Crepe paper and its manufacturing method

Abstract

To provide crepe paper having improved absorbency in the MD direction. [Solution] Crepe paper having a plurality of ridges extending in the MD direction, the ridges being made of a paper body, and the width / spacing ratio of the ridges being 0.55 or less.

Description

[Technical Field]

[0001] The present invention relates to crepe paper with improved absorbency and a method for making the same. [Background technology]

[0002] Conventionally, there has been a demand for sheets that are excellent in absorbing liquids, including blood, that ooze out of meat and other foods (hereinafter referred to as "drip") when used to package, place, or store foods such as meat, in order to prevent or reduce quality deterioration of the food due to oxidation, etc., and crepe paper has been proposed as such a sheet (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-63712 Summary of the Invention [Problem to be solved by the invention]

[0004] Crepe paper has many wrinkles (called "crepes") that extend in the direction perpendicular to the machine direction (hereinafter referred to as the "MD") of the paper (hereinafter referred to as the "CD"), so the drip absorption rate is fast in the CD and slow in the MD. In other words, crepe paper has relatively low absorbency in the MD and relatively high absorbency in the CD.

[0005] Therefore, if the drips absorbed by the crepe paper reach both ends in the CD, there is a risk that the drips will leak out of the crepe paper. In that case, even if the crepe paper in the MD is unused, it will have to be replaced with a new one, which is less economical.

[0006] An object of the present invention is to provide a crepe paper having improved absorbency in the MD direction. [Means for solving the problem]

[0007] As a result of extensive research, the inventors discovered that by producing crepe paper with multiple ridges extending in the MD direction, it is possible to provide crepe paper with improved absorbency in the MD direction, and thus completed the present invention.

[0008] A first aspect of the present invention is A crepe paper having a plurality of protrusions extending in the MD direction, The protrusions are made of paper, The crepe paper has a width / spacing ratio of the ridges of 0.55 or less.

[0009] The width / spacing ratio of a ridge means the value of (width length of the ridge) divided by (spacing length).

[0010] The width of the ridges is preferably 1800 μm or less.

[0011] The interval between the ridges is preferably 1500 μm to 7000 μm.

[0012] The crepe paper of the present invention has a basis weight of 20 g / m 2 ~60g / m 2 It is preferable that:

[0013] The crepe ratio of the crepe paper of the present invention is preferably 5% to 50%.

[0014] The crepe paper of the present invention is preferably a sanitary paper.

[0015] The crepe paper of the present invention is preferably used for packaging, placing or storing food.

[0016] A second aspect of the present invention is A process of drying the wet paper on the surface of a rotating cylindrical dryer to form a paper body; peeling the paper body from the surface of the cylindrical dryer with a doctor blade A method for producing crepe paper, comprising: the doctor blade has a blade surface that abuts or is close to the surface of the cylindrical dryer; The blade surface of the doctor blade has a plurality of grooves extending in the MD direction of the paper body, The present invention relates to a method for producing crepe paper, wherein the groove width / groove spacing ratio of the grooves is 0.55 or less.

[0017] The ratio of groove width to groove spacing means the value of (groove width) / (groove spacing).

[0018] It is preferable that the groove width of the groove is 1800 μm or less.

[0019] The groove spacing is preferably 1500 μm to 7000 μm.

[0020] In the method for producing crepe paper of the present invention, the crepe ratio is preferably 5% to 50%. [Effects of the Invention]

[0021] The present invention can provide crepe paper with improved absorbency in the MD direction.

[0022] The crepe paper of the present invention has improved absorbency in the MD direction, and can have high absorbency not only in the CD direction but also in the MD direction.

[0023] Therefore, the crepe paper of the present invention can have high water absorption and / or water retention properties.

[0024] The method for producing crepe paper of the present invention can produce crepe paper with improved absorbency in the MD direction.

[0025] The method for producing crepe paper of the present invention has improved absorbency in the MD direction, making it possible to produce crepe paper with high absorbency not only in the CD direction but also in the MD direction.

