A food tray

Abstract

The present invention relates to a food tray, in particular a tray having an edge coated with adhesive and unstacking (denesting) means. In particular, the invention relates to a food tray (1) of the type closable by means of a sealing film, comprising a substantially flat bottom (2), side walls (3a, 3b, 3c, 3d) delimiting an inner space (I) of the tray (1), and an edge (4) extending from the side walls (3a, 3b, 3c, 3d) outwards, i.e., in the opposite direction to the inner space (I), wherein the side walls (3a, 3b, 3c, 3d) are joined by angular portions (5), said tray (1) comprising, at said angular portions (5), denesting means (8), characterized in that said denesting means (8) comprise a stepped portion (9) placed at a lowered level with respect to the edge (4), wherein a ridge (10), having an upper surface (10a) placed at an intermediate level between the stepped portion (9) and the edge (4), extends upwards from the stepped portion (9).

Description

Technical field of the invention

[0001] The present invention relates to a food tray, in particular a tray having an edge coated with adhesive and unstacking (denesting) means.Prior art

[0002] Trays made of a transparent plastic or colored material are commonly used for packaging food products. Such trays are made using various materials, including virgin or recycled, crystalline or amorphous polyethylene terephthalate (PET), or a mixture of such forms, and can be in single layer or multi-layer.

[0003] In some cases, the trays are completely wrapped, after packing, with a plastic film, but it is becoming increasingly popular to have trays comprising a plastic sealing film, typically polypropylene (PP) and / or polyethylene (PE), sealingly adhered to the upper edge of the tray. It is thus also possible to pack the food in a controlled environment (e.g. , carbon dioxide and a controlled amount of oxygen), maintaining such an environment inside the package for a certain period of time by virtue of the seal between the sealing film and the tray. Such packages allow for better and longer storage of the food product stored therein.

[0004] In order to facilitate the food packaging for the end user, trays have been suggested having a layer of thermoadhesive glue which, after being applied or spread onto the edge of the tray, acquires a semi-solid appearance, then regaining a certain fluidity by heating during the step of adhering the sealing film.

[0005] One problem encountered by the end user who receives the trays stacked on top of one another from the manufacturer, is to singularize them and pick up a tray from the stack quickly and easily. This problem becomes even more crucial with the trays described above having a layer of glue on the edge because as the glue softens, e.g., under hot weather conditions, it can cause the trays to stick to one another in the stack, thus making them practically impossible to be separated.

[0006] In order to overcome this drawback, trays have been suggested having an unstacking (commonly known by the term denesting) area, i.e., a system which allows keeping the staked trays slightly separate from one another so as to promote the picking up thereof by special denesting machines. In principle, this system also avoids the edge of a tray comprising the glue from coming into contact with the lower part of the edge of the tray above.

[0007] An example of such a system is described in EP 2845819 to LINPAC PACKAGING, including an unstacking area at the corners of the tray, where the unstacking area is placed at a lower level with respect to the edge having the glue and where the unstacking area further comprises a cavity or recess which created a protrusion on the opposite face of the tray, i.e., the lower face, intended to rest on the unstacking area of a tray placed below in the pile. Ideally, this system avoids the glue from also being applied to the unstacking area.

[0008] However, this solution also has limitations. In fact, under certain conditions, the glue can drip over the unstacking area, or the lower protrusion at the recess can touch the surface of the glued edge during stacking, thus becoming dirty and then causing a tray to be glued to the one below.

[0009] Therefore, the need still exists to provide a tray having unstacking means which solve the problems highlighted above in relation to the prior art.Summary of the invention

[0010] Such a problem is solved by a food tray as outlined in the appended claims, the definitions of which form an integral part of the present description for the purposes of sufficiency of disclosure.

