Cap for container and method for manufacturing cap for container

Abstract

A method of manufacturing a lid (1; 101; 101; 201); 301); 401) comprising the steps of: inserting a material in a solid state or in a form in which a solid is dispersed in a liquid into a mould, said material comprising at least 70% by weight of cellulose; pressing the material in a mould in order to obtain a cup-shaped part (2) having a skirt (3) extending about an axis (Z) and an end wall (4; 304) in the housing; at least one breakable line (5; 6) is formed on the skirt (3). 305, 306; 405) at least partially surrounding the axis (Z) to define a closure body (6; 306; 406) and an endless belt (7); a portion (18) of the endless band (7) is folded inwardly towards the interior of the cup-shaped part (2) to obtain at least one retaining element (26) projecting inwardly towards the interior of the endless band (7) so that the endless band (7) remains engaged to the neck of the container.

Description

Technical Field

[0001] The present invention relates to a cap which is intended for closing containers such as bottles, cans, cups and other containers. The cap according to the present invention is mainly made of a natural fiber-based material, such as a material whose main component is cellulose.

[0002] The present invention also relates to a method for manufacturing a cover which is mainly made of a natural fiber-based material, such as a material whose main component is cellulose. Background Art

[0003] For reasons related to environmental protection, it is desirable to use natural and renewable materials (e.g. cellulose-based materials) to manufacture lids for containers. In fact, these materials are less polluting and easier to handle than the synthetic polymers currently widely used in the packaging industry.

[0004] A container cap made of microfibrillated cellulose (MFC) is known, for example, from European patent EP 3080003. The cap disclosed in EP3080003 comprises a closure body with an internal thread, which can be applied to and removed from the container neck as many times as desired.

[0005] It is desirable that the cap for the container be provided with a tamper-evident device so that the consumer can notice whether the cap has been tampered with.

[0006] However, making an anti-tampering device in a lid of a container made of a material containing natural fibers is not simple. In fact, making a lid including an anti-tampering device involves the complexity of the mold used to make the lid and the complexity of the process that can be used to obtain the lid. In addition, if the material containing natural fibers is not processed correctly, the lid with the anti-tampering device may be defective or there is a great risk of breaking.

[0007] Known caps for containers comprise a tamper-evident ring adapted to remain anchored to the neck of the container and a closure body which can be repeatedly applied to and removed from the neck of the container.

[0008] The tamper-evident ring is connected to the closure body by at least one connecting portion which allows the closure body to rotate relative to the tamper-evident ring so that the closure body remains attached to the tamper-evident ring even when the closure body is in the open position, i.e. even after the closure body has been removed from the neck of the container.

[0009] This type of cap (in the case of cellulose) may have disadvantages mainly related to the risk of fracture of the connection portion joining the closure body to the tamper-evident ring. Due to the repeated bending of the connection portion when the closure body is placed in the closed position or, alternatively, in the open position, small cracks may form in the connection portion, which may propagate until they lead to fracture. Summary of the invention

[0010] It is an object of the present invention to improve closures for containers which are made primarily of natural fiber-based materials, in particular materials whose main component is cellulose.

[0011] Another object is to provide a cap for a container, which cap is made mainly of natural and renewable materials, so that the consumer can verify whether the container closed by the cap has been opened.

[0012] Yet another object is to provide a cover for a container which is made predominantly of natural and renewable materials and which can be manufactured in a relatively simple manner.

[0013] Another object is to produce a cap for a container having a closure body and a tamper-evident ring, wherein the closure body is connected to the tamper-evident ring even when the closure body is in an open position and the cap is mainly made of natural and renewable materials.

