High-transparency drawing paper with improved crease whitening, preparation method and application

Abstract

The present application relates to the technical field of papermaking, and particularly relates to high-transparency drawing paper with improved crease whitening, a preparation method and application. The high-transparency drawing paper with improved crease whitening is prepared from pulp raw materials, and the pulp raw materials are composed of the following components in percentage by mass: 20-40% of bleached kraft softwood pulp; 40-60% of bleached kraft hardwood pulp; 10-30% of bleached bamboo pulp and / or hemp pulp; and the following additives are added in percentage by mass of the pulp: 0.5-1.5% of a flexibility agent; 0.2-1.0% of a wet strength agent; and 1.0-3.0% of a softening agent. The present application meets the composite requirements of transparency, flexibility and environmental protection in the high-end packaging field.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of papermaking, and particularly relates to a high-transparency drawing paper with improved crease whitening, a preparation method and application. BACKGROUND

[0002] Among paper varieties, the use of a special paper is very unique, that is, drawing paper. Drawing paper was indispensable for engineering drawing. Before the popularization of computers, the best way to preserve engineering drawings for a long time was to make blueprints. To make blueprints, drawing paper was used for copying. Moreover, because drawing paper has a small shrinkage rate and a main waterproof property, some nautical charts are also made of drawing paper.

[0003] With the popularization of computer drawing and the use of CAD and other drawing tools, computer drawing has basically replaced manual drawing, and the use of drawing printers has declared that drawing paper has basically left the drawing industry.

[0004] However, with the improvement of people's living standards, the packaging requirements for gifts and high-end commodities are becoming higher and higher. The unique appearance and printing performance of drawing paper are valued by the packaging industry and introduced into the high-end packaging industry. The nearly transparent paper quality, the matte texture, the superior printing performance, and the appropriate stiffness make it successfully replace plastic and cartons in the high-end application field of the packaging industry. At the same time, as a printed matter of trademarks and the like, it is very suitable for use in high-end packaging. At present, it is mainly used in the printing of trademarks of some high-end gifts, cakes, moon cakes, and cigarettes.

[0005] When drawing paper is used in the high-end packaging industry, it has always been a crushing existence, but when it is used in the outermost layer of packaging, it has a problem that cannot be overcome. Because the beating degree of the raw material used in drawing paper is very high, generally above 85°SR, to achieve a nearly transparent effect, the fiber brought by the high beating degree basically disappears. When the paper is folded, a light white line is left at the crease, and at the corner, because it needs to be folded in two directions, an obvious white spot appears at the overlapping part, affecting the appearance of the product. Of course, if the bag or box is used in the inner layer, there will be no effect, but if it is used in the outer layer, it will greatly affect the grade of the product. SUMMARY

[0006] In order to solve the above technical problems, the purpose of the present application is to provide a high-transparency drawing paper with improved crease whitening, which improves the crease whitening phenomenon of high-transparency drawing paper and meets the combined requirements of transparency, flexibility, and environmental protection of high-transparency drawing paper in the high-end packaging field.

[0007] In order to achieve the above purpose, the present application adopts the following technical solutions:

[0008] A high transparency tracing paper with improved crease whitening, the pulp raw material of the tracing paper is composed of the following components in percentage by mass:

[0009] bleached kraft softwood pulp 20-40%;

[0010] bleached kraft hardwood pulp 40-60%

[0011] bleached bamboo pulp and / or hemp pulp 10-30%;

[0012] and the following additives are added with the pulp weight being 100%:

[0013] flexibility agent 0.5-1.5%

[0014] wet strength agent 0.2-1.0%

[0015] softening agent 1.0-3.0%.

[0016] As a preference, the pulp raw material of the tracing paper is composed of the following components in percentage by mass:

[0017] bleached kraft softwood pulp 25-35%;

[0018] bleached kraft hardwood pulp 45-55%

[0019] bleached bamboo pulp and / or hemp pulp 15-25%;

[0020] and the following additives are added with the pulp weight being 100%:

[0021] flexibility agent 0.8-1.2%

[0022] wet strength agent 0.4-0.8%

[0023] softening agent 1.5-2.5%.

[0024] As a preference, the flexibility agent uses one or more of carboxymethyl cellulose, gelatin and starch.

[0025] As a preference, the wet strength agent uses one or more of PAM, PAE and PPE.