[0011] Therefore, the objects of the present invention are: 1) a food tray of the type closable by means of a sealing film, comprising a substantially flat bottom, side walls delimiting an inner space of the tray, and an edge extending from the side walls outwards, i.e., in the opposite direction to the inner space, wherein the side walls are joined by angular portions, said tray comprising, at said angular portions, denesting means, characterized in that said denesting means comprise a stepped portion placed at a lowered level with respect to the edge, wherein a ridge, having an upper surface placed at an intermediate level between the stepped portion and the edge, extends upwards from the stepped portion; 2) a tray as in 1, wherein the edge comprises a raised central portion which runs along the entire edge and is configured to receive a layer of thermoadhesive glue, wherein the central portion is externally flanked by a lowered portion which runs along the entire perimeter of the edge, while it is internally flanked, in turn, by a lowered portion which is present at least at the angular portions; 3) a tray as in 2, wherein the upper surface of the ridge is placed at an intermediate level between the stepped portion and the inner lowered portion of the edge; 4) a tray as in any one of 1 to 3, wherein the edge or the central portion of the edge comprises a layer of thermoadhesive glue; 5) a tray as in any one of 1 to 4, wherein the ridges are placed on the stepped portion in different positions at the four angular portions of the tray; 6) a tray as in 5, wherein two ridges are each placed on the respective stepped portion in a position adjacent to the respective end of a first side of the tray, while the other two ridges are each placed on the respective stepped portion in a position spaced apart from the respective end of a second side opposed to the first side; 7) a tray as in any one of 1 to 6, wherein the side walls have a flared shape and are joined by angular portions having a beveled or curvilinear shape; 8) a tray as in any one of 1 to 7, wherein the side walls have raised ribs and the bottom of the tray comprises a raised peripheral portion joined to the side walls by means of curvilinear portions, which in turn can comprise ribs; 9) a tray as in any one of 1 to 8, wherein the stepped portion has a convexity facing the interior of the tray and wherein the ridge has a substantially triangular shape with a vertex facing the interior of the tray; 10) a method of stacking trays as outlined in any one of 1 to 9, comprising the step of rotating a tray to be superimposed by 180° about an axis perpendicular to a superimposition plane of said trays; 11) a method of producing trays as outlined in any one of 1 to 9, comprising the step of providing a tray mold comprising a plurality of tray impressions, wherein said impressions are alternately rotated by 180° with respect to a main plane of the mold.

[0012] Further features and advantages of the present invention will become more apparent from the description of embodiments, given below by way of a non-limiting example, with reference to the following figures.Brief description of the figures

[0013] Figure 1 shows a perspective view of a food tray according to the invention; Figure 2 shows a top plan view of the tray in Figure 1; Figure 3 shows a view according to section D-D in Figure 2 of two superimposed trays; Figure 4 shows a side view (long side) of the tray in Figure 1; Figure 5 shows a section view of a detail of an angular portion of the tray in Figure 1; Figure 6 shows a perspective view of a food tray according to a different embodiment of the invention; Figure 7 shows a longitudinal section view of the tray in Figure 6. Detailed description of the invention

[0014] With reference to the figures, the food tray according to the invention, indicated by reference numeral 1 as a whole, comprises a substantially flat bottom 2, preferably rectangular in shape, side walls 3a, 3b, 3c, 3d delimiting an inner space I of tray 1, and an edge 4 extending from the side walls 3a, 3b, 3c, 3d outwards, i.e., in the opposite direction with respect to the inner space I. The side walls 3a, 3b, 3c, 3d are joined by angular portions 5, preferably beveled or curvilinear in shape.

[0015] The tray 1 comprises mutually opposed first 30a and second 30b sides and mutually opposed third 30c and fourth 30d sides, where when the tray 1 is rectangular in shape, the first and second sides 30a, 30b represent the short sides of the rectangle.

[0016] In the embodiment in the figures, the side walls 3a, 3b, 3c, 3d are typically flared in shape.

[0017] The side walls 3a, 3b, 3c, 3d can have raised ribs 6 or be smooth or have decorations or channels.

