0%, the D fluorescent brightness is smaller than or equal to 1.5%, the opacity is larger than or equal to 85%, the longitudinal stiffness is larger than or equal to 70 mN.m, the transverse stiffness is larger than or equal to 40 mN.m, the bulk is 1.2-1.7 cm < 3 > / g, the surface roughness is smaller than or equal to 60 ml / min, the smoothness is 40-50 S, and the front and back face difference is smaller than or equal to 15%. The prepared quick printing paper has the advantages of being low in cost, not prone to moisture regaining, high in stiffness, free of paper jamming, free of ink staining, free of powder falling and the like when passing through a machine, meets the national compulsory standard and can be widely applied to the field of student learning paper.

Description

Technical Field

[0001] The present application relates to the technical field of printing paper, and in particular to a quick-printing paper and a preparation process thereof. Background Art

[0002] Before 2022, there was no corresponding national standard for quick-print paper (or test paper). It was only mentioned in GB40070-2021 (national mandatory standard) that student test papers should be implemented according to the standards of textbooks and supplementary materials. As a result, there is no unified standard for quick-print paper on the market, and the quality is uneven. When using it, problems such as poor machine feeding, paper jams, page clipping, wrinkling, multiple sheets, heavy dust, uneven paper floating at the paper outlet, overlapping images, and dirty ink often occur. This not only brings great troubles to the user unit when purchasing, but also brings troubles to the user.

[0003] At present, most enterprises and schools still use ordinary offset paper and copy paper as quick printing paper. However, there are some problems. For example, the disadvantages of copy paper as quick printing paper include: (1) The cost is too high. The main users of copy paper are schools, so the price is high and the cost performance is low; (2) The sizing, smoothness and bulk of copy paper are inconsistent with the requirements of quick printing paper. In addition, due to process reasons, the copy paper is prone to moisture regain after opening, and the stiffness decreases, which can easily lead to paper jams and the second page of the paper cannot be used, resulting in paper waste. (3) The main purpose of copy paper is office use, which requires a whiteness of ≥90%, while the main users of quick printing paper are schools. The whiteness and fluorescent agent of this specification can easily damage students' eyesight and affect their skin. Summary of the invention

[0004] The purpose of the present application is to provide a quick printing paper, which has the advantages of low cost, not easy to regain moisture, no paper jam, no ink stain, no powder loss, etc.

[0005] Another object of the present application is to provide a preparation process of quick-printing paper, which is simple and convenient.

[0006] In order to solve the above technical problems, the technical solution adopted in this application is:

[0007] On the one hand, the present application provides a quick printing paper, the parameters of the quick printing paper are: weight ≥ 65g / m 2 , thickness ≥ 0.08mm, D65 brightness ≥ 55.0% and ≤ 85.0%, D fluorescence brightness ≤ 1.5%, opacity ≥ 85%, longitudinal stiffness ≥ 70mN·m, transverse stiffness ≥ 40mN·m, bulk thickness 1.2-1.7cm 3 / g, surface roughness ≤60ml / min, smoothness 40-50S and front and back surface difference ≤15%.

[0008] In another aspect, the present application provides a method for preparing quick-print paper, comprising the following steps:

[0009] S1. Pulping: taking bleached coniferous wood pulp and bleached broadleaved wood pulp, removing impurities from them, and then beating them separately for later use;

[0010] S2, slurry preparation: the above wood pulp is mixed, and then calcium carbonate, aluminum sulfate, dye, AKD, fungicide, bentonite, wet strength agent and rosin are added, and mixed evenly to obtain a mixed slurry;

[0011] S3, papermaking: the mixed slurry is passed through a fourdrinier paper machine with a sizing press to form paper, to obtain base paper;

[0012] S4, surface sizing: After the base paper is dried and formed, surface sizing is performed, and the quick printing paper is obtained after drying, rolling and cutting.