[0026] As a preference, the softening agent uses glycerin, soybean oil and linseed oil; preferably, the softening agent uses glycerin and linseed oil, glycerin 0.8-1.2%, linseed oil 0.1-0.5%.

[0027] As a preference, the additives further include a smoothing agent, the smoothing agent being 0.2-0.5%; preferably, the smoothing agent is selected from silicone oil.

[0028] As preferred, the beating degree of the bleached sulfate broadleaf wood pulp, bleached sulfate coniferous wood pulp, bleached bamboo pulp or hemp pulp is 80-90°SR.

[0029] As preferred, the surface is further provided with a sizing liquid or coating liquid, the sizing amount of the sizing liquid or coating liquid is 0.5-1.5 g / m2, and the sizing liquid or coating liquid is a 5% PVA solution; preferably, the PVA solution is 5% micro-fine titanium dioxide as a filler.

[0030] Further, the application also discloses a preparation method of the high-transparency tracing paper.

[0031] 1) Three kinds of pulp are respectively subjected to beating treatment, the three kinds of pulp are 80-90°SR, the beating concentration is controlled to be 4.0-6.0%, and the wet weight is greater than or equal to 4 g; after the beating is completed, the three kinds of pulp are respectively put into corresponding pulp forming tanks;

[0032] 2) The bleached sulfate broadleaf wood pulp, the bleached sulfate coniferous wood pulp and the bleached bamboo pulp are mixed in the beating machine in a proportion; an additive is added into the pulp and is fully mixed;

[0033] 3) Long net paper machines are used for papermaking, the prepared pulp is diluted to a concentration of 0.02-0.06%, and is respectively formed, pressed and dried by a drying cylinder through a pulp pumping pump.

[0034] Further, the application also discloses application of the high-transparency tracing paper in preparation of high-end packaging paper.

[0035] The application has the following remarkable technical effects by using the above technical scheme, through careful selection of raw materials, careful proportioning of additives and optimization of process:

[0036] 1. Significantly improving the whitening problem at the crease

[0037] By using a specific proportion of softening agents (especially a combination of glycerol and linseed oil) and smoothing agents (such as silicone oil), the whitening phenomenon at the crease when folding the paper is significantly reduced. This is crucial for maintaining the aesthetics of high-end packaging materials, especially in outer packaging applications, which can greatly improve the overall appearance and feel of the product.

[0038] 2. Improving the transparency of the paper

[0039] By optimizing the pulp ratio, especially increasing the proportion of bleached bamboo pulp or hemp pulp, and controlling the appropriate beating degree, the application significantly improves the transparency of the tracing paper. Such high-transparency paper is very suitable for high-end packaging that needs to display internal items or designs, as well as other applications that require transparent effects.

[0040] 3. Optimizing the physical properties of the paper

[0041] The use of bleached sulfate softwood pulp and hardwood pulp, combined with the use of flexing agents and wet strength agents, effectively enhances the strength and flexibility of the paper. This allows the paper to maintain sufficient durability and handling performance even with high transparency, meeting various packaging and printing needs.

[0042] 4. Enhancing the environmental characteristics of the paper

[0043] By selecting environmentally friendly pulp raw materials (such as bleached bamboo pulp and hemp pulp) and biodegradable additives, the tracing paper of the present invention is more environmentally friendly, meeting the current market demand for sustainable products. This has a positive impact on brand shaping and consumer choice.

[0044] 5. Improving printing and handling performance

[0045] Through process optimization, such as surface sizing or coating treatment, using PVA solution, etc., not only the smoothness of the paper is improved, but also the printability is enhanced. This tracing paper can support high-precision pattern and text printing, suitable for complex and high-quality printing needs. DETAILED DESCRIPTION

[0046] The technical solutions in the embodiments will be described below in a clear and complete manner. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present invention.

[0047] Embodiment 1:

[0048] A high-transparency tracing paper with improved crease whitening, the pulp raw materials of the tracing paper consist of the following components by mass percentage:

[0049] Bleached sulfate softwood pulp 30%

[0050] Bleached sulfate hardwood pulp 50%

[0051] Bleached bamboo pulp 20%

[0052] And the following additives are added, with the pulp weight being 100%:

[0053] Flexing agent (carboxymethyl cellulose) 1%

[0054] Wet strength agent (PAM) 0.5%

[0055] Softener (glycerol 1.5% + linseed oil 0.3%)

[0056] Smoothness agent (silicone oil) 0.3%.

