Two-side painting water color paper with lines on two sides and production method thereof

Abstract

The invention relates to the technical field of water color paper for painting, in particular to two-sided painting water color paper with lines on two sides and a production method thereof, and is characterized in that the water color paper comprises an upper water color paper layer, a middle paper layer and a lower water color paper layer, the upper layer and the lower layer of the middle paper layer are respectively compounded with the upper layer water color paper layer and the lower layer water color support to form the water color paper with the water color paper layers on the two surfaces, and the upper side of the upper layer water color paper layer and the lower side of the lower layer water color paper layer are respectively provided with grains. The water color paper has the advantages of simple structure, double-side availability, improvement of the use efficiency of the water color paper, avoidance of waste of paper materials and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of watercolor paper for painting, and specifically to a two-sided painting watercolor paper with patterns on both sides and its production method. Background Art

[0002] As is well known, watercolor paper, as the name implies, is a type of paper used for painting watercolor paintings. According to the different fiber materials used in its production, watercolor paper is divided into all-cotton watercolor paper, semi-cotton watercolor paper, and all-wood watercolor paper. According to the different surface textures, it is divided into rough-textured watercolor paper, medium-textured watercolor paper, and fine-textured watercolor paper. At present, manufacturers both at home and abroad produce watercolor paper, and the brands include Arches watercolor paper, Fabriano watercolor paper, Bockingford watercolor paper, Baohong watercolor paper, and Kelly watercolor paper. Regardless of whether the above watercolor paper is all-cotton watercolor paper, semi-cotton watercolor paper, or all-wood watercolor paper, its surface has rough, medium, or fine textures on one side of the paper, and it can only be painted on one side of the paper, that is, on the side with the texture. At present, the levels of watercolor painters are different. There are master painters who frame their paintings for collection or sale as artworks, art lovers who collect paintings, and a large number of beginners or those in the initial growth stage of painting skills. Their paintings still have many defects and cannot be collected or sold as perfect works. They still need to continuously practice painting. And at present, most of the watercolor paper is used by painting practitioners. When painting, only one side is used, that is, one piece of paper can only be used once, resulting in huge waste. To meet the practice needs of watercolor painting learners, save the consumption of watercolor paper materials, reduce the production cost of watercolor paper, a watercolor paper with watercolor patterns on both sides that can be painted on both sides is provided for watercolor painting enthusiasts. One piece of paper can be used twice, front and back, and the utilization rate of the watercolor paper is increased by 50%, effectively controlling the waste of paper materials.

[0003] Currently, the invention patent of the existing patent CN112252082A discloses a watercolor paper with printing function and its preparation method. One side has a texture for watercolor painting, while the other side is a coated processing paper for color printing. The back of this paper is a coating without a texture and cannot achieve watercolor painting on both sides. Summary of the Invention

[0004] The purpose of the present invention is to solve the deficiencies of the above-mentioned existing technologies, and provide a two-sided painting watercolor paper with patterns on both sides and its production method, which has a simple structure, can be used on both sides, improves the utilization rate of watercolor paper, and avoids waste of paper materials.

[0005] The technical solution adopted by the present invention to solve its technical problems is: A two-sided painting watercolor paper with patterns on both sides, characterized in that the watercolor paper comprises an upper watercolor paper layer, a middle paper layer and a lower watercolor paper layer. The upper and lower sides of the middle paper layer are respectively laminated with the upper watercolor paper layer and the lower watercolor paper layer to form a three-layer structure watercolor paper with watercolor paper layers on both sides. The upper side of the upper watercolor paper layer and the lower side of the lower watercolor paper layer are respectively provided with patterns.

[0006] The upper watercolor paper layer described in the present invention is formed by pressing through a felt roller passing through the felt below, and the lower watercolor paper layer is formed by pressing through a patterned roller with patterns.

[0007] The upper watercolor paper layer and the lower watercolor paper layer described in the present invention are 100% cotton pulp fiber, i.e., all-cotton watercolor paper layer, cotton-containing watercolor paper layer containing cotton pulp fiber and softwood pulp, or 100% wood pulp layer.

[0008] The middle paper layer described in the present invention is a mixed paper layer of softwood pulp and hardwood pulp, or a recycled pulp paper layer.

