TRANSPARENT CELLULOSIC PACKAGING

Abstract

The invention is directed to a three-dimensional food packaging (100) having a packaging interior (V) and being made of a cellulosic fibrous material (200). At least a portion (111) of the food packaging (100) delimiting at least part of the packaging interior (V) is impregnated with a polymer (300) such that the impregnated portion (111) has a light transmittance above 60% for visible light.

Claims

1. A three-dimensional food packaging made of a cellulosic fibrous material and defining a packaging interior, wherein at least a portion of the food packaging defining at least part of the packaging interior is impregnated with a polymer such that the impregnated portion has a light transmittance above 60% for visible light.

2. The three-dimensional food packaging according to claim 1, wherein the impregnated portion has a light transmittance above 65% for visible light.

3. The three-dimensional food packaging according to claim 1, wherein the polymer is a food grade material, is biodegradable and has a refractive index similar or identical to the cellulosic fibrous material.

4. The three-dimensional food packaging according to claim 1, wherein the polymer is selected from the group consisting of Polyolefin, Polyacrylate, Polycaprolactone, Polyester, Polyalcohol, Polyhydroxyalkanoate, thermoplastic starch, cellulose derivative, Epoxy resin, and combinations thereof.

5. The three-dimensional food packaging according to claim 1, wherein the impregnated portion comprises a concentration of the polymer that is continuous along at least one of its extension directions.

6. The three-dimensional food packaging according to claim 1, wherein the impregnated portion comprises at least one sealing portion having a concentration of the polymer that allows for sealing the impregnated portion by heat sealing and/or ultrasonic sealing, wherein preferably the sealing portion is provided at one side of the impregnated portion that comprises a higher concentration of the polymer than a respective other opposite side.

7. The three-dimensional food packaging according to claim 1, wherein the food packaging comprises a plurality of the impregnated portions.

8. The three-dimensional food packaging according to claim 1, wherein the food packaging and/or at least the impregnated portion comprises an oxygen barrier, a grease barrier, and a moisture barrier.

9. The three-dimensional food packaging according to claim 1, wherein the food packaging and/or at least the impregnated portion has a thickness that is of 5 microns or above.

10. The three-dimensional food packaging according to claim 1, wherein the cellulosic fibrous material is selected from the group consisting of paper, paperboard, a cellulosic pulp adapted for being molded, a cellulose nanofibres sheet or film, airlaid cellulose and delignified wood.

11. The three-dimensional food packaging according to claim 1, wherein the food packaging comprises more than 70 wt % of cellulose.

12. The three-dimensional food packaging according to claim 1, wherein the impregnated portion forms at least one window for displaying a food product being placed inside the food packaging in the packaging interior.

13. The three-dimensional food packaging according to claim 1, wherein the food packaging comprises at least one packaging wall defining a body.

14. The three-dimensional food packaging according to claim 1, wherein the food packaging comprises a grammage between 30 g/m.sup.2 and 800 g/m.sup.2.

15. The three-dimensional food packaging according to claim 1, wherein the food packaging comprises a lid, the packaging interior is closed by the lid and the food packaging sealingly encloses the packaging interior for containing an edible product for human and/or animal consumption.

Description

BRIEF DESCRIPTION OF FIGURES

[0071] FIGS. 1 to 3 show schematic cross-sectional views of different steps of the impregnation process of a cellulosic fibrous material according to an embodiment of the invention.

[0072] FIGS. 4 to 7 show schematic front or side (FIG. 5) views of an impregnated portion according to different embodiments of the invention.

[0073] FIGS. 8 to 11 show schematic sectional views of different embodiments of the food packaging according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0074] The figures show different views and aspects of a three-dimensional food packaging 100 according to the present invention.

[0075] FIGS. 8 to 11 show different examples of the food packaging 100. For example, in FIGS. 8 and 9, the food packaging 100 is exemplarily illustrated as a tray 101, in FIG. 10, the food packaging 100 is exemplarily illustrated as a cup 102, and, in FIG. 11, the food packaging 100 is exemplarily illustrated as a bottle 103. However, this is not a complete enumeration and other embodiments of the food packaging 100 are conceivable, such as boxes, capsules or sachets, for example.

