Patent Application
20230044870
Various embodiments disclosed herein relate generally to a bottle having a small volume, or a high ratio of surface area to volume, with a high resistance to CO2 transmission.
Carbonated beverages are frequently packaged in plastic bottles, such as polyethylene terephthalate bottles. Over time, carbon dioxide escapes through the wall of the bottle, rendering the product undesirable to the consumer and reducing its shelf life (“Kodapak PET Thermoplastic Polyester and Shelf Life of Carbonated Beverages,” Eastman, FIGS. 1-4, 7, and 8; see: http://www.burchamintl.com/papers/petpapers/Eastman %20-%20Gas %20Permeability%20of%20PET.pdf; Coriolani et al., Italian Journal of Food Science, January 2007, pp. 453-455). Other gasses such as hydrogen or nitrogen, nutrients, etc. may also degrade and/or escape. Bottles containing larger volumes of a carbonated beverage ranging from 473 mL to 2000 mL or greater maintain shelf life in a polyethylene terephthalate bottles that are typically measured in months (Licciardello et al., Italian Journal of Food Science, January 2011, pp. 115-117). However, bottles containing small volumes of a carbonated beverage ranging from 300 mL or less, 250 mL or less, 200 mL or less, 150 mL or less, or 100 mL or less, or 74 mL or less, or 60 mL or less or 37 mL or less maintain a shelf life frequently measured in weeks. While the shelf life of a carbonated beverage in a small bottle may be extended by increasing the thickness of the wall of the bottle, the extended shelf life gained from this increase in bottle wall thickness is insignificant and has many drawbacks and therefore, impractical for CPG (consumer product goods) commercialization of carbonated beverages. The increased costs associated with production of thicker bottles is economically undesirable. Most importantly, reducing the carbon footprint and environmental impact associated with production of thinner wall plastic bottles, a massive benefit of this invention, results in using lighter weight and less plastic, consequently, meeting local, national and global sustainability initiatives (Alfarisi et al., ICCSET 2018, October 25-26, Kudus, Indonesia).
Furthermore, increasing the thickness of the wall of the bottle has very little impact on maintaining and containing for example, carbon dioxide or hydrogen gas inside lower volume capacity carbonated plastic bottles.
It is important to meet consumer expectations for sustainability, convenience, flavor and functionality with, “Innovation that exceeds all expectation!”
In view of the foregoing, it is desirable to develop improved bottles for packaging small volumes of carbonated beverages that overcome the aforementioned challenges. More specifically, it is desirable to develop improved bottles which significantly extend shelf life of carbonated beverages by reducing permeation of carbon dioxide, hydrogen, nitrogen and/or other gases, and also maintaining nutrient potency, flavor and function etc. through the bottle walls.
In light of the need discussed above for a high resistance to carbon dioxide, hydrogen, and nitrogen gas transmission, and to prevent degradation of nutrients and flavors, in bottles having a high ratio of surface area to volume, a brief summary of various embodiments disclosed herein is presented. Some simplifications and omissions may be made in the following summary, which is intended to highlight and introduce some aspects of the various disclosed embodiments, but not to limit the scope of the invention. Detailed descriptions of embodiments adequate to allow those of ordinary skill in the art to make and use the inventive concepts will follow in later sections.
Various embodiments disclosed herein relate to a blow-molded bottle for a carbonated beverage with a standard fill capacity of 30 mL to 300 mL, 30 mL to 120 mL, 45 mL to 250 mL, 60 mL to 200 mL, 75 mL to 150 mL, or 75 mL to 105 mL. In certain embodiments, the bottle includes a mouth; a cylindrical side wall; an optional shoulder connecting the mouth to the side wall, and a bottom. The bottom may have a punt, or an indentation or dimple. In various embodiments, the bottle is blow-molded from a laminated preform weighing from 12 to 17 grams, from 13 to 16 grams, from 14 to 15.5 grams, or about 15 grams. In other embodiments, the bottle is blow-molded from a laminated preform weighing from about 4 to 17 grams. The laminated preform includes:
In various embodiments, the blow-molded bottle has superior resistance to carbon dioxide, hydrogen, and nitrogen transmission, and prevents the degradation of nutrients and flavors, when compared to a comparative bottle with a standard fill capacity of 75 mL to 105 mL, where the comparative bottle is blow-molded from a non-laminated preform including a single polyethylene terephthalate layer, where the non-laminated preform has a weight of 13 grams to 22 grams, from 14.5 to 21 grams, 14.5 to 18 grams, from 15 to 18 grams, from 15 to 17.5 grams, or 13 to 16 grams.