[0009] A production method of a two-sided painting watercolor paper with patterns on both sides, characterized in that the steps of the production method are as follows: (1) Making the upper watercolor paper layer and the lower watercolor paper layer: The upper watercolor paper layer and the lower watercolor paper layer are made by conventional methods; (2) Making the middle paper layer: The middle paper layer is made by conventional methods; (3) The first pressing process: The upper watercolor paper layer, the middle paper layer, and the lower watercolor paper layer are simultaneously pressed through the first pressing roller to laminate the three paper layers into one sheet of paper; (4) The second pressing process: The second pressing roller in the second pressing process includes an upper pressing roller and a lower pressing roller. The upper pressing roller is a felt roller, and the felt passes through below the felt roller. The lower pressing roller is a patterned roller with patterns. The three-layer laminated paper in step (3) is passed through below the felt and above the patterned roller for embossing to make a paper with patterns on both sides: (5) Drying, sizing and forming; The paper with patterns on both sides obtained in step (4) is dried by hot air. After the patterns are shaped, it enters the pre-sizing dryer before surface sizing, then enters the surface sizing machine for surface sizing, and after surface sizing, it enters the post-sizing dryer for drying and is wound into paper, forming a watercolor paper with thick patterns on both sides that can be painted on both sides.

[0010] In the steps (1) and (2) of the present invention, two sets of pulp sizing systems are used to make the upper watercolor paper layer and the lower watercolor paper layer, and the middle paper layer. The two sets of pulp sizing systems include an A sizing system and a B sizing system. The A sizing system is the system for making the upper watercolor paper layer and the lower watercolor paper layer, and the B sizing system is the system for making the middle paper layer.

[0011] In the sizing systems A and B of the present invention, 1.8 - 2.4% of PAE wet strength agent is respectively added to the sizing materials to improve the wet strength of the paper, so as to meet the requirements for the wet strength of the paper during watercolor painting modification.

[0012] In step (5) of the present invention, during the drying and sizing and forming process, 100% gum arabic is used for surface sizing at the surface sizing position.

[0013] For the pulp of the upper watercolor paper layer and the lower watercolor paper layer and the pulp of the middle paper layer of the present invention, they are respectively sized by sizing systems A and B, and 1.0 - 1.6% of neutral sizing agent AKD is respectively added during the process to improve the sizing performance of the paper.

[0014] The preparation method of the gum arabic in the present invention is as follows: Weigh the gum arabic, gelatinize it in hot water at 80°C for 15 minutes, keep it warm for 5 minutes, with a gelatinization concentration of 10%, dilute it with water to the use concentration of 5 - 7%, with a use temperature of 50 - 60°C, and perform paper surface sizing treatment through a surface sizing machine. The sizing amount on both sides of the paper is 1.5 - 3.0 g / m 2 。

[0015] Due to the adoption of the above structure and method, the present invention has the advantages of simple structure, being usable on both sides, improving the use efficiency of watercolor paper, and avoiding waste of paper materials. Brief Description of the Drawings

[0016] Figure 1 It is a schematic diagram of the roll pressing of the second press roll of the present invention. Detailed Embodiments

[0017] The present invention will be further described below in conjunction with the drawings: As shown in the drawings, a two-sided painting watercolor paper with patterns on both sides, characterized in that the watercolor paper includes an upper watercolor paper layer, a middle paper layer, and a lower watercolor paper layer. The upper and lower sides of the middle paper layer are respectively laminated with the upper watercolor paper layer and the lower watercolor paper layer to form a three-layer structure of watercolor paper with watercolor paper layers on both sides, and the upper side of the upper watercolor paper layer and the lower side of the lower watercolor paper layer are respectively provided with patterns.

[0018] Further, the upper watercolor paper layer is formed by being pressed by a felt roll passing through from below the felt, and the lower watercolor paper layer is formed by being pressed by a pattern roll with patterns.

[0019] Further, the upper watercolor paper layer and the lower watercolor paper layer are 100% cotton pulp fiber, i.e., a pure cotton watercolor paper layer, a cotton-containing watercolor paper layer containing cotton pulp fiber and softwood pulp, or a 100% wood pulp layer.

[0020] Further, the middle paper layer is a mixed paper layer of softwood pulp and hardwood pulp, or a recycled pulp paper layer.

