JP2006521975A - Glass sheet packaging - Google Patents

Abstract

Materials and methods for packaging a plurality of thin glass sheets are described. These materials and methods include placing the glass sheet (21) in the container (20) at an angle (a) to the container wall. The spacer (10) contacts the glass sheet at the peripheral edge of the glass sheet.

Description

Related applications

  This application claims priority from US Patent Application No. 10 / 405,667, dated April 1, 2003, the contents of which are incorporated herein by reference.

  The present invention relates to packaging of glass sheets, particularly glass substrates for liquid crystal displays.

  A large thin glass sheet such as a liquid crystal display (LCD) glass substrate is flexible. LCD substrates generally have an area of 1 square meter and a thickness of less than 0.8 mm. Due to the desire for a larger and lighter LCD substrate, the area of the LCD substrate exceeds 1 square meter and has a thickness of less than 0.7 mm, and in some cases less than 0.5 mm. Currently, LCD substrates are typically packaged vertically in foamed plastic boxes. The periphery of each substrate is supported in a vertical groove on the side wall of the box.

  As the length and width of thin glass sheets such as LCD sheets increase and the thickness decreases, the substrate is more flexible and the glass is damaged or broken by mutual contact due to excessive vibration during transportation In order to prevent this, the glass spacing in the container must be increased. In view of these constraints, a packaging method and packaging material is needed that provides sufficient packaging density and prevents breakage for the storage and shipping of thin glass sheets.

  The present invention relates to a method and material for packaging a plurality of thin glass sheets in a container with at least one wall. The plurality of glass sheets are arranged at an angle with respect to the wall of the container. The plurality of glass sheets lean against the main support member, and a plurality of spacers keep the plurality of glass sheets spaced from each other. In one embodiment, each spacer supports the four corners of the plurality of glass sheets, and in one particular embodiment, the spacer is frame-shaped. In one embodiment, the container is tilted so that the tilt angle of the plurality of glass sheets is reduced during loading and unloading of the glass sheets. The above summary and the following detailed description are exemplary and serve to further explain the invention as claimed.

  It should be noted prior to the description of several embodiments of the present invention that the present invention is not limited to the detailed structure and method description described below. The present invention allows other embodiments and methods implemented or performed in various ways.

  One embodiment of the invention relates to a spacer for thin glass sheets, in particular LCD glass sheets. Referring to FIGS. 1 and 2, there is shown a spacer 10 comprising a frame-like member 12 and a cushion 14 that contacts the glass on the surface of this member. The spacer 10 according to the present invention supports the glass sheet at the four corners. When the glass sheet is tilted and supported at the four corners, the glass sheet is sufficiently rigid to prevent bending or breakage of the glass sheet during transportation of the package. In the embodiment shown in FIG. 1, the cushion 14 is a continuous body that extends around the entire circumference of the frame-shaped member 12. However, according to another embodiment, the cushions may be arranged separately around the frame-shaped member. A specific example of a suitable frame member for a glass sheet having dimensions of 985 mm × 300 mm × 0.7 mm is a frame member made of an acrylic material. This frame-like member has a thickness t of about 4 mm and a frame width w between about 10 mm and 50 mm, more preferably between about 10 mm and 20 mm. The overall width and length of the frame member are approximately equal to the dimensions of the glass sheet. The frame width w is selected so that the cushion 14 contacts only the peripheral edge of the glass sheet that is discarded. In a particularly preferred embodiment, the frame-shaped member 12 has a width w narrower at one end 15 than the width of the other three ends of the frame-shaped member. For example, in one embodiment, the one end 15 of the frame-like member has a width w that is substantially the same as the width of the cushion material. In a preferred embodiment, as shown in FIG. 2, one end 15 of the frame-like member 12 supports a glass sheet at the bottom of the container. According to one embodiment, the cushion material comprises a rubber tape having a thickness between about 0.2 mm and 2 mm, preferably about 0.5 mm or less. Cushion materials include, but are not limited to, foamed plastic tapes such as rubber tape, plastic tape, and foamed polyethylene tape. In some embodiments, a sufficiently rigid material provides a cushion for the glass sheet so that the frame member functions as both a support and cushion for the glass sheet. In other words, a single frame member with cushioning properties and sufficient rigidity to support the glass sheet in a tilted state in the container can be used without providing cushioning material on the frame member It is. By using a frame and a cushion of such dimensions, the spacing between the glass sheets is between about 2 mm and 10 mm, preferably between about 3 mm and 4 mm. The spacer 10 must be made from a material with sufficient rigidity and strength to support a stack of glass sheets. Suitable materials include, but are not limited to, acrylic resin, polyvinyl chloride resin and foamed plastic. FIG. 2 shows a state in which a plurality of glass sheets are stacked using a plurality of the spacers shown in FIG.