[0014] In a first aspect of the present invention, there is provided a method of manufacturing a lid for a container, comprising the steps of:

[0015] - inserting a material in the form of a solid or a solid dispersed in a liquid into a mold, said material comprising at least 70% by weight of cellulose;

[0016] - pressing the material in a mould so as to obtain a cup-shaped part having a skirt extending around an axis and an end wall closing the skirt at one end of the skirt;

[0017] - forming at least one breakable line on the skirt, the at least one breakable line at least partially surrounding the axis to define a closed body and an annular band on the cup-shaped part;

[0018] - Folding a portion of the annular band inwardly towards the interior of the cup-shaped part so as to obtain at least one retaining element projecting inwardly towards the interior of the annular band, so as to retain the annular band in association with the neck of the container.

[0019] Thanks to the first aspect of the invention, a cap for a container is obtained with a tamper-evident device, i.e., a consumer can determine by means of the tamper-evident device whether the container has been opened. This can be achieved by a breakable line that allows the closure body to be partially or completely separated from the tamper-evident ring formed by the annular band. The folded portion of the annular band defines one or more retaining elements that keep the tamper-evident ring engaged to the neck of the container even when the closure body is removed from the neck to access the interior of the container.

[0020] The retaining element defined by the folded portion of the endless band can be produced by a folding operation without the need for special devices in the mold structure. In particular, in order to produce the retaining element, it is not necessary to provide a protrusion in the cup-shaped part, which would make the mold more complicated and make it difficult to maintain a constant degree of compaction of the material used to manufacture the cup-shaped part.

[0021] The cover obtained by the method according to the first aspect of the invention is mainly made of natural fiber-based material and contains a significant amount of cellulose, the amount of cellulose being equal to at least 70% by weight.

[0022] Thus, cellulose is the main component of the cap and should be considered as the matrix of the cap within which additives or fillers may be dispersed.

[0023] Thus, the cap produced by the method according to the first aspect of the invention is made of an environmentally friendly material which has a lower impact on the environment and is less polluting than the synthetic polymer materials commonly used to make caps for containers.

[0024] In one embodiment, the material from which the cap is made may comprise at least 80% by weight cellulose.

[0025] In one embodiment, the method further comprises the step of forming a plurality of cutting lines extending transversely to the free edge of the skirt in an end region of the skirt opposite the end wall.

[0026] The portion of the annular band folded inwards towards the interior of the cup-shaped part to obtain the at least one retaining element may be a flap defined between two consecutive cutting lines.

[0027] In this way, by means of a cutting operation alone and a subsequent bending operation, a plurality of folded flaps are obtained which act as retaining elements so as to effectively keep the annular band engaged to the neck of the container also after the closing body has been removed.

[0028] In a second aspect of the present invention, a cap for a container is provided, the cap comprising a cup-shaped part, the cup-shaped part being made of a material comprising a cellulose matrix, wherein at least 70% by weight of the material used to make the cap is cellulose, the cup-shaped part having a skirt extending around an axis and an end wall closing the skirt at one end of the skirt, wherein at least one breakable line is provided on the skirt, the at least one breakable line at least partially surrounding the axis to define a closed body and an anti-tampering ring on the cup-shaped part, the anti-tampering ring comprising an annular band, a portion of which is folded inwardly toward the interior of the cup-shaped body to define a retaining element extending inwardly toward the interior of the anti-tampering ring, thereby keeping the anti-tampering ring associated with the neck of the container.

[0029] The cap provided by the second aspect of the present invention is an environmentally friendly cap, and since the closure body is completely or partially separated from the annular band along the breakable line, consumers can immediately notice whether the relevant container has been opened. Since the retaining element is engaged with the annular flange formed on the neck of the container, the annular band remains anchored to the neck of the container when the closure body is separated from the annular band.

[0030] The retaining element defined by the folded portion of the endless band can be produced in a simple manner, for example by a folding operation, without the need for a complex mould.

[0031] In one embodiment, the natural fiber-based material used to manufacture the cover comprises an amount of cellulose equal to at least 80% by weight.

[0032] This further reduces the environmental impact of the cover.

