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JP-2026074583-A - Paper base for cushioning materials and paper cushioning materials

JP2026074583AJP 2026074583 AJP2026074583 AJP 2026074583AJP-2026074583-A

Abstract

[Problem] To provide a base paper for cushioning material that allows for easy formation of convex shapes, minimizes tearing of the convex parts, and provides excellent cushioning properties when multiple convex shapes are applied to form the convex parts, and a paper cushioning material having multiple convex parts formed on one or both sides of the surface of the base paper for cushioning material. [Solution] A base paper for cushioning material, wherein a plurality of protrusions of 70 or more per 100 cm² are formed on one or both sides of the paper surface, the fiber orientation strength is 1.00 or more and 1.45 or less, and the synergistic mean of the Clark stiffness in the longitudinal direction and the Clark stiffness in the transverse direction is 33 or more and 70 or less. A paper cushioning material, wherein a plurality of protrusions of 70 or more per 100 cm² are formed on one or both sides of the paper surface of the cushioning material base paper. [Selection Diagram] None

Inventors

  • 大塚 真理子
  • 東川 一希

Assignees

  • 王子ホールディングス株式会社

Dates

Publication Date
20260507
Application Date
20241021

Claims (7)

  1. A base paper for cushioning material, which has 70 or more protrusions per 100 cm² formed on one or both sides of the paper surface, The fiber orientation strength is 1.00 or more and 1.45 or less. The geometric mean of the vertical Clark fear score and the horizontal Clark fear score is between 33 and 70. Base paper for cushioning materials.
  2. The base paper for cushioning material according to claim 1, having a thickness of 110 μm or more and 160 μm or less.
  3. The cushioning paper according to claim 1, wherein the content of softwood pulp in the raw pulp constituting the cushioning paper is 80% by mass or more.
  4. The base paper for cushioning material according to claim 1, wherein the synergistic mean of the tensile modulus in the longitudinal direction and the tensile modulus in the transverse direction is 1.2 GPa or more and 3.5 GPa or less.
  5. The base paper for cushioning material according to claim 1, wherein the basis weight is 70 g/ m² or more and 110 g/ m² or less.
  6. A paper cushioning material comprising a base paper for cushioning material according to any one of claims 1 to 5, wherein a plurality of protrusions are formed on one or both sides of the paper surface, with 70 or more protrusions per 100 cm² .
  7. The paper cushioning material according to claim 6, wherein the volume of each of the plurality of protrusions is 20 mm³ or more and 150 mm³ or less.

Description

This invention relates to base paper for cushioning materials and paper cushioning materials. Cushioning materials are used to fill gaps between items stored in envelopes, cardboard boxes, and other packaging materials, and to absorb vibrations and shocks to the contents during transportation. Traditionally, cushioning materials have been made from resins such as polyethylene and polyurethane foam. In recent years, the global problem of plastic waste has become increasingly serious. To improve the global environment, there is a growing movement to reduce and eliminate plastic in packaging materials, and to replace plastic packaging with paper-based packaging. From an environmental protection perspective, paper-based cushioning materials are becoming more widespread as an alternative to plastic cushioning materials. Patent Document 1 discloses a paper-based protective sheet for the purpose of providing a protective sheet that can improve portability, wherein the protective sheet is made of kraft paper containing coniferous pulp, the content of the coniferous pulp is 90% by mass or more and 95% by mass or less relative to the mass of the kraft paper, and the kraft paper has a thickness of a specific value or less and a basis weight within a specific range. Patent Document 2 discloses a cushioning packaging sheet and a packaging bag used when packaging articles, which protects articles, and the cushioning packaging sheet is an embossed paper having numerous uneven shapes over substantially the entire surface of the paper base, and the height of the uneven shapes is greater than the thickness of the paper base and below a specific value. Japanese Patent Publication No. 2023-44936Japanese Patent Publication No. 2018-177304 This is a schematic diagram illustrating an example of the structure of a paper cushioning material in which a plurality of protrusions are formed on one side of the surface of the cushioning paper base of the present invention.This is a schematic diagram illustrating an example of the structure of a paper cushioning material in which multiple protrusions are formed on both sides of the paper surface of the cushioning material base paper of the present invention.Figure 1 is a cross-sectional view of the paper cushioning material shown as an example.Figure 2 is a cross-sectional view of the paper cushioning material shown as an example.This is a plan view showing the paper cushioning material according to the embodiment.Figure 5 is a cross-sectional view of the paper cushioning material. [Base paper for cushioning material] The cushioning paper according to this embodiment (hereinafter also simply referred to as cushioning paper) is a cushioning paper for which a plurality of protrusions of 70 or more per 100 cm² are formed on one or both sides of the paper surface to form a paper cushioning material, wherein the fiber orientation strength is 1.00 or more and 1.45 or less, and the synergistic mean of the Clark stiffness in the longitudinal direction and the Clark stiffness in the transverse direction is 33 or more and 70 or less. In this specification, the numerical range represented by "X to Y" means a numerical range that includes X as the lower limit and Y as the upper limit. When the numerical range is described in steps, the upper and lower limits of each numerical range can be arbitrarily combined. Furthermore, the cushioning paper of the present invention can have any combination of the characteristics or physical properties described in this specification. The longitudinal direction of the cushioning paper means the papermaking direction (MD), and the transverse direction means the direction perpendicular to the papermaking direction (CD). In this embodiment, the base paper for cushioning material has a fiber orientation strength below a specific value, resulting in high isotropy in strength and elongation, and reducing tearing of the convex parts when multiple convex shapes are added to form the convex parts. In this embodiment, the base paper for cushioning material has a synergistic mean value of the Clark stiffness in the vertical and horizontal directions that is above a specific value. As a result, the shape of the protrusions in the paper cushioning material, which has multiple protrusions formed on it, is easily restored after being subjected to a load, and as a result, the cushioning performance is easily maintained. Furthermore, if the synergistic mean value of the Clark stiffness in the vertical and horizontal directions is below a specific value, the protrusions are more easily formed when multiple protrusions are created. In this embodiment, a paper cushioning material is formed by creating a specific number or more protrusions per 100 cm² on the base paper for cushioning material. When a load is applied to the paper cushioning material, the multiple protrusions make it easier to cushion the load, resulting in superior cushioning performance. The cushioning paper of this em