[0021] A production method of double-sided painting watercolor paper with patterns on both sides, characterized in that the steps of the production method are as follows: (1) Produce the upper watercolor paper layer and the lower watercolor paper layer: The upper watercolor paper layer and the lower watercolor paper layer are produced by conventional methods; (2) Produce the middle paper layer: The middle paper layer is produced by conventional methods; (3) The first pressing process: The upper watercolor paper layer, the middle paper layer, and the lower watercolor paper layer are simultaneously pressed by the first pressing roller to press the three paper layers together to form a single sheet of paper; (4) The second pressing process: The second pressing roller in the second pressing process includes an upper pressing roller and a lower pressing roller. The upper pressing roller is a felt roller, and the felt passes under the felt roller. The lower pressing roller is a patterned roller with patterns. The three-layer paper from step (3) passes under the felt and above the patterned roller for embossing to produce a paper with patterns on both sides: (5) Drying, sizing, and forming; The paper with patterns on both sides obtained in step (4) is dried by hot air. To reduce the loss of patterns, after the patterns are shaped, it enters the drying cylinder before surface sizing for drying, then enters the surface sizing machine for surface sizing, and after surface sizing, it enters the drying cylinder after sizing for drying, and is wound into paper, forming watercolor paper with thick patterns on both sides that can be painted on both sides.

[0022] Further, in steps (1) and (2), two sets of sizing systems are used to produce the upper watercolor paper layer, the lower watercolor paper layer, and the middle paper layer. The two sets of sizing systems include an A sizing system and a B sizing system. The A sizing system is for producing the upper watercolor paper layer and the lower watercolor paper layer, and the B sizing system is for producing the middle paper layer.

[0023] The above-mentioned upper watercolor paper layer and lower watercolor paper layer are 100% cotton pulp fiber, i.e., all-cotton watercolor paper layer, cotton-containing watercolor paper layer containing cotton pulp fiber and softwood pulp, or 100% wood pulp layer. The cotton pulp is beaten by a large taper beater, and the beating degree is 32 - 38 o SR, and the wood pulp is beaten by a double-disc refiner, and the beating degree is 30 - 36 o SR.

[0024] The slurry of the above-mentioned A sizing system is equally divided into two parts, which respectively pass through two forming meshes, and are dehydrated and formed through the wire section to form wet paper layers of two surface layers. The B sizing system passes through the middle layer forming mesh and is dehydrated and formed through the wire section to form a wet paper layer of the middle layer. The wet paper layer of the middle layer is first compounded with the lower paper layer, then compounded with the upper paper layer, and then enters the pressing section of the paper machine together, and the three-layer paper is pressed together through the first pressing to form a wet paper layer of three-layer paper.

[0025] To reduce the loss of the grain, before entering the size press, the paper passes through a hot air oven for drying first to dry and shape the grain on both sides of the paper by hot air, then undergoes drying on the size press dryer, and finally enters the size press to improve the water absorption and bleeding effect of the watercolor paper.

[0026] The above-mentioned felt blankets are divided into coarse-grained felt blankets, medium-grained felt blankets, and fine-grained felt blankets, and the bottom rollers are divided into coarse-grained, medium-grained, and fine-grained.

[0027] The grain of the above-mentioned embossing roller is engraved according to the grain pressed by the felt blanket to form a coarse-grained roller, a medium-grained roller, and a fine-grained roller corresponding to the coarse-grained felt blanket, the medium-grained felt blanket, and the fine-grained felt blanket.

[0028] The formation of the three-layer paper sheet formed by the above-mentioned upper watercolor paper layer, the middle paper layer, and the lower watercolor paper layer can be a triple wire formed by three fourdrinier wires, or the middle paper layer can be a fourdrinier wire, and the two watercolor grain layers on both sides are a triple wire formed by cylinder wires. It can also be a triple wire formed by three cylinder wires, or a triple wire formed by two fourdrinier wires plus one cylinder wire.

[0029] Further, 1.8 - 2.4% of PAE wet strength agent is added to the slurries of the above-mentioned A sizing system and B sizing system respectively to improve the wet strength of the paper to meet the requirements for the wet strength of the paper during watercolor painting modification.

[0030] Further, in the step (5), during drying and sizing and forming, 100% gum arabic is used for surface sizing at the surface sizing section.

[0031] Further, the pulp of the above-mentioned upper watercolor paper layer and the lower watercolor paper layer and the pulp of the middle paper layer are sized by the A sizing system and the B sizing system respectively, and 1.0 - 1.6% of neutral sizing agent AKD is added respectively in the process to improve the sizing performance of the paper.