[0076] The three-dimensional food packaging 100 is made of a cellulosic fibrous material 200. This is exemplarily illustrated in FIG. 1. Therein, it is exemplarily shown that cellulosic fibres may form a matrix with gaps 201 therebetween. For example, the cellulosic fibrous material 200 may comprise or may be paper, paperboard, a cellulosic pulp adapted for being molded, a cellulose nanofibres sheet or a cellulose nanofibres film, airlaid cellulose and/or delignified wood.

[0077] The three-dimensional food packaging 100 defines a packaging interior V. This is exemplarily illustrated in FIGS. 8 to 11. The packaging interior may be suitable or configured for receiving a food item. The packaging interior V may be open or closed. For example, the food packaging 100 may at least partially enclose the packaging interior V as exemplarily illustrated in FIG. 10 or 11. Alternatively, the food packaging 100 may fully and preferably sealingly enclose the packaging interior V such as exemplarily illustrated in FIGS. 8 and 9, where the packaging interior V is shown as being closed by a lid 112. For example, the packaging interior V may be closed by the lid 112 by applying heat sealing or ultrasonic sealing.

[0078] For this, the packaging interior V may be delimited by a packaging wall 110 that forms at least part of the food packaging 100. For example, in the FIGS. 10 and 11, the packaging wall 110 is exemplarily illustrated as defining a single body of the food packaging 100. In comparison, the food packaging 100 exemplarily illustrated in FIGS. 8 and 9 comprises at least two packaging walls 110, one of which may form the lid 112 while the other one of the packaging walls 110 may form the body of the tray 101.

[0079] Therein, the packaging wall 110 may generally enclose or surround the packaging interior V such that an opening (in the body) to the space (e.g. the packaging interior V in FIGS. 8 to 11) may be provided with an opening preferably to one side.

[0080] The body of the food packaging 100 may be rigid or flexible. The configuration of the body may depend, for example, on the food packaging application and/or the intended content of the food packaging 100. For example, the body of the food packaging 100 may be provided as being rigid for the food packaging 100 being a food tray 101 or a capsule. In comparison, the body of the food packaging 100 may be provided as being flexible for the food packaging 100 being a pouch or a wrap.

[0081] Generally, the body of the food packaging 100 may be provided as a single-piece or may consist of one or more (single-piece) half-shells that may be bonded (e.g. sealed) together. For example, the food packaging 100 exemplarily illustrated in FIG. 11 may be a bottle 103 that may be made from a cellulosic molded pulp, and/or may be made of two half-shells (half-bottles) or may be a single piece. The bottle 103 may be closed by a lid, such as a screw cap. Similarly, the food tray 101 as exemplarily illustrated in FIGS. 8 and 9, respectively, may be manufactured also from a molded cellulosic pulp and/or may be a single piece, for instance. The cup 102, which is exemplarily illustrated in FIG. 10, may be made from carton and/or may be a single piece. The tray 101 and the cup 102 may be closed by the lid 112, which preferably may be made from carton, for example.

[0082] At least a portion 111 of the food packaging 100 that delimits at least part of the packaging interior V is impregnated with a polymer 300. This is exemplarily illustrated in FIGS. 4 to 11.

[0083] For example, a solid impregnation process, liquid impregnation process, or a vacuum impregnation process can be used for this purpose. The different steps of the impregnation process are exemplarily illustrated in FIGS. 1 to 3. Therein, it is exemplarily illustrated how the gaps 201 between the fibres of the cellulosic fibrous material 200 (as illustrated in FIG. 1) can be filled with particles of the polymer 300. This is exemplarily illustrated in FIG. 2. Then the polymer 300 and the cellulosic fibrous material 200 can be bonded together to form a preferably contiguous impregnated material 230 (e.g. by heat treatment or other treatment methods). This is exemplarily illustrated in FIG. 3.

[0084] Therein, the polymer 300 may preferably be a food grade material. Alternatively or additionally, the polymer 300 may be biodegradable. Preferably, the polymer 300 may be provided as a powder and/or may be soluble in a solvent. Advantageously, the polymer 300 may have a refractive index similar or identical to the cellulosic fibrous material 200. For example, the polymer 300 and the cellulosic fibrous material 200 may have both a refractive index of 1.5. Accordingly, the resulting refractive index of the impregnated material 230 may be uniform.

