Moisture-Barrier Packaging

The present application claims priority to earlier European application No EP22172784-5 filed on May 11, 2022 in the name of AISAPACK HOLDING SA, the content of this earlier application being incorporated in its entirety by reference in the present application.

The field of the invention is packaging based on biosourced and/or biodegradable and/or recyclable materials. The invention relates more specifically to packaging with low environmental impact. The invention applies to cylindrical packagings that require good moisture-barrier properties. The invention applies in particular to cellulose-based packaging. The invention is notably in the field of packaging for dry products.

Publication US 2013/153586 discloses a package for ice cream consisting of a) a container component made of polystyrene comprising a base and a side wall extending from the perimeter of the base to form the cavity of the container component, and b) a closing means removable manually and comprising a top side adapted to seal the cavity of the container component and a side wall extending from the perimeter of the top side and adapted to encircle the side wall of the container component.

Publication U.S. Pat. No. 5,348,180 discloses a container having a tamper-evident seal. The container, suitable for receiving and shipping various products, includes a hollow body member and a removable cover positioned on an open upper end of the body member and has a tamper-evident seal device connecting the body member and the cover to evidence any premature removal of the cover. The seal device includes two sets of superimposed apertures extending through the body member and the cover, a closed sealing wire or member extending through the sets of apertures and around respective inside and outside portions of the body member and cover between the sets of apertures and being sealed to form a closed loop. A patch member is secured to the inside surface of the body member and covers the apertures to prevent contaminants from entering the container through the apertures and to strengthen the area of the body member having the apertures. The patch member preferably defines a guided passageway between the apertures so that the sealing wire may be inserted through one set of the apertures, guided through the passageway and passed out through the other set of the apertures.

Publication JP 2021 137982 discloses a double-sided laminated paper and paper-cup.

The invention is in field of packaging and in particular tubular packagings based on biosourced or biodegradable or recyclable materials for preserving dry products. According to a preferred embodiment, the packaging is based on cellulose and can be recycled in the paper industry. The packaging comprises at least one container and a lid which slides over the said container and the packaging retains good moisture-barrier properties throughout its service life.

The invention more specifically relates to a tubular packaging comprising a container and a close-fitting lid that slides over the outer surface of the container over a height referred to as “sealing height”. More specifically, and in some embodiments, the invention relates to a packaging formed by two tubular bodies of slightly different diameters, one of the said bodies forming the container, and the other one of the said bodies forming the lid. According to the invention, the lid has a diameter slightly larger than that of the container and it is push-fitted onto and slides over the outer surface of the container with a clearance necessary for the opening and closing operations. In the closed position of the packaging, the wall of the lid is superposed on the wall of the container over a sealing height which ensures the moisture barrier of the packaging, even after the first opening or subsequent opening of the packaging.

According to the invention, the container and the lid are based on biosourced or biodegradable or recyclable materials and comprise at least one layer providing the moisture-barrier properties.

According to the preferred embodiment of the invention, the container and the lid are based on cellulose and comprise at least one cellulose-based structural layer and one functional layer providing the moisture-barrier properties.

Surprisingly, it has been shown that a cellulose-based tubular packaging formed by a container and a lid which is push-fitted onto and slides over the outer wall of the container according to the principles of the present invention can, in certain conditions explained in the rest of the present description, have identical or even improved barrier properties in relation to the same container were it to be closed by a sealed lid.

More specifically, it has been shown that, to provide the improved barrier properties mentioned above, the radial clearance between the outside diameter of the container and the inside diameter of the lid must be between 0.05 mm and 0.25 mm, and preferably between 0.1 mm and 0.2 mm.

Similarly, it has been shown that the sealing length (that is, the length of the push-fit between the container and the lid) must be greater than 50 mm and preferably greater than 100 mm.

According to the invention, the packaging is based on materials that are recyclable or biodegradable and/or originate from renewable resources.

According to a preferred embodiment of the invention, the packaging is based on cellulose and can be recycled at the end of its life in the paper industry. Preferably, the cellulose content of the packaging is greater than 85% and advantageously greater than 90%. Preferably, the cellulose content of the packaging and that of the lid are identical or similar. In another embodiment, these contents may be different.

According to the invention, the packaging may also have air inlet and outlet means which make it easier to open and close the packaging. The air inlet and outlet means are advantageously, but not exclusively, linked to the lid.

According to the invention, the packaging may also have tamper-evident means which evidence the first opening of the packaging.

In embodiments, the invention relates to a packaging comprising at least one first body that forms a container and one second body that forms a lid, the container and the lid having moisture-barrier properties at their respective walls, the lid having an inner dimension larger than the outer dimension of the container and sliding over at least part of the outer surface of the container, in the process defining a sliding length when the packaging is being opened or closed, the clearance created by the difference in the said dimensions enabling the said opening and the said closing without adversely affecting the moisture-barrier properties of the packaging.