[0032] Further, the preparation method of the gum arabic is as follows: Weigh the gum arabic, gelatinize it in hot water at 80°C for 15 minutes, keep it warm for 5 minutes, the gelatinization concentration is 10%, add water to dilute it to the use concentration of 5 - 7%, the use temperature is 50 - 60°C, and perform surface sizing treatment on the paper surface by a surface sizing machine. The sizing amount on both sides of the paper is 1.5 - 3.0 g / m 2 。

[0033] Determination of the basis weight of the above-mentioned painted paper layer: According to the different requirements of different watercolor painters for watercolor painting, the sizing system A sizing material can be a full cotton, cotton-containing, and all-wood pulp ratio. Full cotton means using 100% cotton pulp fiber, and cotton-containing means containing a certain proportion of cotton pulp fiber. For example, the following cotton pulp ratios can be used: cotton pulp 90% + wood pulp 10%, cotton pulp 80% + wood pulp 20%, cotton pulp 70% + wood pulp 30%, cotton pulp 60% + wood pulp 40%, cotton pulp 50% + wood pulp 50%, cotton pulp 40% + wood pulp 60%, cotton pulp 30% + wood pulp 70%, cotton pulp 20% + wood pulp 80%, cotton pulp 10% + wood pulp 90%. The all-wood pulp ratio means using 100% softwood pulp. The sizing system B sizing material is a supporting layer of the paper, which maintains the stability of the paper shape after the watercolor ink dries. The sizing material of the sizing system B sizing layer is a mixture of softwood pulp and hardwood pulp in a certain proportion. For example, softwood pulp 20% + hardwood pulp 80%, softwood pulp 30% + hardwood pulp 70%, softwood pulp 40% + hardwood pulp 60%, softwood pulp 50% + hardwood pulp 50%, softwood pulp 60% + hardwood pulp 40%, softwood pulp 70% + hardwood pulp 30%, softwood pulp 80% + hardwood pulp 20%, softwood pulp 90% + hardwood pulp 10%, softwood pulp 100%. The wood pulp layer of the sizing system B can also be mixed with a certain proportion of recycled fibers to make full use of recycled fibers and improve the recycling efficiency of the paper. For example, softwood pulp 0 - 90%, recycled pulp 100 - 10%.

[0034] Basis weight of the paper: A watercolor paper with patterns on both sides and suitable for painting on both sides is a three-layer structure watercolor paper, and the basis weight of the paper is 300 - 600 g / m 2 . That is, 300 g / m 2 For the three-layer structure watercolor paper, each sizing layer for painting on both sides is 100 g / m 2 , and the middle sizing layer is 100 g / m 2 . 350 g / m 2 For the three-layer structure watercolor paper, each sizing layer for painting on both sides is 100 g / m 2 , and the middle sizing layer is 150 g / m 2 . 400 g / m 2 For the three-layer structure watercolor paper, each sizing layer for painting on both sides is 100 g / m 2 , and the middle sizing layer is 200 g / m 2 . 450 g / m 2 For the three-layer structure watercolor paper, each sizing layer for painting on both sides is 100 g / m 2 , and the middle sizing layer is 250 g / m 2 . 500 g / m 2 For the three-layer structure watercolor paper, each sizing layer for painting on both sides is 100 g / m 2 , and the middle sizing layer is 300 g / m2 。550 g / m 2 The sizing layer for painting on both sides of the three-layer watercolor paper is 125 g / m each 2 , and the middle sizing layer is 300 g / m 2 。600 g / m 2 The sizing layer for painting on both sides of the three-layer watercolor paper is 150 g / m each 2 , and the middle sizing layer is 300 g / m 2 。

[0035] A watercolor paper with patterns on both sides that can be painted on both sides. Patterns on both sides: The watercolor paper is divided into rough-grained, medium-grained, and fine-grained watercolor papers. The patterns are formed by three wet paper sheets in the press section of the paper machine. One side of the wet paper sheet contacts the felt with a woven base pattern, and the other side contacts the engraved pattern roll. Through the pressing pressure, the pattern of the woven base pattern on the felt is transferred to one surface of the wet paper sheet, and the pattern on the engraved pattern roll is transferred to the other side of the wet paper sheet, forming a watercolor paper with patterns on both sides that can be painted on both sides. Different textures give different watercolor art effects to the paper surface, increasing the three-dimensional sense of painting. There are the following ways to match the textures on both sides: ① The front is rough-grained and the back is rough-grained, ② The front is rough-grained and the back is medium-grained, ③ The front is rough-grained and the back is fine-grained, ④ The front is medium-grained and the back is medium-grained, ⑤ The front is medium-grained and the back is fine-grained, ⑥ The front is fine-grained and the back is fine-grained. The engraving of the rough, medium, and fine-grained pattern rolls is carried out according to the patterns formed by the corresponding rough felt pattern, medium felt pattern, and fine felt pattern on the paper surface

