1. Field of the Invention
This invention relates to items such as hangers for apparels, display board for stores, etc. made from corrugated boards.
2. Description of the Related Art
Hangers for apparels have traditionally been made from plastic, metal or wood materials. Recently, there have been disclosed clothes hangers made from corrugated boards. For example, U.S. Pat. No. 7,267,252, issued Sep. 11, 2007, entitled “Corrugated clothes hanger structure,” describes a clothes hanger construction of folded corrugated paper with two interconnected neck members. The neck members are intertwined via coordinated opposing slots in the hook portion of a clothes hanger having two shoulder portions. The structure is cut from a single piece of corrugated cardboard and folded along a single fold line to form the hanger. U.S. Patent Appl. Pub. No. 2004/0031825, published Feb. 19, 2004, entitled “Garment hanger,” describes a garment hanger comprising two parts or elements which are hinged together so that they can be folded from a first relatively flat or opened out configuration to a second configuration in which the two parts or elements are adjacent and facing each other, at least one of the parts including first means by which the hanger can depend from a support when in its second configuration, the two parts providing second means from which a garment can be hung. The two parts or elements are preferably of a flexible stiff sheet material such as a corrugated material, e.g. corrugated cardboard.
The present invention provides an improved hanger for apparels made of one, two or more sheets of stacked corrugated cardboards, where the corrugations of the cardboard sheets at the peripheral areas of the hangers are crushed to result in reduced air gaps in the corrugations.
The present invention also provides other useful items made by the above technique, such as display boards used in stores for displaying promotional information, dummy boards used in stores for selling certain items, other items used in product packaging, etc.
An object of the present invention is to provide a more environmentally friendly way of manufacturing hangers for apparels and other items.
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 an item which comprises a stack of one or more shaped sheets of corrugated boards, wherein corrugations of the sheets of corrugated board are crushed in a peripheral area of the boards with reduced air gaps in the corrugations. In one embodiment, the stack includes two or more shaped sheets of corrugated boards stacked together, and an adhesive material (heat-sensitive or pressure-sensitive) is applied between adjacent sheets of corrugated boards. In another embodiment, the stack includes a single shaped sheet of corrugated boards.
In one particular example, the sheets of corrugated boards are shaped into a hanger for apparels.
In another aspect, the present invention provides a method for making an item which includes: (a) stacking two or more sheets of corrugated boards together; (b) applying an adhesive material between adjacent sheets of corrugated boards; (c) applying a pressure to the stacked corrugated boards in band shaped areas containing an outline of the item to crush corrugations in the boards to reduce air gaps in the corrugations in the band shaped areas; (d) sealing the two or more sheets of corrugated boards with the adhesive material; and (e) cutting the boards along the outline to form the item. In one embodiment, the adhesive is a heat-sensitive adhesive, and steps (c) and (d) are performed concurrently using a heated press. In another embodiment, the adhesive is a pressure-sensitive adhesive, and steps (c) and (d) are performed concurrently using a press. In another embodiment, the adhesive is a heat-sensitive or pressure-sensitive adhesive, and steps (c), (d) and (e) are performed concurrently using a cutting die, wherein the cutting die has a cutting edge and a shoulder portion adjacent to the cutting edge, wherein a height of the shoulder portion above an end point of the cutting edge is smaller than a thickness of the stacked boards being cut.
In another aspect, the present invention provides a method for making an item which includes: (a) providing a sheet of corrugated board; (b) applying a pressure to the corrugated board in band shaped areas containing an outline of the item to crush corrugations in the board to reduce air gaps in the corrugations in the band shaped areas; and (c) cutting the board along the outline to form the item.
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.
a) and 2(b) schematically illustrate cross-sectional views of the display pack of
a)-4(c) show examples of the shapes of a hanger for apparel.
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.
Many types of sealer machines may be used to carry out the sealing process. One example 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. 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 package in
The packaging technique according to embodiments of the present invention has many advantages. The packages are more secure and harder to tear from the edge and the center than packages made by conventional methods. They are also aesthetically more appealing 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. These packages according are more environmentally friendly because it uses primarily cardboards which is made of post-consumer recycled materials. The sealing technique is also faster than in conventional techniques. Although the packaging techniques in 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.
