EP3473560B1

EP3473560B1 - Snap-on lid

Info

Publication number: EP3473560B1
Application number: EP18170008.9A
Authority: EP
Inventors: Adam Törnqvist; Hein VAN DEN REEK
Original assignee: Billerudkorsnas AB
Current assignee: Billerudkorsnas AB
Priority date: 2018-04-30
Filing date: 2018-04-30
Publication date: 2021-03-03
Anticipated expiration: 2038-04-30
Also published as: EP3473560A1; PL3473560T3

Description

Technical field

The present disclosure relates to packages and packaging technology, and in particular to so called snap-on or clip-on lids for cup-shaped receptacles.

Background

The development of packaging technologies has revolutionized how products are stored, distributed and sold, and nowhere is this more significant than in the food and beverages sector. Over time, glass and metal based packaging solutions have been replaced by plastic and lately also fibre based, i.e. cellulose based materials. Today, fibre based packaging materials are widely used for both packaging and serving both solid, semi-liquid and liquid foods. Examples include, but are not limited to cup-shaped and tray-shaped receptacles with removable lids. An illustrative example is the paper cup used for serving various beverages, such as coffee, tea and soft drinks. Such cups are frequently closed with a plastic snap-on lid, having an opening through which the beverage can be consumed, eigher directly or through a straw. Other examples are found in the convenience food sector, where for example ready meals are served on a fibre-based tray suitable for heating, and covered by a removable plastic lid.
US 4,589,569 discloses a thermoformed plastic snap-on lid for a drinking cup, having a mounting portion including a resilent annular gripping portion, configured to grip the bead on the lip of the cup and seal thereagainst. Such lids as disclosed in US 4,589,569 and similar constructions have become widely used.
European patents 1 367 001 B1 and 2 159 161 B1 disclose an improved plastic clip-on (snap-on) lid especially for a cup-shaped paper or cardboard receptacle having an outwardly projecting bead, especially a curled rim, wherein said lid is formed with a peripheral clamping groove which is open on the lower surface of the lid for receiving therein the bead of said receptacle.
Such lids are easily attached and provide a tight seal, and have become popular in the packaging of food and beverages, not only for take-away coffee, tea and soft drinks, although this remains the main use. The lids are made of food grade plastics, most frequently polypropylene. Billions of coffee cup lids are used every year, and it is estimated that only a small percentage of them are recycled. Therefore it is desirable to minimize or entirely avoid the use of plastic snap-on lids.
WO 2015/189130 discloses a new type of paper laminate having stretchable outer layers and an intermediate layer of less stretchability. The intermediate layer is designed to at least partly break when the new laminate is provided with folding lines, while the outer layers are designed to stretch and thus hold the laminate together at the folding lines. Further, the stretchable outer layers allow formation of reliefs in the laminate, e.g. by embossing, such that it can compete with plastics. Fig. 3 of WO 2015/189130 shows a lid, comprising two pairs of opposing side walls and an upper wall, formed in a paper laminate wherein the top portion comprises a bulge or relief formed by stretching a portion of the paper laminate. The disclosure of WO 2015/189130 however does not address how a lid for a receptacle, e.g. a cup-shaped or tray-shaped receptacle should be formed to allow a releasable attachment and at the same time creating a tight seal. US2008099481 discloses a combination of a receptacle and a snap-on lid for the receptacle, wherein the receptacle has an opening surrounded by a rim, wherein said lid has a top portion and a side wall extending from said top portion, wherein said lid is made of a fibre based material, and wherein a distal edge of said side wall is folded inwards, forming an inward lip for engaging with said receptacle. EP3000745 discloses a combination of a receptacle and a snap-on lid for the receptacle, wherein the receptacle has an opening surrounded by a rim, wherein said lid has a top portion and a side wall extending from said top portion, wherein said lid is made of a fibre based material, and wherein a distal edge of said side wall is folded inwards, forming an inward lip for engaging with receptacle, and wherein said side wall has a circumferential recess for engaging with said rim. US4209126 discloses a combination of a receptacle and a snap-on lid for the receptacle, wherein the receptacle has an opening surrounded by a rim and a membrane affixed to said opening, wherein the area of said membrane is larger than that of said opening and said membrane projects outward over the rim of said opening and said membrane extends at least partially over the rim capable of forming a skirt having a substantially circumferential edge positioned at said rim, wherein said lid has a top portion and a side wall extending from said top portion, wherein said side wall has a circumferential recess for engaging with said rim and with said membrane.