[0033] In one embodiment, the annular band comprises a plurality of retaining elements defined by respective flaps folded inwardly towards the interior of the cup-shaped part, each flap extending from an end region of the tamper-evident ring opposite the breakable line.

[0034] Due to the plurality of retaining elements, the tamper-evident ring can be effectively prevented from being pulled off the neck of the container. The folding flap can be obtained only by a cutting operation and a folding operation without the need for a complicated mould.

[0035] In a third aspect of the present invention, a cap for a container is provided, the cap comprising: a closure body having an internal fixing structure for removably fixing the closure body to the neck of the container; an anti-tampering ring intended to remain anchored to the neck of the container, and at least one connecting band which keeps the closure body fixed to the anti-tampering ring even after the closure body is removed from the neck, wherein the cap is made of a natural fiber-based material containing a certain amount of cellulose, the amount of cellulose being equal to at least 70% by weight, and wherein the natural fiber-based material has an elastic modulus between 200 MPa and 2000 MPa, a tensile strength between 15 MPa and 70 MPa, and a degree of deformation under maximum tensile stress between 3% and 30%.

[0036] The cover according to the third aspect of the present invention is made of a material with a low pollution level and limited impact on the environment.

[0037] The environmental impact of the cap according to the third aspect of the invention is also lower due to the connection band, which keeps the closure body connected to the tamper-evident ring even after the container has been opened. This prevents the closure body from being thrown on the ground intentionally or in an undesired manner. This makes it more likely that the closure body will be properly disposed of together with the rest of the container.

[0038] The values ​​of the modulus of elasticity, the tensile strength and the degree of deformation at maximum tensile stress are such that the connecting strip can be deformed several times to bring the closure body into the open position without damaging the connecting strip.

[0039] Furthermore, good mechanical strength is ensured, which makes it less likely that the connecting strip will accidentally break and thus separate the closure body from the tamper-evident ring, which would be undesirable.

[0040] In one embodiment, the natural fiber-based material used to manufacture the cover comprises an amount of cellulose equal to at least 80% by weight.

[0041] This further reduces the environmental impact of the cover. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The invention may be better understood and implemented with reference to the accompanying drawings, which show several exemplary and non-limiting embodiments of the invention, in which:

[0043] Figure 1 is a perspective view showing a cup-shaped member in an initial step of a method of manufacturing a cover;

[0044] Figure 2 is similar to Figure 1 , showing a cup-shaped member having a breakable line formed thereon;

[0045] Figure 3 is similar to Figure 1 , showing a cup-shaped member on which a plurality of cutting lines arranged transversely to the breakable line have been formed;

[0046] Figure 4 is similar to Figure 1 , showing the final step of the method of manufacturing the cover;

[0047] Figure 5 is similar to Figure 4 , showing a cover according to a first alternative embodiment;

[0048] Figure 6 is similar to Figure 4 , showing a cover according to a second alternative embodiment;

[0049] Figure 7 is a perspective view of a lid provided with a hinge structure joining a closure body to a tamper-evident ring;

[0050] Figure 8 is a perspective view of a cap, wherein the tamper-evident ring and the closure body are joined by at least one connecting band;

[0051] Fig. 9 Shown from different angles Figure 8 In the cover. DETAILED DESCRIPTION

[0052] Figures 1 to 4 The main steps of a method for obtaining a cover 1 mainly made of a natural fiber-based material, in particular a natural fiber-based material having a high weight percentage of cellulose are shown.

[0053] Cellulose is the main component of the cover and accounts for at least 70% of the material used to make the cover.

[0054] In addition to cellulose, the material used to make the cap 1 may also contain other ingredients, such as limited amounts of synthetic polymers, in particular biodegradable synthetic polymers. In addition to cellulose, the material used to make the cap 1 may also contain limited amounts of additives, such as substances suitable for increasing the density by compacting the starting material, or substances suitable for improving a specific type of properties of the cap 1, such as barrier properties to liquids or gases, or other properties.