[0018] In the embodiment in the figures, the bottom 2 comprises a raised peripheral portion 2a, joined to the side walls 3a, 3b, 3c, 3d by means of curvilinear portions 7, which in turn can comprise ribs 6'.

[0019] It should be understood that the shape of the tray described so far is only an exemplary embodiment, whereby the curvilinear portions 7, the ribs 6' and / or the raised peripheral portion 2a can also be omitted.

[0020] In preferred embodiments, the edge 4 comprises a raised central portion 4a which runs along the entire edge 4 and is configured to receive a layer of thermoadhesive glue. In certain embodiments, the central portion 4a of the edge 4 comprises a layer of thermoadhesive glue. The end user - i.e., the person who packs a food product in the tray - can easily hot glue a sealing film - typically a film made of polypropylene or polyethylene - onto the edge 4 which has already been provided with glue.

[0021] The central portion 4a is externally flanked by a lowered portion 4b which runs along the entire perimeter of the edge 4, while it is internally flanked, in turn, by a lowered portion 4c which is present at least at the angular portions 5 of tray 1 or runs along the entire inner edge.

[0022] Therefore, the lowered portions 4b, 4c do not receive the thermoadhesive glue during the glue application step.

[0023] The central portion 4a of the edge 4 can have a flat or slightly rounded upper surface.

[0024] In the embodiment in figures 6 and 7, the tray 101 is completely similar to the tray 1 described so far, but it comprises, instead, a flat edge 4, i.e., without a raised central portion. In this case, the glue can be arranged over the entire surface of the edge 4.

[0025] The angular portions 5 of tray 1, 101 comprise denesting means 8. The denesting means 8 comprise a stepped portion 9 placed at a lowered level with respect to the edge 4 and / or the inner lowered portion 4c of the edge 4, which can have a convexity 9a, for example, facing the interior of tray 1. A ridge 10, having an upper surface 10a placed at an intermediate level between the stepped portion 9 and the edge 4 and / or the inner lowered portion 4c of the edge 4, extends upwards from the stepped portion 9.

[0026] The term "level" is understood to mean the height or top of the indicated element along a direction orthogonal to the plane of the bottom 2 of tray 1.

[0027] For example, the ridge 10 can be substantially triangular in shape with a vertex facing the interior of tray 1.

[0028] The ridges 10 are placed on the stepped portion 9 in different positions at the four angular portions 5 of tray 1. In a preferred embodiment, two ridges 10 are each placed on the respective stepped portion 5 in a position adjacent to the respective end of a first side 30c, while the other two ridges 10 are each placed on the respective stepped portion 5 in a position spaced apart from the respective end of a second side 30d opposed to the first side 30c. Such a configuration is clearly visible in the drawings, in particular in figure 2. When a tray needs to be stacked on top of another, as shown in figure 3, or more typically during molding, it is thus sufficient to rotate the upper tray, or the impression of the mold during the production, by 180° about an axis perpendicular to the plane of the bottom 2 to avoid a shape coupling between the two trays that does not allow them to unstacked. In fact, since the trays are made by molding, a recess corresponds at the bottom to the ridge 10, which would couple to the ridge 10 of the tray placed at the top, if they were in the same position.

[0029] Vice versa, as shown in figure 3, this contrivance allows the upper surface 10a of a tray 1, 101 to abut against the lower surface 9' of the stepped portion 9 of a second tray 1, 101 placed on top, which allows obtaining a separation s of the edges 4 such as to allow for an easy unstacking by the unstacking machines or even by a manual worker.

[0030] The configuration described above also has a further advantage as compared to the prior art described above, in which the ridge 10 was replaced by a recess: in fact, in the latter solution, it is always possible for the abutment surface (lower surface) of the recess to get dirty with glue, in contact with the upper surface of the tray edge. Vice versa, in the tray according to the present invention, the upper surface 10a of the ridge 10 abuts against the lower surface 9' of the stepped portion, therefore the lower surface of tray 1, which, under no circumstances, can get dirty with glue, the latter being arranged on the upper surface of the tray edge.