[0026] Therefore, the method for producing crepe paper of the present invention can produce crepe paper with high water absorption and / or water retention properties. [Brief explanation of the drawings]

[0027] [Figure 1] 1 is a schematic enlarged cross-sectional view showing one embodiment of the crepe paper of the present invention. [Figure 2] 1 is a schematic cross-sectional view showing one embodiment of a crepe paper manufacturing method of the present invention. [Figure 3] 3 is an enlarged cross-sectional view of a portion of FIG. 2 where the doctor blade 2 contacts or is close to the surface of the Yankee dryer 3. FIG. [Figure 4] 1 is a schematic enlarged cross-sectional view showing one embodiment of the cutting surface of a doctor blade in the manufacturing method of the present invention. [Figure 5] FIG. 10 is a diagram showing the correspondence between the grooves on the blade surface and the protrusions on the crepe paper. DETAILED DESCRIPTION OF THE INVENTION

[0028] [First aspect] A first aspect of the present invention is A crepe paper having a plurality of protrusions extending in the MD direction, The protrusions are made of paper, The crepe paper has a width / spacing ratio of the ridges of 0.55 or less.

[0029] The fiber material constituting the crepe paper is not particularly limited, and examples thereof include natural fibers such as cotton, wood pulp, and wool; recycled fibers such as rayon; and synthetic fibers made from synthetic polymers such as vinylon, nylon, polyester, polyethylene, polypropylene, and acrylic. Natural fibers are preferred, and cellulose fibers are more preferred. These fibers may be used alone or in combination.

[0030] The fiber material constituting the crepe paper is preferably wood pulp, and virgin wood pulp, recycled paper pulp, or a mixture thereof can be used. Examples of wood pulp that can be used include softwood pulp such as NBKP (softwood bleached kraft pulp) and NUKP (softwood unbleached pulp), hardwood pulp such as LBKP (hardwood bleached kraft pulp) and LUKP (hardwood unbleached pulp), and mixtures of softwood pulp and hardwood pulp.

[0031] The crepe paper according to the first embodiment of the present invention has numerous wrinkles extending in the CD direction, as is the case with ordinary crepe paper.

[0032] Furthermore, the crepe paper of the first embodiment of the present invention has a plurality of ridges extending in the MD direction.

[0033] The "ribs" in this invention refer to elongated protrusions, which extend in the MD direction in the crepe paper of the first embodiment of this invention. Therefore, the "ribs" of the crepe paper of the first embodiment of this invention are different from the numerous wrinkles that crepe paper usually has, which extend in the CD direction. The "ribs" can be continuous or discontinuous in the MD direction.

[0034] The protrusions of the crepe paper of the first embodiment of the present invention are made of a paper body. That is, in the crepe paper of the present invention, the protrusions are formed from the paper body. In this invention, "paper body" means an object made of a material that constitutes paper, and is usually in the form of a sheet. The "paper body" can be made from paper stock. The "protrusions" of the crepe paper of the first embodiment of the present invention are not made of resin.

[0035] In addition to the above-mentioned fibrous materials, the paper stock may contain various additives, such as softeners, bulking agents, dyes, dispersants, wet strength agents, dry strength agents, drainage aids, pitch control agents, and retention aids.

[0036] The ridges are preferably made of the same paper stock as the crepe paper. That is, in the crepe paper of the first aspect of the present invention, the ridges are preferably made of the same paper stock as that constituting the crepe paper. In other words, the ridges are preferably made of the same material as the crepe paper or are integral with the crepe paper.

[0037] The crepe paper according to the first embodiment of the present invention has a ridge width / spacing ratio of 0.55 or less. Crepe paper with a ridge width / spacing ratio of more than 0.55 is difficult to manufacture.

[0038] FIG. 1 shows one embodiment of the crepe paper of the present invention.

[0039] Fig. 1 is a schematic enlarged cross-sectional view of a crepe paper 1 of the present invention in the CD direction, which has a plurality of spaced apart ridges 11 extending in the MD direction. Although Fig. 1 shows only two ridges 11, the crepe paper 1 has many more ridges in the CD direction (not shown).