[0055] Therefore, from a technical point of view, the material used to manufacture the cover 1 can be regarded as a material having a cellulose matrix, which contains small amounts of other substances to enhance the performance of the cover 1 or to enable easier manufacture of the cover.

[0056] The amount of cellulose should be as high as possible to eliminate or minimize synthetic components and obtain an easily recyclable cap.

[0057] In one embodiment, the amount of cellulose present in the lid may be greater than or equal to 80% by weight.

[0058] The length of the cellulose fibers contained in the cover 1 may be in the range of 0.2 mm to 3.0 mm. The width of these fibers (ie the transverse dimension relative to the length, such as the diameter) may be in the range of 0.01 mm to 0.05 mm.

[0059] These values ​​of length and transverse dimensions may represent at least 50% of the cellulose fibers used to make the cover 1. In one embodiment, the values ​​of length and transverse dimensions as indicated above represent at least 70% of the cellulose fibers used to make the cover 1.

[0060] from Figure 1 The cover 1 is obtained starting from the cup-shaped part 2 shown in . The cup-shaped part 2 includes a skirt 3 extending around the axis Z. At least a portion of the skirt 3 can have a columnar structure. The cup-shaped part 2 also includes an end wall 4 that closes the skirt at one end of the skirt 3. The end wall 4 is arranged transversely to (e.g., perpendicular to) the axis Z. The end wall 4 can be flat. In the example shown, the end wall 4 has a circular shape in a plan view.

[0061] The cup-shaped member 2 can be obtained by pressing or compression molding the above-described cellulose-containing material in a mold.

[0062] The material used to make the cover 1 may be inserted into the mold in a dry solid state, for example in the form of powder, granules, solid film, fluff or air-laid structure.

[0063] Alternatively, the material for making the cap can be inserted into the mold in a pasty state, in which case the material can be obtained by adding water or other liquid to the dry starting material. In this way, a pasty substance is obtained in which the solid is dispersed in the liquid (i.e., the cellulose particles and other solid components are dispersed in the liquid).

[0064] The material from which the cap is made is inserted into the mould in a non-molten state.

[0065] The material from which the cap is made is not extrudable. This material cannot be extruded because it will degrade, i.e., it will burn before melting. The material from which the cap is made can be heated to make it easier to compact, but only to a temperature below the theoretical melting point.

[0066] A cellulose-containing material is inserted between the two mould parts, one of which is moved towards the other, in order to compress the material and obtain a cup-shaped part 2 .

[0067] During the compression molding process aimed at obtaining the cup-shaped part 2, a pressure greater than 200 bar may be applied to the cellulose-containing material inside the mold. The cellulose-containing material may be heated until it reaches a temperature in the range of 150° C. to 200° C. The heating of the cellulose-containing material may be performed in the mold and / or upstream of the mold, so that the cellulose-containing material is already at the desired temperature when it arrives in the mold.

[0068] After compression molding, in the finished cap 1, the cellulose-containing material used to make the cap 1 may have a viscosity of 0.75 g / cm 3 Up to 1.3g / cm 3 density.

[0069] The grammage of the starting material, i.e. the grammage of the starting material before being subjected to compression moulding, may be 500 g / m 2 Up to 1100g / m 2 .

[0070] With regard to mechanical properties, in the finished cap 1 , the cellulose-containing material used to manufacture the cap 1 may have an elastic modulus of 200 MPa to 2000 MPa.

[0071] The tensile strength (ie, the maximum tensile stress that a material can withstand before breaking) can range from 15 MPa to 70 MPa.

[0072] The degree of deformation at the maximum permissible tensile stress may be between 3% and 30%.

[0073] The values ​​of tensile strength and elastic modulus are measured by performing a tensile stress test on the material used to manufacture the molded cover 1, specifically, on a rectangular sample with a size of 18 mm x 5.8 mm cut from the end wall or upper panel of the cover 1, which generally has a flat structure. The end wall of the cover 1 and therefore the sample may have a thickness of 0.5 mm to 0.95 mm.