[0013] Compared with the prior art, the embodiments of the present application have at least the following advantages or beneficial effects:

[0014] 1. The raw material of this application is 100% virgin pulp paper to ensure the stiffness of the paper (vertical stiffness ≥ 70mN·m, transverse stiffness ≥ 40mN·m), reduce impurities in wood pulp, and the prepared quick printing paper is not easy to lose powder during the printing operation, which is more environmentally friendly and safe.

[0015] 2. The basis weight (grammage) of the quick-print paper for this application is ≥ 65g / m 2 According to the inventor's research over the years, it is found that when the quantitative quantity of the quick-print paper product meets the above standards, problems such as uneven paper floating at the paper outlet and ink stains can be avoided, thereby reducing paper waste.

[0016] 3. The bulk thickness of the quick printing paper for this application is 1.2-1.7cm 3 / g, different from traditional offset paper (bulk thickness 1.01-1.2cm 3 / g), light paper (1.7-2.2cm 3 / g), the bulk thickness can achieve better paper smoothness, so that the final quick printing paper product can avoid problems such as poor machine passing, paper jams, wrinkles, etc., and the cost of the prepared quick printing paper is lower than that of ordinary copy paper. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 The quick-print paper (off-white) prepared in the examples of the present application;

[0019] Figure 2 The quick-print paper (off-white + beige) prepared in the examples of the present application; DETAILED DESCRIPTION

[0020] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to the conventional conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0021] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to specific embodiments.

[0022] A quick printing paper, the parameters of which are: weight ≥ 65g / m 2 , thickness ≥ 0.08mm, D65 brightness ≥ 55.0% and ≤ 85.0%, D fluorescence brightness ≤ 1.5%, opacity ≥ 85%, longitudinal stiffness ≥ 70mN·m, transverse stiffness ≥ 40mN·m, bulk thickness 1.2-1.7cm 3 / g, surface roughness ≤60ml / min, smoothness 40-50S and front and back surface difference ≤15%.

[0023] In some embodiments of the present application, the above-mentioned D fluorescent brightness specifically includes: natural white eye protection paper ≤1.5%, off-white eye protection paper ≤0.1%.

[0024] A method for preparing quick-print paper comprises the following steps:

[0025] S1. Pulping: taking bleached coniferous wood pulp and bleached broadleaved wood pulp, removing impurities from them, and then beating them separately for later use;

[0026] S2, slurry preparation: the above wood pulp is mixed, and then calcium carbonate, aluminum sulfate, dye, AKD, fungicide, bentonite, wet strength agent and rosin are added, and mixed evenly to obtain a mixed slurry;

[0027] S3, papermaking: the mixed slurry is passed through a fourdrinier paper machine with a sizing press to form paper, to obtain base paper;

[0028] S4, surface sizing: After the base paper is dried and formed, surface sizing is performed, and the quick printing paper is obtained after drying, rolling and cutting.

[0029] In some embodiments of the present application, the concentration of the bleached coniferous pulp after beating in the above step S1 is 3.8-4.1%, the beating degree is 35-41°SR, and the wet weight is 8-10g.

[0030] In some embodiments of the present application, the concentration of the bleached hardwood pulp after beating in the above step S1 is 3.5-3.9%, the beating degree is 38-43°SR, and the wet weight is 5-8g.

[0031] In some embodiments of the present application, in the above step S1, the mass ratio of bleached coniferous wood pulp to bleached broadleaf wood pulp is 1:(4-5); the broadleaf wood includes maple, birch and poplar, and the mass ratio thereof is (4-5):(2-3):1.

[0032] In some embodiments of the present application, the amounts of additives added in the above-mentioned S2 step are: 150-200 kg / t slurry of calcium carbonate, 1-2 kg / t slurry of aluminum sulfate, 0.05-0.2 kg / t slurry of dye, 8-12 kg / t slurry of AKD, 0.5-0.6 kg / t slurry of fungicide, 0.5-1 kg / t slurry of bentonite, 2.8-5 kg / t slurry of wet strength agent and 0.5-1.2 kg / t slurry of rosin.