In addition to display packs, the technique described above can be used to make other items, such as hangers for apparels, display boards used in stores for displaying promotional information, dummy boards used in stores for selling certain items, other items used in product packaging, etc. These items are generally made of a stack of one, two or more corrugated cardboards (as used in this disclosure, a “stack” can include a single board). The boards are adhered together (in the case of two or more boards) by an adhesive. A peripheral area of the items is crushed by applying a pressure to result in reduced air gaps in the corrugations in those areas.
A hanger for apparel (clothes hanger) is described as an example of the various items that can be made using such techniques.
The corrugated board construction provides sufficient strength for the clothes hanger for its intended use. According to tests conducted by the inventor, a clothes hanger made of a single F flute corrugated board ( 1/32 inches thick) has a holding capacity of approximately 6-7 lbs. A hanger made of a single E flute corrugated board ( 1/16 inches thick) has a holding capacity of approximately 10 lbs. The holding capacities for a hanger made of double F flute boards and double E flute boards are approximately 10 and 26 lbs, respectively. Optionally, a litho laminate may be added on one or both sides of the hanger, which further increase its strength.
Several methods may be used to manufacture the corrugated board clothes hangers. The first method is similar to the method described above for making the display packaging. Corrugated cardboards are cut into the shape of a hanger. Two or more shaped boards are stacked with an adhesive applied between the boards. Alternatively, two or more corrugated boards may be stacked with an adhesive applied between the boards, and the stack is cut into the shape of a hanger. Alternatively, one sheet of corrugated board may be cut into an appropriate shape and folded over to create a stack of two boards having the shape of a hanger, and an adhesive is applied on the inside of the folded sheets. The adhesive may be applied to only a peripheral area of the hanger, or to a peripheral area and selected interior areas, or to the entire area of the hanger. Then, the shaped stack of corrugated boards is pressed around the peripheral area using a press (sometimes also referred to as a sealing press) to crush the corrugations of the boards in that area, in a manner similar to that shown in
In one particular implementation of the first method, the adhesive is a heat-sensitive adhesive and is applied between the boards in the peripheral area. A heated press is used where the platens of the press are heated, and the pressing step activates the heat-sensitive adhesive in the peripheral area to adhere the two or more corrugated boards together. As explained earlier in connection with the packaging embodiments, the crushing of the corrugations reduces the air gaps within the corrugated boards to allow heat to be properly conducted from the sealing press to the adhesive material. Using this implementation, the crushing of the corrugations and the adhering of the two or more boards are accomplished in a single step.
In another implementation of the first method, the adhesive is a pressure-sensitive adhesive, such as a pressure sensitive wax. Such a material is activated and becomes adhesive when an appropriate pressure is applied to it. The pressure-sensitive adhesive is applied between the boards in the peripheral area. The pressing step activates the pressure-sensitive adhesive to adhere the two or more corrugated boards together. This implementation can also accomplish the crushing of the corrugations and the adhering of the two or more boards in a single pressing step. A pressure sensitive adhesive does not require the platens to be heated during pressing, thereby simplifying the structure of the press.
Heat-sensitive and pressure-sensitive adhesives have their relative advantages and disadvantages. The heat-sensitive adhesive requires a heated press while the pressure-sensitive adhesive does not. The pressure-sensitive adhesive, on the other hand, may be more costly to use because a protective sheet (e.g. waxed paper) may be required to protect the adhesive. In addition, some pressure-sensitive adhesives may be too sensitive and cannot be stacked without the protective paper. Thus, a presently preferred embodiment uses a heat-sensitive adhesive, but a pressure-sensitive adhesive is also within the scope of this invention.
Of course, non-heat-sensitive and non-pressure sensitive adhesives may also be used. When such an adhesive is used, the adhesive is applied, and the boards are stacked within an appropriate time period from the application of the adhesive.