[0074] The instrument used to make the measurements may be a commercially available tool for performing tensile stress tests on various materials, for example, an instrument known as Instron 3366.

[0075] The test speed was 50 mm / min and the preload value was 10 N. A 500 N load cell was used.

[0076] In this way, a diagram is obtained in which the tension in MPa is shown as a function of the degree of deformation, which is a dimensionless quantity.

[0077] This diagram is used to obtain the tensile strength or maximum stress (understood as the maximum point reached by the curve) and the elastic modulus (understood as the gradient of the first part of the curve, with a linear trend).

[0078] A breakable line 5 is formed on the skirt 3 , which at least partially surrounds the axis Z. The breakable line 5 extends transversely to the axis Z. In the example shown, the breakable line 5 lies in a plane arranged perpendicular to the axis Z.

[0079] The breakable line 5 defines a closed body 6 and an annular band 7 on the cup-shaped part 2. The closed body 6 comprises an end wall 4 and a portion of the skirt 3 between the breakable line 5 and the end wall 4. This portion defines a side wall 8 of the closed body 6.

[0080] The annular band 7 extends between the breakable line 5 and a free edge 9 of the skirt 3. The free edge 9 is situated on the side of the skirt 3 opposite to the end wall 4.

[0081] The closure body 6 is intended to be applied in a removable manner to the neck of a container. For this purpose, the closure body 6 may have an internal fixing structure 11 which may include one or more helical threads 12 projecting inwardly from the inner surface of the closure body 6 towards the interior.

[0082] The helical thread 12 or threads 12 formed inside the closure body 6 are intended to engage with a corresponding external helical thread present on the neck of the container, the neck of which the cap 1 is capable of closing. In this way, the closure body 6 can be repeatedly screwed onto the neck to bring it into the closed position, or alternatively unscrewed to open the container.

[0083] In an alternative embodiment, instead of one or more helical threads 12 , the internal fixing structure 11 may comprise other elements allowing the closing body 6 to be removably connected to the neck of the container, such as a cam element.

[0084] In an alternative embodiment, the cap may be of the snap-on type and not have helical threads.

[0085] On the outer surface of the cup-shaped part 2, a plurality of knurling lines 13 may be provided, which are intended to enable a consumer or a capper to grip the closure body 6 more stably. In the example shown, the length of the knurling lines 13 is less than the height of the side wall 8, measured parallel to the axis Z. In an alternative embodiment not shown, the knurling lines 13 may extend over the entire height of the side wall 8, that is, over the entire dimension of the side wall 8 parallel to the axis Z.

[0086] In the example shown, the knurling lines 13 are grouped to form groups 14. Two adjacent groups 14 of knurling lines 13 are separated by a portion of the smooth surface 15 in which no knurling lines 13 are present. This condition is not essential, and the knurling lines 13 may alternatively be distributed without interruption along an angle of 360° around the axis Z.

[0087] The breakable line 5 can be obtained after the cup-shaped part 2 has been formed in a relevant mold. In this case, the breakable line 5 can be obtained by a cutting operation (for example using a cutting blade) or by laser cutting.

[0088] In the case where the breakable line 5 is produced by a cutting operation, this operation can be carried out after the cup-shaped part 2 has been removed from the mould, or while the cup-shaped part 2 is still associated with a part of the mould in which it was produced.

[0089] Alternatively, the breakable line 5 may be obtained during the molding process of manufacturing the cup-shaped part 2 by using a suitably designed mold.

[0090] In the example shown, Figure 2 As shown in FIG, the breakable line 5 comprises a plurality of breakable bridges 10 joining the closed body 6 and the annular band 7. The breakable bridges 10 are distributed around the axis Z, for example with a constant angular distance between two consecutive breakable bridges 10.

[0091] A separation section is interposed between two consecutive breakable bridges 10. This separation section may comprise a cutout 16, for example a through-cutout through the thickness of the skirt 3.

