Patent Application
20080032007
Referring to the drawings, like numerals represent like elements throughout the several views. The present invention is applicable to coffee containers of any shape, such that the actual shape of the container forms no part of the present invention. However, in order to describe the invention, a typical container system 10 is described herein and shown in
In container system 10, main body 14 includes the four surrounding side walls, a bottom wall, a handle 18 formed in one (rear) side wall, and a top 20 forming a central and circular opening (to which a separate removable lid 16 is removably attached). It will be appreciated that the differently identified parts of main body 14 described above are all integrally formed in a single blow molding operation, with all of main body 14 formed of a laminate wall of plastics materials as shown by the cross section thereof depicted in
It will also be appreciated that roast coffee 12 naturally releases aromatic off gases and oils after container system 10 is filled with roast coffee 12, so that such aromatic ingredients will come into contact with main body 14 during shipping and storage as well as after container system 10 is opened by the consumer. Such aroma ingredients are beneficial to the taste of the liquid coffee drink produced by the roast coffee, so that reducing as much as possible the loss of such aroma ingredients from the roast coffee is desired. One source of loss of such aroma ingredients in prior art containers was due to absorption by the plastics materials of the main body, as ready evident by the aroma left when the container is emptied.
In order to prevent the absorption, or any substantial absorption of aroma ingredients by main body 14, main body 14 of the present invention is formed as a hollow laminate structure having integral containing walls made of an outer layer 22a and an inner barrier layer 24a as shown in
As known in the art, EVOH serves as a good barrier layer for plastic laminates where O2 absorption is to be prevented, but it is also known that EVOH is sensitive to water or moisture. For that reason, such EVOH layers have been used in many containers including those for roast coffee, but only in the middle of such plastic laminates due to the sensitivity of EVOH to moisture. However, in accordance with the present invention, an EVOH layer has also been found to provide against absorption of aromatic ingredients, including both off gases and oils. Thus, in accordance with the preferred embodiment of the present invention depicted in
As outer layer 22a forms the structural component of main body 14, outer layer 22a has a thickness of between about 30-70 mils in accordance with the preferred embodiment. Preferably, outer layer 22a is HDPE and comprises about 96.75% of the thickness; and is in the preferred range of 40-60 mils and is most preferably about 50 mils. Outer layer 24a is followed by tie layer 28a which comprises about 1.75% of the thickness. Finally, the inner layer 24a is EVOH which comprises about 1.5% of the thickness. Thus, the preferred container 14 can have an overall wall thickness as desired but within about the above noted ranges.
In an alternative embodiment depicted in
In another alternative preferred embodiment depicted in
It will be appreciated that adherence layer 32 is only needed where the open top to which the foil membrane is to be attached is formed by an out-turned upper rim or flange 36 of main body 14 as depicted in
An example of the benefit of using an EVOH inner layer is described below. Two sets of round test bottles were prepared. These bottles weighed about 18 grams, were about 23 mils thick, and had a volume of about 400 ml. One set of bottles was made of HDPE having a density of 0.950 grams/cc, and the other set was made of HDPE having the same density of 0.950 grams/cc but additionally with an inner layer of EVOH which was about 3% of the wall thickness. Bottles of each type were flushed with N2 to mimic actual packaging conditions and then filled with fresh ORIGINAL MAXWELL HOUSE blend roast and ground coffee. Each bottle was sealed with a screw cap and parafilm, and placed in a constant 40° C. oven. The bottles were tested after one week of storage by standard GC/MS procedures to determine the absorbed amounts of a standard profile of coffee aromas. The results are shown below:
From the above testing, it will be appreciated that the bottles with the described EVOH barrier layer absorbed only about 16% as much as the PE layer, which is defined herein as the Aroma Retention Effectiveness (ARE) of the bottle composition. It will thus be appreciated that the present invention is designed to provide an ARE for a container of less than about 30%, and preferably below about 20% such as with the above described test container.
It will also be appreciated that while structural layer 22 has been depicted as a single HDPE layer, structural layer 22 could be formed of two or more layers of plastics materials having purposes in addition to forming the structural body 14. For example, there could be a thinner pigmented layer followed by a natural HDPE layer.
Consistent with the above description of container system 10, it will be appreciated that the present invention also includes a method for reducing the loss of coffee aroma ingredients from a roast coffee. This method begins with the step of forming main body 14 of container unit 10 with a main plastic outer layer such as layer 22a which would otherwise absorb some of the coffee aroma ingredients. This forming step then includes the step of lining an inside of the outer layer with a barrier material layer such as inner barrier layer 24a, so that the barrier material layer is closely adjacent the roast coffee and prevents coffee aroma ingredients from being absorbed by the outer layer which is lined thereby. As noted above, this step can be performed in a blow-molding process, and include a tie layer such as tie layer 28 between the main plastic layer and the inner barrier layer. The main body is thus provided with an ARE of less than about 30%. Finally, the roast coffee is delivered into and stored in the main body.
In this method, the barrier material layer is preferably formed of EVOH and the roast coffee is stored in contact with the EVOH layer. Alternatively, there may be a step of providing the barrier material layer with a thin adherence layer as shown in
In the preferred embodiment of the method, the structural plastic layer is formed to have a thickness of between about 30-70 mils, the EVOH layer is formed to have a thickness of between about 0.3-2.0 mils, and the thin adherence layer is formed to have a thickness of between about 0.5-1.5 mils. Preferably, the thin adherence layer, if present, is formed of HDPE to have a thickness of about 1 mil.
Also in a preferred embodiment of the method, the outside plastic layer is formed of HDPE. Alternatively, the outside plastic layer is formed as a sandwich of two or more polymer layers, such as a sandwich of HDPE and a regrind resin.
Although the present invention has been described with respect to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that variations and modifications can be effected within the scope and spirit of the invention.