In embodiments, the clearance is preferably between 0.02 mm and 0.5 mm.

In embodiments, a ratio H/D is greater than 1, preferably greater than 2, H being the sliding length and D being the outer dimension of the container.

In embodiments, the container and the lid each comprise an end wall or a bottom.

In embodiments, the container and/or the lid and/or the bottom comprise a structural layer and a functional layer that provide water vapour-barrier properties.

In embodiments, the structural layer is based on cellulose with a cellulose content preferably greater than 70%.

In embodiments, the functional layer is made of high-density polyethylene (HDPE) or polypropylene (PP). Other equivalent materials or blends of materials are possible.

In embodiments, the functional layer that forms the inner surface of the lid slides over the structural layer that forms the outer surface of the container.

In embodiments, the functional layer that forms the inner surface of the lid slides over the functional layer that forms the outer surface of the container.

In embodiments, the structural layer of the container is trapped between a first functional layer that forms the outer surface of the container and a second functional layer that forms the inner surface of the container.

In embodiments, the lid comprises a flared end for making it easier to insert the lid on the container. In some embodiments, the end of the container on which the lid is push-fitted comprises a narrowing. A flared portion and a narrowing can also be used on one and the same packaging.

In embodiments, the packaging comprises a tamper-evident system evidencing that the packaging has been opened, for example the first time the packaging is opened.

In embodiments, the packaging comprises a membrane seal secured to the end of the container. The membrane seal can form a tamper-evident system or be part of one.

In embodiments, the packaging comprises air outlet or air inlet means for making it easier to open and close the packaging.

In embodiments, the packaging has a circular, oval, oblong or rectangular cross section. Of course, other shapes are possible.

In embodiments, the container and/or the lid are formed from tubular bodies (or bodies of another shape) fabricated from a sheet, the ends/edges of which are welded or adhesively bonded and form a joining zone.

In embodiments, the ends/edges of the sheet are butt-welded via reinforcing strips, or welded or adhesively bonded by overlapping the ends/edges.

illustrates an exemplary embodiment of a packaging having water vapour-barrier properties according to the invention. The packagingcomprises a tubular bodythat forms a container and is closed by a lidthat slides over the outer surface of the said container. The containerand the lidhave moisture-barrier properties at their respective walls. The lidis superposed on the containerover part of the height of the tubular bodyin order to obtain water vapour-barrier properties for the packaging. The inner dimension of the lid, such as its diameter, is larger than the outer dimension of the container, for example as its diameter, such that the clearance formed by the difference in dimensions, for example in diameters, makes it possible to open and close the lid without adversely affecting the moisture-barrier properties of the packaging. The packagingmay comprise a tamper-evident indicatorevidencing the first time the packagingis opened. An example of a tamper-evident indicatoris a label that is adhesively bonded or welded between parts of the packagingand that is ripped or torn off when the said packagingis being opened.

illustrates the sectional view of an embodiment of the packagingaccording to the invention. The containercomprises a tubular walland an end wall or bottom. The tubular wallhas a geometry which is preferably cylindrical but numerous other geometries can be envisaged within the scope of the present invention, such as tubular bodies with an oval or rectangular cross section or other cross section, such as oblong etc. As will be explained in the rest of the summary of the invention, the end wallis preferably secured to the tubular wallby welding or adhesive bonding. The lidis similar to the container composed of a tubular walland of an end wall or bottomsecured to the tubular wallby welding or adhesive bonding. The sectional view of the packagingillustrated inshows the sliding lengthof the tubular wallof the lid and of the tubular wallof the container.does not show the functional clearance between the inner side of the wallof the lidand the outer side of the wallof the containerthat is necessary for the push-fitting of the lid and the sliding of the lid while the packaging is being opened or closed. A detailed view of the sliding zonebetween the lidand the containeris illustrated in.illustrates an embodiment with a membrane seal(which is optional) that is welded to the end of the wallof the containerand can serve as tamper-evident indicator (instead of the labelillustrated inor in addition to the said label) and can also improve the impermeability of the packagingto water vapour before it is opened for the first time.

According to a preferred embodiment of the invention, the examples of the packagingthat are illustrated inare based on cellulose with a cellulose content greater than 70%, preferably greater than 85% and advantageously greater than 90% and can consequently be recycled in the paper industry.