[0040] Each of the ridges 11 shown in FIG. 1 has a width (W), and the ridges 11 are spaced apart at intervals (M).

[0041] The "width" (W) of the ridges 11 refers to the width of the base of the ridges 11 and can be determined, for example, by observation under a microscope. If the width of the ridges 11 varies slightly along the MD of the crepe paper 1, the widths of the ridges 11 can be measured at five equally spaced locations along the length of the ridges 11 on a microscope image, and the average value can be used as the "width."

[0042] The "spacing" (M) of the ridges 11-11 refers to the spacing between the tops of the ridges 11-11, and can be determined, for example, by observation under a microscope. If the spacing between the ridges 11-11 varies slightly along the MD of the crepe paper 1, the spacing can be measured at five equally spaced locations along the length of the ridges 11-11 on a microscope image, and the average value can be used as the "spacing."

[0043] In the embodiment shown in Fig. 1, grooves (hereinafter referred to as "longitudinal grooves") are present at positions corresponding to the protrusions 11·11 on the surface (back surface) opposite to the surface on which the protrusions 11·11 are present of the crepe paper 1. The longitudinal grooves extend along the MD direction of the crepe paper 1, and the cross-sectional shape of the longitudinal grooves corresponds to the cross-sectional shape of the protrusions 11·11.

[0044] Although longitudinal grooves are not essential for the crepe paper of the present invention, their presence is preferred to further enhance absorbency in the MD direction. Furthermore, when forming protrusions in the production of the crepe paper of the present invention, as described below, forming protrusions with longitudinal grooves is easier.

[0045] The ratio (W / M) of the width (W) to the spacing (M) of the protrusions of the crepe paper of the first embodiment of the present invention is preferably 0.54 or less, more preferably 0.53 or less, even more preferably 0.52 or less, and particularly preferably 0.51 or less.

[0046] The ratio (W / M) of the width (W) to the spacing (M) of the ridges of the crepe paper according to the first embodiment of the present invention is preferably 0.1 or more, more preferably 0.2 or more, and even more preferably 0.3 or more.

[0047] The width (W) of the protrusions of the crepe paper according to the first embodiment of the present invention is preferably 1800 μm or less, more preferably 1600 μm or less, and even more preferably 1400 μm or less.

[0048] The width (W) of the protrusions of the crepe paper according to the first embodiment of the present invention is preferably 400 μm or more, more preferably 500 μm or more, and even more preferably 600 μm or more.

[0049] The spacing (M) between the ridges of the crepe paper according to the first embodiment of the present invention is preferably in the range of 1500 μm to 7000 μm, more preferably 2000 μm to 5000 μm, and even more preferably 2000 μm to 3000 μm.

[0050] The crepe paper of the present invention is 20 g / m 2 ~60g / m 2The crepe paper preferably has a basis weight of 25 g / m (measurement method: JIS P 8124

[2011] ). 2 ~50g / m 2 is preferred, and 30 g / m 2 ~40g / m 2 is more preferred.

[0051] The crepe ratio of the crepe paper of the present invention is preferably 5% to 50%. The "crepe ratio" in the present invention is a characteristic that represents the degree of crepe formation, which is defined based on the speed difference between a cylindrical dryer such as a Yankee dryer and a reel, as described below, and is defined by the following formula: Crepe rate (%) = (Cylindrical dryer moving speed (m / min) - reel speed (m / min)) / reel speed (m / min) x 100

[0052] To improve the absorbency of the crepe paper of the present invention in the CD direction, the crepe ratio can be increased to form more wrinkles along the CD direction. However, increasing the crepe ratio makes the crepe paper more likely to stretch in the MD direction, which reduces hand tearability (ease of cutting the crepe paper in the CD direction) and productivity, so excessively increasing the crepe ratio is not desirable. Therefore, the crepe ratio of the crepe paper of the present invention is more preferably 5% to 40%, even more preferably 5% to 30%, and particularly preferably 5% to 20%.