Summary

The present disclosure aims at solving problems associated with the use of non-renewable plastic snap-on lids, and to replace the plastic with a renewable, fibre based lid while maintaining or improving the functions associated with plastic lids. Other problems and solutions may be identified upon a closer study of the present disclosure.
The present invention makes available a receptacle 2, 200 having an opening surrounded by a rim 3, 300, and a membrane 40 affixed to said opening, wherein the area of said membrane 40 is larger than that of said opening and said membrane 40 projects outward over the rim 3, 300 of said opening, wherein said membrane 40 extends at least partially over the rim 3, 300 capable of forming a skirt 41 having a substantially circumferential edge positioned at or below said rim 3, 300 when a lid 10, 100 is attached to said receptacle.
Said membrane 40 may have an openable portion 50, which when open provides access to the inside of said receptacle 2, 200 without removal of the entire membrane 40.
According to the invention, said lid 10, 100 further has a top portion and a side wall 12, 112 extending from said top portion, wherein said lid is made of a fibre based material, and wherein a distal edge of said side wall is folded inwards, forming an edge or lip 20, 120 for engaging with said membrane 40, and wherein said side wall has a circumferential recess 130 for engaging with said rim 3, 300 and with said membrane 40. When engaging with said membrane, the lip 20, 120 and/or recess 130 is/are preferably also engaging with the edge of a skirt 41 formed by the membrane 40 when the lid is placed in position on said receptacle.
The lid can be made substantially of a paper laminate comprising at least a first stretchable paper layer and a second stretchable paper layer, wherein the first and the second stretchable paper layer preferably have a stretchability (ISO 1924/3) of at least 5 % in both the machine direction (MD) and the cross direction (CD). Preferably the stretchability is at least 10 % in both the MD and CD, more preferably at least about 15 % the MD and at least about 10 % in the CD.
The laminate preferably also comprises an intermediate paper layer arranged between the first and the second stretchable paper layer, wherein the stretchability (ISO 1924/3) of said intermediate paper layer is less than 3 % in the MD and/or the CD.
The lid may comprise an embossed shape or pattern 70 in the top portion of said lid.

Brief description of the drawings

The invention is now described, by way of example, with reference to the accompanying drawings, in which Figures 1-5 and 7-9 disclose embodiments, which do not form part of the present invention. Figure 10 is related to two embodiments, one of which is not part of the present invention, as will be indicated below.

