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JP-2026074584-A - Paper base for cushioning materials and paper cushioning materials

JP2026074584AJP 2026074584 AJP2026074584 AJP 2026074584AJP-2026074584-A

Abstract

[Problem] To provide a base paper for cushioning material in which multiple protrusions are formed on one or both sides of the paper surface, wherein when multiple protrusion shapes are applied to form the protrusions, tearing of the protrusions is reduced and a paper cushioning material with excellent cushioning properties is obtained, and the generation of paper dust is suppressed when processing into a paper cushioning material, and a paper cushioning material having multiple protrusions formed on one or both sides of the paper surface of the cushioning material base paper. [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, wherein the proportion of fine fibers with a fiber length of less than 0.2 mm in the pulp fibers constituting the base paper for cushioning material is 35% or less, the synergistic mean of the longitudinal elongation at break and the transverse elongation at break is 4.00% or more and 9.00% or less, and the bursting strength is 250 kPa or more. 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 base paper for cushioning material. [Selection Diagram] Figure 5

Inventors

  • 東川 一希
  • 大塚 真理子

Assignees

  • 王子ホールディングス株式会社

Dates

Publication Date
20260507
Application Date
20241021

Claims (6)

  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, In the pulp fibers that make up the base paper for cushioning material, the proportion of fine fibers with a fiber length of less than 0.2 mm is 35% or less. The geometric mean of the longitudinal elongation at break and the transverse elongation at break is between 4.00% and 9.00%. The burst strength is 250 kPa or more. Base paper for cushioning materials.
  2. The base paper for cushioning material according to claim 1, wherein the ratio of the elongation at break in the longitudinal direction to the elongation at break in the transverse direction (elongation at break in the longitudinal direction / elongation at break in the transverse direction) is 0.60 or more and 1.40 or less.
  3. The base paper for cushioning material according to claim 1, wherein the basis weight is 60 g/ m² or more and 110 g/ m² or less.
  4. The base paper for cushioning material according to claim 1, wherein the density is 0.5 g/ cm³ or more and 0.9 g/ cm³ or less.
  5. A paper cushioning material comprising a base paper for cushioning material according to any one of claims 1 to 4, wherein a plurality of protrusions are formed on one or both sides of the paper surface, with 70 or more protrusions per 100 cm² .
  6. The paper cushioning material according to claim 5, wherein the volume of each of the multiple 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 describes a paper-based protective sheet that can improve portability, comprising kraft paper containing coniferous pulp, wherein 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 0.2 mm or less and a basis weight of 45 g/ m² or more and 95 g/ m² or less. Patent Document 2 describes a cushioning paper for use as a paper cushioning material when folded, with the aim of providing a paper cushioning material with excellent cushioning properties and suppressing the generation of paper dust during processing into a paper cushioning material. The paper has a basis weight of 35 g/ m² to 150 g/ m² , a synergistic mean of the specific tensile strength in the longitudinal direction and the specific tensile strength in the transverse direction measured in accordance with JIS P 8113:2006 of 17.0 Nm/g or more, a wax pick value of 7A or more on both the front and back surfaces, and a surface layer on both sides containing at least one selected from the group consisting of water-soluble resins and water-suspendable resins, and the amount of solids added to both sides of the surface layer is 0.3 g/ m² to 3.0 g/ m² . Japanese Patent Publication No. 2023-44936Patent No. 7526331 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 a plurality of 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 manufactured in the example.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 proportion of fine fibers with a fiber length of less than 0.2 mm in the pulp fibers constituting the cushioning paper is 35% or less, the synergistic mean of the longitudinal elongation at break and the transverse elongation at break is 4.0% or more and 9.0% or less, and the bursting strength is 250 kPa or more. In this specification, a numerical range represented as "X to Y" means a numerical range that includes X as the lower limit and Y as the upper limit. When a numerical range is described in steps, the upper and lower limits of each numerical range can be combined in any way. Furthermore, the cushioning paper of the present invention may have any combination of the characteristics or physical properties described in this specification. In addition, each component contained in the cushioning paper of the present invention may be used individually or in combination of two or more. 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 synergistic mean of longitudinal and transverse elongation at break of 4.0% or more, which allows it to follow the deformation when forming convex shapes and thus suppress tearing of the convex parts. If it is 9.0% or less, it is thought that excessive elongation will occur when the paper cushioning material is subjected to a load, suppressing a decrease in stress and thus making it easier to maintain the cushioning properties of the paper cushioning material. Furthermore, if the ratio of fine fibers is 35% or less, the fibers will be more likely to entangle, and if th