[0057] The preparation method of the high-transparency tracing paper, which comprises the following steps:

[0058] 1) Three kinds of pulp are respectively subjected to beating treatment, the 85°SR of the three kinds of pulp is controlled to be 4.0-6.0%, and the wet weight is greater than or equal to 4 g; after the beating treatment, the three kinds of pulp are respectively placed into corresponding pulp pools;

[0059] 2) The bleached kraft broadleaf wood pulp, the bleached kraft softwood pulp and the bleached bamboo pulp are mixed in the beating machine; the additives are added into the pulp and are fully mixed;

[0060] 3) The long net paper machine is used for papermaking, the prepared pulp is diluted to a concentration of 0.02-0.06%, is pumped to corresponding pre-pulping pools, is respectively formed, is pressed, is dried by a drying cylinder, is wound, is inspected, is cut and is packaged.

[0061] Example 2:

[0062] A high-transparency tracing paper with improved crease whitening, the paper pulp raw material of the tracing paper is composed of the following components in percentage by mass:

[0063] bleached kraft softwood pulp 25%

[0064] bleached kraft broadleaf wood pulp 45%

[0065] bleached bamboo pulp 25%

[0066] and the following additives are added, taking the weight of the pulp as 100%:

[0067] flexibility agent (carboxymethyl cellulose + gelatin) 1.2%

[0068] wet strength agent (PAM) 0.6%

[0069] softening agent (glycerol 2%)

[0070] smoothing agent (silicone oil) 0.4%.

[0071] The preparation method is shown in Example 1.

[0072] Example 3:

[0073] A high-transparency tracing paper with improved crease whitening, the paper pulp raw material of the tracing paper is composed of the following components in percentage by mass:

[0074] bleached kraft softwood pulp 20%

[0075] bleached kraft broadleaf wood pulp 40%

[0076] bleached bamboo pulp 30%

[0077] The following additives are added to 100% of the weight of the pulp:

[0078] Flexibility agent (carboxymethyl cellulose) 0.8%

[0079] Wet strength agent (PAM) 0.4%

[0080] Softening agent (glycerol 1% + linseed oil 0.4%)

[0081] Smoothness agent (silicone oil) 0.2%.

[0082] The preparation method of the high-transparency tracing paper, the method comprising the following steps:

[0083] 1) Three kinds of pulp are respectively subjected to beating treatment, the three kinds of pulp have 85°SR, and the beating concentration is controlled to be 4.0-6.0%, and the wet weight is greater than or equal to 4 g; after the beating is completed, the three kinds of pulp are respectively placed into corresponding pulp pools;

[0084] 2) The bleached kraft broadleaf wood pulp, the bleached kraft softwood pulp and the bleached bamboo pulp are mixed in the beating machine in a proportion; the additives are added to the pulp, and the additives are fully mixed;

[0085] 3) The long net paper machine is used for papermaking, the prepared pulp is diluted to a concentration of 0.02-0.06%, is pumped to a corresponding pre-pulping pool, is respectively formed, is pressed, is dried by a drying cylinder, is wound, is inspected, is cut and is packaged.

[0086] Example 4:

[0087] Bleached kraft softwood pulp 35%

[0088] Bleached kraft broadleaf wood pulp 45%

[0089] Bleached bamboo pulp 15%;

[0090] The following additives are added to 100% of the weight of the pulp:

[0091] Flexibility agent (carboxymethyl cellulose + starch) 1%

[0092] Wet strength agent (PAM + PAE) 0.8%

[0093] Softening agent (glycerol 2.5%)

[0094] Smoothness agent (silicone oil) 0.5%.

[0095] The preparation method is shown in Example 1.

[0096] Example 5:

[0097] A high-transparency tracing paper for improving crease whitening, the pulp raw material of the tracing paper is composed of the following components in percentage by mass:

[0098] Bleached sulphate softwood pulp 28%

[0099] Bleached sulphate hardwood pulp 47%

[0100] Bleached bamboo pulp 20%

[0101] The following additives were added with the weight of the pulp being 100%:

[0102] Flexibility agent (carboxymethyl cellulose) 1%

[0103] Wet strength agent (PAM) 0.7%

[0104] Softener (glycerin 1.8% + linseed oil 0.2%)

[0105] Smoothness agent (silicone oil) 0.35%.