[0053] Since the crepe paper of the present invention has multiple protrusions in the MD direction, liquid that comes into contact with the crepe paper is guided not only in the MD direction by the numerous wrinkles extending in the CD direction, but also in the MD direction along the multiple protrusions extending in the MD direction, and is efficiently absorbed throughout the crepe paper.

[0054] As a result, when the crepe paper of the present invention is used to absorb liquids such as drips, the unused portion in the MD direction is reduced, which reduces the frequency of replacement and improves economy. Therefore, the crepe paper of the present invention can be suitably used to absorb liquids such as drips.

[0055] As described above, the crepe paper of the present invention has excellent absorbency not only in the CD direction but also in the MD direction, and therefore the crepe paper of the present invention can have high water absorption and / or water retention properties.

[0056] The crepe paper of the present invention is preferably used as sanitary paper. Sanitary paper is paper used for the purpose of improving sanitary conditions, and examples thereof include disposable papers such as tissue paper (such as facial wipes and cosmetic paper), tissue paper, paper towels (such as kitchen paper), toilet paper, and watting (cotton paper) (see, for example, Paper and Pulp Technology Handbook, 5th edition, p. 459, published January 30, 1992, edited and published by the Paper and Pulp Technology Association). Sanitary paper is also called sanitary paper (JIS P0001:1998).

[0057] As the sanitary paper, paper towels such as kitchen paper are preferred. Kitchen paper (including cooking paper) is mainly used in the kitchen for draining water and oil from meat, fish, vegetables, etc., as a cutting board cover, wiping dishes, wiping oil from frying pans, maintaining gas ranges and ventilation fans, wiping dirt from dining tables, etc.

[0058] Sanitary paper is porous and has the ability to absorb liquids, such as water and oil. The crepe paper of the present invention is not only water-absorbent but also oil-absorbent, making it suitable for use in kitchens, for example.

[0059] The form of the sanitary paper is not particularly limited, and may be a roll in which a long length of sanitary paper is wound up, or a non-roll form. In the non-roll form, it is more preferable that the flat sanitary paper is folded and placed in a packaging bag. The sanitary paper may be in the form of a single sheet (so-called 1-ply) folded in half for use, or a set of two sheets (so-called 2-ply) or three or more sheets (so-called 3-ply) in a laminated structure folded in half for use in the same way as a single sheet.

[0060] [Second aspect] A second aspect of the present invention is A process of drying the wet paper on the surface of a rotating cylindrical dryer to form a paper body; peeling the paper body from the surface of the cylindrical dryer with a doctor blade A method for producing crepe paper, comprising: the doctor blade has a blade surface that abuts or is close to the surface of the cylindrical dryer; The blade surface of the doctor blade has a plurality of grooves extending in the MD direction of the paper body, This is a method for producing crepe paper, wherein the groove width / groove spacing ratio of the grooves is 0.55 or less.

[0061] The wet paper in the method for producing crepe paper of the present invention can be prepared by wet-processing a paper stock containing a fibrous material such as pulp using a conventional paper machine.

[0062] In the method for producing crepe paper of the present invention, the step of drying a wet paper on the surface of a rotating cylindrical dryer to form a paper body can be carried out, for example, by pressing the wet paper onto the surface of a heated cylindrical Yankee dryer with a roll or the like to adhere it, and then drying the wet paper on the surface of the Yankee dryer while rotating the Yankee dryer to form a paper body.

[0063] The Yankee dryer is not particularly limited, but for example, a metal drum equipped with a heating mechanism can be used, and the outer diameter of the drum can be set to 1 m to 5 m.

[0064] The "paper body" in the method for producing crepe paper of the present invention has the same meaning as the "paper body" in the crepe paper of the present invention, and is usually in sheet form.

[0065] The degree of drying of the paper body can be set as appropriate, and it may be in a completely dry state or in a state before it is completely dry.