In various embodiments, the blow-molded bottle has superior resistance to carbon dioxide, hydrogen, and nitrogen transmission, and prevents the degradation of nutrients and flavors, when compared to a comparative bottle with a standard fill capacity of 75 mL to 105 mL, where:
Various embodiments disclosed herein relate to a bottle for a carbonated beverage with a standard fill capacity of 30 mL, to 120 mL, blow-molded from a laminated preform weighing from about 4 to 17 grams, where the laminated preform includes an outer layer and an inner layer formed from polyethylene terephthalate, and an intermediate gas barrier layer between the outer and inner layers. The intermediate gas barrier layer is formed from a polyamide including:
In various embodiments, the dicarboxylic acid component of the polyamide comprises adipic acid in combination with an isomer of benzenedicarboxylic acid. The dicarboxylic acid component may be 40% to 100%, 50% to 90%, 60% to 80%, or about 70% adipic acid, and from 0% to 60%, 10% to 50%, 20% to 40%, or about 30% of terephthalic acid, isophthalic acid, or a mixture thereof. The dicarboxylic acid component may be 100% adipic acid.
In various embodiments, the polyamide is a polymer having formula I, where n is an integer:
Various embodiments disclosed herein relate to a method of making a blow-molded bottle for a carbonated beverage, by:
The method of making a blow-molded bottle may also include a step of producing the laminated preform, by:
Various embodiments disclosed herein relate to storage of a carbonated beverage for an extended period of time, e.g., up to three months, up to four months, up to six months, or up to 12 months, without loss of carbonation in a blow-molded bottle with a standard fill capacity of 37.5 mL to 105 mL. The carbonated beverage may be stored in a bottle blow-molded from a laminated preform including:
It should be apparent that, in this manner, various exemplary embodiments enable production and use of a bottle combining a small volume, or a high ratio of surface area to volume, a high resistance to carbon dioxide, hydrogen, and nitrogen transmission as well as being able to prevent the degradation of nutrients and flavors.
In order to better understand various exemplary embodiments, ence is made to the accompanying drawings, wherein:
Referring now to the drawings, in which like numerals refer to like components or steps, there are disclosed broad aspects of various exemplary embodiments.
Bottles with a polymeric wall made of a polyester monolayer, e.g., a monolayer of polyalkylene terephthalate, such as polyethylene terephthalate, are frequently used to store carbonated beverages. At an initial CO2 level of 4.2 cc/mL beverage, a 300 mL bottle manufactured from a polyethylene terephthalate preform containing 21 g polymer has a shelf life of 8.6 weeks, as shown in Table 1 below. At the end of this period, the CO2 level has declined to 3.4 cc/mL, a decline in carbonation level of about 20%. At an initial CO2 level of 4.2 cc/mL beverage, the carbonation level in a beverage stored in a 300 ml bottle manufactured from a 14.5 g polyethylene terephthalate preform declines by 20% in 5.3 weeks.