[0033] In some embodiments of the present application, the papermaking parameters of the above step S3 are: beating degree is 38-40°SR; web mass concentration is 0.9-1.3%; web pH value is 7.0-8.5.

[0034] In some embodiments of the present application, the sizing agent used for surface sizing in the above step S4 is a mixture of polyvinyl alcohol and starch, the mass ratio of the two is 1: (100-150), and the mixture is gelatinized by adding water; the concentration of the sizing agent is 8-12%.

[0035] The features and performance of the present application are further described in detail below in conjunction with the embodiments.

[0036] Example 1

[0037] A quick printing paper is prepared by the following process:

[0038] S1. Take bleached coniferous pulp and bleached broadleaf pulp, wherein the mass ratio of white coniferous pulp to bleached broadleaf pulp is 1:4; the broadleaf wood is a mixture of maple, birch and poplar in a mass ratio of 4:2:1; the bleached coniferous pulp and the bleached broadleaf pulp are respectively subjected to impurity removal treatment, and then pulped separately for use; the concentration of the bleached coniferous pulp after pulping is 4.0%, the beating degree is 38°SR, and the wet weight is 9.5g; the concentration of the bleached broadleaf pulp after pulping is 3.5%, the beating degree is 40°SR, and the wet weight is 6g

[0039] S2, pulping: the softwood pulp and the hardwood pulp are mixed, and then additives are added, including 180kg / t of calcium carbonate, 1.5kg / t of aluminum sulfate, 0.1kg / t of dye, 10.5kg / t of AKD, 0.5kg / t of fungicide, 0.8kg / t of bentonite, 3kg / t of wet strength agent and 0.7kg / t of rosin, and mixed evenly to obtain a mixed pulp;

[0040] S3. Papermaking: the mixed slurry is passed through a fourdrinier paper machine with a sizing press to form paper, and base paper is obtained; the papermaking parameters are: beating degree is 39°SR; the mass concentration of the web is 1.2% and the pH value of the web is 7.5.

[0041] S4, surface sizing: After the base paper is dried and formed, surface sizing is performed, the concentration of the sizing agent is 10.5%, and the sizing agent is prepared by mixing starch and polyvinyl alcohol in a mass ratio of 100:1 and gelatinizing. The sizing agent is evenly coated on the front and back of the base paper, and then dried, rolled and cut to obtain the instant printing paper.

[0042] Example 2

[0043] A quick printing paper is prepared by the following process:

[0044] S1. Take bleached coniferous pulp and bleached broadleaf pulp, wherein the mass ratio of white coniferous pulp to bleached broadleaf pulp is 1:5; the broadleaf wood is a mixture of maple, birch and poplar in a mass ratio of 5:2:1; the bleached coniferous pulp and the bleached broadleaf pulp are respectively subjected to impurity removal treatment, and then pulped separately for use; the concentration of the bleached coniferous pulp after pulping is 4.1%, the beating degree is 38°SR, and the wet weight is 10g; the concentration of the bleached broadleaf pulp after pulping is 3.9%, the beating degree is 42°SR, and the wet weight is 6.5g

[0045] S2, pulping: the softwood pulp and the hardwood pulp are mixed, and then additives are added, including 160kg / t of calcium carbonate, 1.7kg / t of aluminum sulfate, 0.15kg / t of dye, 10.5kg / t of AKD, 0.6kg / t of fungicide, 1.0kg / t of bentonite, 3kg / t of wet strength agent and 0.9kg / t of rosin, and mixed evenly to obtain a mixed pulp;

[0046] S3. Papermaking: the mixed slurry is passed through a fourdrinier paper machine with a sizing press to form paper, and base paper is obtained; the papermaking parameters are: beating degree is 39°SR; the mass concentration of the web is 1.2%, and the pH value of the web is 7.7.

