WO1994027818A1

WO1994027818A1 - Aluminum foil laminate and recycling method

Info

Publication number: WO1994027818A1
Application number: PCT/US1994/005838
Authority: WO
Inventors: Mary C. Speight; Thomas P. Christino; James H. Guida; Walter H. Knox; Gene C. Matthews
Original assignee: Reynolds Metals Company
Priority date: 1993-05-24
Filing date: 1994-05-24
Publication date: 1994-12-08

Abstract

An aluminum foil laminate (10) comprising an aluminum foil layer (1), an adhesive (3) and a film layer (5) is adapted for recycling in aluminum beverage container recycling streams. The organic content of the aluminum foil laminate is controlled to a maximum of 20 % by weight of the overall weight of the laminate to permit safe recycling. The aluminum foil laminate can be used as a substitute for plastic films or film/paper composites in intimate wrap applications or pouches or enclosures for food and non-food items. The aluminum foil laminate permits printing and/or embossing on the foil component to enhance the product enclosure packaging and improve machine performance during foiling, wrapping, sealing and filling operations.

Description

"ALUMINUM FOIL LAMINATE AND RECYCLING METHOD"

Field of the Invention

The present invention is directed to an aluminum foil laminate, and in particular, an aluminum foil laminate used as an intimate wrap or a pouch for food or non-food use which can be recycled into an aluminum can recycling stream.

Background Art

In the prior art, various types of packaging and/or laminated material have been proposed for use as intimate wraps for products such as confections, or pouches for storing products or food items.

For example, confection wrap laminates or layered materials comprising foil-glue-tissue or foil-wax-tissue are employed to wrap chocolate bars, chewing gum, bouillion cubes or other food items. Likewise, pouches for non-food use include a foil layer in conjunction with multiple layers of polyethylene or foil-polyethylene in combination with other organic materials such as glues or the like. Examples of pouches for non-food items include transdermal devices or condom overwraps . Examples of pouches for food items includes snack bags and packages for powder dressings, seasonings and chewing tobacco.

In pouches requiring a good oxygen transmission rate or moisture vapor transmission rate, foil layers are used in combination with polyester and either polyethylene or tissue.

However, none of the types of packaging or laminates mentioned above meet current aluminum can industry standards for recycling. For example, laminates or other containers primarily made of plastics such as polyethylene or polyester or laminates including glue or paper materials such as tissue contain too much organic material for recycling with aluminum cans . Although most aluminum cans include a thin layer of a plastic or organic material thereon, the quantity of plastic in relation to the overall aluminum content of the can is minimal such that addition of these organics to the aluminum can recycling stream is not disruptive.

During the melting of aluminum beverage cans, excessive levels of organic materials in the recycling stock can increase the temperature of the melting furnace due to their inherent fuel value. This increase in temperature can cause oxidation of the aluminum metal thereby negating any advantages of the recycling process . Excessive levels of the organic materials in the aluminum can recycling stock can also create an explosion hazard during furnace operation. In view of the inability of prior art packaging or wrap material to be recycled, a need has developed to provide a packaging material capable of meeting the standards of the packaging industry for either intimate wrap or containers for food or non-food items and being recycled along with aluminum cans in aluminum can recycling methods and apparatus.

Summary of the Invention

It is a first object of the present invention to provide an aluminum foil laminate for use in aluminum can recycling methods and apparatus . It is a further object of the present invention to provide an aluminum foil laminate which can be utilized as a wrap or enclosure for a food or non-food item which may be readily recycled after the food or non-food item has been separated from the aluminum foil laminate. Another object of the present invention is to provide an aluminum foil laminate having a maximum organic content weight percentage to permit recyclability with aluminum beverage cans .

Other objects and advantages of the present invention will become apparent as the description thereof proceeds. In satisfaction of the foregoing objects and advantages, there is provided a product enclosure comprising an aluminum foil laminate having a layer of aluminum foil, a film layer and an adhesive disposed between the aluminum foil and film. The adhesive and film layer comprise organic compounds and have a weight percentage of the total weight of the product enclosure which is less than a maximum organic compound weight percentage allowed when recycling aluminum containing beverage containers in an aluminum recycling stream. Preferably, the product enclosure contains less than 20% by weight of organic components or at least 80% by weight of aluminum foil. More preferably, the maximum organic content ranges between 5 and 15%.

The product enclosure may also include on one or both surfaces thereof a printed layer of ink for advertisement purposes or the like or a sealant layer for pouch manufacture.