[0066] In the method for producing crepe paper of the present invention, the step of peeling the paper body from the surface of the cylindrical dryer with a doctor blade can be carried out, for example, by bringing the blade surface of the doctor blade into contact with or close to the surface of the Yankee dryer and peeling the paper body from the surface of the Yankee dryer.

[0067] The above process allows the production of crepe paper with multiple ridges extending in the MD. The ridges are made of a paper body, and the ridge width / spacing ratio is preferably 0.55 or less.

[0068] FIG. 2 shows one embodiment of the method for producing crepe paper of the present invention.

[0069] In the schematic cross-sectional view of Figure 2, a wet paper web 1' is pressed onto the surface of a heated cylindrical Yankee dryer 3 by a press roll 4, and the wet paper web 1' is dried on the surface of the rotating Yankee dryer 3 to form a sheet-like paper body. A doctor blade 2 is then brought into contact with or close to the surface of the Yankee dryer 3, and the dried sheet-like paper body is peeled off from the surface of the Yankee dryer 3, producing crepe paper 1.

[0070] The crepe paper 1 shown in FIG. 2 is wound around a reel (a roll for winding up the crepe paper 1), not shown. The crepe ratio of the crepe paper 1 can be controlled by controlling the rotation speed of the Yankee dryer 3 and the rotation speed of the reel. In the method for producing crepe paper of the present invention, the crepe ratio is preferably 5% to 50%, more preferably 5% to 40%, even more preferably 5% to 30%, and particularly preferably 5% to 20%.

[0071] FIG. 3 shows an enlarged cross section of the portion of FIG. 2 where the doctor blade 2 contacts or is close to the surface of the Yankee dryer 3.

[0072] In the example shown in Figure 3, the tip of a plate-shaped doctor blade 2 abuts against or is close to the surface of the Yankee dryer 3. The tip of the doctor blade 2 is cut in advance at a predetermined angle, forming a flat blade surface 21 with a predetermined area. Therefore, when the tip of the doctor blade 2 abuts against or is close to the surface of the Yankee dryer 3, the blade surface 21 at the tip abuts against or is close to the surface of the Yankee dryer 3. The flat blade surface 21 abuts against or is close to the surface of the Yankee dryer 3, allowing the sheet-like paper body to be effectively peeled off from the surface of the Yankee dryer 3.

[0073] When the sheet-like paper body is peeled off from the surface of the Yankee dryer 3 by the doctor blade 2, the paper body is immediately creped, forming numerous wrinkles extending in the CD direction (the direction of the rotation axis of the Yankee dryer 3), and becoming crepe paper 1.

[0074] In the method for producing crepe paper of the present invention, the blade surface of the doctor blade that contacts or is close to the surface of the cylindrical dryer is provided with a plurality of grooves extending in the MD direction of the paper body.

[0075] In the example shown in FIG. 3, a blade surface 21 at the tip of the doctor blade 2 is formed with a plurality of grooves extending in the MD direction (the direction of rotation of the Yankee dryer 3) of the sheet-like paper body.

[0076] One embodiment of the grooves on the cutting surface of the doctor blade is shown in FIG.

[0077] Figure 4 is a schematic enlarged cross-sectional view of the cutting surface of a doctor blade as viewed from the CD direction, with the cutting surface 21 having a plurality of spaced grooves 22. Although only two grooves 22 are shown in Figure 4, there are many more grooves (not shown) in the CD direction of the cutting surface 21.

[0078] The grooves 22-22 shown in Figure 4 each have a groove width (L) and a groove depth (K), and the grooves 22-22 are spaced apart at a pitch (D) at their bases. M in Figure 4 is the groove spacing, which refers to the distance between the deepest points of the grooves. The groove spacing (M) between the grooves 22-22 coincides with the spacing (M) between the protrusions 11-11 of the crepe paper 1 (see Figure 1).

[0079] The cross-sectional shape of the groove is not particularly limited, and may be a V-shape as shown in Fig. 4, or a concave shape. That is, the deepest part of the groove may be a point or a flat surface.