[0047] S4, surface sizing: After the base paper is dried and formed, surface sizing is performed, the concentration of the sizing agent is 11%, and the sizing agent is prepared by mixing starch and polyvinyl alcohol in a mass ratio of 120:1 and gelatinizing. The sizing agent is evenly coated on the front and back of the base paper, and then dried, rolled and cut to obtain the instant printing paper.

[0048] Example 3

[0049] A quick printing paper is prepared by the following process:

[0050] S1. Take bleached coniferous pulp and bleached broadleaf pulp, wherein the mass ratio of white coniferous pulp to bleached broadleaf pulp is 1:4; the broadleaf wood is a mixture of maple, birch and poplar in a mass ratio of 5:3:1; the bleached coniferous pulp and the bleached broadleaf pulp are respectively subjected to impurity removal treatment, and then pulped separately for use; the concentration of the bleached coniferous pulp after pulping is 4.1%, the beating degree is 38°SR, and the wet weight is 10g; the concentration of the bleached broadleaf pulp after pulping is 3.6%, the beating degree is 42°SR, and the wet weight is 6.5g

[0051] S2, pulping: the softwood pulp and the hardwood pulp are mixed, and then additives are added, including 190kg / t of calcium carbonate, 1.7kg / t of aluminum sulfate, 0.08kg / t of dye, 9kg / t of AKD, 0.55kg / t of fungicide, 1.0kg / t of bentonite, 4.2kg / t of wet strength agent and 1.2kg / t of rosin, and mixed evenly to obtain a mixed pulp;

[0052] S3. Papermaking: the mixed slurry is passed through a fourdrinier paper machine with a sizing press to form paper, and base paper is obtained; the papermaking parameters are: beating degree is 38°SR; the mass concentration of the web is 0.9%, and the pH value of the web is 8.5.

[0053] S4, surface sizing: After the base paper is dried and formed, surface sizing is performed, the concentration of the sizing agent is 8.5%, and the sizing agent is prepared by mixing starch and polyvinyl alcohol in a mass ratio of 150:1 and gelatinizing. The sizing agent is evenly coated on the front and back of the base paper, and then dried, rolled and cut to obtain the instant printing paper.

[0054] Example 4

[0055] A quick printing paper is prepared by the following process:

[0056] S1. Take bleached coniferous pulp and bleached broadleaf pulp, wherein the mass ratio of white coniferous pulp to bleached broadleaf pulp is 1:4; the broadleaf wood is a mixture of maple, birch and poplar in a mass ratio of 5:2:1; the bleached coniferous pulp and the bleached broadleaf pulp are respectively subjected to impurity removal treatment, and then pulped separately for use; the concentration of the bleached coniferous pulp after pulping is 3.8%, the beating degree is 36°SR, and the wet weight is 8g; the concentration of the bleached broadleaf pulp after pulping is 3.8%, the beating degree is 39°SR, and the wet weight is 6.5g

[0057] S2, pulping: the softwood pulp and the hardwood pulp are mixed, and then additives are added, including 150kg / t of calcium carbonate, 1.7kg / t of aluminum sulfate, 0.12kg / t of dye, 10kg / t of AKD, 0.55kg / t of fungicide, 1.0kg / t of bentonite, 4kg / t of wet strength agent and 1.2kg / t of rosin, and mixed evenly to obtain a mixed pulp;

[0058] S3. Papermaking: the mixed slurry is passed through a fourdrinier paper machine with a sizing press to form paper, and base paper is obtained; the papermaking parameters are: beating degree is 38°SR; the mass concentration of the web is 0.9%, and the pH value of the web is 8.5.

[0059] S4, surface sizing: After the base paper is dried and formed, surface sizing is performed, the concentration of the sizing agent is 9%, and the sizing agent is prepared by mixing starch and polyvinyl alcohol in a mass ratio of 150:1 and gelatinizing. The sizing agent is evenly coated on the front and back of the base paper, and then dried, rolled and cut to obtain the instant printing paper.