[0031] The tray 1 can be made of a plastic material normally used for this type of applications, e.g., polypropylene or crystalline or amorphous polyethylene terephthalate, or a mixture thereof, in a single layer or multi-layer, and it can be made by heat molding (thermoforming) or injection molding.

[0032] The application of the thermoadhesive glue to the edge 4 or raised portion 4a can be carried out according to conventional methods, such as roller methods, spray coating, hot glue gun or by molding techniques.

[0033] It is apparent that only some particular embodiments of the present invention have been described, to which those skilled in the art may make all the necessary changes to adapt it to particular applications, without departing from the scope of protection of the present invention.

Claims

1. A food tray (1, 101) of the type closable by means of a sealing film, comprising a substantially flat bottom (2), side walls (3a, 3b, 3c, 3d) delimiting an inner space (I) of the tray (1), and an edge (4) extending from the side walls (3a, 3b, 3c, 3d) outwards, i.e., in the opposite direction to the inner space (I), wherein the side walls (3a, 3b, 3c, 3d) are joined by angular portions (5), said tray (1) comprising, at said angular portions (5), denesting means (8), characterized in that said denesting means (8) comprise a stepped portion (9) placed at a lowered level with respect to the edge (4), wherein a ridge (10) having an upper surface (10a), the upper surface (10a) placed at an intermediate level between the stepped portion (9) and the edge (4), extends upwards from the stepped portion (9).

2. The tray (1) according to claim 1, wherein the edge (4) comprises a raised central portion (4a) which runs along the entire edge (4) and is configured to receive a layer of thermoadhesive glue, wherein the central portion (4a) is externally flanked by a lowered portion (4b) which runs along the entire perimeter of the edge (4), while it is internally flanked, in turn, by a lowered portion (4c) which is present at least at the angular portions (5).

3. The tray (1) according to claim 2, wherein the upper surface (10a) of the ridge (10) is placed at an intermediate level between the stepped portion (9) and the inner lowered portion (4c) of the edge (4).

4. The tray (1, 101) according to any one of claims 1 to 3, wherein the edge (4) or the central portion (4a) of the edge (4) comprise a layer of thermoadhesive glue.

5. The tray (1, 101) according to any one of claims 1 to 4, wherein the ridges (10) are placed on the stepped portion (9) in different positions at the four angular portions (5) of the tray (1, 101).

6. The tray (1, 101) according to claim 5, wherein two ridges (10) are each placed on the respective stepped portion (5) in a position adjacent to the respective end of a first side (30c) of the tray (1, 101), while the other two ridges (10) are each placed on the respective stepped portion (5) in a position spaced apart from the respective end of a second side (30d) opposed to the first side (30c).

7. The tray (1, 101) according to any one of claims 1 to 6, wherein the side walls (3a, 3b, 3c, 3d) have a flared shape and are joined by the angular portions (5) having a beveled or curvilinear shape.

8. The tray (1, 101) according to any one of claims 1 to 7, wherein the side walls (3a, 3b, 3c, 3d) have raised ribs (6) and the bottom (2) comprises a raised peripheral portion (2a) joined to the side walls (3a, 3b, 3c, 3d) by means of curvilinear portions (7), which in turn can comprise ribs (6').

9. The tray (1, 101) according to any one of claims 1 to 8, wherein the stepped portion (9) has a convexity (9a) facing the interior (I) of the tray (1) and wherein the ridge (10) has a substantially triangular shape with a vertex facing the interior (I) of the tray (1).

10. A method of stacking trays (1, 101) as outlined in any one of claims 1 to 9, comprising the step of rotating a tray (1, 101) to be superimposed by 180° about an axis perpendicular to a superimposition plane of said trays (1, 101).

11. A method of producing trays (1, 101) as outlined in any one of claims 1 to 9, comprising the step of providing a tray mold comprising a plurality of tray (1, 101) impressions, wherein said impressions are alternately rotated by 180° with respect to a main plane of the mold.

Images