JP2018130508A - Paper towel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a paper towel that can be provided with moderate stiffness, softness and water absorbency without need for a large equipment investment.SOLUTION: The paper towel contains one or more of chemical pulp, mechanical pulp, de-inked pulp and recycled pulp, is provided with crepes in an off-machine process by use of a microcreper, such as a MICREX(R)/Microcreper(TM) system, and has a basis weight of 32.2 to 64.3 gsm (g/m), a density of 0.130 to 0.150 g/cm, which is obtained by dividing the basis weight by the caliper (μm), and a number of crepes (cpi) from 12 to 30.SELECTED DRAWING: None

Description

  The present invention relates to a paper towel, and more particularly to a paper towel to which a dry crepe is applied without requiring a large capital investment. In addition, the present invention has moderate rigidity, flexibility and water absorption, and is not for home use, but commercial and industrial facilities such as offices, public facilities, hotels, schools, commercial facilities, such as airports, amusement parks, The present invention relates to roll-type paper towels used in toilets and kitchens of facilities such as hospitals and highway rest areas.

  U.S. Pat. No. 7,449,085 B2 discloses an absorbent paper product, such as a paper towel, that has a combination of high absorption capacity and moderate to low absorption rate for hand protection. More specifically, a low density paper product having one or more plies is disclosed that consists essentially of hardwood kraft pulp, softwood kraft pulp, or blends thereof, and has a discontinuous moisture barrier coating on its surface. Yes.

Example 3 in columns 14-15 of the same US Pat. No. 7,490,085 B2 discloses a paper towel having a basis weight of 58.4 gsm and a crepe rate of 20%. It uses a MICREX® / Microcreper® system manufactured by Micrex Corporation, and the density of the paper product (measured in bulk) is preferably 10 cm ³ per gram or more (0 .10 g / cm ³ ).

  U.S. Pat. No. 7,490,085 B2 also discloses a nonwoven fabric for applying crepes using the MICREX® / Microcreper ™ system. The paper towel disclosed in this patent is inevitably expensive because it is composed primarily of virgin pulp.

  References cited herein are not intended to be prior art to any claim in this application, nor are they intended to be an important factor in the patentability of that claim. I'm not doing it. The descriptions of the contents of the documents or the dates of the documents are based on information obtained by the applicant at the time of filing and do not approve the correctness of the description.

US Pat. No. 7,449,085

  In view of the problem that the paper towel of the above-mentioned U.S. Pat. No. 7,490,985 is expensive, the present invention includes inexpensive recycled pulp, especially deinked pulp, OCC (Old Corrugated Container) pulp, etc. It is an object of the present invention to provide a paper towel that is high and can be adjusted in color by appropriately adjusting the contents of chemical pulp, mechanical pulp, deinked pulp, and recycled pulp.

  In addition, the present invention can easily obtain a creping raw material without a large capital investment, and thus can be produced efficiently and at low cost, with appropriate rigidity, flexibility, and water absorption. It is an object of the present invention to provide a paper towel that can be provided with.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have achieved an appropriate rigidity, flexibility, and water absorption by performing offline creping using inexpensive deinked pulp and recycled pulp. As a result, the present invention has been completed.

That is, the present invention contains one or more of chemical pulp, mechanical pulp, deinked pulp, and recycled pulp, and the crepe is formed in an off-machine process by the MICREX (registered trademark) / Microcreper (trademark) system. The paper towel was given, the basis weight was 32.2 to 64.3 gsm, the density obtained by dividing the basis weight by the thickness (μm) was 0.130 to 0.150 g / cm ³ , and the number of crepes (cpi; 1 The number of crepe irregularities per inch) is 12 to 30.

  In one embodiment, the longitudinal stiffness is 170-240 mN · m and the water absorption is 250-420 sec / 100 μL.

  Since the present invention is as described above, and imparts elongation when creping offline, a creped product can be easily obtained without requiring a large capital investment. There is an effect that a paper towel having moderate rigidity, flexibility, and water absorption can be obtained efficiently at low cost.

The paper towel according to the present invention contains one or more of chemical pulp, mechanical pulp, deinked pulp, and recycled pulp, and is creped in an off-machine process by the MICREX® / Microcreper ™ system. The paper towel was given, the basis weight was 32.2 to 64.3 gsm, the density obtained by dividing the basis weight by the thickness (μm) was 0.130 to 0.150 g / cm ³ , and the crepe number (cpi) was 12-30. Further, the paper towel has a longitudinal rigidity of 170 to 240 mN · m and a water absorption of 250 to 420 sec / 100 μL.