[0085] Suitable material choices for the polymer 300 may be, for example, a Polyolefin, Polyacrylate, Polycaprolactone (PCL), Polyester, Polyalcohol, Polyhydroxyalkanoate (PHA), thermoplastic starch (TPS), cellulose derivative, Epoxy resin, or any combination thereof.

[0086] Polethylene (PE) or Polypropylene (PP) may be used as a Polyolefin for the polymer 300.

[0087] It is also conceivable to use (additionally or alternatively) Polyethylene terephthalate (PET), polybutylene adipate terephthalate (PBAT), polylactic acid (PLA) and/or Polybutylene succinate-co-butylene adipate (PBSA) as a Polyester for the polymer 300.

[0088] Further, cellulose acetate (CA), cellulose acetate-butyrate (CAB), cellulose acetate-propionate (CAP), carboxymethyl cellulose acetate butyrate (CMCAB), and/or hydroxy methyl ethyl cellulose (HMEC) may be (additionally or alternatively) used as a cellulose derivative for the polymer 300.

[0089] Moreover, Polyvinyl alcohol (PVOH), Butenediol Vinyl Alcohol Co-polymer (BVOH), Polyvinylacetate (PVAC, PVA) may be (additionally or alternatively) used as a Polyalcohol for the polymer 300.

[0090] Polyhydroxybutyrate (PHB), polyhydroxyvalerate (PHV), Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), and/or PHBH (a random copolymer of (R)-3-hydroxybutyrate (3HB) and (R)-3-hydroxyhexanoate (3HHx)) may be (additionally or alternatively) used as a polyhydroxyalkanoate (PHA) for the polymer 300.

[0091] The at least one packaging wall 110 may comprise the impregnated portion 111. Therein, the impregnated portion 111 may be integrally formed with the at least one packaging wall 110. This is exemplarily illustrated in all Figures.

[0092] The impregnated portion 111 may be provided anywhere on the food packaging 100. For example, the impregnated portion 111 may be comprised by the lid 112 of the food packaging 100 as exemplarily illustrated in FIG. 8. Alternatively or additionally, the body of the food packaging 100 may comprise the impregnated portion 111, such as exemplarily illustrated in FIGS. 9 to 11. Naturally, it is also conceivable that the food packaging 100 may comprise more than one impregnated portion 111, as exemplarily shown in FIGS. 8 and 10.

[0093] The portion 111 of the food packaging 100 is impregnated with the polymer 300 such that the impregnated portion 111 has a (direct) light transmittance above 60% for visible light. Thereby, the cellulosic fibrous material 200 can be provided with an integral transparent field.

[0094] Generally, the transparency of the impregnated portion 111 may increase as the impregnation of the cellulosic fibrous material 200 increases. Alternatively or additionally, the transparency of the impregnated portion 111 may increase with increasing uniformity of the polymer 300 distribution in the cellulosic fibrous material 200. Similarly, the transparency of the impregnated portion 111 may increase with increasing approximation of the refractive index of the polymer 300 onto the refractive index of the cellulosic fibrous material 200.

[0095] Accordingly, the impregnated portion 111 may have a light transmittance above 65%, or above 70%, or above 75%, or above 80%, or above 85%, or above 90%, or above 95%, or 100% for visible light.

[0096] Therein, the transparency may be measured in line with industrial standards, such as ASTM D 1746-03. Therein, for example, the light transmittance may be calculated as a percent ratio of the light intensity with a specimen, such as the impregnated portion 111, being placed in a test light beam and compared to the light intensity with no specimen in the test light beam.

[0097] As illustrated exemplarily in FIGS. 4 to 11, the impregnated portion(s) 111 may form one or more windows for displaying a food product being placed inside the food packaging 100 in the packaging interior V.

[0098] Preferably, the food product may be placed in relative proximity to the impregnated portion 111. For example, the distance between the impregnated portion 111 and the food product may be below 1 mm, or below 2 mm, or below 3 mm, or below 4 mm, or below 5 mm, or below 10 mm, or below 15 mm, or below 20 mm, or below 30 mm, or below 40 mm, or below 50 mm.

[0099] Preferably, the impregnated portion 111 may comprise a concentration of the polymer 300 that may be continuous. This is exemplarily illustrated in FIG. 4.