  Thinner spacers are desirable to obtain a high packing density of glass sheets, but they must be thick enough so that adjacent glass sheets do not contact each other during transportation of shipping containers holding multiple glass sheets. Don't be. Accordingly, the thickness of the spacer depends on the thickness of the glass sheet and the stacking parameters described in more detail later. The spacer must be sufficiently stiff to maintain the shape of the spacer when the spacer is stacked vertically in the container.

  Referring to FIG. 3, a shipping container 20 for a glass sheet 21 is shown. The container 20 has at least one substantially vertical wall 22, a floor 24 and a lid 26. The container 20 must be formed of a material having sufficient mechanical strength to support the packaged glass sheet. As used herein, “substantially vertical” means that the wall 22 is substantially perpendicular to the floor 24 of the container 20. A main support member 28 that is inclined by an angle “a” with respect to one of the walls 22 is arranged in the container 20. The main support member 28 is preferably L-shaped and includes an upper portion 29 and a lower portion 30. The upper portion 29 is leaning against the wall 22 of the container 20. The main support member 28 must have sufficient mechanical strength to support a plurality of glass sheets with spacers and satisfy the cleanliness required for the packaged LCD glass sheet. According to one embodiment, the main support member 28 is formed of an acrylic plate reinforced with a steel frame. In a preferred embodiment, the container 20 supports approximately 20-100 glass sheets with the required number of spacers. A backing plate (not shown) may be disposed between the upper portion 29 and the first glass sheet leaning against the main support member 28.

  Although the upper portion 29 of the main support member 28 is illustrated as being straight, the upper portion 29 may be curved as shown in FIGS. 4A and 4B. In FIG. 4A, the corresponding parts are indicated by reference numerals with a ', and in FIG. 4B, the corresponding parts are indicated by reference numerals with a "". As shown in FIG. 4A, the main support member 28 is shown. ′ Includes a curved upper portion 29 ′ that allows increasing the packing density of the glass sheets within the container 20 ′. In another embodiment shown in FIG. 4B, the main support member 28 ″. Is linear, but a curved backing plate 31 is used to increase the packing density of the glass sheets in the container 20 ″.

  Referring again to FIG. 3, the main surface of the glass sheet 21 leans against the upper portion 29 of the main support member 28, and the edge of the glass sheet 21 is supported by the lower portion 30 of the main support member 28. The spacer 10 keeps the glass sheets 21 spaced from each other, and is in contact with the glass sheet only at the peripheral edge of the glass sheet 21. The stack of glass sheets 21 is fixed by an auxiliary support member 32 that encloses the stack of sheets in the container 20. When the main support member 28 and the auxiliary support member 32 are secured together, an internal package disposed within the container 20 is formed.

  According to one embodiment of the present invention, a plurality of glass sheets and a plurality of frame-like spacers are stacked alternately and supported at an angle “a” with respect to a substantially vertical wall of the container. It is leaned against the member. When glass sheets are packaged in this manner, each glass sheet is supported along the four corners, and the unsupported region of the glass sheet hangs down due to gravity. The amount of sag is controlled by adjusting the tilt angle. An ideal sagging level can be imparted to the glass sheet so that the glass sheet is distorted and stiffened by elastic deformation. Once the ideal tilt angle is selected, the glass sheet becomes stable against external forces such as vibration and sway during transport. The plurality of glass sheets are arranged in the container so that adjacent glass sheets do not come into contact with each other. Referring again to FIG. 3, according to one preferred embodiment, when loading and unloading a glass sheet, the container 20 is angled so that the angle of inclination of the glass sheet relative to the surface on which the container 20 is placed decreases. It is tilted by “b”. In general, the surface on which the container 20 is placed is a horizontal plane. When the container is tilted in this state, the glass sheet is oriented in a direction substantially perpendicular to the lower portion of the main support member in the container. Unloading becomes easy. In a preferred embodiment, during container transportation and storage, the angle “b” of the container relative to the support surface on which the container is placed is reduced so that the bottom surface of the container lies flat on the support surface. .

  Tests were conducted to derive the ideal tilt angle and spacing of the glass sheets in the container. A glass sheet having a thickness of about 0.7 mm and a size of about 985 mm × 1300 mm was attached to a support member of the type shown in FIG. 3 together with a 3 mm thick acrylic frame spacer in contact with the periphery of the glass sheet. The spacer also includes a cushion (rubber type) having a thickness of 0.5 mm around the frame-shaped spacer, and the total thickness is about 4 mm. Five glass sheets and six spacers were placed in the container, but no auxiliary support member was placed in the container. Using either a caliper or a laser interval measuring device, the amount of sag at the center of the glass sheet was measured. The sagging values at various angles are listed in Table 1.