Fig. 1 is a perspective view illustrating the state of the art, here exemplified by a plastic snap-on lid 1 and a cup 2, for example a paper cup having a rolled rim 3.
Fig. 2 shows in cross section how the plastic lid 1 engages the rolled rim 3 of cup 2. Typically, snap-on lids according to the state of the art have a flared out lower portion, receiving the rolled rim of the cup or receptacle.
Fig. 3 is a partial cross section showing an embodiment wherein a fibre based lid 10 has a side wall 12, wherein the distal edge of said side wall is folded inwards, forming an inward lip 20 with an edge for engaging with the rolled rim 3 of a receptacle 2 when the lid 10 is placed on the receptacle 2.
Fig. 4 is a partial cross section showing another embodiment where a fibre based lid 100 has a side wall 112, wherein the distal edge of said side wall is folded inwards, forming an edge or inward lip 120, but where said side wall additionally has a circumferential recess 130 for engaging with the rim 3 when the lid 100 is placed on the receptacle 2.
Fig. 5 is a partial cross section showing another embodiment including a fibre based lid 10 having a side wall 12, wherein the distal edge of said side wall is folded inwards, forming an inward lip 20. Here, the opening of the receptacle 2 is covered with a membrane 40, for example glued or welded to the rim 3, wherein the area of the membrane is larger than the opening of the receptacle forming an overhang 41. Thus, when the lid 10 is in place, the overhang 41 of the membrane is pressed down at least partially over the rim 3, pinched between the rim 3 and the lid, and engages with the lip 20.
Fig. 6 is a partial cross section showing another embodiment where a fibre based lid 100 has a side wall 112, wherein the distal edge of said side wall is folded inwards, forming an inward lip 120, but where said side wall additionally has a circumferential recess 130. Also here, the opening of the receptacle 2 is covered with a membrane 40, for example glued or welded to the rim 3, wherein the area of the membrane is larger than the opening of the receptacle, forming an overhang 41. Thus, when the lid 100 is in place, the overhang 41 of the membrane is pressed down at least partially over the rim 3, pinched between the rim 3 and the lid, and engages with the lip 120.
Fig. 7 is a partial cross section showing another embodiment including a fibre based lid 10 having a side wall 12, wherein the distal edge of said side wall is folded inwards, forming an inward lip 20. Here the lid 10 is shown placed on a receptacle 200, having a rim 300, which rim is not a rolled rim, wherein the lip 20 engages with the rim 300 of the receptacle 200 when the lid is placed on the receptacle.
Fig. 8 is a partial cross section showing another embodiment where a fibre based lid 100 has a side wall 112, wherein the distal edge of said side wall is folded inwards, forming an inward lip 120, and where said side wall additionally has a circumferential recess 130. This lid is here shown placed on a receptacle 200, having a rim 300, which rim is not a rolled rim, wherein at least one of the features 120 and 130 engage with the rim 300 when the lid 100 is placed on the receptacle 200.
Fig. 9 is a partial cross section showing an embodiment wherein a receptacle 200 having a straight rim 300 is closed or sealed with membrane 40, attached to the rim 300. The area of the membrane 40 may be larger than the area of the opening of the receptacle including the rim 300, so the membrane 40 forms an overhang or skirt 41 (not shown), or in the alternative, the membrane 40 ends at or approximately at the circumference of the rim 300 (as shown in Fig. 9). When the lid 10 is in place, the lip 20 formed on the inside of the wall 12 engages the rim 300, holding the lid 10 securely in place. In the case there is an overhang, the membrane becomes pinched between the rim 300 and the lid 10, additionally improving the attachment of the lid to the receptacle.
Fig. 10 is a partial cross section showing a receptacle 200 with a rim 300 and a membrane 40, and a lid 100 having a side wall 112, wherein the distal egde of said side wall is folded inwards, forming an inward lip 120. Additionally there is arranged a circumferential recess 130 in the side wall 112. When said lid is placed on the receptacle, at least one of the features 120 and 130 engage the rim 300, for example the recess 130 engages the rim 300 and the inward lip 120 engages in an embodiment which is not covered by the claims the rim 300, or in an embodiment of the invention a skirt formed by the membrane (not shown). The skirt becomes pinched between the rim 300 and the lid 10, engaging the recess 130 and the inward lip 120, which additionally improves the attachment of the lid to the receptacle.
Fig. 11 is a perspective view illustrating a receptacle 2 or 200 sealed with a membrane 40, the area of which is larger than the opening of the receptacle, so that the membrane 40 forms a skirt 41 which preferably extends below the rim 3 or 300. Fig. 11 also shows a lid 100 having a side wall 112 and an inward lip 120, and additionally a circumferential recess 130. It is also indicated that the top portion of the lid 100 may be embossed creating a raised shape or pattern 70, for example a purely decorative pattern, or a pattern conwaying information about content, use, or storage of the content of the packaging for which the lid is intended. Naturally also the lid 10 can have a raised shape or pattern 70 (not shown).
Fig. 12 is a perspective view illustrating a receptacle as shown in Fig. 11, where the membrane can be removed totally, or in part, when the membrane 40 has a tearable part 50, for example a tab 60 and where a portion of the membrane is delimited by indented lines, perforations or similar, indicated as a dashed line in Fig. 12. Thus the membrane can be removed totally or in part, the contents accessed and the receptacle closed again, using the fibre based snap-on lid 10, 100.