  Thus, a cheap and highly productive paper towel can be obtained by containing cheap deinked pulp and recycled pulp. Moreover, the color of a paper towel can be adjusted by appropriately adjusting the contents of chemical pulp, mechanical pulp, and recycled pulp.

  As the paper towel pulp, known pulp can be used. Specifically, as the chemical pulp, NBKP, NUKP, LBKP, LUKP, NBSP, NUSP, LBSP, LUSP and the like can be used. GP, TMP, CTMP, etc. can be used as the mechanical pulp. As the recycled pulp, used paper pulp such as deinked pulp, OCC (Old Corrugated Container) pulp, and NCC (New Corrugated Container) pulp can be used.

  By using the MICREX® / Microcreper ™ system, a paper towel having moderate rigidity and flexibility can be obtained by applying a specific number of crepes (cpi) to the paper towel in an off-machine process. . Moreover, the paper towel which concerns on this invention can be manufactured with a compact installation, without requiring large capital investment. Furthermore, management of adhesives, mold release agents and doctor blades applied to dryer cylinders used during off-machine creping is simplified. In particular, the MICREX® / Microcreper ™ system from Micrex Corporation is compact with a width of 1067-3150 mm (and is therefore suitable for the practice of the present invention), and crepes are applied to paper towels. It is suitable as a system used in an off-machine process for forming.

  The microcreping process is preferably carried out using a system commercially available from Micrex Corporation, Walpole, MA 02081 called MICREX® / Microcreper®, but is not limited thereto. Any other microcreping process or system may be employed. In a process that uses a microcreper, such as the MICREX® / Microcreper ™ system, pressure is applied to the sheet in advance by a pressure plate and the sheet is conveyed by a drive roll. As the drive roll, a normal plain roll or a groove cutting roll (grooved roll) is used. The sheet applied with pressure and pressed onto the driving roll is further pressed between the retarding plate and the driving roll. The sheet is then conveyed between a retarding plate and a creping blade installed on the sheet path. As the creping blade, a flat plate type is used when the driving roll is a plain type, and a comb type type is used when the driving roll is a grooved type. The combination of retarding plate and applied pressure creates a crepe on a flat sheet.

By setting the basis weight within the range of 32.2 to 64.3 gsm, a paper towel excellent in strength and productivity can be obtained. Moreover, the paper towel which has moderate softness | flexibility and rigidity is obtained by making a density into the range of the said 0.13-0.150 g / cm < ³ >.

  As described above, the crepe number (cpi) of the paper towel according to the present invention is defined in the range of 12-30. By setting the crepe number (cpi) within this range, a paper towel having moderate softness and rigidity can be obtained. Further, by setting the number of crepes (cpi) to 12-30, the surface area increases with water absorption, and dust is picked up between the crepes, so that the dirt and dust removal performance is improved when used for cleaning by wiping. . In addition, if the number of crepes (cpi) is in the range of 12 to 30, moderate rigidity can be obtained. For example, it is suitable as a roll-shaped paper towel used for toilets in public facilities such as sports grounds and movie theaters. is there

  The paper towel according to the present invention has a longitudinal rigidity of 170 to 240 mN · m and a water absorption of 250 to 420 sec / 100 μL. When the longitudinal rigidity and water absorption are within this range, a paper towel having moderate rigidity and water absorption can be obtained.

  The number of crepes (cpi), defined as the number of irregularities per inch, is useful for use as an indicator of feel and water absorption. The crepe number (cpi) is preferably 12 or more, particularly preferably in the range of 20-25. When the number of crepes is less than 12, the processed paper towel is hard and inferior to the touch, and the water absorption rate is slow, so that the paper towel has insufficient functions. On the other hand, when the number of crepes (cpi) exceeds 12, the feel of the hand and the water absorption speed are good and the paper towel becomes flexible.

  The rigidity in the longitudinal direction is preferably 170 to 240 mN · m. When the rigidity in the vertical direction is within this range, for example, moderate rigidity can be obtained as a paper towel used for a toilet in a public facility. Moreover, it is preferable that the water absorption of the paper towel for towel use exists in the range of 250-420 sec / 100 microliters.

  In the off-line creping process, various elongations can be imparted, but it is most suitable to impart an elongation of 5 to 10% in the longitudinal direction. If the elongation is within this range, no problem will occur in roll processing or embossing. However, if the elongation is less than 5%, a hole will open during embossing due to insufficient elongation. Or small holes may occur, causing operational and quality problems. On the other hand, if the elongation exceeds 10%, for example, the tension at the time of the small winding process performed after embossing of the creping paper is not stable, which causes a quality problem such that the product appearance is not uniform.