[0036] Due to the adoption of the above structure and method, the present invention has the advantages of simple structure, double-sided usability, improving the use efficiency of watercolor paper, and avoiding waste of paper materials

[0037] Example 1 300 g / m 2 Watercolor paper with patterns on both sides that can be painted on both sides Specifically: The sizing system A uses 100% cotton pulp and is beaten with a large taper beater. The beating degree is 38 o SR. The sizing system B uses a mixed pulp of softwood pulp and hardwood pulp, with 10% softwood pulp and 90% hardwood pulp. The softwood pulp and hardwood pulp are mixed and beaten, and a double-disc refiner beater is used for beating. The beating degree is 36 o SR. 2.4% of PAE wet strength agent is added to the pulp of the sizing system A, and 1.8% of PAE wet strength agent is added to the pulp of the sizing system B. 1.0% of AKD neutral sizing agent is added to the process of both sizing systems A and B. The pulp of the sizing system A is divided into two equal parts and is respectively formed into a web through two headboxes. The absolute dry sizing amount is 100 g / m 2, The sizing stock of the B sizing system is formed on the wire through the flow system, and the absolute dry sizing amount is 100 g / m². 2 , After the sizing stock on the three wires is dewatered by the wire section and combined through the first press, it then passes through the second press with a coarse felt pattern and a coarse pattern roll. The paper web passes through between the felt of the top press roll (i.e., the felt roll) and the coarse pattern roll. After passing through the second press, both sides of the paper are respectively provided with a coarse felt pattern and an engraved coarse pattern. After passing through the second press, it enters a non-contact hot air drying process. The hot air temperature is above 140 °C. After the pattern is fixed, it enters the drying cylinder before surface sizing for drying, and then enters the surface sizing machine for surface sizing. The surface sizing uses 100% gum arabic, the surface sizing liquid concentration is 5.0%, and the total sizing amount on both sides is 1.5 g / m². 2 . After surface sizing, it is dried by the sizing dryer and wound into paper, forming a watercolor paper with coarse patterns on both sides that can be painted on both sides.

[0038] Example 2 350 g / m² 2 Watercolor paper with patterns on both sides that can be painted on both sides Specifically: The A sizing system uses a pulp mixture of 90% cotton pulp and 10% softwood pulp, and is beaten using a large taper beater. The beating degree of beating is 37 SR. o The B sizing system uses a mixed pulp of softwood pulp and hardwood pulp, with 40% softwood pulp and 60% hardwood pulp. The softwood pulp and hardwood pulp are mixed and beaten, and a double-disc refiner beater is used for beating treatment. The beating degree of beating is 35 SR. o In the sizing stock of the A sizing system, 2.3% of PAE wet strength agent is added. In the sizing stock of the B sizing system, 1.9% of PAE wet strength agent is added. In the process of the A and B sizing systems, 1.1% of AKD neutral sizing agent is added respectively. The sizing stock of the A sizing system is divided into two equal parts and is formed on the wire through two headboxes respectively, and the absolute dry sizing amounts are 100 g / m² respectively. 2 , The sizing stock of the B sizing system is formed on the wire through the flow system, and the absolute dry sizing amount is 150 g / m². 2 , After the sizing stock on the three wires is dewatered by the wire section and combined through the first press, it then passes through the second press with a coarse felt pattern and a medium pattern roll. The paper web passes through between the felt of the top press roll (i.e., the felt roll) and the medium pattern roll. After passing through the second press, both sides of the paper are respectively provided with a coarse felt pattern and an engraved medium pattern. After passing through the second press, it enters a non-contact hot air drying process. The hot air temperature is above 140 °C. After the pattern is fixed, it enters the drying cylinder before surface sizing for drying, and then enters the surface sizing machine for surface sizing. The surface sizing uses 100% gum arabic, the surface sizing liquid concentration is 5.5%, and the total sizing amount on both sides is 1.8 g / m². 2 . After surface sizing, it is dried by the sizing dryer and wound into paper, forming a watercolor paper with a coarse pattern on one side and a medium pattern on the other side that can be painted on both sides.

