Patent Application
20060029697
The present invention relates to wraps and bags. Specifically, this invention relates to wraps and bags having protrusions that exhibit adhesive like qualities extending from a surface of the wrap or bag.
In today's food industry, plastic films as well as metal foils are extensively used to wrap and package food products. The plastic film and the metal foil can either directly wrap the food product or they can be used as a top or a cover to the bowl or plate in which the food product is contained. Unless an adhesive is applied on one or more sides of the plastic film or metal foil, it is usually difficult for the film or foil to adhere (i.e. attach or cling) to the different types of surfaces that might be used in the bowls or plates that are used to contain the food product. For instance, Reynolds Plastic Wrap is made from a polyvinyl chloride based plastic. Even though Reynolds Plastic Wrap easily adheres to a surface such as glass, it does not adhere very well to surfaces made from wood or some plastics. As stated above, in order to increase the ability of the plastic film or foil to adhere to a particular surface, such as wood or plastic, some products are comprised of a high density polyethylene film with an adhesive on one side. One drawback of using such an adhesive, however, is that the adhesive can be transferred to the actual food product or it can be transferred to the bowl or plate in which the food product is contained.
Metal foils, such as those made from aluminum, generally do not have any adherence (i.e. cling) properties. In other words, metal foils that are currently used in the industry do not adhere to most surfaces. Accordingly, when a metal foil is used either as a food wrap or as a cover to a bowl or plate the metal foil is typically crimped around the food product or the food container in order to secure the metal foil to the food product or to the food container.
Plastic storage bags typically used in the food industry have a tongue and groove recloseable zipper with or without a slider assist. Some cooking and storage bags, however, which rely on a twist tie or some other closure mechanism that is a separate and distinct piece from the cooking or storage bag in order to seal or close the bag. One drawback to these closure mechanisms is that they can fail periodically. For instance, the recloseable zipper might not be closed sufficiently to prevent the food contents from escaping between the two flanges that typically comprises a recloseable zipper. If a twist tie is used on the bag, then the twist tie could accidentally be removed thereby allowing the contents of the cooking or storage bag to escape from the bag.
Trash bags and trash liners are similar to metal foil in that they generally do not adhere to most surfaces. In other words, a typical trash bag or trash liner does not adhere to the waste container in which it is placed. Accordingly, a typical trash bag or trash liner is susceptible to unwanted movement when an item is placed in the waste container. For example, if a heavy item is dropped into the waster container there is a possibility that the trash bag or liner would cave in (i.e. collapse) on itself.
Therefore, there exists a need for a bag or wrap having the ability to adhere to a variety of surfaces without having to rely on traditional adhesives to provide the adhesive properties.
This invention is a response to his need by disclosing a food wrap having hair like protrusions extending substantially perpendicular to a surface of the food wrap thereby enabling the food wrap to attach or cling to other surfaces.
This invention also discloses a bag having hair like protrusions extending substantially perpendicular to a surface of the bag thereby enabling the bag to attach or cling to other surfaces.
This invention also discloses a trash bag having hair like protrusions extending substantially perpendicular to a surface of the trash bag thereby enabling the trash bag to attach or cling to other surfaces.
This invention also discloses a method of preparing a wrap or bag having hair like protrusion extending substantially perpendicular to a surface of the wrap or bag thereby enabling the wrap or bag to attach or cling to other surfaces. The method includes using electron beam lithography or laser ablation to prepare a positive surface relief on a master substrate that is suitable for electroforming, electroforming a layer of metal onto a surface of the master substrate to produce a first metal layer having a negative image of the master substrate, affixing the first metal layer onto a first roll or belt, and advancing the wrap or bag through a nip that is located between the first roll or belt and a second roll or belt.
This invention also discloses a method of preparing a wrap or bag having hair like protrusion extending substantially perpendicular to a surface of the wrap or bag thereby enabling the wrap or bag to attach or cling to other surfaces. The method includes using electron beam lithography or laser ablation to prepare a negative surface relief on a master substrate that is suitable for electroforming, electroforming a layer of metal onto a surface of the master substrate to produce a first metal layer having a positive image of the master substrate, removing the first metal layer from the master substrate and electroforming a layer of metal onto a surface of the first metal layer to produce a second metal layer having a negative image of the first metal layer, affixing the second metal layer onto a first roll or belt, and advancing the wrap or bag through a nip that is located between the first roll or belt and a second roll or belt.
