Package and method for producing same

Abstract

The present invention relates to a compostable food product package comprising: a) a compostable molded tray having an inner cavity for receiving food products, an opening through which the food products can be taken, and a lip extending at least partially around the opening; b) wherein the compostable molded tray forms a compostable barrier, or wherein the compostable molded tray comprises a compostable barrier film extending over the inner cavity and lip of the tray and bonded to the inner cavity and lip of the tray by means of a paper and biofilm heat seal adhesive; and c) a compostable lid that is peelably adhered about the opening using a peelable adhesive and extends to the lip. The package is particularly suitable for producing single-serving sauce cans for fast food restaurants and take-out exports, but can also be used for single-serving cooking sauces and concentrated raw materials. The invention also relates to a method for producing such compostable food packaging.

Description

field

[0001] The present invention relates to compostable packaging and methods of producing such packaging. In particular, the present invention relates to compostable single-use packaging, which is particularly suitable for liquid foods, such as sauces. background

[0002] From an environmental point of view, single-serving packaging is problematic because not all components are usually recyclable or compostable. This may be confusing for consumers, who may not be sure how to best dispose of the packaging after use, and as a result, the packaging is usually simply placed in general waste. Some single-serving sachets or "dip" jars (such as ketchup, mayonnaise, barbecue sauce, mustard, etc.) containing sauces in fast food restaurants and take-out outlets have caused specific problems because sauces need to have a reasonable shelf life between six to twelve months, and are usually transported over long distances before being delivered to a specific restaurant or outlet. Due to the relatively small size of single-serving sachets or dip jars, these types of packaging are difficult to recycle, considering the different materials used and being contaminated by unused products. Therefore, although it would be preferred to develop recyclable packaging, considering the difficulty of accompanying small product forms, developing compostable packaging would produce more positive environmental impacts in the short term.

[0003] Due to the high water content in sauces, it has proven difficult for the packaging industry to provide suitable compostable single-serve packaging, as compostable materials typically begin to decompose rapidly in the presence of moisture.

[0004] Multi-component packaging, where the user has to physically deconstruct the packaging into individual components, has been proposed and used for many foods, such as fresh meat and fish. However, such packaging is not suitable for sauces, given the sticky and messy nature of sauces and the eating environment where the ease and speed of food consumption (and subsequent disposal of its associated packaging) is the primary driver of the experience.

[0005] There is an unmet need in the packaging industry to provide compostable single serving packages. It would be desirable for such compostable single serving packages to be fully compostable, that is, all components are compostable. It would further be desirable to provide a compostable single serving package that is suitable for use with sauces (such as ketchup) and also enables the sauce to have a long shelf life. It would also be beneficial if such a single serving package was as easy to use as existing single serving packages. SUMMARY OF THE INVENTION

[0006] It is one of the various objects of the present invention to provide a compostable packaging that addresses at least one disadvantage of the prior art, whether noted herein or elsewhere, or provides an alternative to existing compostable packaging.

[0007] According to a first aspect of the present invention, there is provided a compostable food packaging comprising:

[0008] a) a compostable molded tray having an inner cavity for receiving food, an opening through which the food can be accessed, and a lip extending at least partially around the opening;

[0009] b) wherein the compostable molded tray forms a compostable barrier, or wherein the compostable molded tray comprises a compostable barrier film extending over the inner cavity and lip of the tray and bonded to the inner cavity and lip of the tray by means of a paper and biofilm heat seal adhesive; and

[0010] c) A compostable cover releasably adhered around the opening and extending to the lip using a releasable adhesive.

[0011] The barrier or barrier film can be formed from many materials, which will be apparent to those skilled in the art. The barrier or barrier film can be formed from compostable bioresin materials. Compostable bioresin materials (particularly those suitable for the present invention) will be apparent and well understood by the skilled person. The barrier or barrier film can include polyimide and / or epoxy resin.

[0012] The barrier or barrier film may be formed from a single layer or multiple layers. If the barrier film is formed from multiple layers, each layer may be applied individually or simultaneously. The barrier or barrier film may be extruded into a sheet.

[0013] The lid may include a variety of compostable materials. Preferably, the lid is formed from cellulose and one or more polymers. The underside of the lid may include a peelable adhesive. In certain embodiments, a heat seal lacquer is used to form the peelable adhesive. The heat seal lacquer will preferably be a biodegradable or compostable lacquer. In an alternative embodiment, the peelable adhesive is a cold seal adhesive.

[0014] The heat seal adhesive may include polyurethane. The polyurethane may include one or more of the following: 5-chloro-2-methyl-4-isothiazolin-3-one and / or 2-methyl-4-isothiazolin-3-one.

[0015] Where the compostable moulded pallet comprises a compostable barrier film extending over the inner cavity and lip of the pallet and bonded to the inner cavity and lip of the pallet by means of a paper and biofilm heat seal adhesive:

[0016] - The compostable molded pallet may be a compostable molded fiber pallet. The compostable molded fiber pallet may be a dry molded fiber pallet. Alternatively, the molded fiber pallet may be wet molded or semi-wet molded.