The film layer of the aluminum foil laminate can include polypropylene, polyethylene, polyester and vinyl, alone or in combination in multiple layers. The film layer may be clear or pigmented. The adhesive should be of sufficient weight to bond the film to the foil and can include vinyl, polyester, polyethylene or wax-based adhesives, either overall applied or pattern-applied. The foil component may be of any known aluminum alloy capable of being made into a foil material and can include any temper or any foil gauge. The inventive aluminum foil laminate can be used in a method of recycling aluminum beverage wherein beverage containers are melted down to recover aluminum therein. In the inventive method, a product enclosure is provided comprising an aluminum foil laminate including a layer of aluminum foil, a film layer and an adhesive disposed therebetween. The film layer and adhesive comprise organic compounds having a weight percentage of the total weight of the aluminum foil laminate being equal to less than the organic content of aluminum containing beverage containers during recycling. Preferably, the organic content is limited to -20% by weight and more preferably, less than 10% by weight. The product enclosure can be readily recycled in an aluminum beverage container recycling stream for aluminum recovery after a product has been removed from the product enclosure.

Brief Description of the Drawings

Reference is now made to the drawings accompanying the invention wherein:

Figure 1 is a sectional view illustrating a first embodiment of the inventive aluminum foil laminate;

Figure 2 is a cross sectional view of a second embodiment of the aluminum foil laminate;

Figure 3 is a flow diagram depicting the use of the inventive aluminum foil laminate in an aluminum beverage can recycling stream.

Description of the Preferred Embodiments

The present invention provides an aluminum foil laminate capable of being recycled in aluminum beverage container recycling streams. In addition, and besides providing recyclability, the inventive aluminum foil laminate provides unique characteristics not attributable to prior art unsupported foil or film structure. For example, using the inventive aluminum foil laminate provides improved machine performance during wrapping and/or sealing processes. In addition, the aluminum foil laminate according to the present invention provides increased barrier protection from moisture and/or oxygen and improved external appearance over unsupported foil structures .

For example, prior art two piece intimate wrap/sleeve packages utilizing a film/film combination lack dead fold and are not recyclable. In contrast, the inventive aluminum foil laminate has excellent dead fold, i.e., will fold flat, and requires minimum sealing, especially for cold seal applications. The foil surface of the inventive laminate can be used to enhance packaging of the particular article or food item, e.g., embossed lettering or the like. These advantages are not attainable using prior art plastic film laminate or two piece wrap using a film and paper sleeve.

In the inventive aluminum foil laminate, the organic content is limited, in the broadest embodiment, to a maximum of 20% of the total weight of the laminate, either as a unit value or in a particular product shape such as pouch or the like. It should be understood that the organic content of the non-aluminum foil components of the inventive laminate include any non- metallic substance or compound that contains the element carbon with the exception of carbon dioxide and various carbonates . It is important to limit the organic content of the aluminum foil laminate to avoid the drawbacks described above during aluminum beverage container recycling.

With reference now to Figure 1, a first embodiment of the inventive aluminum foil laminate is generally designated by the reference numeral 10 and is seen to include a foil layer 1, an adhesive 3 and a film layer 5. The foil material may be any aluminum alloy having any known temper and gauge. For example, an AA1100 alloy having an H19 temper with a gauge thickness of between 0.006 and 0.0004 inches can be selected.

The adhesive film 3 should be of sufficient weight to bond the film layer 5 to the foil layer 1. The adhesive 3, although shown continuously applied between the foil 1 and film member 5, may also be pattern applied. Typical adhesives include vinyl, polyester, polyurethane or wax-based types.

The film layer 5 can be a variety of chemistries ranging from polypropylene to polyethylene to polyester and vinyl. The film layers 5 can be clear or pigmented. The gauge of the film layer can vary dependent on the laminate end use. For example, pouches requiring good OTR and MVTR may require a heavier gauge film layer. In another embodiment and with reference to Figure 2, an aluminum foil laminate is generally designated by the reference numeral 20 and is seen to include the foil, adhesive, and film layer depicted in Figure 1 with additional layers 7 and 9. Layer 7 disposed on the exposed surface of the foil 1 can be a coating or printed pattern. The printing can include flexo, litho or gravure applications of typical ink and coating systems include water-based types, solvent, nitrocellulose, vinyl, polyester or acrylic. Alternatively, a coating layer can be applied as layer 7 as a sealable layer to facilitate enclosure manufacture. These coating systems include pressure-sensitive types, cold or heat sealed types, polyamids and vinyl. The aluminum foil laminate 20 can also have a layer

9 adjacent the film layer 5. The layer 9 can be any one of the type described above for layer 7. Furthermore, and although each layer of the organic containing layers has been described above as a single layer, multiple layer applications may also be utilized.

