1. Field of the Invention
This invention relates to product packaging, and in particular, it relates to packaging for products suitable for store merchandising.
2. Description of the Related Art
A first type of conventional packaging for consumer products, shown in FIGS. 6(a) and 6(b) (which is a cross-sectional view along the direction of arrows 2-2), is made of two sheets of corrugated cardboard 101 and 102, and a clear plastic container 103 having a flat insertion portion 103a and a chamber portion 103b. The insertion portion is sandwiched between the two cardboard sheets 101 and 102, and the chamber portion 103b protrudes from the plane of the cardboard sheets via a cut (opening) on one cardboard sheet 101 and is used to hold the product inside. A second plastic container 103′ may be provided and protrudes from the other cardboard sheet 102 to form a continuous space for hold the product. The two cardboard sheets 101 and 102 are adhered together around the periphery with an adhesive 104. A commonly used adhesive is a hot melt glue. The front and back sides of the package are typically printed with product information and other information. (In these drawings, the spaces between the various layers are exaggerated to illustrate the relationship among the various layers.) One disadvantage of this type of conventional packaging is that the hot melt glue is typically applied by hand, and thus the seal quality is often difficult to control due to, for example, the varying drying speed of the glue, the placement of the glue, etc. Another disadvantage is that the corrugation of the cardboard is visible at some of the side edges of the finished packaging (see
A second type of conventional packaging, shown in
A disadvantage of the second type of conventional packaging is that it sometimes lacks sufficient structural strength. Display packs are often transported in an assembly where a plurality of display packs are stood on their sides in a container with half-height walls (i.e. walls not as high as the packs themselves), and wrapped together to form a box-shaped bundle. When two or more of such bundles are stacked on top of each other, the weight of the top one is supported directly by the packs in the bottom bundle. The packs therefore must have sufficient structural strength and rigidity to prevent them from bending. The lack of physical strength also makes it difficult to make larger packages (e.g. larger than 10 by 15 inches), or to pack heavier items.
Accordingly, the present invention is directed to a display pack and packaging method that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.
Additional features and advantages of the invention will be set forth in the descriptions that follow and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims thereof as well as the appended drawings.
To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, the present invention provides a display pack for a product including a first and a second corrugated cardboard sheet, at least one cardboard sheet defining at least one opening; at least one container having a flat insertion portion and a chamber portion for holding the product, the insertion portion being sandwiched between the two cardboard sheets and the chamber portion protruding from a plane of the cardboard sheets via the opening; and an adhesive material between the first and the second cardboard sheets in at least a peripheral area of the two cardboard sheets to join the two cardboard sheets together, wherein the first and second cardboard sheets are crushed in the peripheral area with reduced air gaps in the corrugations. The adhesive material may be a heat-sensitive adhesive material.
In another aspect, the present invention provides a method of making a display pack including the steps of providing a first and a second corrugated cardboard sheet, at least one cardboard sheet defining at least one opening; providing at least one container having a flat insertion portion and a chamber portion for holding the product; placing the insertion portion between the two cardboard sheets so that the chamber portion protrudes from a plane of the cardboard sheets via the opening; applying an adhesive material between the first and second cardboard sheets in a peripheral area of the cardboard sheets; and applying a pressure to the peripheral area of the two cardboard sheets to crush the corrugations inside the cardboard sheets in the peripheral area. The adhesive material may be a heat-sensitive adhesive material, in which case the method further includes applying heat to the heat-sensitive adhesive to activate it.
In another aspect, the present invention provides a device for sealing a display pack, which includes an upper and a lower platen, at least one of the platens having a rim and a recessed central area; and a drive mechanism for driving the platens, the drive mechanism capable of applying a force of 25 tons or more at the platens. The platens may be heated.
The present invention provides another device for sealing a display pack, which includes a transport mechanism for transporting a package; one or more sets of rollers disposed along a path of the transport mechanism, each set of rollers including an upper row and an opposing lower row of rollers, the upper and lower rows of rollers disposed at a tapering angle with respect to each other; and a press for applying a force to at least one of the upper and lower rows of each set of rollers. The device may include two or four sets of rollers. The rollers may be heated.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
FIGS. 2(a) and 2(b) schematically illustrate cross-sectional views of the display pack of
FIGS. 5(a) and 5(b) are schematic cross-sectional views showing rollers of a sealer machine according to another embodiment of the present invention.
FIGS. 5(c) and 5(d) schematically illustrate sealer machines employing rollers according to other embodiments of the present invention.
FIGS. 6(a)-(c) illustrate a package made according to a first conventional packaging technique.
FIGS. 7(a) and 7(b) illustrate a package made according to a second conventional packaging technique.
To seal the package, the peripheral areas 11a, 12a of the two overlaying cardboard sheets are subject to a sufficient amount of pressure to crush the corrugations inside the cardboard sheets and flatten them in that area. Heat is applied, either simultaneously with or subsequent to the application of pressure, to the outer side of either one or both cardboard sheets in the peripheral area. Because the corrugations inside the cardboard are crushed and the air gaps are substantially eliminated, the crushed cardboard becomes a better heat conductor. Sufficient heat can be conducted from the outer side to the inner side where the heat-sensitive adhesive has been applied to activate the adhesive and seal the package. In one preferred embodiment, the width of the crushed peripheral areas is approximately 0.5 inches. Any suitable sealing width may be used, but it is desirable that the adhesive not be adhered to the insertion portion of the container, so that the container can be easily removed from the packaging for recycling. This is desirable because it facilitates recycling of the container. In addition, the container may be made as a re-usable container, and easy removal may facilitate re-use in such a case.