[0017] The heat seal adhesive may be applied at a dry coating weight in the range of about 10 gsm to about 24 gsm. Preferably, the heat seal adhesive is applied at a dry coating weight in the range of about 12 gsm to about 20 gsm. More preferably, the heat seal adhesive is applied at a dry coating weight in the range of about 14 gsm.

[0018] - Preferably, the barrier film thickness may be greater than or equal to about 110 μm. More preferably, the barrier film thickness is greater than or equal to about 135 μm. Most preferably, the barrier film thickness is greater than or equal to about 150 μm.

[0019] - In highly preferred embodiments, the thickness of the barrier film may be in the range of about 150 μm to about 170 μm.

[0020] - The barrier film may be extruded into a sheet and / or directly onto the molded fiber tray. The barrier film may be at least partially sprayed onto the tray.

[0021] - The barrier film may be thermoformed at a temperature in the range of about 100°C to about 110°C.

[0022] In the case of compostable molded trays forming a compostable barrier:

[0023] The thickness of the compostable barrier may be in the range of about 100 μm to about 600 μm, preferably in the range of about 400 μm to about 600 μm.

[0024] The compostable barrier may be about 400 μm thick and may be formed of three layers, each layer being about 130 μm thick.

[0025] - Each layer may be formed from a compostable bio-resin material.

[0026] - The middle layer may comprise a compostable material that acts as an oxygen scavenger, for example where the middle layer comprises plant by-products such as those derived from coffee bean skins.

[0027] - The compostable barrier may be thermoformed at a temperature in the range of about 100°C to about 170°C, preferably in the range of about 100°C to about 120°C, most preferably in the range of about 105°C to about 120°C.

[0028] - The compostable barrier can be thermoformed with a thermoforming residence time of less than about 1000 ms, preferably with a thermoforming residence time of less than about 800 ms, most preferably with a thermoforming residence time of less than about 700 ms.

[0029] - The method may comprise urging the lid towards the opening under heating conditions so as to heat seal the cavity with the lid, preferably at a temperature less than about 200°C, more preferably at a temperature equal to or less than 170°C, most preferably at a temperature in the range of about 160°C to 170°C.

[0030] In the case of compostable molded trays forming a compostable barrier:

[0031] - The compostable molded tray may be impregnated with a compostable barrier material, for example by dispersing the barrier material in the fibers of the compostable molded fiber tray in the region of or near the inner cavity. This may be referred to as an integrally formed or integrally provided compostable molded tray with a compostable barrier.

[0032] In an embodiment related to the first aspect, there is provided a compostable food package comprising:

[0033] a) a compostable molded fiber tray having an inner cavity for receiving food, an opening through which the food can be accessed, and a lip extending at least partially around the opening;

[0034] b) a spray-applied compostable barrier film extending over and bonded to the interior cavity and lip of the pallet; and

[0035] c) A compostable cover releasably adhered around the opening and extending to the lip using a releasable adhesive.

[0036] In an embodiment further related to the first aspect, there is provided a compostable food package comprising:

[0037] a) a compostable molded fiber tray having an inner cavity for receiving food, an opening through which the food can be accessed, and a lip extending at least partially around the opening;

[0038] b) a compostable barrier material impregnated throughout said molded fiber tray; and

[0039] c) A compostable cover releasably adhered around the opening and extending to the lip using a releasable adhesive.

[0040] The food package will further preferably include food in the cavity. This food can be liquid food. The food can be a sauce, such as a condiment, and can be one or more of the following: ketchup, barbecue sauce, mayonnaise, mustard, hot sauce, ranch salad dressing, curry sauce, and sweet and sour sauce.

[0041] According to a second aspect of the present invention, there is provided a method for producing a compostable food packaging, comprising:

[0042] a) providing a compostable molded tray having an inner cavity for receiving food, an opening through which the food can be accessed, and a lip extending at least partially around the opening;

[0043] b) wherein said providing a compostable moulded tray forms a compostable barrier film, or wherein said method further comprises applying and / or forming and bonding a compostable barrier film over said inner cavity and lip of said tray by means of a paper and biofilm heat seal;

[0044] c) providing a compostable cover and applying it around said opening and at least a portion of said lip with the aid of a compostable peelable adhesive; and

[0045] d) urging the cover toward the opening under heating to heat seal the cavity with the cover.

[0046] Prior to step c), a liquid food may be placed in the cavity.

[0047] Step d) may be performed at about 120°C and / or at about 450 lbf and / or for about 1 second.

[0048] Where the method comprises applying and / or forming and incorporating a compostable barrier film:

[0049] - The bond strength between the barrier film and the tray is stronger than the bond created by the heat seal adhesive between the barrier film and the compostable cover.

[0050] -The barrier film can be applied to the inner cavity and lip of the tray by applying hot air to the film and applying negative pressure to the outside of the tray. The hot air can be in the range of about 120°C and 140°C, but is preferably in the range of about 136°C. In another embodiment, the hot air can be in the range of about 100°C to about 110°C. The hot air is dispensed using a hot air gun. The hot air gun can be moved from a distance of about 200 mm from the barrier film to a distance of about 100 mm from the barrier film for up to about 2 to about 4 seconds. The hot air gun can be moved from a distance of about 190 mm from the barrier film to a distance of about 85 mm from the barrier film for about 4 seconds.