[0039] Example 3 400 g / m 2 Watercolor paper with patterns on both sides for painting on both sides Specifically: The sizing system A uses a pulp mixture of 70% cotton pulp and 30% softwood pulp, and is beaten using a large taper beater. The beating degree of beating is 36 o SR. The sizing system B uses a mixed pulp of softwood pulp and hardwood pulp, with 70% softwood pulp and 30% hardwood pulp. The softwood pulp and hardwood pulp are mixed and beaten, and a double-disc refiner beater is used for beating treatment. The beating degree of beating is 34 o SR. 2.2% of PAE wet strength agent is added to the pulp of the sizing system A, and 2.0% of PAE wet strength agent is added to the pulp of the sizing system B. 1.2% of AKD neutral sizing agent is added to the processes of both sizing systems A and B. The pulp of the sizing system A is divided into two equal parts and is respectively sent onto the wire through two head boxes. The absolute dry sizing amount is 100 g / m 2 , and the pulp of the sizing system B is sent onto the wire through the flow system for forming. The absolute dry sizing amount is 200 g / m 2 , After the pulp on the three wires is dewatered by the wire section and combined together through the first press, it then passes through the second press with a coarse blanket pattern and a fine pattern roll. The paper web passes through between the coarse blanket of the top press roll (i.e., the blanket roll) and the fine pattern roll. After passing through the second press, both sides of the paper are respectively provided with a coarse blanket pattern and an engraved fine pattern. After passing through the second press, it enters a non-contact hot air drying process. The hot air temperature is above 140 °C. After the pattern is fixed, it enters the dryer of the pre-sizing cylinder before surface sizing, and then enters the surface sizing machine for surface sizing. The surface sizing uses 100% gum arabic, the concentration of the surface sizing liquid is 6.0%, and the total sizing amount on both sides is 2.0 g / m 2 . After surface sizing, it is dried by the sizing cylinder after sizing and wound into paper, forming watercolor paper with a coarse pattern on one side and a fine pattern on the other side for painting on both sides.

[0040] Example 4 450 g / m 2 Watercolor paper with patterns on both sides for painting on both sides Specifically: The sizing system A uses a pulp mixture of 50% cotton pulp and 50% softwood pulp, and is beaten using a large taper beater. The beating degree of beating is 35 o SR. The sizing system B uses 100% softwood pulp, and the softwood pulp is beaten using a double-disc refiner beater. The beating degree of beating is 33 o SR. 2.1% of PAE wet strength agent is added to the pulp of the sizing system A, and 2.1% of PAE wet strength agent is added to the pulp of the sizing system B. 1.3% of AKD neutral sizing agent is added to the processes of both sizing systems A and B. The pulp of the sizing system A is divided into two equal parts and is respectively sent onto the wire through two head boxes. The absolute dry sizing amount is 100 g / m 2, the sizing stock of the B sizing system is formed on the wire through the flow system, and the bone-dry sizing amount is 250 g / m 2 , after the sizing stock on the three wires is dewatered by the wire section and combined together through the first press, and then through the second press with a middle felt pattern and a middle pattern roll, the paper passes through between the felt of the top press roll (i.e., the felt roll) and the middle pattern roll. After passing through the second press, both sides of the paper are respectively with middle felt patterns and engraved middle patterns. After passing through the second press, it enters a non-contact hot air drying, the hot air temperature is above 140°C. After the pattern is fixed, it enters the dryer cylinder before surface sizing for drying, and then enters the surface sizing machine for surface sizing. The surface sizing uses 100% gum arabic, the surface sizing liquid concentration is 6.0%, and the total sizing amount on both sides is 2.2 g / m 2 . After surface sizing, it is dried by the dryer cylinder after sizing and wound into paper, forming a watercolor paper with middle patterns on both sides that can be painted on both sides.