[0100] Alternatively or additionally, it also conceivable that the impregnated portion may be at least partially continuous, such as exemplarily illustrated in FIGS. 6 and 7. In FIG. 6, for example, the impregnated portion 111 may alternate between sections of the packaging wall 110 that either comprise a high concentration of the polymer 300 and a section 235 that may comprise a lower or no concentration of the polymer 300. In FIG. 7, for example, the concentration of the polymer 300 may vary for longitudinally or laterally different sections 231, 232, 233 of the packaging wall 110 while the concentration of the polymer 300 within each of individual section 231, 232, 233 may be constant. Therein, in FIG. 7 different patterns are used to illustrate different concentrations.

[0101] Moreover, it is also conceivable that at the impregnated portion 111 the concentration of the polymer 300 may vary along its extension direction that defines the thickness of the impregnated portion 111 (e.g. the direction from the packaging interior V to the outside of the food packaging 100). This is exemplarily illustrated in the schematic sectional side view of FIG. 5. Therein, the concentration of the polymer 300 may vary for (radially) different sections 231, 232, 233, 234 of the packaging wall 110 at the impregnated portion 111 while the concentration of the polymer 300 within each of individual section 231, 232, 233 may be constant. Therein, in FIG. 5 different patterns are used to illustrate different concentrations.

[0102] Furthermore, it is conceivable, for example, that the cellulosic fibrous material 200 may be impregnated with a gradient of impregnation between one and the other of its sides (e.g. thickness or lateral direction). In this case, one side of the impregnated material 230 may comprise a higher concentration of the polymer 300 than the other. This is exemplarily illustrated in FIGS. 5 and 7. By providing the polymer 300 as a sealable polymer, it can be possible that the side of the impregnated material 230, which comprises a higher concentration of the polymer 300 than the other opposite side, may be heat-sealable. Thereby, the impregnated material 300 may be used for forming a three-dimensional packaging, such as the food packaging 100, from a flat sheet.

[0103] Alternatively or additionally, the impregnated portion 111 may comprise at least one sealing portion having a concentration of the polymer 300 that allows for sealing the impregnated portion 111 by heat sealing and/or ultrasonic sealing. A sealable polymer may be used, which may be different from or identical with the polymer 300. Preferably, the sealing portion may be provided at one side of the impregnated portion 111 that comprises a higher concentration of the polymer 300 than a respective other opposite side.

[0104] As mentioned before, the food packaging 100 may comprise a plurality of the impregnated portions 111. As illustrated exemplarily in FIG. 6, at least some of the impregnated portions 111 can be provided separated from each other by one or more sections 235 of the food packaging 100 comprising a lower or no concentration of the polymer 300 in comparison to said impregnated portions 111.

[0105] Alternatively or additionally, the impregnated portion 111 may extend across the entire food packaging 100 as exemplarily illustrated in FIG. 4.

[0106] Preferably, the food packaging 100 and/or at least the impregnated portion 111 may comprise an oxygen barrier. For example, the oxygen transmission rate of the (entire) food packaging 100 may be below 5 cm.sup.3/m.sup.2/day (measured at 23 C. and 50% Relative Humidity).

[0107] Alternatively or additionally, the food packaging 100 and/or at least the impregnated portion 111 may comprise a grease barrier. For example, the kit test value received in a standard grease degree repellence test may be above 10 (with the achievable maximum being 12).

[0108] Alternatively or additionally, the food packaging 100 and/or at least the impregnated portion 111 may comprise a moisture barrier. For example, the moisture transmission rate of the food packaging 100 may be below 5 g/m.sup.2/day (measured at 23 C./85% relative humidity).

[0109] Generally, the food packaging 100 may be configured such that it (despite the provision of barriers and/or the impregnated portion 111) may comprise more than 70 wt %, or 75 wt %, or 80 wt %, or 85 wt %, or 90 wt %, or 95 wt % of cellulose. In particular, the food packaging 100 may be configured in its constitution such that it may be (entirely or all of its components) recyclable preferably in the paper recycling stream, and/or such that it may be (entirely or all of its components) biodegradable.