[0051] - The barrier film may be at least partially applied to the inner cavity and the lip of the tray by spraying.

[0052] Where a compostable moulded tray is provided to form a compostable barrier:

[0053] - The compostable barrier may be thermoformed at a temperature in the range of about 100°C to about 170°C, preferably in the range of about 100°C to about 120°C, most preferably in the range of about 105°C to about 120°C.

[0054] The compostable barrier may be thermoformed with a thermoforming residence time of less than about 1000 ms, preferably with a thermoforming residence time of less than about 800 ms, most preferably with a thermoforming residence time of less than about 700 ms.

[0055] - Driving may preferably be performed at a temperature of less than about 200°C, more preferably at a temperature equal to or less than 170°C, most preferably at a temperature in the range of about 160°C to 170°C.

[0056] In the case of compostable molded trays forming a compostable barrier:

[0057] - The compostable moulded tray may be impregnated with the compostable barrier material, for example by the barrier material being dispersed in the fibres of the compostable moulded fibre tray in the region of or near the inner cavity.

[0058] - The compostable molded tray and the compostable barrier material may be integrally formed.

[0059] In an embodiment related to the second aspect, there is provided a method of producing a compostable food packaging comprising:

[0060] a) providing a compostable molded fiber tray having an inner cavity for receiving food, an opening through which the food can be accessed, and a lip extending at least partially around the opening;

[0061] b) applying and / or forming a compostable barrier film thereon by spraying the compostable barrier onto the inner cavity and over the lip of the tray;

[0062] c) providing a compostable cover and applying it around said opening and at least a portion of said lip with the aid of a compostable peelable adhesive; and

[0063] d) urging the cover toward the opening under heating to heat seal the cavity with the cover.

[0064] In an alternative embodiment of the second aspect, there is provided a method of producing a compostable food packaging comprising:

[0065] a) providing a compostable molded fiber tray having an inner cavity for receiving food, an opening through which the food can be accessed, and a lip extending at least partially around the opening;

[0066] b) saturating the compostable barrier material throughout the tray;

[0067] c) providing a compostable cover and applying it around said opening and at least a portion of said lip with the aid of a compostable peelable adhesive; and

[0068] d) urging the cover toward the opening under heating to heat seal the cavity with the cover.

[0069] The method of the second aspect (and related embodiments) may be used to produce a compostable food packaging according to the first aspect (and related embodiments).

[0070] The invention is described below with reference to the accompanying drawings, which are given by way of example only, in which:

[0071] Figure 1 is a perspective cutaway view of an embodiment of a compostable packaging according to the present invention.

[0072] Figure 2 Yes Figure 1 Schematic cross-section of a compostable package in area X indicated.

[0073] Figure 3 Photographs showing a barrier film being applied to a 3D molded fiber tray using an SLA thermoforming tool, wherein (A) shows the SLA thermoforming tool, (B) shows the film formed after 2 seconds and at 75% heat on the top and bottom, and (C) shows the film formed after 5 seconds and at 75% heat.

[0074] Figure 4 is a perspective view of a plug assist tool used to evaluate whether the tool will be suitable for applying a barrier film to a 3D molded fiber tray.

[0075] Figure 5 is a schematic diagram of the process used to apply the barrier film to the 3D molded fiber tray.

[0076] Figure 6 are photographs of a 150 μm barrier film that has been deformed and applied to a transparent 3D molded tray, where (A) and (B) are plan views of the combined film and tray, and (C) and (D) are side views of the combined film and tray.

[0077] Figure 7 is a graph showing the results of the water vapor transmission rate (WVTR) of various barrier films tested during the trial.

[0078] Figure 8 is a graph showing the results of the oxygen transfer rate (OTR) of various barrier films tested during the trial.

[0079] Fig. 9 is a graph showing peel test results of lidding films applied to lined cans tested during the trial.

[0080] Fig.10 is a graph that plots current lid peel benchmarks and target adhesion strengths for plastic 3D molded trays.

[0081] Fig.11 is a graph showing barrier liner adhesion to a fiber tank versus adhesive grammage.

[0082] Fig.12 is a perspective cutaway view of an alternative embodiment of a compostable package according to the present invention.

[0083] Fig.13 Yes Fig.12 Schematic cross section of a compostable packaging shown.

[0084] Example

[0085] Example 1 - Compostable Sauce Container

[0086] Figure 1 A compostable container according to the present invention is shown. The container 10 is formed of a compostable fiber molded tray 12 having an inner surface covered by a compostable barrier film 14. The molded tray 12 has a lip 16 extending outwardly and around the opening of the tray, and the barrier film 14 extends over the lip 16. A compostable lid 18 is adhered to the barrier film 14 around the lip 16 by means of a peelable adhesive 20. Figure 1 The illustrated container 10 also has a liquid food product 22 , such as ketchup, located within the tray 12 . Figure 2 Shows Figure 1 1 is a cross-section of the area marked X in FIG. 1 and illustrates the delamination of the various components in the lip area to which the cap 18 is adhered.

