Technical Field of the Invention
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The present invention relates to a packaging tray for eggs, which has an application in the food product packaging industry, and more specifically in the area of packages for transporting and marketing eggs.
Background of the Invention
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There are different types of packages for transporting and marketing eggs today. These containers are used both for transporting eggs from the farm and for their storage and marketing at the point of sale, which is usually carried out in a number of units that are a multiple and submultiple of a dozen, given the perishable conditions of the product, especially in the domestic area. Therefore, these containers have to allow transport, storage and exhibition functions for marketing the product, all of which is conditioned by the fragility that characterizes it.
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Considering particularly the aspect relating to marketing, the use of packages formed by a half-tray in which the eggs are housed is known today.
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The half-tray, which is made of molded pulp, continues to offer optimal shock-absorbing performance for the delicate egg transport and storage operations, while at the same time it is strong enough so that the half-tray does not sustain excessive deformations that may damage the product, while being lightweight and inexpensive, in addition to the fact that given its composition, pulp can act due to simple gravity as an egg content absorbing element in the event that any of the units contained in the packaging were to accidentally break, such that in said situation, the remaining eggs packaged in the tray would not be affected, being able to be transferred in such case to another package at the point of sale itself, prior to being marketed.
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For the purpose of optimizing the production process, the bottom part made of pulp is usually manufactured by means of jointly molding two half-trays attached through a linkage. Each half-tray usually comprises a dozen cavities, and the two half-trays are symmetrical with respect to an axis coinciding with the linkage. The two half-trays are subsequently separated to be used independently.
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The process of loading eggs in the trays is automatic, such that the trays are taken from a feeder on a conveyor belt to a loading area, the eggs are automatically deposited in the corresponding cavities of the tray and then, once it is filled, each tray is covered with the plastic lid or with another tray made of pulp. Once covered, the tray loaded with eggs formed by two half-trays attached through the linkage goes to the separation area, where the two half-trays are separated manually or automatically. At this point of the process there are different options, as explained below.
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There are installations that have automatic cutting means which allow separating the half-trays by means of a blade or cutting wheel. However, there are also installations that do not have said automatic cutting means, so the separation of the half-trays must be done manually. To that end, the linkage normally incorporates means to facilitate cutting it, such as a perforated or weakening line, for which reason the linkage is also referred to as the precut area.
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In this latter case, although the linkage is already perforated to facilitate separation, when separation is performed manually it frequently does not occur along a straight, central and homogenous line running through the linkage, but rather the cut is often irregular, and sometimes very irregular, if one does not pay enough attention, yielding half-trays with a rather unpresentable finish, and in a worst-case scenario they are unusable when the separation line intersects one of the cavities.
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In view of the aforementioned drawback, manufacturers of trays made of pulp supplying egg production facilities have to manufacture, have and offer different types of trays depending on the installation for which they are intended, whether or not it has automatic cutting, which differ from one another only by the linkage. These types of trays are the following:
- a) Trays having one and the same thickness throughout the entire surface included the linkage and comprising a perforated line, referred to as guiding perforation, which is not very deep and is discontinuous, i.e., they are not through-and-through surface cuts which are spaced every so far apart and do not allow manual separation of the half-trays. These trays are suitable for installations with automatic cutting of the two half-trays. The perforation serves only to guide the blade or cutting wheel.
- b) Trays having one and the same thickness throughout the entire surface including the linkage and comprising a deeper and more continuous perforated line than the perforated line of the trays mentioned above in a). These trays are suitable for installations that do not have automatic cutting and wherein the separation of the half-trays must be done manually. It is precisely in this case where the aforementioned problems occur upon manually separating the half-trays, because as indicated, the separation line of the half-trays can be irregular and accordingly unacceptable, being able to be deviated such that it cuts into one of the cavities where eggs are already housed given the order of the loading process described above. These trays are used today as a multipurpose format when the recipient does not know beforehand whether or not they will be used in an installation with automatic cutting, because they have manual and automatic lines, although manual separation must be done with utmost care and slowly enough so as to assure a clean cut.
