WO2011150478A1

WO2011150478A1 - Closure for plastic packaging containers

Info

Publication number: WO2011150478A1
Application number: PCT/BR2011/000145
Authority: WO
Inventors: Sérgio ROMEIRO
Original assignee: Mindoro Consultoria E Serviços Em Alimentos Ltda.
Priority date: 2010-05-31
Filing date: 2011-05-10
Publication date: 2011-12-08
Also published as: EP2578508A4; EP2578508A1; BRPI1001431A2; MX2012013997A; US20130202826A1

Abstract

The present invention relates to a closure for plastic packaging containers that exhibits innovative features that can simplify the manufacturing process and the filling with liquid and viscous products, but the main effect of which is to prevent the package walls from collapsing following a change in vapour pressure inside the container, regardless of the filling temperature.

Description

"LID FOR PLASTIC PACKAGING"

FIELD OF INVENTION

The present invention relates to a lid for plastic containers, especially for those thermoformed cup-type containers commonly used for packaging ready-to-drink liquid products and beverages such as teas, soft drinks, etc. The lid object of the present invention is provided with technical and innovative features that prevent the collapse of said packages.

Additionally, the present invention relates to a plastic packaging lid comprising a structure having a configuration capable of hot-filling (up to 95 ° C) liquid or pasty products and thereby reducing or even eliminating preservatives. to extend product life. In addition, by eliminating the collapsing effect of packaging, it makes it possible to properly and safely stack and display these packages on sales shelves.

BACKGROUND OF THE INVENTION

Thermoformed plastic cup-type packaging is commonly used in the market for liquid products, especially ready-to-drink beverages of lower added value, and consists of a plastic cup whose open end is closed with a sealing-type lid. blade.

Usually, said lid is formed of one layer of aluminum and another of polyethylene, the latter being responsible for allowing thermosolding on the edge of the cup.

As should be appreciated by those skilled in the art, the market demands that the final cost of these products be relatively low. To this end, companies are looking for solutions to minimize the expense of manufacture mainly of those secondary items, for example the packaging, the label, the lid. In this sense, as a common practice in industries, packaging is made from the smallest possible amount of material, which makes it thin and light and usually uses so-called thermoformed polymers that are cheaper raw materials.

However, in the case of lower value-added beverages, logically, reducing the wall thickness of these packages promotes a reduction in stiffness and an increase in the level of flexibility of the structure.

As a result, it is observed that during the manufacturing and filling process of these beverages, this fragility compromises the structure of the final product, causing the walls of the package to collapse after the lid is applied and the beverage to cool down.

More specifically, during common filling processes, such beverages are at a temperature of about 30 ° C, and closure of the package by the lid generates an internal air space between the beverage level and the inner face of the lid, also called from "head space". By reducing the temperature of the product in the refrigerator, the vapor pressure of the liquid is reduced precisely in this region of the head space.

However, as should be appreciated by those skilled in the art, in such liquid product packaging and packaging, there is no room to compensate for this reduction in vapor pressure without compromising the structure of the final product. Consequently, by its very nature, this compensation is sought in the most fragile regions, which eventually results in partial collapse of the packaging walls, as these are less rigid and thinner and more flexible, as anticipated above.

This collapsing effect increases with increasing the temperature of the bottled beverage, that is, the higher the temperature of The greater the collapse of the packaging walls when the beverage is cooled, making sterilization by hot filling (up to 95 ° C) impracticable in this type of packaging. In this regard, it is important to note that as filling at temperatures of about 30-35 ° C does not sterilize beverages, the use of preservatives is necessary to extend the life of the beverage. Nowadays, when health and good nutrition are increasingly present in human life, the use of preservatives is seen and considered harmful to health.

Additionally, it is known that the collapse of such packages causes a number of drawbacks of logistics, accommodation and sale of the final product. This is because a "wrinkled" packaging is usually seen as a problem or old product, ie the consumer usually refuses to buy a product when it has a crumpled or collapsed configuration.

There is also the problem of exposure on sales shelves, since, depending on the level of collapse of the package, it will become crooked; consequently, it will be difficult to stack or arrange one package over another on the selling gondolas. This drawback is relatively critical for supermarkets, hypermarkets, markets in general, as the arrangement on gondolas should be as optimized as possible, using as little space as possible to accommodate the widest range of products. Thus, if state-of-the-art packaging suffers this collapsing effect and becomes uneven, it makes stacking unfeasible and therefore it is necessary to dispose them on a single level.

In another situation, for example, in the case of creamy curd cheese, where the filling is necessarily hot (up to 95 ° C) for product sterilization, the partial solution found was to use thick-walled and injected plastic cups. more resistant. Same that much more expensive than the thermoformed plastic cups used for low value-added ready-to-drink beverages are still cheaper than traditional glass cups.

Thus, it is important to note that injected plastic packaging makes those low-value-ready ready-to-drink beverages too expensive, while prior art thermoformed plastic packaging makes it impossible to hot-fill products such as curd creamy.

