Tempered glass cutting method and cutting apparatus

Patent metadata

Field	Value
Publication number	US-9896371-B2
Application number	US-201314407921-A
Country	US
Kind code	B2
Filing date	Jun 12, 2013
Priority date	Jun 12, 2012
Publication date	Feb 20, 2018
Grant date	Feb 20, 2018

Abstract

The present invention is devised to solve the problems of the above-described conventional technologies. The purpose of the present invention is to provide a tempered glass cutting method and cutting apparatus which can prevent the defects of the tempered glass breaking when same is cut and improve the reliability of the product. To this end, provided is a tempered glass cutting method which comprises: a tempering step of generating compressive stress on a glass sheet to temper the glass sheet; a compressive stress relaxation step of applying heat to the cut portion of the tempered glass sheet to relax the compressive stress; and a cutting step of cutting the cut portion.

First claim

What is claimed is:

1. A method of cutting toughened glass comprising:
toughening a raw glass plate by generating compressive stress in a surface layer of the raw glass plate;
reducing the compressive stress in the surface layer at portions of the toughened raw glass plate to be cut by applying heat to the surface layer at the portions to be cut; and
cutting the toughened raw glass plate along the portions to be cut while applying heat to the surface layer at the portions to be cut so that the compressive stress in the surface layer at the portions to be cut remains reduced.

2. The method according to claim 1 , wherein the compressive stress in the surface layer at the portions to be cut is reduced by applying the heat to the surface layer at the portions to be cut with hot wires.

3. The method according to claim 1 , wherein the compressive stress in the surface layer at the portions to be cut is reduced to 100 MPa or less by the step of reducing the compressive stress.

4. The method according to claim 1 , wherein a width of each of the portions to be cut is 5 mm or less.

5. The method according to claim 1 , wherein the raw glass plate is toughened by chemical toughening or thermal toughening.

6. The method according to claim 5 , wherein the chemical toughening comprises coating a surface of the raw glass plate with an ion exchange solution in which a potassium nitrate solution and zinc oxide powder are mixed, followed by drying and subsequently heating a resultant structure.

7. The method according to claim 1 , wherein the toughened raw glass plate is cut along the portions to be cut using a laser or a scribing device.

8. The method according to claim 1 , wherein a temperature of the heat applied to the surface layer at the portions to be cut at the step of reducing the compressive stress is equal to or higher than a transition point and is lower than a melting point of the raw glass plate.

Assignees

• Corning Prec Materials Co Ltd

Inventors

• Cha Jaemin
• Lee Kiyeon
• Lee Youngseok
• Rhee Ji Hoon
• Lee Jaeho

Classifications

• C03B33/091 Primary

  using at least one focussed radiation beam, e.g. laser beam (C03B33/0955 takes precedence) · CPC title

• C03B33/023

  the sheet {or ribbon} being in a horizontal position · CPC title

• B28D1/221

  by thermic methods · CPC title

• C03C21/002

  to perform ion-exchange between alkali ions (C03C21/005 takes precedence) · CPC title

• C03B33/02 Primary

  Cutting or splitting sheet glass {or ribbons}; Apparatus or machines therefor (C03B33/09 takes precedence; glass-cutting tools C03B33/10) · CPC title