[0041] Example 5 500 g / m 2 Watercolor paper with patterns on both sides that can be painted on both sides Specifically: The A sizing system uses a 30% cotton pulp and 70% softwood pulp ratio, and uses a large taper beater for beating treatment, with a beating degree of 34 o SR. The B sizing system uses a mixed pulp of softwood pulp and recycled pulp, 90% softwood pulp and 10% recycled pulp, and uses a double-disc refiner for beating treatment, with a beating degree of 32 o SR. Add 2.0% of PAE wet strength agent to the sizing stock of the A sizing system, add 2.2% of PAE wet strength agent to the sizing stock of the B sizing system, and add 1.4% of AKD neutral sizing agent to each of the A and B sizing system processes. The sizing stock of the A sizing system is divided into two equal parts and respectively formed on the wire through two headboxes, and the bone-dry sizing amounts are respectively 100 g / m 2 , the sizing stock of the B sizing system is formed on the wire through the flow system, and the bone-dry sizing amount is 300 g / m 2 , after the sizing stock on the three wires is dewatered by the wire section and combined together through the first press, and then through the second press with a middle felt pattern blanket and a fine pattern roll, the paper passes through between the middle pattern felt of the top press roll (i.e., the felt roll) and the fine pattern roll. After passing through the second press, both sides of the paper are respectively with middle felt patterns and engraved fine patterns. After passing through the second press, it enters a non-contact hot air drying, the hot air temperature is above 140°C. After the pattern is fixed, it enters the dryer cylinder before surface sizing for drying, and then enters the surface sizing machine for surface sizing. The surface sizing uses 100% gum arabic, the surface sizing liquid concentration is 6.5%, and the total sizing amount on both sides is 2.5 g / m 2 . After surface sizing, it is dried by the dryer cylinder after sizing and wound into paper, forming a watercolor paper with a middle pattern on one side and a fine pattern on the other side that can be painted on both sides.

[0042] Example 6 550 g / m 2 Watercolor paper with patterns on both sides for painting on both sides Specifically: The sizing system A uses a pulp mixture of 10% cotton pulp and 90% softwood pulp, and is beaten with a large taper beater. The beating degree is 33 o SR. The sizing system B uses a mixed pulp of softwood pulp and recycled pulp, with 50% softwood pulp and 50% recycled pulp. It is beaten with a double-disc refiner beater, and the beating degree is 31 o SR. 1.9% of PAE wet strength agent is added to the pulp of the sizing system A, and 2.3% of PAE wet strength agent is added to the pulp of the sizing system B. 1.5% of AKD neutral sizing agent is added to the processes of both sizing systems A and B. The pulp of the sizing system A is divided into two equal parts and is fed onto the wire through two headboxes respectively. The absolute dry sizing amount is 125 g / m 2 , and the pulp of the sizing system B is formed into a sheet through a flow system and fed onto the wire. The absolute dry sizing amount is 300 g / m 2 , After the pulp on the three wires is dewatered in the wire section and combined together through the first press, it then passes through the second press with a fine felt pattern and a fine grain roll. The paper sheet passes through between the fine grain felt of the top press roll (i.e., the felt roll) and the fine grain roll. After passing through the second press, both sides of the paper sheet are respectively provided with a fine felt pattern and an engraved fine grain pattern. After passing through the second press, it enters a non-contact hot air drying process. The hot air temperature is above 140 °C. After the pattern is fixed, it enters the dryer before surface sizing, and then enters the surface sizing machine for surface sizing. 100% gum arabic is used for surface sizing, the concentration of the surface sizing liquid is 6.8%, and the total sizing amount on both sides is 2.8 g / m 2 . After surface sizing, it is dried in the dryer after sizing and wound into paper, forming watercolor paper with fine patterns on both sides for painting on both sides.

[0043] Example 7 600 g / m 2 Watercolor paper with patterns on both sides for painting on both sides Specifically: The sizing system A uses 100% softwood pulp and is beaten with a large taper beater. The beating degree is 32 o SR. The sizing system B uses 100% recycled pulp, and the recycled pulp is beaten with a double-disc refiner beater. The beating degree is 30 o SR. 1.8% of PAE wet strength agent is added to the pulp of the sizing system A, and 2.4% of PAE wet strength agent is added to the pulp of the sizing system B. 1.6% of AKD neutral sizing agent is added to the processes of both sizing systems A and B. The pulp of the sizing system A is divided into two equal parts and is fed onto the wire through two headboxes respectively. The absolute dry sizing amount is 150 g / m 2 , and the pulp of the sizing system B is formed into a sheet through a flow system and fed onto the wire. The absolute dry sizing amount is 300 g / m 2, after the three online slurries are dewatered by the wire section, they are combined together through the first press, and then through the second press with a middle blanket pattern and a coarse pattern roll. The paper web passes through between the middle pattern blanket of the top press roll, i.e., the blanket roll, and the coarse pattern roll. After passing through the second press, both sides of the paper are respectively with a middle blanket pattern and a carved coarse pattern. After passing through the second press, it enters a non-contact hot air drying process. The hot air temperature is above 140°C. After the pattern is fixed, it enters the dryer of the pre-sizing dryer before surface sizing, and then enters the surface sizing machine for surface sizing. The surface sizing uses 100% gum arabic, the surface sizing liquid concentration is 7.0%, and the total sizing amount on both sides is 3.0 g / m 2 . After surface sizing, it is dried by the post-sizing dryer and wound into paper, forming a watercolor paper that can be painted on both sides with a coarse pattern on one side and a middle pattern on the other side.

