Paper sheet fitting method and paper molded article

Patent metadata

Field	Value
Publication number	US-2023302757-A1
Application number	US-202118251820-A
Country	US
Kind code	A1
Filing date	Oct 25, 2021
Priority date	Nov 9, 2020
Publication date	Sep 28, 2023
Grant date	—

Abstract

A method for fitting a paper sheet includes a water absorption step of causing a region of the paper sheet to absorb water, the region being at least a part of the paper sheet; a placing step of placing the region of the paper sheet between one set of first molding surfaces of a press mold; a molding step of molding the region of the paper sheet into a three-dimensional shape, by closing the press mold; a layering step of layering another paper sheet that is not caused to absorb water on the molded paper sheet, after opening the press mold; a fitting step of fitting the molded paper sheet and the another paper sheet by closing the press mold to mold a laminate into a three-dimensional shape; and a removal step of removing a molded article including a fitting portion, after opening the press mold.

First claim

1 . A method for fitting a paper sheet, comprising:
a water absorption step of causing a region of a paper sheet to absorb water, the region being at least a part of the paper sheet; a placing step of placing the region of the paper sheet caused to absorb water, such that the region is located between one set of first molding surfaces of a press mold; a molding step of molding, using the one set of first molding surfaces, the region of the paper sheet caused to absorb water into a three-dimensional shape, by closing the press mold; a layering step of layering another paper sheet that is not caused to absorb water on the molded paper sheet, after opening the press mold; a fitting step of fitting the molded paper sheet and the another paper sheet that is not caused to absorb water by closing the press mold to mold, using the one set of first molding surfaces, a laminate into a three-dimensional shape; and a removal step of removing a molded article including a fitting portion, after opening the press mold.

2 . The method for fitting a paper sheet according to claim 1 , comprising:
a step of molding the another paper sheet that is not caused to absorb water into the same shape as a shape of the molded paper sheet, before the fitting step.

3 . The method for fitting the paper sheet according to claim 1 , wherein
the paper sheet and the another paper sheet are one paper sheet, the region of the single paper sheet that is caused to absorb water is half of the one paper sheet, and the another paper sheet is a region of the one paper sheet that is not caused to absorb water.

4 . A method for fitting a paper sheet, comprising:
a water absorption step of causing a region of one paper sheet to absorb water, the region being half of the paper sheet; a placing step of placing the one paper sheet such that the region of the paper sheet caused to absorb water is located between one set of first molding surfaces of a first press mold and a region of the paper sheet that is not caused to absorb water is located between one set of second molding surfaces provided in a region different from the one set of first molding surfaces and having a reverse shape to a shape of the one set of first molding surfaces; a molding step of molding, using the one set of first molding surfaces, the region of the paper sheet caused to absorb water into a three-dimensional shape and molding, using the one set of second molding surfaces, the region of the paper sheet that is not caused to absorb water into a reverse three-dimensional shape to the three-dimensional shape, by closing the first press mold; a layering step of layering the molded paper sheet using the one set of first molding surfaces and the molded paper sheet using the one set of second molding surfaces, by, after opening the first press mold, folding the molded paper sheet using the one set of second molding surfaces toward the molded paper sheet using the one set of first molding surfaces; a fitting step of fitting the paper sheets molded by the first press mold to each other, by pressing a laminate after placing the laminate between molding surfaces of a second press mold with the same shape as a shape of the one set of first molding surfaces and closing the second press mold; and a removal step of removing a molded article including a fitting portion, after opening the second press mold.

5 . The method for fitting a paper sheet according to claim 1 , wherein
a basis weight of the paper sheet is from 350 g/m 2 to 600 g/m 2 .

6 . The method for fitting a paper sheet according to claim 1 , comprising:
a step of changing a shape of a part of the fitting portion into an undercut shape in the fitting step or after the removal step.

7 . A paper molded article, comprising:
a paper sheet formed of two layers; a fitting portion in which the paper sheet is formed into a three-dimensional shape in a position closer to one end portion of the paper sheet in a plan view; and a region other than the fitting portion, wherein in the fitting portion, the paper sheet on the outside in the fitting portion is in close contact with the paper sheet on the inside in the fitting portion by contraction of the paper sheet on the outside in the fitting portion, and the paper sheets are not in close contact with each other in the region other than the fitting portion.

Assignees

• Nissha Co Ltd

Inventors

• Onishi Atsushi
• Nishikawa Tetsu
• Miyashita Shuhei
• Nakagawa Hajime

Classifications

• B31B50/741 Primary

  Moistening; Drying; Cooling; Heating; Sterilizing · CPC title

• B31B50/592

  using punches or dies · CPC title

• B31B2120/50

  covered or externally reinforced · CPC title

• D21J5/00 Primary

  Manufacture of hollow articles by transferring sheets, produced from fibres suspensions or papier-mâché by suction on wire-net moulds, to couch-moulds · CPC title

• B31F5/00

  Attaching together sheets, strips or webs; Reinforcing edges · CPC title