Shelf life of a bottled carbonated beverage may also be improved by increasing the volume of the bottle, as shown in
One way of improving the shelf life of a carbonated beverage in a less than 100 mL bottle, or a 1.25-3 oz. bottle, is to reduce the initial carbonation level. For example, a 1.25 oz., 1.5 oz., 2 oz., or 3 oz. bottle made from a polyethylene terephthalate preform weighing 4 g to 21 g may be used to store a beverage with an initial CO2 level of ca. 2 cc/mL, with a decline in carbonation level of 6% to 12% over a 10-week period. However, such a reduction in carbonation level is undesirable. Alternatively, the shelf life of a carbonated beverage in a 1.25 oz., 1.5 oz., 2 oz., or 3 oz. bottle may be improved by increasing the preform weight, and thus the wall thickness of the final bottle. However, this requires use of increased amounts of plastic as a raw material and is economically and environmentally undesirable.
Bottle 10 includes a tubular sidewall 5 having a diameter D, and a bottom 6. Bottom 6 may include a punt or indentation 7. In some embodiments, diameter D is greater than the diameter of mouth 1, and a shoulder 3 connects mouth 1 and sidewall 5. A standard fill capacity, measured at fill level 4, of bottle 1 may be 30 mL to 120 M, 37.5 mL to 105 M, from 60 mL to 102.5 mL, from 80 mL to 100 mL, or from 87 mL to 90 mL. Fill level 4 may be on shoulder 3, about halfway between mouth 1 and sidewall 5 of bottle 10. The height B of tubular sidewall 5 and the diameter D of sidewall 5 may be selected to provide the desired fill capacity, measured at 20° C. after 72 hours storage.
While the entire height of tubular sidewall 5 may be a right cylinder of constant diameter if desired, the bottom portion sidewall 5, having a height C, is normally curved inward, as shown in
HO2C—(CH2)2n—CO2H II
The dicarboxylic acid component of the polyamide may be adipic acid in combination with terephthalic acid, isophthalic acid, or a mixture thereof. The dicarboxylic acid component may be 40% to 100%, 50% to 90%, 60% to 80%, or about 70% adipic acid, and from 0% to 60%, 10% to 50%, 20% to 40%, or about 30% of terephthalic acid, isophthalic acid, or a mixture thereof. The dicarboxylic acid component may be 100% adipic acid. The gas barrier layer 12 may be made from 100% MXD6, which is made by polymerizing m-xylylenediamine with adipic acid as the sole acid component. In various embodiments, the intermediate gas barrier layer 12 has a thickness which is 3%, 4%, 5%, 6%, or 7% of the total thickness of sidewall 5, or from 3% to 7% of the total thickness of sidewall 5.
Referring back to Table 1, a laminated 300 ML multilayer bottle with an inner layer of polyethylene terephthalate, an inner layer of polyethylene terephthalate, and an intermediate gas barrier layer of 100% MXD6 has superior resistance to CO2 gas transmission across the bottle wall. A 300 mL, bottle made from a 21 g polyester monolayer preform has a shelf life of 8.6 weeks before the carbonation level in the bottle has declined by 20% from an initial value of 4.2 cc/mL beverage. A 300 mL multilayer bottle made from a 16 g preform containing an MXD6 interlayer, where the interlayer is 4% of the total mass of the bottle, has a shelf life of 15.9 weeks. Thus, the 16 g multilayer preform uses 24% less plastic than the monolayer preform and increases the shelf life of the carbonated beverage in the bottle by 85%. Similar reductions in the amount of plastic used are expected for smaller volume bottles.