The accompanying figure and the description that follows set forth this invention in its preferred embodiments. However, it is contemplated that persons generally familiar with bags and wraps will be able to apply the novel characteristics of the structures and methods illustrated and described herein in other contexts by modification of certain details. Accordingly, the figures and description are not to be taken as restrictive on the scope of this invention, but are to be understood as broad and general teachings. When referring to any numerical range of values, such ranges are understood to include each and every number and/or fraction between the stated range minimum and maximum. Finally, for purposes of the description hereinafter, the terms “upper”, “lower”, “right”, “left”, “vertical”, “horizontal”, “top”, “bottom”, and derivatives thereof shall relate to the invention, as it is oriented in the drawing figures.
This invention discloses using a surface topography similar to what is observed on the feet of the gecko family, which can be applied to a film, wrap, or bag in order to impart adhesive like qualities to the surface of the film, wrap, or bag. This invention also discloses a method of manufacturing such a surface topography on the film, wrap, or bag.
In another embodiment, the food wrap 2 has an embossable layer 8. As depicted in
In one embodiment, the thickness of the film or foil used in the food wrap 2 would range from about 0.000508 cm (0.0002 in) to about 0.00508 cm (0.002 in). It is noted, however, that the thickness of the film or foil used in the food wrap 2 could also be thicker or thinner. For instance, the thickness of the film or foil used in the food wrap 2 could range from about 0.000508 cm (0.0002 in) to about 0.0254 cm (0.010 in).
In another embodiment, the protrusions 4 can also be applied to the recloseable storage or cooking bag to supplement the closure mechanism in order to increase the bag's ability to remain sealed.
In one embodiment, the protrusions 4 are located on the interior surface 28 of each polymeric panel 26 above or below the recloseable zipper (i.e. closure mechanism) 12. In this particular embodiment, the protrusions 4 would supplement the recloseable zipper 12 in maintaining a sealed or closed bag 10 when the male and female profiles 20, 22 of the first and second skirts 14, 16 are interlocked since the protrusions 4 would adhere to one another when they come into contact. In another embedment, the protrusions 4 would once again be located either above or below the recloseable zipper 12. Unlike the previous embodiment, however, the protrusions 4 in this embodiment would be located on the interior surface 28 of only one polymeric panel 26.
In yet another embodiment, the recloseable plastic storage bag 10 does not have a recloseable zipper 12 (closure mechanism). Rather, the recloseable plastic storage bag 10 is sealed by protrusions 4 that extend from the interior surface 28 of each polymeric panel or film 26. In other words, in this particular embodiment the protrusions 4 replace the recloseable zipper 12 as the mechanism to close the recloseable plastic storage bag 10. Accordingly, the protrusions 4 would extend along the length of the recloseable bag 10 while extending substantially perpendicularly from the interior surface 28 of each polymeric panel. In another embodiment, the protrusions 4 would extend from the interior surface 28 of only one polymeric panel 26.
If the material used to manufacture the recloseable storage or cooking bag is a plastic film or a plastic coated paper, then the plastic can be manufactured from polyethylene, polypropylene, polystyrene, polyvinyl chloride, ethylene copolymers, polyester, styrene butadiene copolymer, or any material suitable for plastic films.
In one embodiment, the thickness of the film or used in the recloseable storage or cooking bag would range from about 0.000508 cm (0.0002 in) to about 0.00508 cm (0.002 in). It is noted, however, that the thickness of the film or foil used in the storage or cooking bag could also be thicker or thinner. For instance, the thickness of the film or foil used in the recloseable storage or cooking bag could range from about 0.000508 cm (0.0002 in) to about 0.0254 cm (0.010 in).
As can be seen from
If the material used to manufacture the trash bag is a plastic film, then the plastic can be manufactured from polyethylene, polypropylene, polystyrene, polyvinyl chloride, ethylene copolymers, polyester, styrene butadiene copolymer, or any material suitable for plastic films.