[0106] The preparation method is shown in Example 1.

[0107] Example 6:

[0108] A high transparency tracing paper with improved crease whitening, the papermaking formula of the tracing paper is shown in Example 1. The preparation method of the high transparency tracing paper, the method comprises the following steps:

[0109] 1) three kinds of pulp are respectively subjected to beating treatment, the three kinds of pulp have 85°SR, and the beating concentration is controlled to be 4.0-6.0%, and the wet weight is greater than or equal to 4g; after beating is completed, the three kinds of pulp are respectively placed into corresponding pulp pools;

[0110] 2) the bleached sulphate hardwood pulp, the bleached sulphate softwood pulp and the bleached bamboo pulp are mixed in the beating machine in proportion; the additives are added into the pulp, and the additives are fully mixed;

[0111] 3) long net paper machines are used for papermaking, the prepared pulp is diluted to 0.02-0.06% concentration, and is respectively drawn into corresponding pre-pulping pools through a pulping pump to be formed, pressed, dried by a drying cylinder and dried by a drying channel;

[0112] 4) after drying, a sizing liquid is further arranged on the surface, the sizing liquid or the coating liquid has a sizing amount of 1.0g / m 2 , the sizing liquid or the coating liquid is a 5% PVA solution; the 5% PVA solution further comprises fine titanium dioxide as a filler;

[0113] 5) drying cylinder or drying channel drying, winding, inspection, slitting and packaging.

[0114] Comparative Example 1

[0115] A high transparency tracing paper, the paper pulp raw material of the tracing paper comprises the following components in percentage by mass:

[0116] Bleached sulphate softwood pulp 30%

[0117] bleached sulphate hardwood pulp 50%

[0118] bleached bamboo pulp 20% ;

[0119] The following additives were added, based on 100% of the weight of the pulp:

[0120] wet strength agent (PAM) 0.5%.

[0121] The method of preparation was as described in Example 1.

[0122] Comparative Example 2

[0123] A high transparency tracing paper, the pulp raw material of which consists of the following components in mass percentage:

[0124] bleached sulphate softwood pulp 30%

[0125] bleached sulphate hardwood pulp 50%

[0126] bleached bamboo pulp 20% ;

[0127] The following additives were added, based on 100% of the weight of the pulp:

[0128] flexibility agent (carboxymethyl cellulose) 1%

[0129] wet strength agent (PAM) 0.5%

[0130] smoothness agent (silicone oil) 0.3%.

[0131] The method of preparation was as described in Example 1.

[0132] Comparative Example 3

[0133] A high transparency tracing paper, the pulp raw material of which consists of the following components in mass percentage:

[0134] bleached sulphate softwood pulp 30%

[0135] bleached sulphate hardwood pulp 50%

[0136] bleached bamboo pulp 20% ;

[0137] The following additives were added, based on 100% of the weight of the pulp:

[0138] wet strength agent (PAM) 0.5%

[0139] softening agent (glycerol 1.5% + linseed oil 0.3%)

[0140] smoothness agent (silicone oil) 0.3%.

[0141] The method of preparation is as shown in Example 1.

[0142] Comparative Example 4

[0143] A high transparency tracing paper, the pulp raw material of which consists of the following components in mass percentage:

[0144] Bleached kraft softwood pulp 40%

[0145] Bleached kraft hardwood pulp 60%

[0146] The following additives are added, taking the weight of the pulp as 100%:

[0147] Flexibility agent (carboxymethyl cellulose) 1%

[0148] Wet strength agent (PAM) 0.5%

[0149] Softener (glycerol 1.5% + linseed oil 0.3%)

[0150] Smoothness agent (silicone oil) 0.3%.

[0151] The method of preparation is as shown in Example 1.

[0152] Test Example

[0153] 1. Test method for mass per unit area

[0154] Standard: ISO 536:2019

[0155] Method summary: A standard sized paper sample is weighed using a precision electronic balance, and the mass per unit area (usually per square metre) is calculated.

[0156] 2. Test method for transparency

[0157] Standard: ISO 2471

[0158] Method summary: A transparency meter is used to measure the transmittance of a paper sample to light, expressed as a percentage.