[0092] In an alternative embodiment not shown, the separation section between two breakable bridges 10 may comprise a weakening line having the shape of a non-through cut.

[0093] It is also possible to configure the breakable line 5 similar to a line of weakness, along which the thickness of the material forming the cup-shaped part 2 is smaller than in the surrounding areas.

[0094] In one embodiment, the breakable line 5 may comprise a line of weakness of small (eg constant) thickness extending 360° around the axis Z. In this case, there are no breakable bridges.

[0095] The annular band 7 may have a cylindrical or frustoconical structure, or may comprise a cylindrical portion and a frustoconical portion.The annular band 7 may have a substantially constant thickness.

[0096] The subsequent steps include the following steps: forming a plurality of cutting lines 17 in the end region of the skirt 3 opposite to the end wall 4 (more specifically, on the annular band 7), such as Figure 3The cutting line 17 extends transversely (eg perpendicularly) to the free edge 9 of the skirt 3. The cutting line 17 extends transversely (eg perpendicularly) to the breakable line 5.

[0097] In the example shown, the cutting lines 17 are straight lines, each of which extends parallel to the axis Z. Thus, the cutting lines 17 extend substantially vertically when the cap 1 is in the operating position (which corresponds to the position when the cap 1 is applied to a container), i.e. in which the axis Z is vertically positioned and the recess of the cup-shaped part 2 points downwards.

[0098] As shown in the example, the cutting lines 17 may be parallel to each other. However, this condition is not essential, and in alternative embodiments, the cutting lines 17 may be non-parallel.

[0099] Furthermore, the cutting line 17 may be positioned in an inclined manner relative to the breakable line 5, ie the cutting line is neither parallel nor perpendicular to the breakable line.

[0100] As shown in the example, the cutting lines 17 can have the same length. The cutting lines 17 can also have different lengths from each other.

[0101] The cutting line 17 is obtained by a cutting operation (e.g. using a cutting blade) or by laser cutting. The cutting operation can be performed while the cup-shaped part 2 is still in the mold used to make it, for example when the cup-shaped part 2 is partially supported by the mold. Alternatively, the cutting operation to produce the cutting line 17 can be performed after the cup-shaped part 2 is removed from the mold.

[0102] The cutting line 17 may be a through-line extending along its entire length through the entire thickness of the material used to make the cover 1. In an alternative embodiment, the cutting line 17 may be a line of weakness that locally weakens the material used to make the cover 1, making it easier to break during subsequent operations to which the cover 1 is intended to be subjected. In the latter case, the cutting line 17 may be a line at which the thickness of the material used to make the cover 1 is small but greater than zero.

[0103] The length of the cutting lines 17 is less than the distance between the free edge 9 and the breakable line 5. Each cutting line 17 has a first end close to the breakable line 5 and a second end away from the breakable line 5. The first end is at a distance from the breakable line 5.

[0104] In the example shown, this second end is arranged on the free edge 9 , ie each cutting line 17 reaches the free edge 9 of the cup-shaped part 2 .

[0105] In an embodiment, there may be one or more joints along each cutting line 17, which are intended to be broken during subsequent operations to which the cover 1 will be subjected. For example, there may be joints at the free edge 9.

[0106] The portion of the endless band 7 shaped in the shape of a flap 18 is arranged between two consecutive cutting lines 17. Each flap 18 has a long side 20 defined by a free edge 9 and two short sides defined by two consecutive cutting lines 17.

[0107] The angular amplitude of each fin 18 , ie the angular extent over which each fin extends around the axis Z, may be greater than or equal to 10°.

[0108] The angular extent of the fins 18 may be constant for all fins 18 distributed around the axis Z. Alternatively, the angular extent of the fins 18 may not be constant around the axis Z, ie there may be some fins 18 with a greater angular extent than others.