It should be understood that the disclosed layers 3, 5, 7 and 9 as well as the additional layers constitute the organic component of the inventive aluminum foil laminate. That is, the total weight percentage of the layers comprising an organic compound or material should not exceed 20% by weight of the overall laminate structure or unit value.

Table 1 hereinbelow lists unit weights of the aluminum foil and other components for a given foil gauge. The unit weights of the foil and other organic components are based on a pound per ream unit value wherein a ream is equivalent to 3,000 square feet of laminate. As can be seen from Table 1, the organic component weight percentage is less than about 20% of the total unit weight. Table 1 also exemplifies a range of preferred foil gauges for the inventive aluminum foil laminate. It should be understood that the thicknesses of the organic component layers such as 3, 5, 7 and 9 may vary providing the total organic weight percentage is kept at below 20% of the total weight. For example, for a .0005 inch gauge foil, 18 or 23 gauge polyester may be utilized therewith. For a .0008 inch foil, 18, 23 or 32 gauge polyester can be used. TABLE I

Foil Gauge Foil Weight #/R* Other Organic Components #/R*

.0015" 63.1 15.8

.001" 42.0 10.5

.0008" 33.8 8.4

.0006" 25.3 6.3

.0005" 21.1 5.3

.0004" 17.0 4.2

* #/R = Pounds/3000 sq. ft. of laminate

In a more preferred embodiment, the inventive aluminum foil laminate can be used as intimate wrap for food items such as chocolate bars, confections, chewing gum or bullion cubes. In this embodiment, a foil gauge can range between .0004 and .0015 inches which may include printing on the foil side. A sealing coating on either side of the laminate may also be used. In this embodiment, the weight percentage of the organic content is preferably limited to a 15% maximum with a preferred range of 5 to 15%. This type of intimate wrap can be used to substitute for prior art foil-glue-tissue or foil-wax-tissue wrappings.

The aluminum foil laminate can also be used as an enclosure or pouch for non-food items. Preferably, the foil gauge for these pouches ranges between .0008 inches and .0015 inches, has an H19 temper and printing thereon. Alternatively, a foil gauge between .001 and .002 inches having an 0-temper with printing thereon can be utilized. In either case, a sealant coating layer can be added to either the foil or film side. For these types of pouches, a preferred range of maximum organic content is 5 to 15%. Exemplary uses include condom overwrap or packaging for transdermal or surgical devices such as blades. These types, of inventive pouches are adaptable for uses requiring only moderate oxygen transmission rate and moisture vapor transmission rate.

In another use, the inventive aluminum foil laminate can be utilized as a pouch for food items. Preferably, the foil gauge ranges between .0015 to .002 inches for this application. The film layer 5 is preferably a one half mil sealable film which is thermally mounted to the aluminum foil. The preferred range of maximum organic content is 15 to 20%.

In these types of applications, the inventive aluminum foil laminate can be used as a substitute for current po lye s te r / po lyethyl ene / f o i l pou che s or polyester/tissue/foil/tissue films. Exemplary uses include snack bags and packages for powder dressings, seasonings and chewing tobacco. The inventive aluminum foil laminate is also advantageous in that it can be run on most existing machine setups for sheeting, folding, or printing or form/seal/fill machines with little or no modifications. Thus, the recyclable aluminum foil laminate can be readily produced with little or no capital expenditures on existing processing lines.

With reference now to Figure 3, a method of using the inventive aluminum foil laminate in an aluminum beverage can recycling stream is generally designated by the reference numeral 40. In a first step of the flow diagram, the aluminum foil laminate is used to wrap or enclose a given product. Once the aluminum product is covered by the aluminum foil laminate, the product may be distributed through normal channels of distribution for its ultimate use. Once a user of the product obtains the aluminum foil laminate covered product, the aluminum foil laminate is removed so that the product can be used or consumed. The removed aluminum foil laminate is then recycled to the aluminum beverage can recycling stream along with aluminum beverage cans to produce aluminum and by-products of the recycling stream. As described above, the aluminum foil laminate can be used as intimate wrap where the product is eaten by the consumer. ' Alternatively, the laminate may be used in pouch form to enclose a product, e.g., surgical blades, which can be later used after which the packaging can be recycled.