[0060] The quick-print paper product prepared in the present application example is as follows Figure 1 and Figure 2 As shown, Figure 1 It is white quick-print paper. Figure 2 The left one is white quick-print paper. Figure 2 On the right is beige quick-print paper.

[0061] The quick-printing paper prepared in this application meets the following technical parameters:

[0062] 1. Specifications: 8-fold (270mm*390mm, 260mm*362mm; 285mm*420mm), B4 (257mm*364mm);

[0063] 2. Quantity and deviation: ≧65g / m2 (±4%);

[0064] 3. Color: natural white or beige, light green, gray and other environmentally friendly colors;

[0065] 4. Thickness: ≧0.08mm;

[0066] 5. D65 brightness ≥55.0% and ≤85.0%;

[0067] 6. D fluorescence brightness ≤1.5% (white eye protection paper), ≤0.1% (beige eye protection paper)

[0068] 7. Opacity: ≧85%;

[0069] 8. Water absorption: 29.5g / m 2 (mean);

[0070] 9. Tightness: ≧0.85g / cm 3 ;

[0071] 10. Average longitudinal and transverse length of the fault: ≧3800m;

[0072] 11. Smoothness: 46s (average) on the front and back sides, ≤15% (front and back difference);

[0073] 12. Folding endurance: ≧60 times;

[0074] 13. Expansion rate: ≤1%;

[0075] 14. Printing surface strength: ≧3.0mm / s;

[0076] 15. Sizing degree: neutral sizing (0.8-1.0);

[0077] 16. Dust content (ash content): 0 / m 2 ;

[0078] 17. Thickness and banner difference: ≤1.22%;

[0079] 18. Stiffness (longitudinal): 0.25mN·m; Stiffness (transverse): 0.10mN·m;

[0080] 19. Delivery moisture: 5.0-6.0%;

[0081] 20. Bulk thickness: 1.2-1.7cm 3 / g;

[0082] 21. Net content: 3500 sheets / item or 2000 sheets / item;

[0083] 22. Surface roughness: ≤60mL / min;

[0084] 23. Tensile strength: ≧50N.m / g (roll longitudinally);

[0085] 24. Elasticity (transverse direction of roll): ≤±3.5%

[0086] 25. Storage: Under normal natural environment (not exposed to water or rain), it is better to store it for 2-3 months or more.

[0087] 26. Low static (or no static) treatment.

[0088] The quick-print paper prepared in Example 1 was sent to the Sichuan Paper Quality Supervision and Inspection Center of Leshan Product Quality Supervision and Inspection Institute for testing. The inspection was based on GB / T 7974-2013 "Determination of D65 brightness of blue light diffuse reflection factor of paper, paperboard and pulp (diffuse / vertical method, outdoor daylight conditions)" and the judgment was based on GB 40070-2021 "Hygiene requirements for myopia prevention and control of children and adolescents' learning supplies", and the inspection environment was temperature (23.0±1.0)℃ and humidity (50.0±2.0)%RH. The test results are shown in Table 1.

[0089] Table 1

[0090]

[0091] It can be seen from Table 1 that the quick printing paper prepared in this application meets the relevant standards and is suitable for students to use.

[0092] In summary, a quick printing paper and a preparation process thereof according to an embodiment of the present application have the following advantages: 1. The raw material of the present application is 100% virgin pulp paper, which ensures the stiffness of the paper (longitudinal stiffness ≥ 70mN·m, transverse stiffness ≥ 40mN·m), reduces impurities in wood pulp, and the prepared quick printing paper is not easy to lose powder during the printing operation, which is more environmentally friendly and safe.

[0093] 2. The basis weight (grammage) of the quick-print paper for this application is ≥ 65g / m 2 According to the inventor's research over the years, it is found that when the quantitative quantity of the quick-print paper product meets the above standards, problems such as uneven paper floating at the paper outlet and ink stains can be avoided, thereby reducing paper waste.