In one embodiment, the thickness of the film used in the trash bag or trashcan liner 32 would range from about 0.000508 cm (0.0002 in) to about 0.00508 cm (0.002 in). It is noted, however, that the thickness of the film used in the trash bag or trashcan liner 32 could also be thicker or thinner. For instance, the thickness of the film or foil used in the recloseable storage or cooking bag could range from about 0.000508 cm (0.0002 in) to about 0.0254 cm (0.010 in).
By using embossing techniques similar to the techniques that are currently used to produce holograms in substrates, the surface topography of a plastic or metal substrate may be altered to contain the hair like protrusions that are disclosed in this invention. The major difference between the technique that is used to produce holograms and the technique that is used to create the protrusions lies in the preparation of the master shim. In the method that is disclosed in this invention, a positive or negative image of the desired shape as well as the density of the hair like protrusions are generated into a master substrate, which is a substrate that is suitable for electroforming, using electron beam lithography or laser ablation. In one embodiment, the master substrate that is used is manufactured from silicon, tungsten carbide, or silicon nitride. The dimensions of the original master substrate could be several square centimeters and can be replicated by techniques known in the art of holography to obtain a larger square area thereby allowing the user to produce an area having the hair like protrusions in the dimensions that are required for a particular product. In other words, Techniques common to the reproduction of holographic images can be used to replicate the original pattern to provide a larger surface area of the desired pattern on the original positive or negative master substrate. For clarity, the surface of a negative master substrate is comprised of “pillars” that are in the shape and the density of the hair like protrusions that are to be imparted onto the surface of the panel or film. In contrast, the surface of a positive master substrate is comprised of holes that are in the shape and the density of the hair like protrusions that are to be transferred onto the surface of the panel or film. In other words, these holes could be cylindrical, conical, rectangular, pentagonal, hexagonal, or octagonal in shape.
A first metal layer is then electroformed onto the positive or negative master substrate using techniques that are well known in the art. In one embodiment, the metal that is used in the first metal layer is nickel. If the original master substrate is a negative image of the hair like protrusions, then the first metal layer that is applied over the negative master substrate would be a positive image of the hair like protrusions. The first metal layer having the positive image of the hair like protrusions is then peeled away or removed from the negative master substrate and a second metal layer is electroformed onto the first metal layer. In one embodiment, the metal that is used in the second metal layer is nickel. Accordingly, the second metal layer is a negative image of the first metal layer. In other words, the second metal layer is a reproduction of the original negative master substrate. This second metal layer is then affixed to an embossing roll or belt as the master shim in order to impart or transfer the hair like protrusions onto the surface of the film or panel by passing the film or panel through an embossing nip that is located between the embossing roll and a second roll.
If the original master substrate was a positive image of the hair like protrusions, then the first metal layer that is applied over the original positive master would be a negative image of the hair like protrusions. In one embodiment, the metal that is used in the first metal layer is nickel. This first metal layer, which is a negative image of the original positive master, would then be affixed to an embossing roll or belt as the master shim so that the hair like protrusions can be transferred onto the film or panel by passing the film or panel through an embossing nip that is located between the embossing roll and a second roll.
It is noted that each electroformed metal layer is considered a generation. Accordingly, subsequent generations may be electroformed from previous generations. The number of generations created prior the final generation, which is used as the shim or tooling to impart the hair like protrusions on the film or panel, is not meant to be limiting so long as the final generation is a negative image of the hair like protrusions. In other words, the metal layer that is used as the final generation will have hair like protrusions (i.e. pillars) extending substantially perpendicularly from a surface of the metal layer thereby allowing this metal layer to transfer a positive image of the hair like protrusions onto the plastic or metal substrates.
Having described the presently preferred embodiments, it is to be understood that the invention may be otherwise embodied within the scope of the appended claims.
This application claims the benefit of U.S. Provisional Application Ser. No. 60/599,470, filed on Aug. 5, 2004, the disclosure of which is fully incorporated by reference herein.
| Number | Date | Country | |
|---|---|---|---|
| 60599470 | Aug 2004 | US |