  The paper towel according to the present invention can be manufactured by any type of papermaking machine including a well-known long paper machine, a twin wire paper machine (including a gap former and a hybrid former), a circular paper machine, and a Yankee. Furthermore, although the paper towel according to the present invention is mainly made by single-layer papermaking, it can be made by multi-layer papermaking. Further, a wet paper strength enhancer such as a polyamide epichlorohydrin agent or a rosin sizing agent can be added to the pulp slurry as a raw material necessary for papermaking.

By selecting the pulp formulation, it can be adjusted to the color desired by the customer. An example of blending the pulp is as follows.
Brown color 1: 5% NUKP, 25-35% RGP, and 60-70% OCC
Brown color 2: 5-10% NUKP, 30-40% RGP, 50-65% OCC
Natural color: 5-10% NBKP, 30-60% RGP, 30-60% DIP

  Examples of the present invention will be described below, but these examples are not intended to limit the present invention.

[Example]
Paper towels obtained by creping a base paper produced by a twin-wire paper machine using a MICREX® / Microcreper ™ system (3,150 mm width) were evaluated. Examples 1 to 3 in which the processing speed of the MICREX (registered trademark) / Microcreper (trademark) system was fixed at 140 mm / min (450 fpm) and the compression ratio (index indicating the speed difference between the microcreper and the winder in%) was changed And Comparative Examples 1-3 were produced. Comparative Example 1 does not satisfy the requirements of the present invention in terms of density obtained by dividing basis weight by thickness (μm), rigidity in the longitudinal direction, and the number of crepes. Comparative Example 2 does not satisfy the requirements of the present invention in terms of the density, and Comparative Example 3 does not satisfy the requirements of the present invention in terms of the density and the number of crepes.

[Test and evaluation method]
Table 1 shows test methods and evaluation methods. From the results of Table 1 below, Examples 1 to 3 satisfying all the requirements of the paper towel of the present invention were excellent in all points of workability, rigidity and water absorption. The thickness was measured by a thickness micrometer (model number: 2W) manufactured by BCAmes Inc.
<Table 1>

  Although the present invention has been described, those skilled in the art will understand that it can be practiced within a wide range of equivalent parameters, concentrations and conditions without undue experimentation and without departing from the spirit and scope of the present invention. Will do.

  Although the present invention has been described with reference to specific embodiments thereof, it will be understood that further modifications are possible. This application is generally intended to cover any variations, uses, or adaptations of the invention in accordance with the principles of the invention and is within the scope of known or customary practice in the art to which the invention pertains. It is intended to include matters not disclosed herein that may be derived and applied to the essential features recited in the appended claims.

  All references cited herein, including journal articles or abstracts, published or corresponding US or foreign patent applications, issued US patents or foreign patents, or other references, all data by reference , Tables, figures and texts presented in the cited references, as well as the entire contents of the references cited in the references cited herein are incorporated by reference in their entirety.

  Reference to known method steps, conventional method steps, known methods or conventional methods in no way acknowledges that any aspect, description or embodiment of the invention is disclosed, taught or suggested in the related art. is not.

  The foregoing description of specific embodiments can be easily modified and / or adapted by others applying the knowledge of those skilled in the art, including the contents of the references cited herein. Such specific embodiments can be used in a variety of applications without departing from the general concept of the present invention and without undue experimentation. Accordingly, such adaptations and modifications are intended to be within the meaning and scope of the equivalents of the disclosed embodiments based on the teachings and guidance presented herein. The expressions or terms in this specification are intended to assist in explanation rather than limitation, as it will be interpreted by one of ordinary skill in the art in light of the teachings and guidance presented herein. It should be interpreted based on the knowledge and combination of vendors.

[Test and evaluation method]
Table 1 shows test methods and evaluation methods. From the results of Table 1 below, Examples 1 to 3 satisfying all the requirements of the paper towel of the present invention were excellent in all points of workability, rigidity and water absorption. The thickness was measured by a thickness micrometer (model number: 2W) manufactured by BCAmes Inc.
<Table 1>

Claims (3)

A paper towel comprising a crepe comprising one or more of chemical pulp, mechanical pulp, and recycled pulp and applied by a microcreper in an off-machine process, having a basis weight of 32.2-64. A paper towel having a density of ³ gsm, a basis weight divided by a thickness (μm) of 0.130 to 0.150 g / cm ³ , and a crepe number (cpi) of 12 to 30.   2. The paper towel according to claim 1, wherein the longitudinal stiffness is 170 to 240 mN · m, and the water absorption is 250 to 420 sec / 100 μL.   Paper towel according to claim 1 or 2, wherein the off-machine process for applying crepe is by use of a MICREX (R) / Microcreper (TM) system.