[0080] When the groove has a V-shape as shown in FIG. 4, the angle formed by the deepest part is preferably 90 to 150 degrees, more preferably 100 to 140 degrees, and even more preferably 110 to 130 degrees.

[0081] In the method for producing crepe paper of the present invention, a doctor blade having a blade surface with multiple grooves extending in the MD direction of the paper body is used, thereby making it possible to produce crepe paper with multiple ridges extending in the MD direction.

[0082] In the embodiment shown in Figure 4, the ridges 11 on the crepe paper 1 are formed to correspond to the shape of the grooves 22-22 on the blade surface 21. The correspondence between the grooves 22 on the blade surface 21 and the ridges 11 on the crepe paper 1 is shown in Figure 5. The groove width of the grooves 22 is slightly wider than the width of the ridges 11. In other words, the width of the ridges 11 is slightly narrower than the groove width of the grooves 22.

[0083] When a doctor blade with a cutting surface having multiple grooves extending in the MD direction of the paper body is used, longitudinal grooves are formed at positions corresponding to the protrusions 11 on the surface (back surface) opposite to the surface on which the protrusions 11 are present of the crepe paper 1, as shown in Figure 5. The longitudinal grooves extend along the MD direction of the crepe paper 1, and the cross-sectional shape of the longitudinal grooves corresponds to the cross-sectional shape of the protrusions 11.

[0084] Although the crepe paper of the present invention does not necessarily need to have longitudinal grooves, it is preferable to have longitudinal grooves in order to further enhance absorbency in the MD. Furthermore, forming protrusions with longitudinal grooves is easier because it allows the protrusions on the crepe paper to be efficiently formed using a doctor blade with a cutting surface having multiple grooves extending in the MD of the paper body.

[0085] The ratio (L / M) of the groove width (L) to the groove spacing (M) of the grooves on the cutting surface of the doctor blade used in the second embodiment of the present invention is 0.55 or less. If the ratio of groove width (L) to groove spacing (M) exceeds 0.55, the area of ​​the region where the cutting surface of the doctor blade abuts or is close to the cylindrical dryer becomes small, making it difficult to peel the sheet-like paper body from the surface of the cylindrical dryer and making it difficult to produce crepe paper.

[0086] The ratio (L / M) of the groove width (L) to the groove spacing (M) of the grooves on the cutting surface of the doctor blade used in the second embodiment of the present invention is preferably 0.54 or less, more preferably 0.53 or less, even more preferably 0.52 or less, and particularly preferably 0.51 or less.

[0087] The ratio (L / M) of groove width (L) to groove spacing (M) of the grooves on the cutting surface of the doctor blade used in the second embodiment of the present invention is preferably 0.1 or more, more preferably 0.2 or more, and even more preferably 0.3 or more.

[0088] The groove width (L) of the grooves on the cutting surface of the doctor blade used in the second embodiment of the present invention is preferably 1800 μm or less, more preferably 1600 μm or less, and even more preferably 1400 μm or less.

[0089] The groove width (L) of the grooves on the cutting surface of the doctor blade used in the second embodiment of the present invention is preferably 400 μm or more, more preferably 500 μm or more, and even more preferably 600 μm or more.

[0090] The groove spacing (M) of the grooves on the cutting surface of the doctor blade used in the second embodiment of the present invention is preferably in the range of 1500 μm to 7000 μm, more preferably 2000 μm to 5000 μm, and even more preferably 2000 μm to 3000 μm.

[0091] The groove width (L) / pitch (D) ratio (L / D) of the grooves on the cutting surface of the doctor blade used in the second aspect of the present invention is preferably 1.2 or less. The groove width (L) / pitch (D) ratio refers to the value of (length of groove width (L)) / (length of pitch (D)). If the groove width (L) / pitch (D) ratio exceeds 1.2, the area of ​​the region where the cutting surface of the doctor blade abuts or is close to the cylindrical dryer becomes small, making it difficult to peel the sheet-like paper body from the surface of the cylindrical dryer, which may make it difficult to produce crepe paper.