[0159] 3. Test method for tear resistance

[0160] Standard: ISO 1974

[0161] Method summary: A tear tester is used to measure the force required to tear a paper sample under specified conditions, expressed in millinewtons (mN).

[0162] 4. Test method for smoothness

[0163] Standard: ISO 5627

[0164] Method Summary: The smoothness of the paper surface is measured using a Bekk smoothness tester or a Pfaltzgraff smoothness tester. The result is expressed in seconds, which is the time it takes for air to pass through a certain area between the paper sample and a smooth glass plate.

[0165] 5. Test method for shrinkage

[0166] Standard: ISO 1924-2

[0167] Method Summary: The shrinkage of the paper is evaluated by measuring the degree of elongation under a certain tension, expressed in percentage.

[0168] 6. Test method for the degree of whitening at the crease

[0169] Method Summary: The degree of whitening at the crease is evaluated qualitatively by a visual assessment method using an expert scoring system. Scoring explanation: The degree of whitening is scored from 1 to 5, 1 indicating almost no whitening and 5 indicating severe whitening.

[0170] The formulation data is shown in Table 1.

[0171] Table 1

[0172] Formulation Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Bleached kraft softwood pulp 30% 25% 20% 35% 28% 30% 30% 30% 30% 40% Bleached kraft hardwood pulp 50% 45% 40% 45% 47% 50% 50% 50% 50% 60% Bleached bamboo pulp 20% 25% 30% 15% 20% 20% 20% 20% 20% - Flexibilizer (carboxymethyl cellulose) 1% 1.2% (with gelatin) 0.8% 1% (with starch) 1% 1% - 1% 1% 1% Wet strength agent (PAM) 0.5% 0.6% 0.4% 0.8% (with PAE) 0.7% 0.5% 0.5% 0.5% 0.5% 0.5% Softener (glycerin) 1.5% 2% 1% 2.5% 1.8% 1.5% - - - 1.5% Softener (linseed oil) 0.3% - 0.4% - 0.2% 0.3% - - - 0.3% Smoothness agent (silicone oil) 0.3% 0.4% 0.2% 0.5% 0.35% 0.3% - - - 0.3% Coating - - - - - Yes - - - -

[0173] The test data is shown in Table 2.

[0174] Table 2

[0175] Test index Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Mass per unit area g / m² 60 58 62 62 60 65 62 63 62 63 Transparency % 88 86 90 85 87 80 80 82 80 78 Tear resistance mN 214 227 212 234 224 215 189 214 218 220 Smoothness Bekk s 36 34 32 35 32 45 25 24 22 27 Shrinkage (machine direction) % 2.6 2.0 2.5 1.8 2.2 2.7 3.5 2.4 2.8 2.6 Shrinkage (cross direction) % 9.5 8.7 9.3 8.5 9.1 8.9 10.5 9.6 9.4 9.7 Crease whitening (1-5 points) 1 2 1 2 1 1 4 4 4 3

[0176] Result analysis:

[0177] Transparency: The examples show significantly higher transparency than the comparative examples, especially Example 3, due to the high proportion of bleached bamboo pulp increasing the transparency.

[0178] Tear resistance: The tear resistance in the examples is generally higher than in the comparative examples, especially Example 4, which shows that the added flexibilizer and wet strength agent effectively improve the mechanical strength of the paper.

[0179] Smoothness: By adding a smoothing agent (silicone oil), the smoothness of the example paper is significantly better than that of the comparative examples, which is beneficial for printing and writing.

[0180] Shrinkage: The paper in the examples has lower shrinkage in both the longitudinal and transverse directions than the comparative examples, indicating better dimensional stability of the paper.

[0181] Degree of whitening at the crease: The degree of whitening at the crease of the paper in the examples is significantly lower than that of the comparative examples, especially Examples 1, 3, 5, and 6, which demonstrates that the glycerol + linseed oil additive can further reduce the degree of whitening at the crease.

[0182] Test Example 2

[0183] To demonstrate the effect of sizing treatment and filler addition on the print and handling performance of the tracing paper, the following experiments were conducted based on Example 1. These data compare the performance of papers under different treatment conditions in terms of print quality, ink absorbency, and handling ease (such as folding and cutting).