[0087] The molded tray 12 can be formed of any compostable material and can be wet or dry fiber molded. In one embodiment, the molded tray 12 is pre-3D molded into the desired shape before the barrier film 14 is attached or applied to the inner surface. In another embodiment, the molded tray 12 is 3D molded into the desired shape while the barrier film 14 is applied to the inner surface - that is, the tray 12 and the barrier 14 are molded together at the same time. In certain embodiments, an adhesive (not shown) is used between the barrier film 14 and the molded tray 12. In other embodiments, no adhesive is used between the barrier film 14 and the molded tray 12, and the barrier film 14 is adhered to the inner surface of the molded tray 12 by means of a forming or driving process or by spraying the barrier film 14 directly onto the molded tray 12.

[0088] The molded tray may be formed using a method of dry molding a fiber matrix using cellulosic fibers. This method may form a multi-layer cellulosic blank structure, wherein the method includes the steps of: forming the multi-layer cellulosic blank structure from at least one first layer of dry-formed cellulosic fibers and a second layer of a cellulosic fiber web structure by arranging the at least first layer and the second layer in an overlapping relationship with each other and arranging the at least first layer and the second layer in contact with each other in the overlapping relationship; arranging the multi-layer cellulosic blank structure in a forming mold; heating the multi-layer cellulosic blank structure to a forming temperature in the range of about 100° C. to about 300° C., and forming a cellulosic product from the multi-layer cellulosic blank structure in a forming mold by pressing the heated multi-layer cellulosic mold blank structure at an isostatic forming pressure of at least about 1 MPa, preferably 4-20 MPa, wherein the multi-layer cellulosic blank structure is formed into a two-dimensional or three-dimensional fiber composite structure having a single-layer configuration. Alternatively, the molded pallet can be formed by a process utilizing a web of fibrous cellulosic material derived from wood pulp, the web being suitable for three-dimensional molding to form a packaging product, wherein the web comprises about >40% by weight softwood chemical pulp and at least one strength enhancer, wherein the web has a strength of less than about 400 g / m 2 and wherein the cellulose fibers of the softwood chemical pulp comprise about >9% fiber curl.

[0089] Alternatively, the molded tray may be formed using a method of wet or semi-wet molding a fiber matrix using cellulose fibers, wherein a wet or semi-wet cellulose material is delivered to a mold and formed into a 2D or 3D shape using a forming tool for forming a three-dimensional product from a wet or semi-wet cellulose material. The forming may be performed by means of thermoforming or other forming methods that form and dry the cellulose material into the shape of the mold.

[0090] The barrier film 14 can be formed of any suitable compostable film having appropriate moisture and oxygen barrier properties. It will be appreciated by those skilled in the art that the moisture and oxygen barrier properties will be determined by the form and type of food to be held in the container. Typically, the container will be used for fluid foods with a relatively high water content, such as ketchup. The moisture properties will need to prevent moisture from being lost from the food through the matrix used to form the molded tray. The oxygen barrier properties will need to prevent oxygen from flowing into the container in order to prevent oxidation of the undesirable food.

[0091] The barrier film 14 may be formed from a variety of materials. The barrier film may be formed from a compostable bio-resin material. In one embodiment, the barrier film 14 will be formed from one or more layers of modified polybutylene succinate (PBS).

[0092] The lid 18 can be formed from a variety of materials. Preferably, the lid 18 is formed from a composite cellulose and polymer material. More preferably, the lid 18 is formed from a composite of cellulose and a polymer resin or cellulose and PBS. The cellulose can be methylcellulose or other variants of cellulose. Typically, the lid will contain graphics and other printed materials indicating the food in the container, as well as instructions for peeling off the lid and disposing of the container after use. The graphics or other printed materials will preferably be made of compostable and food-safe inks.

[0093] The adhesive may be a food safe compostable heat seal.

[0094] Example 2 - Thermoforming Test

[0095] Thermoforming trials were conducted on various barrier liners to evaluate the best method and liner for use in conjunction with preformed 3D dry-formed moulding trays.

[0096] Two films were provided for thermoforming trials, the first being a 110 μm composite film formed from 30 μm / 50 μm / 30 μm layers and the second being a 150 μm composite film formed from 50 μm / 50 μm / 50 μm.

[0097] It should be understood that the film thicknesses described herein are examples only. In some experiments, film thicknesses in the range of about 150 μm to about 170 μm were employed.