[0092] The ratio (L / D) of the groove width (L) to the pitch (D) of the grooves on the cutting surface of the doctor blade used in the second embodiment of the present invention is preferably 0.1 or more, more preferably 0.3 or more, and even more preferably 0.5 or more.

[0093] The pitch (D) of the grooves on the cutting surface of the doctor blade used in the second embodiment of the present invention is preferably in the range of 700 μm to 6000 μm, more preferably 900 μm to 5000 μm, and even more preferably 1000 μm to 4000 μm.

[0094] The crepe paper 1 produced in the second embodiment of the present invention has numerous wrinkles in the CD direction, which gives the paper bulk, softness, absorbency, surface smoothness, and aesthetic appearance (crepe shape).

[0095] The crepe paper 1 manufactured in the second embodiment of the present invention further has multiple ridges in the MD direction, so that liquid that comes into contact with the crepe paper 1 is guided not only in the CD direction but also in the MD direction along the multiple ridges extending in the MD direction, and is efficiently absorbed throughout the crepe paper 1. Therefore, the crepe paper 1 can have excellent water absorption or water retention in both the CD and MD directions. [Industrial Applicability]

[0096] The crepe paper of the present invention has improved absorbency and can be used as sanitary paper such as paper towels.

[0097] The crepe paper of the present invention can also be suitably used for packaging, placing, or storing food. Because the crepe paper of the present invention has excellent absorbency, it can be used, for example, to absorb drips exuded from meat, such as livestock meat. Because the crepe paper of the present invention can efficiently absorb drips, it has a high food quality preservation effect, effectively protecting food from discoloration, loss of flavor, spoilage, etc., and enabling food to be stored for a relatively long period of time.

[0098] The method of manufacturing crepe paper of the present invention can produce crepe paper with improved absorbency. [Example]

[0099] The present invention will be described in more detail below using examples and comparative examples, but the scope of the present invention is not limited to the examples.

[0100] [Example 1] A dry strength agent (DS4424 manufactured by Seiko PMC) and a wet strength agent (WS4030 manufactured by Seiko PMC) were added to a slurry containing wood pulp (freeness 450cc) made by mixing NBKP (softwood bleached kraft pulp) and LBKP (hardwood bleached kraft pulp) in a weight ratio of 40:60, at a concentration of 0.2% by weight of the wood pulp, respectively, and bleached crepe paper was produced on a cylinder Yankee paper machine.

[0101] Specifically, the wet paper was pressed against the surface of a heated cylindrical Yankee dryer, dried while being transferred, and then a doctor blade was brought into contact with the surface of the Yankee dryer to peel the paper from the surface of the Yankee dryer, producing crepe paper. The basis weight and crepe ratio of the bleached crepe paper ((Yankee dryer rotation speed / paper winding speed on a reel) × 100) are shown in Table 1.

[0102] The blade surface of the doctor blade that contacts the surface of the Yankee dryer had multiple grooves extending in the paper flow direction (MD) as shown in Figure 4. The values ​​of each element that makes up the surface shape of the doctor blade blade surface are shown in Table 1. K, M, L, and D in Table 1 correspond to K, M, L, and D in Figure 4, respectively.

[0103] [Example 2] Bleached crepe paper was produced in the same manner as in Example 1, except that the basis weight of the crepe paper was changed as shown in Table 1. A plurality of protrusions extending in the MD direction were formed on the bleached crepe paper.

[0104] [Example 3] Bleached crepe paper was produced in the same manner as in Example 2, except that the crepe ratio was changed as shown in Table 1. A plurality of protrusions extending in the MD direction were formed on the bleached crepe paper.

[0105] [Example 4] Bleached crepe paper was produced in the same manner as in Example 1, except that the surface shape of the doctor blade cutting surface was changed as shown in Table 1. A plurality of protrusions extending in the MD direction were formed on the bleached crepe paper.

[0106] [Example 5] Bleached crepe paper was produced in the same manner as in Example 1, except that the surface shape of the doctor blade cutting surface was changed as shown in Table 1. A plurality of protrusions extending in the MD direction were formed on the bleached crepe paper.

