Patent Application
20220219875
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The invention relates to a sealed, overwrapped package containing a corrugated board adjacent a sheet stack of either posterboards, foam core boards or a both of them.
Polyolefin shrink is an extremely durable and versatile ‘premium’ shrink wrap. Polyolefin materials are available with different characteristics, including cross-linked wrap that provides high-tensile strength and incredible clarity for high-speed packaging applications.
With added strength, the ability to create longer rolls of wrap with thinner gauges available that allow for less roll change-over and increased efficiency and productivity.
Polyolefin shrink wrap has excellent puncture-resistance and seal-strength, allowing for irregular-shaped items to have excellent protection throughout its supply chain life-cycle. POF is available in thicknesses as low as 35-gauge (0.35 mil), and is more commonly available in 45, 60, 75 and 100 (1 mil) gauges.
Polyethylene (PE) is a type of polyolefin, meaning it is a single monomer wrap that is formed with the addition of ethylene during polymerization. PE is used in several forms of flexible protective packaging including shrink wrap and stretch wrap, and performs very differently for each.
There are multiple forms that PE can take, but the three most common would be Low-Density Polyethylene (LDPE), Linear Low-Density Polyethylene (LLDPE), & High-Density Polyethylene (HDPE). Each of these are best used in different industrial applications, but for shrink packaging LDPE would be the most common form.
The benefits of using LDPE over the other forms of shrink packaging would be added strength and durability for heavier, larger items. These wraps are also printable and can have excellent graphics added while still maintaining the image and the strength required.
It is known to overwrap a sheet stack of posterboard with plastic film in which sheets of posterboard are arranged one adjacent another in succession. It is also known to overwrap a sheet stack of foam core board with plastic film in which sheets of foam core board are arranged one adjacent another in succession. Conventionally, such overwrapped sheet stacks are placed into opaque boxes for shipment to a desired retail destination. The box protects the sheet stack from damage during transit. Its opaqueness, however, conceals the color of the sheet stacks.
In order to lessen the overall cost for shipment and render visible the color of the sheet stacks, it would be desirable to eliminate the boxes entirely and to have the plastic film overwrap in a seal tight manner. Shipping labels can then be applied to the overwrap. However, the present inventors found that when the plastic film of an overwrapped sheet stack of posterboard is heat shrunk to attain the seal tight manner of the overwrapped plastic film, the sheet stack becomes damaged from forces imposed by the shrinking overwrap during the heat seal process. For example, curling damage may arise along the corners and edges of the sheet stack. The presence of such damage is unacceptable commercially to the consumer. Further, the sheet stack could become further damaged from handling during transit to the retailer destination.
It is therefore desired to provide a manner of providing an overwrapped sheet stack of either posterboards, foam core boards, or both without containing them in opaque boxes for shipment to a destination retailer and yet avoid damaging the sheet stack from forces imposed while the overwrapped plastic film is being sealed tight.
Our invention is a package that includes a conventional plastic film that overwraps both a sheet stack and a corrugated board and subjecting the overwrap to heat shrink sealing. The plastic film may be polyolefin or polyethylene. The sheet stack may be sheets of conventional posterboards, sheets of conventional foam core board, or both.
The package of the overwrapped plastic film and the corrugated board in effect hold the sheet stack together with its sheets arranged one after another in succession until the package reaches a retail store, where the plastic film and the corrugated board are removed and discarded. The sheet stack is then put onto a display rack for sale without the discarded plastic film or the discarded corrugated board.
For a better understanding of the present invention, reference is made to the following description and accompanying drawings, while the scope of the invention is set forth in the appended claims. The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.
Turning to the drawing, a package is shown that includes a plastic film overwrapping both a corrugated board 10 and a sheet stack of posterboard sheets 12 that are arranged adjacent one another. The plastic film has a midway seam or crease 14 that extends about midway across the front of the package and extending to opposite sides. Although not shown in
The process of forming the package involves sheeting the posterboard in batches of various counts from rolls to form sheet stacks and then dropping in line onto each of the batches a sheet of corrugated board from a hopper. Thereafter, each batch of the sheet stacks with the corrugated board are overwrapped with the plastic film to form a pack then the pack is heat shrunk to seal the pack and then placed on a skid for subsequent delivery.
The essence of the invention is that the corrugated board is preferably thicker than an individual sheet of the sheet stack to strengthen the plastic film wrapped pack when being shipped. It is preferred that the areal size of the corrugated board be larger than the areal size of an individual sheet of the sheet stack to provide additional protection of the corners and edges of the sheet stack by virtue of being larger in size.
Nevertheless, the corrugated board could be the same areal size as an individual sheet of the sheet stack and still provide protection of the corners and edges of the sheet stack. While it is not preferred that the corrugated board be smaller than the areal size of an individual sheet of the sheet stack, such is still viable because its greater thickness would provide some degree of protection as a barrier against damage to the sheet stack during transit and might prevent some damage to the corners and edges of the sheet stack during heat shrink sealing especially if it were only slightly smaller in areal size. The corrugated board is sturdier than any of the individual sheets of the sheet stack and might even be sturdier than the entire sheet stack as a whole, depending upon the number of individual sheets in the stack.
Some benefits of the pack include that that the pack costs less to manufacture than providing and assembling an opaque box to contain the posterboards instead and that the color of the posterboard can be visually seen through the plastic film, unlike the case for the opaque box containing the posterboards instead that hides the color from view from outside the box.
The corrugation of the corrugated board is preferably in a flute direction that supports the long direction of the posterboard, although flute direction may instead be in the short direction of the corrugated board.
The plastic film that overwraps is preferably a strong heat shrink type plastic film, although the plastic film may alternatively be any other type—just that the strong heat type is considered the better choice. The plastic film of the pack is preferably heat shrunk to make the pack stronger and more protective, although the pack does not need to be heat shrunk to be useful.
The corrugated board protects the sheet stack from damage otherwise arising from bending or curling forces imposed as the overwrap plastic film is heat shrunk. Such damage 20 is to corner regions of the posterboard sheets as exemplified in
The previously discussed sheet stack of conventional posterboard sheets may be replaced by a stack of conventional foam core board sheets instead. A foam core board (or foam board) sheet is more rigid than a posterboard sheet. Alternatively, the stack could have both posterboards and foam core boards. That is, both a set of individual sheets of posterboard and a set of individual sheets of foam core board.
While the foregoing description and drawings represent the preferred embodiments of the present invention, various changes and modifications may be made without departing from the scope of the present invention.
U.S. provisional patent application No. 63/137,205 filed Jan. 14, 2021 from which the present application asserts the benefit of invention priority.
| Number | Date | Country | |
|---|---|---|---|
| 63137205 | Jan 2021 | US |