A second method of manufacturing the hangers is a variation to the first method, whereby multiple hangers are simultaneously formed from large sheets of corrugated boards. Two or more large sheets of corrugated boards are stacked, with an adhesive applied between the boars. The boards may be, for example, 40 by 48 inches in size. The adhesive may be applied only in areas corresponding to the peripheral areas of the hangers that will be cut from the boards, or it may be applied in the entire area of the hangers to be cut, or the entire area of the boards. Then, the stacked boards are cut along the outlines of multiple hangers, but the cut is an incomplete cut whereby short segments along the outlines are uncut. As a result, the hangers remain in the stack of boards. The stack is transferred to a press, where the platen(s) of the press have the same shape as the outline of the hangers. The peripheral areas of the hangers are pressed using the press to crush the corrugations of the board. If the adhesive is a heat-sensitive or pressure-sensitive adhesive, the pressing step also activates the adhesive (either by pressure or by heat) to adhere the boards together. Afterwards, the formed hangers can be easily pushed out of the boards.
In the second method, the outlines of the hangers on the board may be arranges in a nested fashion so that more hangers can be formed from each stack of boards, as shown in
In the first and second methods, the platens of the press may be made to have a slanted or curved contact surface so that the boards are pressed thinner toward the edge than toward the interior of the hanger. As shown in
A third method of manufacturing the hangers uses a cutting tool with a special cutting die.
For the above two manufacturing methods, the corrugated boards may be pre-applied with the adhesive on their surfaces during manufacturing of the boards. Multiple corrugated boards may also be pre-stacked together with an adhesive applied between the boards. Using such pre-stacked boards, cutting and pressing steps, either as separate steps or as a single combined step, are carried out to form items of desired shapes.
The various manufacturing methods are described above using as examples a stack of two or more corrugated boards to cut the hangers. Hangers may also be made from a single layer of corrugated board. The same manufacturing methods described above can be used, except that no adhesive is needed on the surface of the boards.
In an alternative embodiment, an adhesive material such as a pressure sensitive wax or a heat sensitive adhesive is applied inside the corrugated board between the two flat sheets and the corrugations. This may be accomplished by adding the adhesive during the manufacturing of the corrugated boards. When the peripheral area of the hangers is pressed to crush the corrugations, the adhesive material is activated (either by the pressure or by the heat using a heated press), and the corrugations and the two flat sheets of the board are adhered together in the peripheral areas of the hangers. This further increases the tear-resistance of the hangers.
Corrugates boards typically use an adhesive material to adhere the corrugations to the two flat sheets that sandwich the corrugations. In many currently commercially available corrugated boards, the adhesive material used within the board is a corn starch based adhesive. The inventor of the current invention discovered that such cornstarch-based adhesive can be activated or re-activated (i.e. become sticky again) by heat. One possible explanation of the re-activation mechanism is that moisture which naturally exists in the boards is evaporated under heat, and the evaporated moisture re-activates the adhesive. Thus, such currently available corrugated boards can be used without modification to make single-board hangers using a heated press or heated cutting die, with the result that the existing adhesive material is re-activated during pressing or cutting-pressing to adhere the corrugations and the two flat sheets of the board together in the peripheral areas of the hanger.
The hangers described above are optionally printed with desired colors and patterns to enhance their appeal. The corrugated boards may be directly printed on, or a litho laminate with printed patterns may be adhered to the corrugated boards. As mentioned earlier, the laminate will also increase the holding capacity of the hanger.
It will be apparent to those skilled in the art that various modification and variations can be made in the method and manufactured product 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.
This application is a continuation-in-part of U.S. patent application Ser. No. 11/374,769, filed Mar. 14, 2006, now pending, which is a continuation-in-part of U.S. Provisional Appl. No. 60/711,024, filed Aug. 24, 2005, both of which are herein incorporated by reference in their entirety.
Number | Date | Country | |
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60711024 | Aug 2005 | US |
Number | Date | Country | |
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Parent | 11374769 | Mar 2006 | US |
Child | 12131835 | US |