[0098] Stage 1 - Thermal properties (110μm film)

[0099] like Figure 3 As shown, the test results indicate that the film is not thermoformable like conventional films. The main observation is that heating the film too much or for too long makes it brittle. Moreover, it is expected that from the beginning of this stage, plug assistance will be required to fully form the liner into the can, and vacuum alone will not be sufficient. Using the SLA thermoforming tool, its

[0100] Stage 2 - Plug Assisted Formation (110 μm Film)

[0101] To improve the forming %, a plug assist tool was machined to apply pressure into the corners of the membrane. Figure 4 An embodiment of a plug assist tool is shown, wherein the tool 100 is formed of a flat base 102 having a shaped cavity 104 shaped to the outer dimensions of a preformed tray 106, and a press 108 having a plug 110 extending downwardly toward the cavity formed therein, and the plug is shaped to the inner dimensions of the preformed tray 106. In use, the press 108 is operated in a vertical direction to press a film (not shown) into the preformed tray as the plug 110 is urged toward the forming cavity 104. Unfortunately, this approach has been found to be unsuccessful because the temperature sensitivity and crystallization of the film means that by the time the plug can reach the mold (once the heater platen is retracted), the film has cooled and is no longer formable.

[0102] Stage 3 - Hot Air Gun Method (110μm Film)

[0103] Due to the sensitivity of the formed film, a hot air gun was used to evaluate whether the method would help form a barrier film on the inner surface of the preformed tray. The results of the test were that >140°C resulted in cracking, 120°C to 140°C resulted in good formation, and <120°C resulted in poor formation.

[0104] Alternative tests were conducted in the range of about 100° C. to about 110° C. This was found to also result in good formation.

[0105] During trials, attempts were made to bring the film up to temperature in a rapid time space (2-4 seconds) using a hot air gun method. The concept was that the positive heat flow towards the film also assisted the vacuum through the tray to aid formation, but in a short (controllable) cycle time. The method resulted in approximately 70% formation of a 110 μm film in the can.

[0106] Stage 4a - Positive Pressure Test (110 μm Membrane)

[0107] Since the hot air gun forming method obtained encouraging results, it is expected that by applying high concentrations of pressure and hot air flow during forming, the ultimate stretching / flow of the film into the corner can be achieved. Positive pressure forming on 110μm film ensures that this method can lead to improved performance. A formation percentage of 81% was achieved. In addition to this, the positive pressure method resulted in a low level of adhesion of the film to the can (no adhesive on the film is required).

[0108] Stage 4b ​​- Positive pressure test with hot air gun (150μm membrane)

[0109] Unfortunately, the 150 μm film formed using positive pressure did not give the same improvement compared to the hot air gun method. It was found that the film would fill the cavity to a similar % when utilizing a hot air gun. Since the hot air method was easier to control, the results for the 150 μm film were calculated based on the hot air gun method.

[0110] Thermoforming Optimization

[0111] The progress of the experiments to optimize the thermoforming conditions is detailed in Table 1 below.

[0112]

[0113] Table 1

[0114] The final thermoforming parameters using a hot air gun have been Figure 5 This is believed to be the optimum circulation to be consistently formed into the container.

[0115] To calculate the percent formation of the liner, each liner was filled to full capacity with water and the % fill weight was compared to the theoretical fill weight of 28 g.

[0116] 100% formed into the tank (150μm film)

[0117] Thermoforming optimization defined optimal parameters for the 110 μm and 150 μm films (e.g., stretching each film to its threshold). However, the trials were able to show a maximum formation of 94%. It is believed that this is due to differences between the specified films and the films provided for testing.

[0118] The material analysis measured that the 150μm film thickness totaled closer to 136μm than 150μm. This means that the thermoforming results correlate as follows:

[0119] 110μm (73% target thickness) → maximum formation = 81%

[0120] 135μm (90% target thickness) → Maximum formation = 94%

[0121] The following inferences are reasonable to draw from these results:

[0122] 150μm film → Maximum formation >= 100%

[0123] Figure 6 150μm film deformation pattern (when "very well" formed into a cavity) is shown with line spacing = ~5mm. Key observations are that very little stretching of the film around the cavity (wrinkles due to forming sequence & test equipment limitations) is observed as well as evidence of 100% formation.

[0124] The final thermoforming parameters using a hot air gun have been Figure 8 It is believed that this is the optimum circulation to be consistently formed into the tank.

[0125] To calculate the percent formation of the liner, each liner was filled to full capacity with water and the % fill weight was compared to the theoretical fill weight of 28 g.

[0126] Example 3 - Barrier membrane test

[0127] 3D barrier testing of water vapor transmission rate and oxygen transmission rate was performed using a range of barrier film substrates and thicknesses, with the results being Figure 7 and 8 Shown in.

[0128] The differences in water vapor transmission rate and oxygen transmission rate for various film thicknesses for 2D and 3D films are listed below in Tables 2 and 3, respectively.

[0129]

[0130] Table 2

[0131]

[0132] Table 3

[0133] The results showed that the 110 μm film formed 81% of the packing, while the 135 μm film formed 94% of the packing.

[0134] These trials showed that the oxygen barrier achieved in 3D form is very good and directly equivalent to the current best performing containers using plastic pallets.

[0135] Water vapour transmission is slightly higher than the current best performing container using a plastic tray, however this is within the range of theoretical barriers and can still be improved incrementally using 150 μm films.