Claims

1. A double-sided watercolor paper with textures on both sides, characterized in that The watercolor paper comprises an upper watercolor paper layer, a middle paper layer and a lower watercolor paper layer. The upper and lower layers of the middle paper layer are respectively compounded with the upper watercolor paper layer and the lower watercolor paper layer to form a three-layer structure of watercolor paper with watercolor paper layers on both sides. The upper side of the upper watercolor paper layer and the lower side of the lower watercolor paper layer are respectively provided with textures.

2. The double-sided watercolor paper with textures on both sides according to claim 1, characterized in that The upper watercolor paper layer is pressed by a blanket roller passing through a blanket below, and the lower watercolor paper layer is pressed by a pattern roller with patterns.

3. The double-sided watercolor paper with textures on both sides according to claim 1, characterized in that The upper watercolor paper layer and the lower watercolor paper layer are 100% cotton pulp fiber, namely, pure cotton watercolor paper layer, cotton-containing watercolor paper layer containing cotton pulp fiber and coniferous wood pulp, or 100% wood pulp layer.

4. The double-sided watercolor paper with textures on both sides according to claim 1, characterized in that The middle paper layer is a mixed paper layer of coniferous wood pulp and broadleaf wood pulp, or a recycled pulp paper layer.

5. A method for producing double-sided watercolor paper with textures on both sides, characterized in that The steps of the production method are as follows: (1) Making an upper watercolor paper layer and a lower watercolor paper layer: using conventional methods to make an upper watercolor paper layer and a lower watercolor paper layer; (2) Making the middle paper layer: using conventional methods to make the middle paper layer; (3) The first pressing process: the upper watercolor paper layer, the middle paper layer, and the lower watercolor paper layer are pressed by the first pressing roller at the same time to press the three paper layers into one sheet of paper; (4) Second pressing process: The second pressing roller in the second pressing process includes an upper pressing roller and a lower pressing roller. The upper pressing roller is a felt roller, and a felt passes through the bottom of the felt roller. The lower pressing roller is a patterned roller with patterns. The paper pressed together in step (3) is passed under the felt and over the patterned roller for double-sided embossing to produce paper with patterns on both sides. (5) Drying and gluing; the paper with texture on both sides obtained in step (4) is dried by hot air, and after the texture is fixed, it enters the surface sizing machine for surface sizing, and after the surface sizing, it is dried in the post-sizing drying cylinder, and rolled into paper, thereby forming watercolor paper with texture on both sides that can be painted on both sides.

6. The method for producing double-sided watercolor paper with textures on both sides according to claim 5, characterized in that The steps (1) and (2) of making the upper watercolor paper layer, the lower watercolor paper layer, and the middle paper layer use two sets of slurry sizing systems, and the two sets of slurry sizing systems include an A sizing system and a B sizing system. The A sizing system is a system for making the upper watercolor paper layer and the lower watercolor paper layer, and the B sizing system is a system for making the middle paper layer.

7. The method for producing double-sided watercolor paper with textures on both sides according to claim 6, characterized in that 1.8-2.4% of PAE wet strength agent is added to the sizing system A and the sizing system B respectively to improve the wet strength of the paper to meet the requirement of wet strength of the paper when modifying watercolor painting.

8. The method for producing double-sided watercolor paper with textures on both sides according to claim 5, characterized in that In the step (5), 100% gum arabic is used for surface sizing in the dry sizing molding.

9. The method for producing double-sided watercolor paper with textures on both sides according to claim 5, characterized in that The pulp of the upper watercolor paper layer and the lower watercolor paper layer and the pulp of the middle paper layer are sized by sizing system A and sizing system B respectively, and 1.0-1.6% of neutral sizing agent AKD is added in the process to improve the sizing performance of the paper.

10. The method for producing double-sided watercolor paper with textures on both sides according to claim 8, characterized in that The preparation method of the gum arabic is as follows: weigh the gum arabic, gelatinize it in hot water at 80°C for 15 minutes, keep it warm for 5 minutes, gelatinize it to a concentration of 10%, dilute it with water to a use concentration of 5-7%, use it at a temperature of 50-60°C, and apply glue to the surface of the paper with a surface sizing machine, with the amount of glue on both sides of the paper being 1.5-3.0 g / m 2 .

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