The cellulose-based packagingaccording to the invention and that is formed by a containerand a sliding lidwas compared to a packaging formed by the container, the end of which is closed by welding on a moisture-tight membrane seal. Surprisingly, it was determined that, in spite of the clearance between the lid and the container, which makes the packaging not air-tight, such a packaging according to the invention has, under certain conditions, equivalent or even improved water vapour-barrier properties in relation to the entirely sealed packaging.

In particular, and in order to realize this improvement, it was determined that the radial clearance between the outer wall of the containerand the inner wall of the lidmust be between 0.02 mm and 0.5 mm, and preferably between 0.05 mm and 0.25 mm.

Similarly, the ratio H/D, where H is the sliding length and D is the outer dimension of the container(for example its outside diameter) is greater than 1 and preferably greater than 2. If the containerand the lidhave a cylindrical cross section, the outer dimension of the containerand the inner dimension of the lidcorrespond to the respective diameters of the container and of the lid. If the containerand the lidhave a non-cylindrical (such as oval, oblong, square, rectangular or other) cross section, an “equivalent cylinder”, the perimeter of which is equal to the perimeter of the cross section (irrespective of its shape) of the said containerand of the said lidin question, is defined for the containerand the lidand the dimension used is the (outside/inside) diameter of each “equivalent cylinder” determined in this way.

For example, for a container with an outside diameter of 50 mm, the sliding lengthis greater than 50 mm (ratio H/D=1) and preferably greater than 100 mm (ratio H/D=2).

illustrates an example of the packagingin the sliding zone. The containercomprises a wallformed by at least one cellulose-based structural layerand one thin functional layerwhich provides water vapour-barrier properties. Similarly, the lidcomprises a wallformed by at least one cellulose-based structural layerand one thin functional layerwhich provides moisture-barrier properties. The functional layersandare, for example, made of high-density polyethylene (HDPE) or polypropylene (PP) or other equivalent materials. The thickness of the functional layersandis small enough for the mass fraction of cellulose of the part in question (containeror lid) to be greater than 70%.

In the embodiment of, the functional layerthat forms the inner surface of the tubular bodyof the lidslides over the cellulose-based structural layerthat forms the outer surface of the tubular bodyof the container. A clearance between the layerof the lid and the layerof the container is necessary for easy opening and closing of the container. The magnitudes of this clearance and of the sliding lengthformed by the superposition of the lid and of the container influence the sealing of the packaging with respect to water vapour. These magnitudes are for example those mentioned above in accordance with the determinations of the present invention.

illustrates another embodiment of the structure of the packaging in the sliding zone. In this embodiment, the functional layerthat forms the inner surface of the tubular bodyof the lidslides over the functional layerthat forms the outer surface of the tubular bodyof the container. A clearance between the layerof the lid and the layerof the container is necessary for easy opening and closing of the container. The magnitudes of this clearance and of the sliding heightformed by the superposition of the lid and of the container influence the sealing of the packaging with respect to water vapour and are, for example, those mentioned above in accordance with the determinations of the present invention.

illustrates another embodiment of the structure of the packaging in the sliding zone. In this embodiment, the structural layerof the container is trapped between a first functional layerthat forms the outer surface and a second functional layerthat forms the inner surface of the tubular body of the container.

In the embodiment illustrated in, the functional layerthat forms the inner surface of the tubular bodyof the lidslides over the functional layerthat forms the outer surface of the tubular bodyof the container. A clearance between the layerof the lid and the layerof the container is necessary for easy opening and closing of the container. The magnitudes of this clearance and of the sliding heightformed by the superposition of the lid and of the container influence the sealing of the packaging with respect to water vapour and are, for example, those mentioned above in accordance with the determinations of the present invention.

illustrates a preferred embodiment of the tubular bodyof the containerand that 8 of the lid. According to this preferred embodiment, the tubular bodies are fabricated from a sheet, the edges of which are welded or adhesively bonded and form a joining zone. Preferably, the ends of the sheet are butt-welded via reinforcing strips, as described in the publications EP2007567, EP2004389, EP2004506 and EP26030052. As an alternative, the edges of the sheet are welded or adhesively bonded by overlapping its ends.

illustrate embodiments of joining a bottomorto a tubular bodyorto form a containeror a lidand also show the continuity of the functional layer///in the joining zone for obtaining good barrier properties of the final product.

illustrates the joining of an end wallto a tubular bodyin order to form a container. In this example, the functional layerof the end wall that forms the outer surface of the containeris welded to the functional layerof the tubular body that forms the inner surface of the container.also illustrates the joining of an end wallto a tubular bodyin order to form a lid.

In this example, the functional layerof the end wall that forms the outer surface of the lidis welded to the functional layerof the tubular body that forms the inner surface of the lid. Welding the respective functional layers/and/makes it possible to ensure the continuity of the said functional layers.