[0136] The formed 3D tanks used for testing were formed; 81% for 110 μm film and 94% for 135 μm film. This is due to thermoforming / film stretching limitations.

[0137] All successful tests conducted to date indicate that the 150 μm membrane based on a modified PBS matrix is ​​suitable for moving forward into shelf life testing studies.

[0138] Example 4 - Lidding Film Test

[0139] The purpose of these tests was to explore whether certain preferred lidding films were compatible with heat sealing to preferred modified PBS barrier films and whether the biodegradable adhesives provided a sufficiently strong bond when activated in the thermoforming process.

[0140] The test membranes used in the experiments are detailed in Table 4 below.

[0141]

[0142] Table 4

[0143] Test preparation and parameters are as follows: Test bar: 25mm x 150mm; Sealing temperature: 120°C (maximum temperature that can be applied before adversely affecting the liner); Sealing pulse: 1 second; Sealing pressure: 450lbf; Test method: ASTM D1876 (T-peel); Peel rate: 300mm.min -1 .

[0144] Fig. 9 The results of the peel test were compared with the target level of 5 N. It also showed that all values ​​were significantly below the defined upper limit of 10 N.

[0145] The peeled test strips were visually evaluated for failure mode as detailed in Table 5 below.

[0146]

[0147] Table 5

[0148] The film variants with the PBS heat seal layer consistently provided a stronger bond to the backing film. Although Con D showed comparable performance to Con B, the variation in the results was greater, so due to the consistency of the results there will be more confidence in the progress of both films based on PBS as the adhesive layer.

[0149] The peel strength of both Con A & Con B is in the target force region.

[0150] The triple film peel strength display gives the greatest bond to the liner, as the force required for peeling results in delamination of the liner. This should be considered the "bulletproof" option moving forward and can be used for testing in situations where liner peelability is not part of the evaluation criteria and a strong bond is required.

[0151] Example 5 - Adhesive Testing

[0152] Trials were conducted to determine the best peelable adhesive to use.There are several methods of applying adhesive to the construction of a can, each with varying levels of complexity to implement and maintain (from a workmanship quality perspective).

[0153] In order to determine the baseline force required for the adhesive to target, the current McCormick cans were peel tested to show the peak force considered sufficient for consumer use. A custom test rig was created to perform this peel evaluation. Table 6 details the specifications for the variant tested and calls out the 2 different failure forces found in the 10 repeated evaluations.

[0154]

[0155] Table 6

[0156] To be cautious, the test focused on obtaining a safety factor above the maximum mean force recorded. A view of how this can be expressed is in Fig.10 The target range for liner adhesion is 10-15 N, and 5 N is defined as the cover film adhesion. The peel rate is 120 mm.min. -1 .

[0157] In all tested variations, the biodegradable adhesive was found to be compatible with thermoforming, Plantic / modified PBS film and molded dry fiber tray substrates. Fig.11 As shown, the liner peel test also indicated that a dry grammage of about 24 gsm provided sufficient adhesion to the liner to cause delamination of the lining of the slurry tank. This was the maximum adhesion obtainable.

[0158] The biodegradable adhesive selected was a paper and biofilm heat seal adhesive with direct food contact approval. The recommended sealing conditions were >100°C, 20psi, 0.5 seconds.

[0159] The adhesive was applied to the modified PBS substrate at a dry coating weight of 14 gsm, but experiments have shown that a range of 10-24 gsm would also be acceptable.

[0160] The binder is a mixture of 5-chloro-2-methyl-4-isothiazolin-3-one [EC No 247-500-7] {3 parts}, and 2-methyl-4-isothiazolin-3-one [EC No 220-239-6] {1 part}, and has the following properties:

[0161] Appearance: Off-white liquid

[0162] Viscosity: about 150cP, Brookfield sp2, 50rpm, 20℃

[0163] Solid content: about 40%

[0164] Specific gravity: about 1.05g / ml.

[0165] PH: 8-9

[0166] Cleaning: Water

[0167] Shelf life: 6 months

[0168] Advantageously, the adhesive is compatible with thermoformed, modified PBS barrier liner films and molded fiber matrices while being compostable and food safe.

[0169] Example 6 - Alternative Compostable Sauce Container

[0170] Fig.12 An alternative compostable container 10' according to the present invention is shown. The alternative compostable container 10' is similar to Figure 1 (and Figure 2 ) is shown as a compostable container 10. However, the container 10' does not require a compostable molded fiber tray 12, but rather a tray (and barrier film) formed from a single material, such as a thicker barrier film, to form the barrier itself.

[0171] The container 10' is formed from a compostable molded tray 12'. The compostable molded tray 12' forms a barrier membrane 14'. In this embodiment, the tray 12' is formed from the barrier membrane 14', and in this way, the tray 12' itself forms the barrier membrane 14'. This may alternatively be described as a tray 12' providing the barrier membrane 14'. With respect to the alternative container 10', the barrier membrane 14' may be referred to as a "barrier layer 14'" and actually form a barrier. The molded tray 12' has a lip 16' extending outwardly and around the opening of the tray 12'. The compostable lid 18' is adhered to the barrier membrane 14' around the lip 16' by means of a releasable adhesive 20'. Similar to Figure 1 The container 10 shown in Fig.12 The container 10' shown in FIG. 1 has an inner cavity in which a liquid food product 22' (such as ketchup) is contained.