[0184] Experimental design

[0185] Treatment category Description Control group (no sizing) Paper is not subjected to any sizing treatment Sizing group (PVA 5% solution) Paper surface is applied with 5% PVA solution Sizing + filler group (PVA 5% + micro titanium dioxide) Paper surface is applied with 5% PVA solution containing 5% micro titanium dioxide

[0186] Experimental data

[0187] Performance index Control group Sizing group (PVA 5% solution) Sizing + filler group (PVA 5% + micro titanium dioxide) Evaluation criteria or test method Print quality Good Excellent Very excellent Assessed by print clarity, color vividness and image details Ink absorbency High Medium Low Measure the time for ink to completely dry Handling ease Ordinary Good Very good Evaluate the handling ease of paper during folding, cutting, etc.

[0188] Print quality: Compared to the control group, the sizing treated papers showed significant improvement in print quality, especially the sizing + filler group with fine titanium dioxide, which achieved excellent print quality. This is likely because the sizing and filler work together on the paper surface to form a more uniform and smooth printing substrate.

[0189] Ink absorbency: The sizing treated papers showed moderate ink absorbency, while the addition of fillers further reduced ink absorbency, which is beneficial for fast drying and reducing smearing during printing.

[0190] Handling ease: The sizing + filler group showed the best handling ease, including performance during folding and cutting, which indicates that the use of sizing and fillers can effectively improve the mechanical properties of the paper, making it more suitable for complex subsequent processing.

[0191] The above is the description of the embodiments of the present application. Through the above description of the disclosed embodiments, those skilled in the art can implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A high transparency tracing paper having improved crease whitening, characterized by, The pulp raw material of the tracing paper is composed of the following components in percentage by mass: bleached kraft softwood pulp 20-40%; bleached kraft hardwood pulp 40-60% bleached bamboo pulp 10-30%; and the following additives are added in the amount of 100% of the pulp weight: flexibility agent 0.5-1.5% wet strength agent 0.2-1.0% softening agent 1.0-3.0%; smooth agent 0.2-0.5%. The flexibility agent uses one or more of carboxymethyl cellulose, gelatin and starch, the wet strength agent uses one or two of PAM and PAE; the softening agent uses glycerin and linseed oil; the smooth agent uses silicon oil.

2. The high transparency tracing paper for improving crease whitening according to claim 1, wherein The pulp raw material of the tracing paper is composed of the following components in percentage by mass: bleached kraft softwood pulp 25-35%; bleached kraft hardwood pulp 45-55% bleached bamboo pulp 15-25%; and the following additives are added in the amount of 100% of the pulp weight: flexibility agent 0.8-1.2% wet strength agent 0.4-0.8% softening agent 1.5-2.5%.

3. The high transparency drawing paper for improving crease whitening according to claim 1, wherein The softening agent uses glycerin and linseed oil, the amount of glycerin is 0.8-1.2%, and the amount of linseed oil is 0.1-0.5%.

4. The high transparency tracing paper for improving crease whitening according to claim 1, wherein The beating degree of bleached kraft softwood pulp, bleached kraft hardwood pulp and bleached bamboo pulp is 80-90°SR.

5. The high transparency drawing paper for improving crease whitening according to claim 1, wherein The surface of the tracing paper is further provided with a sizing liquid or coating liquid, the sizing amount of the sizing liquid or coating liquid is 0.5-1.5g / m 2 , and the sizing liquid or coating liquid is a 5% PVA solution.

6. The high transparency tracing paper for improving crease whitening according to claim 5, wherein 5% of fine titanium dioxide is added to the PVA solution as filler.

7. The method of producing a high transparency delineator sheet according to any one of claims 1 to 6, characterized in that, The method comprises the following steps: 1) three kinds of pulp are respectively subjected to beating treatment, the beating degree of the three kinds of pulp is 80-90°SR, the beating concentration is controlled at 4.0-6.0%, and the wet weight is ≥4g; after the beating is completed, the three kinds of pulp are respectively placed into corresponding pulp pools; 2) bleached kraft softwood pulp, bleached kraft hardwood pulp and bleached bamboo pulp are mixed in the beating machine in proportion; additives are added to the pulp, and the pulp is mixed thoroughly; 3) long net paper machine is used for papermaking, the prepared pulp is diluted to a concentration of 0.02-0.06%, and is respectively formed, pressed, dried by a drying cylinder through a flushing pump.

8. Use of the high-transparency tracing paper according to any one of claims 1-6 in the preparation of packaging paper.