[0109] In subsequent steps, such as Figure 4 As shown in , at least a portion of the annular band 7 is folded inwardly toward the interior of the cup-shaped part 2. In the example shown, the portion of the annular band 7 folded inwardly toward the interior of the cup-shaped part 2 is a flap 18 defined between two consecutive cutting lines 17.

[0110] More specifically, a plurality of flaps 18 defined by the cut lines 17 are folded inwardly toward the interior of the cup-shaped component 2. This folding is achieved by rotating each flap 18 around its end region opposite to the long side 20. More specifically, each flap 18 is rotated or nearly rotated 180° so as to be in a position facing the inner surface of the cup-shaped component 2 (optionally in contact with the surface).

[0111] Each cutting line 17 defines a tab 18 and the short side 27 of an adjacent tab 18 .

[0112] The flap 18 is folded by performing a folding operation after the cup-shaped member 2 is taken out of the mold and after the cut line 17 is formed.

[0113] In this way, a tamper-evident ring 24 is obtained from the annular band 7 , which, during use of the cap 1 , is intended to remain engaged to the neck of a container closed by the cap 1 .

[0114] Therefore, after the folding operation, we obtain Figure 4The invention relates to a cap 1 of the type shown in the figure, which comprises a closed body 6 joined to an anti-tampering ring 24 along a breakable line 5. The anti-tampering ring 24 has a plurality of retaining elements 26 to keep the anti-tampering ring 24 joined to the neck of the container, each retaining element 26 comprising a folding flap 18. The flap 18 is folded inwardly toward the interior of the cap 1 and extends from an end region 25 of the anti-tampering ring 24 opposite to the breakable line 5. When the cap 1 is applied to the neck of the container to be closed, the flap 18 in the folded configuration is located below the annular flange extending radially outward from the outer surface of the neck. Specifically, the long side 20 of each folding flap 18 faces the annular flange of the neck.

[0115] When the consumer removes the closure body 6 from the container for the first time, the folded flap 18 abuts against the annular flange of the neck, which prevents the tamper-evident ring 24 from being pulled off the neck of the container. The breakable bridge 10 is thereby stretched and broken, so that the closure body 6 can be in an open configuration. In contrast, the tamper-evident ring 24 is still engaged to the neck of the container. The broken breakable bridge 10 indicates to the consumer that the container has been opened.

[0116] The resulting cover 1 is easy to manufacture, since the folded flaps 18 can be obtained by a simple cutting and folding operation, without requiring a complicated mould and without forming areas of greater thickness on the cover 1 where the cellulose-containing material may be difficult to distribute evenly.

[0117] When the flaps 18 are folded inwardly toward the inside of the cup-shaped member 2, interference may occur between the short sides 27 of two adjacent folded flaps 18, such as Figure 4 That is, one folding flap 18 may slightly overlap an adjacent folding flap 18 or may interfere with an adjacent folding flap 18. Figure 4 The detail in FIG. 1 shows how the folding flap 18 arranged in the central position interferes with the folding flap 18 located in the peripheral position and is slightly farther from the inner surface of the cup-shaped part 2 than the folding flap 18 located in the peripheral position.

[0118] The overlap or interference between adjacent folded flaps 18 does not cause a particular disadvantage, and on the contrary, may be helpful in some cases, because it helps to reduce the inner diameter of the tamper-evident ring 24. As a result, the tamper-evident ring 24 fits more tightly on the neck of the container, and accidental movement (e.g. rotation) of the tamper-evident ring 24 becomes more difficult.

[0119] Figure 8 The solution shown in is particularly easy to implement, since a common cutting line 17 separates two adjacent flaps 18. This minimizes the number of cutting lines 17.

[0120] The cutting line 17 is optionally arranged in an angular position within the cutout 16 of the breakable line 5 along a line parallel to the axis Z. In other words, the cutting line 17 is not aligned with the breakable bridge 10. This makes it easier to exert pressure on the breakable bridge 10 when the closure body 6 is first removed from the container.