[0094] 3. The bulk thickness of the quick printing paper for this application is 1.2-1.7cm 3 / g, different from traditional offset paper (bulk thickness 1.01-1.2cm 3 / g), light paper (1.7-2.2cm 3 / g), the bulk can achieve better paper smoothness, so that the final quick-print paper product can avoid problems such as poor machine passing, paper jams, and wrinkles.

[0095] The embodiments described above are part of the embodiments of the present application, rather than all of the embodiments. The detailed description of the embodiments of the present application is not intended to limit the scope of the present application for protection, but merely represents the selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the present application.

Claims

1. A quick printing paper, characterized in that: The parameters of the quick printing paper are: weight ≥ 65g / m 2 , thickness ≥ 0.08mm, D65 brightness ≥ 55.0% and ≤ 85.0%, D fluorescence brightness ≤ 1.5%, opacity ≥ 85%, longitudinal stiffness ≥ 70mN·m, transverse stiffness ≥ 40mN·m, bulk thickness 1.2-1.7cm 3 / g, surface roughness ≤60ml / min, smoothness 40-50s and front and back surface difference ≤15%.

2. A quick printing paper according to claim 1, characterized in that: The D fluorescence brightness specifically includes: white paper ≤1.5%, off-white eye protection paper ≤0.1%.

3. A method for preparing quick-print paper as claimed in claim 1 or 2, characterized in that: The following steps are involved: S1. Pulping: taking bleached coniferous wood pulp and bleached broadleaved wood pulp, removing impurities from them, and then beating them separately for later use; S2, slurry preparation: the above wood pulp is mixed, and then calcium carbonate, aluminum sulfate, dye, AKD, fungicide, bentonite, wet strength agent and rosin are added, and mixed evenly to obtain a mixed slurry; S3, papermaking: the mixed slurry is passed through a fourdrinier paper machine with a sizing press to form paper, to obtain base paper; S4, surface sizing: After the base paper is dried and formed, surface sizing is performed, and the quick printing paper is obtained after drying, rolling and cutting.

4. The method for preparing quick-print paper according to claim 3, characterized in that: In the step S1, the concentration of the bleached coniferous wood pulp after beating is 3.8-4.1%, the beating degree is 35-41°SR, and the wet weight is 8-10g.

5. The method for preparing quick-print paper according to claim 3, characterized in that: In the step S1, the concentration of the bleached hardwood pulp after beating is 3.5-3.9%, the beating degree is 38-43°SR, and the wet weight is 5-8g.

6. The method for preparing quick-print paper according to claim 3, characterized in that: In the step S1, the mass ratio of bleached coniferous wood pulp to bleached broadleaf wood pulp is 1:(4-5); the broadleaf wood includes maple, birch and poplar, and the mass ratio thereof is (4-5):(2-3):

1.

7. The method for preparing quick-print paper according to claim 3, characterized in that: The amounts of additives added in step S2 are: 150-200 kg / t slurry of calcium carbonate, 1-2 kg / t slurry of aluminum sulfate, 0.05-0.2 kg / t slurry of dye, 8-12 kg / t slurry of AKD, 0.5-0.6 kg / t slurry of fungicide, 0.5-1 kg / t slurry of bentonite, 2.8-5 kg / t slurry of wet strength agent and 0.5-1.2 kg / t slurry of rosin.

8. The method for preparing quick-print paper according to claim 3, characterized in that: The papermaking parameters of step S3 are: beating degree of 38-40°SR; web mass concentration of 0.9-1.3%; web pH of 7.0-8.

5.

9. The method for preparing quick-print paper according to claim 3, characterized in that: The sizing agent used in the surface sizing in step S4 is a mixture of polyvinyl alcohol and starch, the mass ratio of the two is 1: (100-150), and the mixture is gelatinized by adding water; the concentration of the sizing agent is 8-12%.

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