The auxiliary support member was placed in the container as shown in FIG. 3, and the auxiliary support member and the main support member were firmly bound. A stack of glass sheets bound between both support members was swung back and forth in the direction indicated by arrow 40 in FIG. The rigidity of the glass at various angles was observed, and the observation results are shown in Table 1. As shown in Table 1, when the angle “a” between the upper portion of the main support member and the wall is about 20 degrees, the glass sheet becomes sufficiently rigid.

  The packaging method described above could also be applied to LCD substrates having dimensions of about 1500 mm × 1800 mm × 0.7 mm. Twenty glass sheets and 21 spacers were alternately arranged in the box with an inclination of 5 degrees. The box was made of an acrylic board reinforced with a steel frame. The spacer was made of an acrylic material having a thickness of about 3 mm, and the cushion was made of a foamed polyethylene tape having a thickness of about 0.5 mm. The stacked glass sheets and spacers were tightly bound and then tilted at an angle of about 5-30 degrees. As the tilt angle increased, the glass sheet drooped by gravity and stabilized against mechanical vibration. The ideal tilt angle was determined by experiments measuring the external vibrations expected during transport of the package.

  Various embodiments of the present invention are particularly useful for storage and shipping of LCD glass substrates having an area of more than 1 square meter. As mentioned above, these glass sheets generally have a thickness of less than 0.8 mm, and some have a thickness of about 0.5 mm or less. The present invention has been demonstrated for LCD glass substrates having dimensions of about 1500 mm × 1800 mm × 0.7 mm. The main surfaces before and after the glass sheet are not in contact with the spacer except for the peripheral portion that is generally discarded by the end user. Since it is not necessary to apply a film or a surface coating on the surface of the glass to prevent scratches, the processing cost of the glass sheet is reduced. Handling of glass sheets is simplified, loading and unloading of shipping containers is simplified, and no special equipment is required. In an embodiment of the invention, the glass sheet is stiffened by gravity when packaged in a container. This stiffening reduces the flexibility of the glass and reduces the chance of glass breakage due to external vibration during transport.

  It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the spirit or scope of the invention. Accordingly, the present invention includes various modifications and changes made within the scope of the appended claims and their equivalents.

It is a perspective view of the spacer used for some embodiments of the present invention. FIG. 2 is a side view of a stack of glass sheets that is spaced by the spacer of FIG. 1. It is a side view of the several glass sheet packaged in the container by one embodiment of this invention. 4A and 4B are side views of a plurality of glass sheets packaged in a container according to another embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Spacer 12 Frame-like member 14 Cushion 20 Container 21 Glass sheet 22 Container wall 24 Container floor 26 Container lid 28 Main support member 29 Upper part of main support member 30 Lower part of main support member 32 Auxiliary support member

Claims (10)

A packaging material for a plurality of thin glass sheets,
At least one substantially vertical wall and a substantially horizontal floor;
A main support member inclined at an angle to the wall;
A plurality of spacers configured to keep the distance between the glass sheets by contacting the peripheral edge of the plurality of glass sheets;
Each of the spacers supports at least one glass sheet at four corners of the glass sheet.   The packaging material according to claim 1, wherein the glass sheet is a liquid crystal display substrate.   The packaging material of claim 2, wherein the glass sheet has a thickness of less than about 0.8 mm.   The packaging material of claim 1, wherein the angle between the wall and a portion of the main support member is greater than about 5 degrees.   The packaging material according to claim 1, wherein the spacer has a flexible frame shape that comes into contact only with the peripheral edge of the glass sheet.   The packaging material according to claim 5, wherein the spacer includes a main frame body made of an acrylic material and an auxiliary cushion material assembled to the main frame body.   The said main support member is provided with the upper part for supporting the main surface of the said glass sheet, and the lower part for supporting the edge of the said glass sheet, It is formed in the L-shape, It is characterized by the above-mentioned. Item 1. A packaging material according to item 1. A method of packaging a plurality of thin glass sheets,
Providing a container having at least one substantially vertical wall and a substantially horizontal floor;
A portion of the main support member inclined at an angle to the wall is disposed in the container;
Maintaining the interval between the plurality of glass sheets by the frame spacer,
The plurality of glass sheets so that the plurality of glass sheets lean on the main support member in a spaced state and each spacer supports at least one glass sheet at four corners of the glass sheet. A packaging method characterized by comprising the steps of placing a container in the container.   During the step of placing the plurality of glass sheets in the container, the container is placed on a horizontal plane, and the container is tilted such that the angle of the plurality of glass sheets with respect to the horizontal plane decreases. The method according to claim 8.   Fixing the plurality of glass sheets between the two supporting members so that the glass sheets are sandwiched between the auxiliary supporting member and the main supporting member and the container is covered. The method according to claim 9.

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