As such, an invention has been disclosed in terms of preferred embodiments thereof which fulfills each and every one of the objects of the present invention as set forth hereinabove and provides a new improved aluminum foil laminate for recycling in aluminum beverage container recycling streams.

Of course, various changes, modifications and alterations from the teachings of the present invention may be contemplated by those skilled in the art without departing from the intended spirit and scope thereof. Accordingly, it is intended that the present invention only be limited by the terms of the appended claims.

Claims

What is Claimed Is:

1. In a method of recycling aluminum beverage containers wherein said aluminum containing beverage containers include at least one layer comprising organic compounds, each said aluminum containing beverage container have an organic content less than 20% by weight, said aluminum containing beverage containers being melted to recover aluminum therein, the improvement comprising: a) providing a product enclosure comprising an aluminum foil laminate including a layer of aluminum foil, a film layer and an adhesive disposed between said aluminum foil and said film layer, said adhesive and said film layer comprising organic compounds having a weight percentage of the total weight of said aluminum foil laminate equal to or less than the weight percentage of the organic content in said aluminum containing beverage containers; and b) recycling said product enclosure in an aluminum beverage container recycling stream to recover aluminum therefrom after a product has been removed from said product enclosure.

2. The method of claim 1 wherein said aluminum foil is provided having a thickness range between .0004 inches and .0015 inches.

3. The method of claim 1 wherein said aluminum foil laminate is provided with an additional layer adjacent one or both of said film layer and said aluminum foil layer, said additional layer selected from the group consisting of an ink, polyester, vinyl, acrylic, polyamid, wax, gel lacquer, and nitrocellulose and wherein the weight percentage of said film layer, said adhesive and said additional layer is less than 20% of the total weight percentage of said aluminum foil laminate.

4. The method of claim 1 wherein said adhesive is applied between said aluminum foil and said film layer in a pattern or as a continuous layer therebetween.

5. The method of claim 1 wherein said product enclosure is provided as a sheet for intimately wrapping food items.

6. The method of claim 1 wherein said product enclosure is provided as a pouch for food items wherein said film layer is sealable to form said pouch.

7. The method of claim 5 wherein said sheet is provided with a foil gauge ranging between .0004 and .0015 inches.

8. The method of claim 6 wherein said pouch is provided with a foil gauge ranging between .0015 and .002 inches.

9. The method of claim 1 wherein said product enclosure is provided as a pouch for non-food items with a foil gauge ranging between .0008 and .0015 inches.

10. A recyclable aluminum foil laminate comprising: a)an aluminum foil layer having first and second surfaces; b) an adhesive layer adjacent to said first surface; and c) a film layer adjacent said adhesive layer; d) wherein said adhesive layer and said film layer comprise organic compounds and the weight percentage of said organic compounds based on the total weight of said recyclable aluminum foil laminate is less than 20% and said aluminum foil laminate is recyclable so that said aluminum foil laminate can be combined with aluminum containing beverages in a recycling stream without adverse affect from the organic compounds.

11. The recyclable aluminum foil laminate of claim 10 wherein said aluminum foil laminate is in sheet form for use as intimate wrap of food items .

12. The recyclable aluminum foil laminate of claim 10 wherein said aluminum foil laminate is in pouch form for use as a food or non-food item container.

13. The recyclable aluminum foil laminate of claim 10 wherein said weight percentage of said organic compounds is less than 10% of the total weight of said aluminum foil laminate.

14. The recyclable aluminum foil laminate of claim 10 wherein said foil layer ranges in thickness between .0004 and .0015 inches.

15. The recyclable aluminum foil laminate of claim 10 wherein said organic compounds of said adhesive layer are selected from the group consisting of polyurethanes, polyesters, vinyls and wax-based adhesives.

16. The recyclable aluminum foil laminate of claim 10 wherein said organic compounds of said film layer are selected from the group consisting of polypropylenes, polyethylenes, polyesters and vinyls.

17. The recyclable aluminum foil laminate of claim 10 further comprising an additional layer adjacent one or both of said film layer and said aluminum foil layer, said additional layer selected from the group consisting of ink, polyester, vinyl, acrylic, polyamid, wax, gel lacquer, and nitrocellulose and wherein the weight percentage of said film layer, said adhesive and said additional layer is less than 20% of the total weight percentage of said aluminum foil laminate.