[0172] Fig.13 Shows Fig.12 1 is a cross-section of the area marked X' in FIG. 1 and illustrates the delamination of the various components in the lip region to which the cap 18' is adhered. Fig.13 , a cross section X' of a compostable container is shown, which is formed of a thick molded compostable barrier film 14'. A compostable lid 18' is adhered to the barrier film 14' by means of a peelable adhesive 20'. By omitting the molded dry fiber tray component, and using the barrier film (e.g., using the same material as the barrier film) to form the tray, fewer components are used, which improves the efficiency of production and reduces the cost and time of manufacturing.

[0173] exist Fig.12 and 13In the embodiment shown, the thick molded compostable barrier film 14' can be formed by lamination of multiple layers or via extrusion before or during shape formation. Preferably, the thickness of the barrier film 14' is in the range of about 100 μm to about 600 μm, for example, in the range of about 400 μm to about 600 μm. Most preferably, the thickness of the barrier film 14' is about 400 μm and is formed by three layers, wherein each layer is about 130 μm thick. In an embodiment, each layer is formed by a compostable bioresin material. In certain embodiments, each layer is formed by the same modified PBS material. In other embodiments where a more robust barrier is required, an intermediate layer may include a compostable material as an oxygen scavenger. Such an intermediate layer may include plant byproducts, such as those derived from coffee bean skins.

[0174] Fig.12 and 13 The manufacturing parameters and performance parameters of the embodiments of can be understood from the following Table 7, in which the embodiments are compared with similarly constructed containers formed from polypropylene (PP) barrier films:

[0175]

[0176] Table 7

[0177] As will be appreciated from Table 7 above, alternative containers can be formed at lower thermoforming temperatures, thereby reducing energy usage and reducing degradation of equipment used in the thermoforming process. Additionally, by thermoforming at lower temperatures, faster manufacturing can be facilitated because heating time and / or cooling time can be reduced.

[0178] Further, the residence time is reduced compared to similar containers formed from PP barrier films. Advantageously, this reduces energy usage and reduces degradation of manufacturing equipment.

[0179] Further, lower sealing temperatures can be used. Advantageously, this reduces energy usage and reduces degradation of manufacturing equipment. This also increases the speed of the manufacturing process.

[0180] It is noteworthy that, as will be appreciated from the above, the WVTR is improved.

[0181] The optional features described herein may be used alone or in combination with each other where appropriate, particularly in the combinations described in the appended claims. Where appropriate, the optional features of each aspect or exemplary embodiment of the invention described herein should also be understood to be applicable to any other aspect or exemplary embodiment of the invention where appropriate. In other words, the technician reading this specification should regard the optional features of each exemplary embodiment of the invention as interchangeable and combinable between different exemplary embodiments.

[0182] Attention is paid to all papers and documents filed concurrently with or prior to this specification in conjunction with this application and are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

[0183] All features disclosed in this specification (including any accompanying claims and drawings) and / or all steps of any method or process so disclosed may be combined in any combination, except combinations in which at least some of such features and / or steps are mutually exclusive.

[0184] Unless expressly stated otherwise, each feature disclosed in this specification (including any attached claims and drawings) may be replaced by alternative features for the same, equivalent or similar purpose. Therefore, unless expressly stated otherwise, each feature disclosed is only an example of a series of general equivalent or similar features.

[0185] The invention is not limited to the details of the foregoing one or more embodiments. The invention extends to any novel one or any novel combination of the features disclosed in this specification (including any attached claims and drawings), or to any novel one or any novel combination of the steps of any method or process disclosed in this manner.

Claims

1. A compostable food package, comprising: a) a compostable molded tray having an inner cavity for receiving food, an opening through which the food can be accessed, and a lip extending at least partially around the opening; b) wherein the compostable molded tray forms a compostable barrier, or wherein the compostable molded tray further comprises a compostable barrier film extending over the inner cavity and lip of the tray and bonded to the inner cavity and lip of the tray by means of a paper and biofilm heat seal adhesive; and c) A compostable cover releasably adhered around the opening and extending to the lip using a releasable adhesive.

2. The food packaging according to claim 1, wherein the barrier or the barrier film is formed from a compostable bio-resin material.

3. Food packaging according to claim 1 or claim 2, wherein the barrier or the barrier film is formed from a plurality of layers.

4. A food package according to any preceding claim, wherein the compostable moulded tray is a compostable moulded fibre tray, optionally a compostable dry moulded fibre tray.

5. The food package of any preceding claim, wherein the compostable molded tray comprises a compostable barrier film extending over the inner cavity and lip of the tray and bonded to the inner cavity and lip of the tray by means of a paper and biofilm heat seal adhesive, and wherein the barrier film has a thickness greater than or equal to about 110 μm.