Table 1 also shows results obtained with 300 mL polyester bottles formed from three different 14.5 g preforms. As noted above, at an initial CO2 level of 4.2 cc/mL beverage, the carbonation level in a beverage stored in a 300 mL bottle manufactured from a 14.5 g polyethylene terephthalate monolayer preform declines by 20% in 5.3 weeks. If an MXD6 interlayer is incorporated into the 14.5 g preform in an amount of 3%, based on the total mass of the preform, the carbonation level in the beverage declines by 20% in 11.8 weeks, more than doubling the shelf life of the beverage in the bottle. If the MXD6 interlayer is used in an amount of 5%, based on the total mass of the preform, the carbonation level in the beverage declines by 20% in 16.3 weeks, essentially tripling the shelf life of the beverage. The 14.5 g multilayer preform uses 31% less plastic than a 21 g monolayer preform and increases the shelf life of the carbonated beverage in the bottle. If the MXD6 interlayer in the 14.5 g preform ranges from 3% to 5% of the preform mass, the shelf life of the carbonated beverage in the resulting bottle increases from 37% to 90%, relative to a beverage stored in a 21 g monolayer preform. Thus, the use of an MXD6 interlayer in a laminated polyester bottle in an amount of 3% to 7%:
Polyamides formed from m-xylylenediamine have superior resistance to carbon dioxide, hydrogen, oxygen, and nitrogen transmission through the wall of the bottle, and prevent degradation of nutrients and flavors, when compared to other polymers. For example, nylon 6 and nylon 6,6 have excellent oxygen barrier properties but are permeable to carbon dioxide (Tsai et al., Desalination 233 (2008), 183-190). Nylon 6 and nylon 6,6 are commonly used in packaging food products, where it is desirable to prevent oxygen permeation into the package while allowing carbon dioxide formed during storage to escape (“Nylon Films,” Polymer Properties Database, URL: http://polymerdatabase.com/Films/Nylon %20Films.html). Thus, nylon 6 and nylon 6,6 are not suitable for maintaining carbonation levels in a carbonated beverage. Additionally, nylon 6 and nylon 6,6 exhibit unacceptably high oxygen transmission rates, and can allow oxygen to diffuse into the bottle as carbon dioxide diffuses out of the bottle (Soltani et al., Food Packaging, 2017, Pages 1-43; see FIG. 1.2). Entry of oxygen into the bottle may affect flavor, due to oxidation of flavoring agents. More importantly, entry of oxygen into the bottle may oxidize important biologically effective constituents of the beverage, e.g., caffeine and creatine, which would produce undesirable side products.
Referring back to
However, increasing the preform mass is not the only way to increase wall thickness. If the preform mass is held constant, and the volume of the bottle produced from the preform decreases from an initial value of 300 mL to a final value of, e.g., 37.5 mL to 105 mL, the sidewalls and bottom of the smaller bottle will have a smaller area than the sidewalls and bottom of the 300 mL bottle but contain the same amount of polymer as the larger bottle. This increases the thickness of the wall of the smaller bottle, relative to the 300 mL bottle, and increases the resistance of the smaller bottle to carbon dioxide, hydrogen, and nitrogen transmission through the bottle wall.
If a preform weighing from about 4 grams to 22 grams, 13 grams to 22 grams, from 14.5 to 21 grams, from 14.5 to 18 grams, from 15 to 18 grams, from 15 to 17.5 grams, or from 13 to 16 grams which is suitable for manufacturing a 300 mL bottle is instead used to manufacture a 37.5 mL, to 105 mL bottle, carbon dioxide, hydrogen, and nitrogen transmission from the bottle decreases due to increased wall thickness. If the preform additionally contains from 3% to 7% by mass of an MXD6 polyamide interlayer, carbon dioxide, hydrogen, and nitrogen transmission from the bottle further decreases due to the gas barrier layer.
The preform of
As shown in
The combined polymer stream flows into a preform-shaped cavity 41 in mold 40, from gate 49 through a passage 50. The combined polymer stream contains an inner skin polymer stream of polyethylene terephthalate which form the inner surface of the preform wall, and an outer annular skin polymer stream of polyethylene terephthalate which forms the outer surface of the preform wall. An annular core polymer stream of MXD6 separates the inner and outer skin polymer stream and forms a gas barrier layer in the preform.
Although the various exemplary embodiments have been described in detail with particular reference to certain exemplary aspects thereof, it should be understood that the invention is capable of other embodiments and its details are capable of modifications in various obvious respects. As is readily apparent to those skilled in the art, variations and modifications can be affected while remaining within the spirit and scope of the invention. Accordingly, the foregoing disclosure, description, and figures are for illustrative purposes only and do not in any way limit the invention, which is defined only by the claims.