- c) Trays having a linkage comprising deep perforations that are close to one another to facilitate separation of the two half-trays. These trays can be separated manually, and the separation produces a clean and uniform separation line.
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Nevertheless, this situation has new drawbacks. First of all, it poses a first logistic problem for tray manufacturers as a result of the need to have to manufacture, store and distribute the three types of trays described above, which is a logistic complication in the production planning, as well as an increment in costs associated with the storage thereof, when in actuality the manufactured product corresponding to the three types is substantially identical with the exception of the mentioned precut area in the linkage.
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Second of all, there is also a second functional problem in trays today, which is common to the three types mentioned above, given that all of them have a marked line in the linkage for separation of the half-trays, although the problem is more noticeable in the case of the trays described in c) above. This functional problem manifests when the trays are stacked in a machine that serves to feed trays into the egg packaging lines and separate the trays automatically, referred to as a denester, consisting of the stacked trays being bent along the linkage as a result of the weight itself of the set of stacked trays, being bent excessively in some cases, especially those trays located at the bottom of the stack, and causing some trays to break. Furthermore, this situation makes the separation operation, and therefore the egg loading and filling operation, difficult or even causes such operations to fail. Since the trays are separated, said trays are not placed in the correct position so the eggs do not fall into it and cause them to break, an operator having to be located in this tray loading area in order to manually solve the problem, should it arise. On the other hand, even without needing for there to be a stack of trays, a single tray can even bend, especially in the case of the trays mentioned in c) above, such that on the conveyor belt itself as the linkage is weakened, the tray may tend to bend or lose its horizontality, even be separated before reaching the cutting operation, so it may cause problems in successive operations in the packaging process.
Description of the Invention
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The present invention relates to a packaging tray for eggs, which allows overcoming the problems of the state of the art, allowing manufacturers to avoid the drawbacks that result from having to have all three types of trays, as the tray of the invention allows a clean and easy separation of the half-trays by any of the manual or automatic methods, while at the same time preventing the trays from bending excessively along the linkage when they are stacked in the separation machine, also referred to as denester.
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The tray proposed by the invention comprises two half-trays made of pulp obtained by means of molding, so said half-trays are obtained such that they are attached through a linkage, which is also made of molded pulp. Each half-tray comprises a plurality of cavities for partially housing eggs.
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In turn, the linkage comprises a precut area, which is usually a straight line, in turn comprising at least one perforation, as described in the preceding section, to facilitate separation of the half-trays.
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According to the invention, the tray comprises at least one pair of projections made of molded pulp separated from one another and located in a facing manner in the linkage, each projection of the pair being located in a half-tray, such that when the half-trays are bent along the linkage, given the separation existing between the pair of projections, which is preferably equivalent to the width of the cuts of the perforation, contact occurs between the upper ends of the projections. This achieves a dual effect, i.e., on one hand it prevents the tray from continuing to bend in the absence of a force in addition to the weight itself of the tray or trays in the stacked position, given that contact of the upper ends of the projections functions like a stop to prevent the tray from continuing to bend. On the other hand, to achieve separation of the trays by continuing to bend them manually, contact between the upper ends has a lever effect which aids in breaking the linkage along the precut area, facilitating separation of the trays, without needing for the linkage to be thinner than the rest of the tray, which causes other drawbacks, as described above.
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It is contemplated that the projections may have different geometries, provided that they are located in the perforated line and are separated from one another. Therefore, when an operator is going to manually separate the half-trays, when such half trays are bent downwards, the projections touch at their ends, and when one half is pushed against the other half, the projections apply a force against one another, such that they act like a lever so that the tray can be separated in a quick and easy manner without being torn or damaged.
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Additionally, depending on their configuration, the projections serve so that when the trays are stacked in the denester, the projections abut against one another, such that it prevents the tray from curving excessively.
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Therefore, the tray of the invention offers a simple solution to the two problems described above given that it serves for any of the separation methods described above and solves the drawback of curving in the tray loading area, given that it has the same thickness and therefore the same strength throughout the entire surface and in turn incorporates means to facilitate manual separation of the two half-trays when there are no automatic cutting means in the installation. Uniform and precise separation lines are obtained as a result of the means provided to facilitate separation of the two half-trays.