[0110] The food packaging 100 and/or at least the impregnated portion 111 may have a thickness (e.g. thickness of the packaging wall 110) that may be 5 microns or above, 40 microns or above, 0.1 mm or above, 0.5 mm or above, 1 mm or above, 2 mm or above, 3 mm or above, 4 mm or above, 5 mm or below, 4 mm or below, 3 mm or below, 2 mm or below, 1 mm or below, 0.5 mm or below, 0.1 mm or below, or 40 microns or below, or any combination thereof.

[0111] Moreover, the food packaging 100 or, if present, the at least one packaging wall 110 may have a grammage between 30 g/m.sup.2 and 800 g/m.sup.2. More preferred, the food packaging 100 may have a grammage above 30 g/m.sup.2, above 40 g/m.sup.2, above 60 g/m.sup.2, above 80 g/m.sup.2, above 100 g/m.sup.2, above 120 g/m.sup.2, above 140 g/m.sup.2, above 160 g/m.sup.2, above 180 g/m.sup.2, above 200 g/m.sup.2, above 220 g/m.sup.2, above 240 g/m.sup.2, above 260 g/m.sup.2, above 280 g/m.sup.2, above 300 g/m.sup.2, above 320 g/m.sup.2, above 340 g/m.sup.2, above 360 g/m.sup.2, above 380 g/m.sup.2, above 400 g/m.sup.2, above 420 g/m.sup.2, above 440 g/m.sup.2, above 460 g/m.sup.2, above 480 g/m.sup.2, above 500 g/m.sup.2, above 520 g/m.sup.2, above 540 g/m.sup.2, above 560 g/m.sup.2, above 580 g/m.sup.2, above 600 g/m.sup.2, above 620 g/m.sup.2, above 640 g/m.sup.2, above 660 g/m.sup.2, above 680 g/m.sup.2, above 700 g/m.sup.2, above 720 g/m.sup.2, above 740 g/m.sup.2, above 760 g/m.sup.2, above 780 g/m.sup.2, or of 800 g/m.sup.2, and/or below 800 g/m.sup.2, below 780 g/m.sup.2, below 760 g/m.sup.2, below 740 g/m.sup.2, below 720 g/m.sup.2, below 700 g/m.sup.2, below 680 g/m.sup.2, below 660 g/m.sup.2, below 640 g/m.sup.2, below 620 g/m.sup.2, below 600 g/m.sup.2, below 580 g/m.sup.2, below 560 g/m.sup.2, below 540 g/m.sup.2, below 520 g/m.sup.2, below 500 g/m.sup.2, below 480 g/m.sup.2, below 460 g/m.sup.2, below 440 g/m.sup.2, below 420 g/m.sup.2, below 400 g/m.sup.2, below 380 g/m.sup.2, below 360 g/m.sup.2, below 340 g/m.sup.2, below 320 g/m.sup.2, below 300 g/m.sup.2, below 280 g/m.sup.2, below 260 g/m.sup.2, below 240 g/m.sup.2, below 220 g/m.sup.2, below 200 g/m.sup.2, below 180 g/m.sup.2, below 160 g/m.sup.2, below 140 g/m.sup.2, below 120 g/m.sup.2, below 100 g/m.sup.2, below 80 g/m.sup.2, below 60 g/m.sup.2, below 40 g/m.sup.2, or of 30 g/m.sup.2.

[0112] For example, the food packaging 100 may be manufactured in a process, which may comprise the steps of:

[0113] A forming step, where the body of the food packaging 100 may be formed such that the packaging interior V may be defined. For example, this may be done in a pulp molding process or with a formable cellulosic sheet material in a thermoforming process. Alternatively or additionally, the food packaging material may be folded and sealed together to form the body with the packaging interior V.

[0114] An impregnation step, where at least a portion of the material of (the body of) the food packaging 100 may be impregnated, for example in a solid impregnation process, to form the above-described impregnated portion 111 (comprising the impregnated material 230). Preferably, the impregnation step may be completed before or after the forming step.

[0115] A filling step, where the packaging interior V may be filled with the food product.

[0116] Finally, the packaging interior V may be sealed closed, e.g., by sealing the lid 112 onto the body, preferably via the sealing portions.

[0117] The invention is not limited by the embodiments as described hereinabove, as long as being covered by the appended claims. All the features of the embodiments described hereinabove can be combined in any possible way and be provided interchangeably.