Many types of sealer machines may be used to carry out the sealing process, some of which are described below. The first is a sealer machine with a heated sealing press. As shown in
Preferably, the force or pressure applied by the platens is such that the cardboard sheets are crushed to up to approximately 50% of their original thickness. Generally speaking, within certain limits, higher pressure results in thinner crushed cardboard sheets, which in turn results in increased heat transfer rate and therefore reduced heat application time required to properly activate the adhesive. The optimum pressure may also depend on the type of the cardboard used. The temperature of the heated surface may be approximately from 100 to 500 degrees F., which is a typical temperature used in the second conventional packaging technique. Those of ordinary skill in the art will be able to find acceptable or optimum pressure, temperature and process time conditions for the particular cardboard used without undue experimentation.
In one particular example, the package uses two sheets of 200 lb test E-flute cardboard coated with a heat sensitive blister card coating as an adhesive, has a size of 10 inches by 15 inches and a sealed width of 0.5 inches. The sealing press has a rim on both platens and both surfaces are heated to a temperature of 300 degrees F. The force on the platens is 25 tons. The pressure and heat was applied simultaneously for 3 seconds.
The sealer machine suitable for the above application may be a machined used to seal a conventional package of the second type (as shown in
In addition to the peripheral areas, the corrugated cardboards 11 and 12 may be crushed and sealed in certain interior areas (spot sealed) to provide additional security, especially for larger packages and packages with multiple separate plastic containers. To achieve spot sealing, as shown in
A second type of sealer machine useful for carrying out the sealing process is a sealing press similar to the one described above, but instead of heated platen(s), hot air or a hot steam is applied to the heat-sensitive adhesive to heat it. The hot air or steam is supplied from the side by a tube or pipe 25 as shown in
FIGS. 4(a) and 4(b) illustrate an alternative embodiment of the sealing press (either heated or unheated). In this embodiment, the platens are similar to those shown in FIGS. 2(a), 2(b), 3(a) and 3(c), but the rim portions 21a and 22a have rounded or chamfered edges 21b and 22b on the inside edges, i.e. the edges that correspond to the border between the crushed and uncrushed portions of the package. The rounded shape of the edges 21b and 22b avoids forming a sharp line between the crushed and uncrushed portions on the package and avoids potentially tearing or cutting the surface sheet of the cardboard. Desirable radius of the rounded edges 21b and 22b depends on the thickness of the corrugated boards, and is preferable about ⅛ to 1 inch. Note that FIGS. 4(a) and 4(b) illustrate the stage of the platens before crushing occurs.
A third type of sealer machine according to an embodiment of the present invention is shown in FIGS. 5(a)-(d). Instead of a press, parallel sets of rollers are used to seal the package in this type of machine.
Similar to the platens shown in FIGS. 4(a) and 4(b), the rollers 51a and 51b may have rounded to chamfered inside edges to avoid potentially tearing or cutting the surface sheet of the cardboard.
The pair of roller sets shown in
The package in
The packaging technique according to embodiments of the present invention has the following advantages. The packages are more secure and harder to tear from the edge and the center than packages made by the first conventional method described above which uses hot melt glue. The sealing quality is also more consistent than seals using glue because the drying (cooling) speed and the placement of the hot melt glue are hard to control. Packages made with the present technique are also aesthetically more appealing than packages made by the first and second conventional techniques in that the corrugations of the cardboard sheets are less visible when viewed from the side edges (e.g. the bottom side) due to the crushing. Compared to the second conventional packaging technique, packaging made with the present method is stronger because it uses two cardboard sheets. As a result, the packages can be made larger and to pack heavier items, and multiple packages can be stacked in bundles. For example, the packages can be as large as 24×24 inches (whereas the second conventional type of packages are typically up to 14×14 inches) and can be used to pack items as heavy as 10 to 20 lbs. Also, the second type of conventional packages have a tendency to warp because the two sheets are of different materials. Packages according to the present invention are also more environmentally friendly because unlike the cardboard used in the present technique, the flat sheet of paper used in the conventional method uses less post-consumer recycled material. The present sealing technique is also faster than the process used in the second conventional technique.
Although the above-described embodiments are most advantageous when used in combination with a heat-sensitive adhesive, the crushing technique described above may also be applied when a regular, non-heat-sensitive adhesive is used. Such a package has the advantages that it is harder to open and tear from the edge than packages made by the first conventional method described above because the corrugations is crushed in the edge areas. It is also aesthetically more appealing than packages made by the first and second conventional techniques in that the corrugations of the cardboard sheets are less visible when viewed from the side edges due to the crushing.
It will be apparent to those skilled in the art that various modification and variations can be made in the display pack and packaging method of the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover modifications and variations that come within the scope of the appended claims and their equivalents.
The present application is a continuation-in-part of U.S. Provisional Application No. 60/711,024, filed Aug. 24, 2005.
Number | Date | Country | |
---|---|---|---|
60711024 | Aug 2005 | US |