Restraining dense packaging system for LCD glass sheets

Abstract

A reusable dense packaging system used to transport large size display substrates, is provided made up of three main components; a pallet frame, a cover, and restraining means. The restraining means securely hold the glass sheets within the cover and on the pallet frame. Restraining means includes one or more retaining bars moving towards and away from the front of the glass sheets and a mechanical system. The mechanical system may include the use of a pressing panel, a belt apparatus, a scissor-like mechanism, positioning devices, or a retaining bar pulling system, each capable of moving towards and away from the front of the glass sheets. Each embodiment allows for packaging from 1 to N glass sheets with flexibility and stability and with manual or automatic operation.

Description

BACKGROUND OF THE INVENTION [0001] 1. FIELD OF THE INVENTION [0002] The present invention relates generally to packaging, and particularly to packaging for large size display substrates, such as a stack of glass sheets. [0003] 2. TECHNICAL BACKGROUND [0004] In recent years, glass substrates for Liquid Crystal Display (LCD) panels have increased in size, along with enlargement of Liquid Crystal Display panel sizes. [0005] Conventional non-contact packaging, such as PP-case and L-supporter, has dominated the market as the delivery model for smaller size glass substrates, such as Gen 4, 730 mm×920 mm, or smaller. Recognizing limitations in packing density, their requirements for significant storage space, and the difficulty to extend their application to ever-increasing sizes, these conventional non-contact or spacer type packages have effectively reached a practical limitation for glass sizes greater than or equal to Generation 5. [0006] Pursuant to the trend for larger and larger sub...

AI Technical Summary

Benefits of technology

[0089] 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 and scope of the invention. Thus it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.

Problems solved by technology

Recognizing limitations in packing density, their requirements for significant storage space, and the difficulty to extend their application to ever-increasing sizes, these conventional non-contact or spacer type packages have effectively reached a practical limitation for glass sizes greater than or equal to Generation 5.

When containers of these types are used, however, the size of glass sheets to be transported is limited.

Further, these containers, though adequate enough in delivery, is poor in mechanical strength.

In addition, the glass sheets are undesirably susceptible to contamination during transportation, since the crates or boxes are also poor in weatherability, often requiring over-pack (e.g. a box within a box).

Further, there is a problem in that a cleaning process for removing adherents, such as a residual adhesive remaining on the glass sheet after removing the adhesive protective films and contaminants which are attached on the glass sheets in the course of the transportation, typically takes a long time.

It should be noted that even some non-adhesive materials, such as polyethylene or polymeric films, if used, may leave some residual organic materials which must also be washed off with a detergent or other like wash; however, these non-adhesive residuals are typically not as difficult to clean off or as time consuming as residuals left behind by adhesives.

However, these and other existing prior art solutions still have several limitations.

Firstly, there is limited protection of container contents from weather during transportation.

Additionally, the disposing of these consumable items becomes an environmental and cost issue as well.

Secondly, there is marginal mechanical strength of the container due to side-wall construction of corrugated plastic materials.

Where tilting is not required (for instance as in typical PP or L type prior art containers), loading glass sheets is complex due to precision of placement in slots.

Additionally, prior art PP or L type containers typically only hold about 20 sheets of glass requiring frequent change-out of containers.

Further, the construction of mild steel with painted surfaces found also in the prior art is susceptible to chipping, flaking and particle generation, as well as corrosion, resulting in marginal clean room compatibility.

Construction is also subject to deformation during normal warehouse handling.

In certain other prior art solutions, there is difficulty in handling containers on conveyors and truck beds due to limited contact area of a pallet base.

Additionally, glass cushioning materials exhibit significant deformation over time, requiring periodic adjustment of packing and unloading robot controls, as well as periodic full replacement due to permanent deformation.

Still further, in certain prior art solutions, there is an inability to scale up for larger sizes of glass without material handling equipment (overhead lift) being involved.

Still further, most of the prior art solutions, include multiple loose parts (some on the order of 10 or more pieces plus hardware) which though allow for collapsibility, are costly both to assemble and to maintain.

One primary limitation of the prior art is that there is marginal retention of glass movement in container.

The prior art methods to secure a stack of glass sheets and to avoid movement during transportation after it has been packed or shipped are not sufficient to retain the glass sheets from moving under all conditions such as transportation conditions of excessive vibration or shock; hence there is the potential for breakage to occur.

Thereby existing methods of packaging LCD glass seem to have met practical limitations in scaling beyond Gen 5 glass sheet size [approximately 1100 mm×1300 mm].

They carry an inherent penalty in space and logistics due to low sheet counts per container volume.

Dense packaging has been proven as a viable delivery model, however, as substrate sizes become even larger, such as with Gen 7 and beyond, new challenges arise for dense packaging, particularly around size and weight of the container components, which become even more unwieldy for operators to handle, as well as transportation constraint issues, for instance, transporting containers through standard size doors, available sizes of shipping containers and standard trucks.

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