Method and device for manufacturing sheet having fine shape transferred thereon

Patent metadata

Field	Value
Publication number	US-9573300-B2
Application number	US-201414455970-A
Country	US
Kind code	B2
Filing date	Aug 11, 2014
Priority date	Sep 28, 2007
Publication date	Feb 21, 2017
Grant date	Feb 21, 2017

Abstract

A method for manufacturing a sheet having a fine shape transferred thereon, in which a sheet base made of a thermoplastic resin is placed between an imprint mold and an intermediate base and the sheet base is then pressed by a pair of pressing plates to imprint the fine shape of surface irregularity of the imprint mold to the sheet-like base. The sheet base is pressed such that, when pressing force of the pressing plates is maximum, an imprinting pressure difference is present in an imprinting surface of the imprint mold, a maximum imprinting pressure section is present in the imprinting surface, and a portion where the imprinting pressure is minimum is not present in the imprinting surface. The method achieves uniform and highly accurate shape transfer without trapping of air.

First claim

The invention claimed is:

1. A method for manufacturing a sheet having at least first and second shapes of texture having convex shapes or concave shapes thereon, comprising:
placing a sheet material comprising a thermoplastic resin between an imprint mold having an imprinting surface provided with the first shapes of texture and an intermediate base; and
pressing the imprint mold and the intermediate base in a direction toward the sheet material by a pair of pressing plates so that the first shapes of texture are imprinted on the sheet material, wherein the sheet material is pressed such that, when a pressing force of the pressing plates is maximum, an imprinting pressure difference is present along an imprinting surface of the imprint mold, a maximum imprinting pressure section of the pressing plates, where the imprinting pressure has a maximum value, is present at a location on the imprinting surface, and wherein the imprinting pressure on the imprinting surface is monotonically decreasing without a relative minimum value that is less than any value of the imprinting pressure on the imprinting surface immediately preceding or following the relative minimum value,
wherein the intermediate base has an imprinting surface having the second shapes of texture thereon such that the second shapes of texture are imprinted on a surface of the sheet material that is opposed to the intermediate base, and wherein the pressing is carried out such that when the pressing force of the pressing plates is maximum, the imprinting pressure difference is present along the imprinting surface of the intermediate base, the maximum imprinting pressure section of the pressing plates, where the imprinting pressure has the maximum value, is present at the location on the imprinting surface, and wherein the imprinting pressure on the imprinting surface is monotonically decreasing without the relative minimum value that is less than any value of the imprinting pressure on the imprinting surface immediately preceding or following the relative minimum value,
wherein the intermediate base has a cushioning property and comprising a cushion material that exhibits substantial volume change upon receiving a stress thereon comprises a polymer material having pores inside, a composite material having a rubber and a volume-changing layer laminated therein, wherein the volume-changing layer is impregnated with the rubber, wherein the volume-changing layer comprises a knitted material, a textile of fibers, a non-woven cloth, or a laminated material,
wherein the intermediate base comprises a laminate comprising a transfer sheet having the at least first and second shapes of texture laminated onto the cushion material.

2. The method according to claim 1 , wherein the imprint mold comprises a concave shape and a plurality of grooves are arranged in parallel with one another, and the pressing is carried out such that, when the pressing force of the pressing plates is maximum, the imprinting pressure difference is present in a longitudinal direction of the grooves.

3. The method according to claim 1 , wherein the pressing is carried out such that, on the imprinting surface of the imprint mold, an absolute value of the imprinting pressure difference is monotonically increased in a decreasing direction of the imprinting pressure from the maximum imprinting pressure section.

4. The method according to claim 1 , wherein when the pressing force of the pressing plates is maximized, the intermediate base has a compressive elastic modulus in a range from 0.1 MPa to 200 MPa over an entire area of the imprinting surface of the intermediate base.

5. The method of claim 1 , wherein the first and second shapes of texture are same.

Assignees

• Toray Industries

Inventors

• Hirai Yuma
• Minoura Kiyoshi
• Nomura Fumiyasu

Classifications

• B29C2059/023

  Microembossing · CPC title

• B29C2033/426

  Stampers · CPC title

• B29C37/006

  Degassing moulding material or draining off gas during moulding (venting means in moulds B29C33/10) · CPC title

• B29C59/022

  characterised by the disposition or the configuration, e.g. dimensions, of the embossments or the shaping tools therefor · CPC title

• B29C35/041

  using liquids · CPC title