Description of the Drawings
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To complement the description that is being made and for the purpose of aiding to better understand the features of the invention according to a preferred practical embodiment thereof, a set of drawings is attached as an integral part of said description where the following has been depicted with an illustrative and non-limiting character:
- Figure 1 shows an elevational view of a preferred embodiment of the tray of the invention, where the two half-trays with the same inclination and which are attached to one another by the precut area can be seen, also being able to see the projections that are arranged in each half-tray, and separated from one another, in correspondence with the precut area.
- Figure 2 shows an elevational view like that of the preceding figure, in a situation in which the tray is stacked in a separation machine for separating half-trays, or denester, such that the half-trays have a different inclination with respect to one another, being bent along the precut area, preventing them from bending further due to contact of the upper ends of the projections located in each of the half-trays.
- Figure 3 shows a perspective view of the outer or bottom face of the tray, opposite the cavities for housing the eggs, where the half-trays have the same inclination, being able to see in the precut area of said outer face the projections that serve both to facilitate separation of the half-trays and to prevent them from bending excessively when the tray is located in the separation machine for separating half-trays.
- Figure 4 shows a view like that of Figure 3 of the inner face of the tray, where the cavities for housing the eggs can be seen.
Preferred Embodiment of the Invention
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In view of the described drawings, it can be seen how in one of the possible embodiments of the invention the packaging tray for eggs proposed by the invention comprises two half-trays (1) made of pulp obtained by means of molding which are attached through a linkage (2), which is likewise made of molded pulp. Each half-tray (1) comprises 12 cavities (4) for partially housing eggs. This format is referred to as 2 x 12 (2 half-trays (1) with 12 cavities (4) each).
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Nevertheless, as mentioned above there are a wide range of tray formats, even though they have not been depicted, in which the invention is applicable, among which the following can be mentioned:
- 4 x 6 (4 half-trays with 6 cavities),
- 2 x 6 (2 half-trays with 6 cavities),
- 2 x 12 (2 half-trays with 12 cavities),
- 2 x 10 (2 half-trays with 10 cavities).
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In turn, the linkage (2) comprises a precut area (3) in turn comprising a perforation.
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The tray also comprises two pairs of projections (5) made of molded pulp separated from one another and located in a facing manner in the linkage (2). Each projection (5) of the pair is located in a half-tray (1), such that when the half-trays (1) are bent along the linkage (2), given the separation existing between the pair of projections (5), which is preferably equivalent to the width of the cuts of the perforation, contact occurs between the upper ends (5') of the projections (5).
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This prevents the tray from continuing to bend in the absence of a force in addition to the weight itself of the tray, in addition to the fact that in order to achieve separation of the trays by continuing to bend them manually, contact between the upper ends (5') of the projections (5) has a lever effect which aids in breaking the linkage (2) along the precut area (3), facilitating separation of the trays.
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As can be seen in the drawings, the cavities (4) have a concave part located in an inner face of the tray, whereas the projections (5) extend substantially perpendicular to an outer face of the tray, opposite the inner face.
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In turn, as discussed above, the lever effect in the separation of the half-trays (1) achieved with the projections (5) allows performing manual separation without the need for weakening the linkage.
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It is also contemplated that the precut area (3) comprises a through-and-through perforation the cuts of which go through the linkage (2), which facilitates separation.
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As seen in Figures 3 and 4, the packaging tray for eggs is rectangular and comprises two rectangular and symmetrical half-trays (1) with respect to the linkage (2), each of which comprises 12 cavities (4), the four corners thereof being rounded.
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In view of this description and set of drawings, the person skilled in the art will be able to understand that the embodiments of the invention that have been described can be combined in multiple ways within the object of the invention. The invention has been described according to preferred embodiments thereof, but it will be obvious for the person skilled in the art that multiple variations can be introduced in said preferred embodiments without exceeding the object of the claimed invention.