Detailed description

Before the present invention is described, it is to be understood that the terminology employed herein is used for the purpose of describing particular embodiments only and is not intended to be limiting, since the scope of the present invention will be limited only by the appended claim.
The present invention makes available a receptacle 2, 200 having an opening surrounded by a rim 3, 300, and a membrane 40 affixed to said opening, wherein the area of said membrane 40 is larger than that of said opening and said membrane 40 projects outward over the rim 3, 300 of said opening, wherein said membrane 40 extends at least partially over the rim 3, 300 forming a an overhang or skirt 41 having a substantially circumferential edge positioned at or below said rim 3, 300. Membranes for sealing receptacles are well known in the art, and can be made of metal foil, plastic foil, paper, or laminates of two or more of the materials metal, plastic and paper. A membrane can be glued, heat sealed or welded to the rim of the receptacle. When making the membrane larger that the opening of the receptacle, a skirt is formed. When placing a lid on such a receptacle, this skirt is pressed down at least partially over the rim 3, pinched between the rim 3 and the lid snap-on lid 10, 100. This improves the attachment of the lid to the receptacle, which is an advantage of this embodiment. Additionally, the combination of a membrane and a lid has other advantages. A membrane which is glued or heat sealed to a receptacle create thight seal, and can be used to seal liquid or semi-liquid foods and protect them from the environment. A membrane can however be punctured or torn durign the transport and handling of the packages, for example when the packages are stacked in the shop, or when transported by the end-user from the shop to the home. A fibre based snap-on lid offers a mechanical protection for the membrane.
Said membrane 40 may have an openable portion 50, which when open provides access to the inside of said receptacle without removal the entire membrane 40. This can be formed as a tab 60, where a portion of the membrane is delimited by indented lines, perforations or similar. Thus the membrane can be removed totally or in part, the contents accessed and the receptacle closed again, using the fibre based snap-on lid 10, 100.
According to the invention, said lid 10, 100 has a top portion and a side wall 12, 112 extending from said top portion, wherein said lid is made of a fibre based material, and wherein a distal edge of said side wall is folded inwards, forming an inward lip 20, 120 for engaging with said membrane 40, and wherein said side wall also has a circumferential recess 130 for engaging with said rim 3, 300 and with said membrane 40. When engaging with said membrane, the lip 20, 120 and/or recess 130 preferably also engage with the edge of a skirt 41 formed by the membrane 40 when the lid is placed in position on said receptacle.
The lid may be made substantially of a paper laminate comprising a first stretchable paper layer and a second stretchable paper layer, wherein the first and the second stretchable paper layer preferably have a stretchability (ISO 1924/3) of at least 5 % in both the machine direction (MD) and the cross direction (CD)
In an embodiment, the laminate also comprises an intermediate paper layer arranged between the first and the second stretchable paper layer, wherein the stretchability (ISO 1924/3) of the intermediate paper layer is less than 3 % in the MD and/or the CD.
Preferably the stretchability of the first and the second stretchable paper layer is at least 6 or 7 % in both the MD and the CD, more preferably at least 10 %.
Preferably the stretchability of the first and the second stretchable paper layer is at least 10 % in both the MD and the CD, more preferably at least about 15 % the MD and at least about 10 % in the CD.
Preferably the density (ISO 534) of the intermediate paper layer is less than 0.8 g/cm³.