In other words, to avoid the collapse of low value-added ready-to-drink beverage packaging, it would be necessary to use injected plastic packaging, which would make it economically unviable, while hot-filling of thermoformed plastic packaging products is not feasible. practical as the packaging would collapse. Therefore, it is evident the current limitations in the packaging and marketing of certain consumer products.

In order to solve some of the above drawbacks, a thermoformed cup-type package is known which has been developed to try to avoid collapse of the structure after filling and closing of the package. This package comprised a kind of valve disposed at the bottom of the cup body; more particularly, said bottom was intended to retract when reducing the vapor pressure within the cup. However, such a configuration was not effective, since it required a high cost manufacturing process with specific equipment, and mainly because it required an accuracy in the conformation of the bottom of the package.

In practice, it was also observed that the walls of the cup structure remained with compromised flexibility and stiffness and eventually collapsing before actuation of said valve. The possible alternative of increasing the wall thickness makes the packaging, in the case of ready-to-drink drinks of low added value, and therefore the final product, economically unviable.

Therefore, it should be clear that, although functional to date, these packages, in particular low-value ready-to-drink thermoformed beverage cups, have drawbacks and limitations mainly related to the quality of the packaging structure, negatively interfering with the packaging. configuration and appearance of the final product.

BRIEF DESCRIPTION OF THE INVENTION

Therefore, it is an object of the present invention to provide a lid for thermoformed plastic packaging for packaging liquid and pasty products, preferably of the ready-to-drink and creamy curd type, which can simply, safely and efficiently solve all the drawbacks revealed in the state of the art. technique as commented above.

More preferably, it is an object of the present invention to provide a thermoformed plastic packaging lid which comprises a configuration capable of efficiently eliminating collapse of the packaging walls after bottling, closing and cooling of the final product, regardless of the beverage filling temperature.

Additionally, it is an object of the present invention to provide a plastic packaging lid that allows the hot filling (up to 95 ° C) of sterile beverages, reducing or eliminating the use of preservatives.

It is also an object of the present invention to provide a thermoformed plastic cup-type lid that ensures the integrity of the entire structure, ie maintains the original appearance, enables the best including the stacking of these packages on sales shelves to optimize manufacturing logistics, transportation and display for sale.

It is a further object of the present invention to provide a thermoformed lid for cup-type packaging capable of simply and inexpensively solving the problems caused in the structure of such packages without the need for reformulation of materials and sizing.

These and other objects, effects and advantages provided by the lid object of the present invention are achieved thanks to the configuration developed and applied on the structure comprising the lid. The lid according to the present invention comprises a structure which efficiently ensures the structural integrity of the packaging body, regardless of the beverage conditions during and after filling, closing and cooling of the final product.

In this regard, it is a preferred object of the present invention a thermoformed plastic packaging lid comprising a blade provided with at least one slot which surrounds at least in part the surface of said blade. Moreover, in a particularly advantageous embodiment, said slots are provided in accordion shape, such as a sequence of protrusions and recesses of triangular section of more or less curved ends.

It should also be made clear that the amount of slots disposed on said blade varies according to the type of beverage and its manufacturing and filling process. More particularly, the larger the hotter the beverage is in the filling process.

Preferably, said blade is comprised of an aluminum layer covered with a polyethylene or polypropylene layer capable of allowing heat sealing of said lid over the edge of the plastic package.

BRIEF DESCRIPTION OF THE FIGURES

These and other objects, technical effects and advantages of the thermoformed plastic packaging lid, object of the present invention, will be apparent to those skilled in the art from the accompanying schematic figures which illustrate preferred but not limiting embodiments of the present invention. which are:

Figures 1A, 1B, 1C and 1D schematically show a lid and a closed thermoformed plastic package according to the state of the art;

Figures 2A and 2B schematically show two preferred embodiments of the packaging lid according to the present invention;

Figure 3 schematically shows a thermoformed plastic package closed by the lid according to the present invention, particularly after beverage filling at a conventional temperature;

Figure 4 schematically shows the sealed package illustrated in Figure 3, but cooled;

Figure 5 schematically shows a thermoformed plastic package closed by the lid in accordance with an alternative embodiment of the present invention, particularly after filling beverages at an elevated temperature;

Figure 6 schematically shows the sealed package illustrated in Figure 5, but cooled;

Figures 7 and 8 show side views of the caps according to the present invention under different conditions of beverage vapor pressure after closure of the plastic containers. DETAILED DESCRIPTION OF THE INVENTION

Initially, it should be reiterated that the lid for plastic packaging, object of the present invention, will be described hereinafter according to preferred rather than limiting embodiments, since its application can be carried out in different packages and for the packaging of different products with variations of vapor pressure when filling and cooling in the manufacturing process.

By way of illustration only, Figures 1A-1D illustrate conventional embodiments of a lid and package known in the art. Figure 1A shows a lid 1 comprised of an aluminum foil and a polyethylene or polypropylene layer. As shown in Figure 1B, said lid 1 is overlapped at the open end 3 of package 2, after filling with a drink 4 at a temperature of about 30-35 ° C, then said lid 1 is thermosolded at the edge. said package 2, making it ready for sale.