6. The food package of claim 5, wherein the barrier film has a thickness greater than or equal to about 135 μm.

7. The food package of claim 6, wherein the barrier film has a thickness greater than or equal to about 150 μm.

8. The food package of claim 7, wherein the barrier film has a thickness in the range of about 150 μm to about 170 μm.

9. The food package of any preceding claim, wherein the heat seal adhesive is applied at a dry coating weight in the range of about 10 gsm to about 24 gsm.

10. The food package of any preceding claim, wherein the heat seal adhesive is applied at a dry coating weight in the range of about 12 gsm to about 20 gsm.

11. A food package according to any preceding claim, wherein the heat seal adhesive is applied at a dry coating weight in the range of about 14 gsm.

12. A food package according to any preceding claim, wherein the barrier or the barrier film is at least partially sprayed onto the tray or impregnated into the tray.

13. The food packaging of claims 1 to 3, wherein the compostable molded tray forms a compostable barrier film, wherein the barrier film has a thickness ranging from about 400 μm to about 600 μm.

14. The food packaging of claims 1 to 3 and 13, wherein the compostable molded tray forms a compostable barrier film, wherein the compostable molded tray and the compostable barrier film are integrally formed.

15. A food package according to any preceding claim, wherein the lid comprises cellulose and a polymer.

16. A food package according to any preceding claim, wherein the heat seal adhesive comprises polyurethane.

17. The food packaging of claim 16, wherein the polyurethane comprises one or more of the following: 5-chloro-2-methyl-4-isothiazolin-3-one and / or 2-methyl-4-isothiazolin-3-one.

18. A food product package according to any preceding claim, wherein the food product package further comprises food within the cavity.

19. The food package of claim 18, wherein the food is a liquid food.

20. The food package of claim 19, wherein the food is a sauce.

21. The food package of claim 20, wherein the condiment is selected from one or more of the following: ketchup, barbecue sauce, mayonnaise, mustard, hot sauce, ranch dressing, curry sauce, and sweet and sour sauce.

22. A method of producing compostable food packaging, the method comprising: a) providing a compostable molded tray having an inner cavity for receiving food, an opening through which the food can be accessed, and a lip extending at least partially around the opening; b) wherein said providing a compostable moulded tray forms a compostable barrier, or wherein said method further comprises applying and / or forming and bonding a compostable barrier film over said inner cavity and lip of said tray by means of a paper and biofilm heat seal adhesive; c) providing a compostable cover and applying it around said opening and at least a portion of said lip with the aid of a peelable adhesive; as well as d) urging the cover toward the opening under heating to heat seal the cavity with the cover.

23. The method of claim 22, wherein the method comprises applying and / or forming and bonding a compostable barrier film over the inner cavity and lip of the pallet with the aid of a paper and biofilm heat seal adhesive, wherein the barrier film is applied to the inner cavity and lip of the pallet by applying hot air to the film and applying negative pressure to the exterior of the pallet.

24. The method of claim 23, wherein the hot air is in the range of about 100°C to about 140°C.

25. The method of claim 24, wherein the hot air is in the range of about 100°C to about 110°C.

26. A method according to any of claims 23 to 25, wherein the hot air is dispensed using a hot air gun.

27. The method of claim 26, wherein the hot air gun is moved from a distance of about 200 mm from the barrier membrane to a distance of about 100 mm from the barrier membrane for up to about 2 to about 4 seconds.

28. The method of claim 27, wherein the hot air gun moves from a distance of about 190 mm from the barrier membrane to a distance of about 85 mm from the barrier membrane in about 4 seconds.

29. The method of claim 22, wherein the method comprises applying and / or forming and bonding a compostable barrier film over the inner cavity and lip of the pallet with the aid of a paper and biofilm heat seal adhesive, wherein the barrier film is at least partially applied to the inner cavity and lip of the pallet by spraying.

30. The method of any one of claims 22 to 29, wherein step d) is performed at about 120°C and / or at about 450 lbf and / or for about 1 second.

31. The method of claim 22, wherein: The compostable molded tray is provided to form a compostable barrier, wherein the compostable barrier is thermoformed at a temperature in the range of about 100°C to about 170°C, preferably at a temperature in the range of about 100°C to about 120°C, and most preferably at a temperature in the range of about 105°C to about 120°C.

32. The method of claim 31 , wherein the compostable barrier is thermoformed with a thermoforming residence time of less than about 1000 ms, preferably with a thermoforming residence time of less than about 800 ms, most preferably with a thermoforming residence time of less than about 700 ms.

33. The method of claim 22, 31 or 32, wherein step d) is formed at a temperature less than about 200°C, preferably at a temperature equal to or less than 170°C, most preferably at a temperature in the range of about 160°C to 170°C.

34. The method of claim 22 or 31 to 33, wherein the compostable molded tray forms a compostable barrier, wherein the compostable molded tray and the compostable barrier are integrally formed.

35. A method according to any one of claims 22 to 34, wherein prior to step c), a liquid food is placed in the cavity.

36. A method according to any one of claims 22 to 35 for producing a compostable food packaging according to any one of claims 1 to 21.

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