Preferably the grammage (ISO 536) of the intermediate paper layer is between 75 and 500 g/m², such as between 100 and 400 g/m², such as between 150 and 350 g/m².
Different fibre based materials can be used for manufacturing the lid 10, 100 disclosed herein. One example of a fibre based material suitable for the manufacture of fibre based snap-on lids as disclosed in the present description is FibreForm® (the trademark is property of BillerudKorsnäs, Sweden). An account of the manufacture and the proprties of FibreForm® is given in WO 2015/189130 .
Different qualities can be used, for example different grammage (ISO 536) such as 80, 100, 150, 200, 250, and 300 g/m² and combinations thereof.
According to an embodiment, the intermediate layer is at least partly formed from pulp comprising mechanical pulp, thermomechanical pulp (TMP) or chemithermomechanical pulp (CTMP).
According to another embodiment, the internal bond strength (TAPPI 569) the first and the second stretchable paper layer is at least 400 J/m², such as at least 500 J/m², such as at least 600 J/m².
Prerferably the geometric bending resistance (ISO 2493, bending angle = 15°, test span length = 50 mm) of the intermediate layer is at least 40 mN, such as at least 50 mN.
According to an embodiment, the paper laminate has a thickness (ISO 534) of about 200 to about 800 µm, preferably 220 - 520 µm and/or a grammage (ISO 536) of about 50 to about 700 g/m², preferably 80 - 400 g/m².
Preferably the paper laminate has a thickness (ISO 534) of 380 µm and/or a grammage (ISO 536) of about 300 g/m².
The lid and receptacle as such, and the combined use thereof, have many advantages. A fibre based snap-on lid can replace plastic lids in numerous applications, providing an environmentally more friendly packaging solution, as the fibre based snap-on lid can be made from entirely renewable resources. A fibre based lid can also be recycled and the fibres used in the production of new products, in different blends of both recycled and fresh fibers.
Surprisingly, the flexibility of the fibre based material allows the lid to be removed and replaced without loss of function. When used in combination with a membrane, the lid functions as an overcap, protecting the membrane during transport and storage. The fibre based lid can be printed and embossed, providing tactile information, and making it esthetically appealing and interesting to the customer. The lid is preferably embossed creating a raised shape or pattern 70, for example a purely decorative pattern, or a pattern conwaying information about content, use, or storage of the content of the packaging for which the lid is intended. A lid indended for food packaging could be provided with an embossed symbol associated with the type of food the packaging will contain, for example an organge for a packaging containg organge marmelade, or a snowflake for a packaging containing icecream.
When the membrane is partially or totally removed, for example to access and consume part of the content of the receptacle, the fibre based snap-on lid can be replaced, closing the receptacle. Thus, the consumer does not have to use the entire content at once, but can instead close the receptacle after removing one or more servings, and store the remaining content.
The fibre based snap-on lid offers a light-weight yet strong and stable protection for the contents of the receptacle, or when a membrane is used, protection also for the membrane.
The inner and/or outer surface of the laminate forming the snap-on lid can be treated to increase the water resistance, to make it impermeable or selectively permeable to gases, to improve printabilty etc. The laminate can for example be waxed in order to improve water resistance in an environmentally friendly fashion. It is of course also possible to add thin polymer or metal laminates to the material forming the lid.
Additionally, the shape and flexible properties of the lid make it possible to stack the lids durign manufacture, storage and transport.