However, as mentioned earlier, said closed packages suffer a temperature reduction, often reaching about 10 ° C or less, as in a refrigerator or refrigerator. Due to this reduction in temperature, the head space - 5 inside the package suffers a vapor pressure drop. Thus, in an attempt to compensate for this vapor pressure drop and consequent head space volume reduction, the walls of the package body 2 collapse 6, as illustrated in Figure 1 C.

Figure 1D illustrates a more critical situation in which beverage 4 was filled at a high temperature, about 95 ° C and then cooled to a temperature of about 10 ° C. In this case, the collapse is more severe. intense and problematic, both structural and visual, also causing inconvenience to the logistics of the final product. Referring now to Figures 2A and 2B, in which two preferred embodiments of the lid according to the present invention are illustrated, it is noted that said lid 10 is provided with slots 1 surrounding the entire lid structure. Preferably, said slots 11 comprise a concertina form, i.e. a sequence of protrusions and recesses of triangular section of greater or lesser curvature.

More preferably, the configuration of said slot 11 may vary according to the type of beverage and its manufacturing and filling process, that is, the amount of protrusions and recesses may increase or decrease according to the properties of the packaged liquid. In other words, depending on the processing conditions, with or without thermal sterilization of the beverage, the number of slots 11 may be larger or smaller, i.e. the accordion configuration may be longer or shorter.

Figures 3, 4, 5 and 6 illustrate two preferred embodiments of the lid 10 according to the present invention by closing a thermoformed plastic packaging 2 which holds a beverage 4. More specifically, the embodiment illustrated by Figures 3 and 4 simulates a conventional situation of beverage processing and packaging, but using lid 0 in question. In this embodiment, the liquid was filled at a temperature of about 30 ° C, which does not cause drastic variations in the configuration of the package 2 nor in the lid 10. However, when the closed package 2 is subjected to a temperature of about 10 ° C. C, it is observed that the pressure in the head space 5 decreases and, in response to compensate for this effect, the accordion configuration of the slots 11 reacts by occupying a part of the head space space 5. As can be seen, the package body 2 remains unchanged without any sign of collapse of its walls.

In the embodiment illustrated in Figures 5 and 6, a cover was used 10 whose accordion configuration of the slots 11 is longer, that is, it has a larger number of protrusions and recesses. In this case, the simulation had as a parameter the sterilization of the drink during the manufacturing and filling process, ie, the use of preservatives was eliminated. As can be seen, at the time of closure of the package 2 by the lid 10, due to the increase of vapor pressure in the head space 5, the lid 10 expands positively. Upon cooling, by reducing the vapor pressure in the head space 5, the lid 10 retracts and expands negatively, causing the folding configuration of the slots 1 1 to be undone into the head space 5, compensating for the aforementioned one. vapor pressure drop.

Such accordion configuration of the slots 11 can be better understood from Figures 7 and 8, in which comparatively illustrated levels of lid surface expansion 10, both positively and negatively.

More specifically, as shown in Figures 7 and 8, it is observed that the natural state of the lid 10 is at level (0) and with the slots 11 formed; after filling and packaging, the temperature of the packaged beverage increases the vapor pressure in the head space 5; thereby said lid 10 expands positively so that the accordion configuration begins to unravel to a straight configuration as indicated by the levels (+1, +2, +3, +4).

Upon cooling, the vapor pressure in the head space begins to decrease and thereby said lid 10 begins to retract and then expand negatively compensating for the space taken by the vapor pressure drop in the head space. "by reaching their respective levels (-1, -2, -3, -4) and eliminating scratches from the packaging wall to collapse.

Importantly, although the illustrations and description above refer to a circular cup-like packaging, nothing Prevents the present lid from being applied to packaging of various configurations, for example: rectangular, triangular, elliptical, etc.

Thus, it is noteworthy that the lid according to the present invention can solve a number of drawbacks revealed by the prior art plastic covers and packaging, especially regarding the integrity of the packaging.

In addition, it makes it possible to improve the manufacturing process in the beverage industries as it enables thermal sterilization of the beverage in the hot container, reducing or eliminating the use of preservatives for such products.

As is well understood by those skilled in the art, numerous modifications and variations of the present invention are possible in light of the above teachings without departing from its scope of protection as delimited by the appended claims.

Claims

Plastic packaging lid, characterized in that it comprises a blade 10 provided with at least one slot 11 which surrounds at least in part the surface of said blade.

Plastic packaging lid according to claim 1, characterized in that said slots 11 comprise an accordion shape such as a sequence of protrusions and recesses of triangular section.

PLASTIC PACKAGE LID according to claim 2, characterized in that the sequence of protrusions and recesses of triangular section have ends which may be of greater or lesser curvature.

Plastic cover according to claim 1, characterized in that the amount of slots 11 varies according to the type of product and its manufacturing and filling process, the larger the warmer the product is. filling process.

PLASTIC PACKAGING COVER according to claim 1, characterized in that said blade is comprised of an aluminum layer covered with a polyethylene or polypropylene layer.

PLASTIC PACKAGING COVER according to claim 1, characterized in that it is heat sealed to the edge of the plastic packaging.