[0107] [Example 6] Bleached crepe paper was produced in the same manner as in Example 1, except that the crepe rate and the surface shape of the doctor blade were changed as shown in Table 1. Multiple protrusions extending in the MD direction were formed on the bleached crepe paper.

[0108] [Comparative Example 1] An attempt was made to produce bleached crepe paper in the same manner as in Example 1, except that the surface shape of the doctor blade cutting surface was changed as shown in Table 1, but production was unsuccessful.

[0109] Comparative Example 2 An attempt was made to produce bleached crepe paper in the same manner as in Example 1, except that the surface shape of the doctor blade cutting surface was changed as shown in Table 1, but production was unsuccessful.

[0110] Comparative Example 3 An attempt was made to produce bleached crepe paper in the same manner as in Example 6, except that the surface shape of the doctor blade cutting surface was changed as shown in Table 1, but production was unsuccessful.

[0111] [Table 1]

[0112] The "Results" in Table 1 indicate whether or not the crepe paper was produced, with ◯ meaning that it was produced and × meaning that it was not produced.

[0113] [evaluation] The width (W) and peak spacing (M) of the ridges in the MD direction formed on the surface of each of the bleached crepe papers in Examples 1 to 6 were measured using a Keyence VHX-2000 digital microscope. The results are shown in Table 2.

[0114] The spacing between the ridges (M) was the same as the spacing between the grooves (M) on the doctor blade. The ridge morphology on the surface of the bleached crepe paper is shown in Table 2. W and M in Table 2 correspond to W and M in Figure 1, respectively.

[0115] [Table 2]

[0116] From Examples 1 to 6 and Comparative Examples 1 to 3, it can be seen that in order to produce crepe paper with multiple protrusions in the MD direction, it is necessary to use a doctor blade with a cutting surface having multiple grooves (extending in the MD direction) with a ratio of "groove width L / groove spacing M" of 0.55 or less, and that by using this doctor blade, it is possible to produce crepe paper with multiple protrusions in the MD direction with a "protrusion width W / spacing M" of 0.55 or less. [Explanation of symbols]

[0117] 1: Crepe paper 1': Wet paper 11: Projection 2: Doctor Blade 21: Blade surface 2: Groove 3: Yankee Dryer 4: Press roll D: Pitch K: Groove depth L: Groove width M: Groove spacing or (ridge) width W: (Protrusion) width

Claims

1. A crepe paper having a plurality of ridges extending in the MD direction, The protrusions are made of paper, The crepe paper has a ratio of the width of the base of the ridges to the spacing between the tops of the ridges of 0.55 or less.

2. 2. The crepe paper according to claim 1, wherein the width of the ridges is 1800 μm or less.

3. The crepe paper according to claim 1, wherein the spacing between the ridges is 1500 μm to 7000 μm.

4. Basis weight: 20 g / m ２ ~60g / m ２ 2. The crepe paper of claim 1, wherein

5. The crepe paper according to claim 1, wherein the crepe ratio is 5% to 50%.

6. 2. The crepe paper of claim 1, which is sanitary paper.

7. 2. The crepe paper according to claim 1, which is used for packaging, placing or storing food.

8. A process of drying the wet paper on the surface of a rotating cylindrical dryer to form a paper body; peeling the paper body from the surface of the cylindrical dryer with a doctor blade A method for producing crepe paper, comprising: the doctor blade has a blade surface that abuts or is close to the surface of the cylindrical dryer; The blade surface of the doctor blade has a plurality of grooves extending in the MD direction of the paper body, A method for producing crepe paper, wherein the ratio of groove width (the width from edge to edge of the groove) to groove spacing (the spacing between the deepest parts of the groove) is 0.55 or less.

9. The manufacturing method according to claim 8, wherein the groove width is 1800 μm or less.

10. The manufacturing method according to claim 8, wherein the grooves have a groove spacing of 1500 μm to 7000 μm.

11. The method according to claim 8, wherein the crepe rate is 5% to 50%.

Images