Examples

Example 1

A round fibre based snap-on lid for a round paper-based receptacle, e.g. a regular single wall paper cup, was manufactured from a round blank of a paper laminate (FibreForm® from BillerudKorsnäs, Sweden). In this example, the laminate comprised two layers of paper (FF150), each having a grammage (ISO 536) of 150 g/m² and a stretchability of 10 % in both MD and CD. The laminate had a thickness of about of 380 µm, and/or a grammage (ISO 536) of 300g/m².
The outermost edge of the blank is folded inwards, towards the center of the blank. The blank is then press formed to form a lid in the shape of a low cylinder, wherein the inner diameter of the cylinder is about 89 mm, which is substantially the same as the outer diameter of the paper based receptacle, with a top portion and a side wall, wherein the side wall has an inward lip. As the rim of the receptacle is about 2 mm high, the height of the side wall is at least 2 mm in addition to the height of the inward lip, so that the upper edge of the inward lip will be positioned below the lower edge of the rim, when the lid is in place on the receptacle.
The prototype lids exhibited a good locking function, and could be removed and replaced on the cups a few times without the loss of function thanks to the flexibility of the fibre based lid.

Example 2

In another example, also using a round blank of a paper laminate (two layers of FF150, i.e. FibreForm® from BillerudKorsnäs, Sweden), the outermost edge of the blank is folded inwards, towards the center of the blank, whereupon a circumferential recess is embossed into the blank. The blank is then pressed to form a lid in the shape of a low cylinder, having an embossed bulge on the outside of the sidewall of the lid, and corresponding recess on the inside of the sidewall. The dimension of this recess is such, that it can receive and hold the rim.
The edge of the inward fold is now positioned in the middle or the lower part of the recess, as shown for example in Figs. 4 and 8, where 130 is the circumferential recess, and 120 is the inward folded part of the laminate.
The lid snaps in place on a receptacle having a rolled rim, as well as on a receptacle having a straight, non-rolled rim. Depending on the tolerances, the recess and the edge formed by the inward folded portion of the side wall, interact to grip and hold the rim. Further, the flexibility of the fibre based lid allows the lid to conform to different shapes and sizes of rims, achieving a releasable locking function.

Example 3

The lid from Example 2 is placed on a round receptacle closed with a plastic membrane. The membrane is slightly larger than the opening of the receptacle, forming an overhang of about 1 - 3 mm. When placing the lid on the receptacle, the lid is pressed down, and in turn folds the overhang of the membrane, forming a skirt wedged or pinched between the rim and the side wall of the lid. The edge of the skirt at least partially engages with the inward folded edge of the lid. The lid is firmly attached to the receptacle, but still easily removable. The firm grip indicates that the recess and the edge formed by the inward folded portion of the side wall, interact and engage both the rim and the membrane.
To test the function of the attachment, the lid is removed, and the membrane peeled off. The lid is then replaced on the receptacle, and lightly pressed to fit over the rim. Even without the membrane, the lid is securely attached to the receptacle, yet easily removable. A snap-on function is achieved both with and without the membrane.
Without further elaboration, it is believed that a person skilled in the art can, using the present description, including the examples, utilize the present invention to its fullest extent. Also, although the invention has been described herein with regard to its preferred embodiments, which constitute the best mode presently known to the inventors, it should be understood that various changes and modifications as would be obvious to one having the ordinary skill in this art may be made without departing from the scope of the invention which is set forth in the claim appended hereto.

Claims

A combination of a receptacle and a snap-on lid (10, 100) for the receptacle, wherein the receptacle has an opening surrounded by a rim (3, 300) and a membrane (40) affixed to said opening, wherein the area of said membrane (40) is larger than that of said opening and said membrane (40) projects outward over the rim (3, 300) of said opening and said membrane (40) extends at least partially over the rim (3, 300) capable of forming a skirt (41) having a substantially circumferential edge positioned at or below said rim (3, 300), wherein said lid (10, 100) has a top portion and a side wall (12, 112) extending from said top portion, wherein said lid is made of a fibre based material, and wherein a distal edge of said side wall (12, 112) is folded inwards, forming an inward lip (20, 120) for engaging said membrane (40) to removably hold the lid in place on said receptacle when in use, and wherein said side wall has a circumferential recess (130) for engaging with said rim (3, 300) and with said membrane (40).