[0121] In an alternative embodiment not shown, the cutting line 17 or some of the cutting lines 17 may be aligned with the breakable bridges 10 .

[0122] Figure 5 A cover 101 is shown, which is different from Figure 4 In the cover 1 shown in FIG. 1 , two adjacent fins 18 are spaced a certain distance from each other along the circumferential line. For this purpose, two adjacent fins 18 are defined by separate cutting lines, rather than as Figure 4 As in the example in FIG. 1 , the embodiment is defined by a common cutting line 17 .

[0123] In this case, the cutting lines 17 include a plurality of pairs of cutting lines, and each pair of cutting lines includes a first cutting line 17a and a second cutting line 17b.

[0124] Between the two cutting lines 17a, 17b of the pair a flap 18 is defined. Each flap 18 has a long side 20 defined by a free edge 9 and two short sides defined by two consecutive cutting lines 17, in the example shown, a first cutting line 17a and a second cutting line 17b belonging to the same pair of cutting lines.

[0125] The angular distance between two cutting lines 17a, 17b defining the short side of the same flap 18 is substantially greater than or equal to 10°, measured around the axis Z. This distance defines the angular amplitude of the flap 18 around the axis Z, which angular amplitude may be constant for all flaps 18 or vary from one flap 18 to another (or from one group of flaps 18 to another).

[0126] The angular distance between two cutting lines 17b, 17a belonging to different pairs (i.e. defining the short sides of two flaps 18 adjacent to each other) may be between 1° and 5°. This angular distance defines a space 22 between two consecutive flaps 18. This angular distance may also be constant around the axis Z, or may vary around the axis Z.

[0127] Since the spaces 22 separate the flaps 18 , overlapping of adjacent flaps 18 can be avoided when the flaps 18 are folded inwardly toward the interior of the endless band 7 to form the retaining elements 26 .

[0128] The cover 101 is manufactured in a similar manner to the cover 1 described previously, starting from the same material. In addition to forming the cut lines 17 , in this case there is the step of removing excess material between the cut lines 17 b , 17 a delimiting two adjacent flaps 18 to form a space 22 .

[0129] Figure 6 A cover 201 according to an alternative embodiment is shown, in which the tamper-evident ring 24 comprises a plurality of flaps 18 folded inwardly towards the interior of the cup-shaped part 2, and in which two consecutive flaps 18 are defined by different cutting lines 17b, 17a. Thus, inside the cover 201, a space 22 is defined between two consecutive folded flaps 18. However, between two consecutive flaps 18, the material used to make the cup-shaped part 2 has not been completely removed. Between two consecutive flaps 18, there is an intermediate element 23, which extends only over a portion of the height of the flaps 18, (i.e., over a portion of the dimension of the flaps 18 along a line parallel to the axis Z).

[0130] The cover 201 is manufactured in a similar manner to the method used to manufacture the cover described above. In addition to forming the cutting lines 17a, 17b, a transverse cut 21 is formed on the cover 201. The transverse cut 21 extends in a direction transverse to (particularly perpendicular to) the axis Z and connects the two cutting lines 17b, 17a between two adjacent flaps 18. That is, the transverse cut 21 can be parallel to the breakable line 5.

[0131] The transverse cutout 21 is made at a distance from the free edge 9 of the endless band 7 which is smaller than the length of the cutting lines 17a, 17b.

[0132] In this way, between two adjacent fins 18, an intermediate element 23 is defined as an extension of the skirt 3 between two adjacent fins 18. Each intermediate element 23 has the structure of a portion of a cylindrical body extending around the axis Z with a predetermined angular amplitude.

[0133] The intermediate element 23 has a dual function. It acts as a reinforcing contact element to prevent or limit lateral deformation of the flap 18, especially after the flap is folded. It also acts as a protective element to prevent dust or dirt from entering the container closed by the lid 201. In the absence of the intermediate element 23, given the rather large dimensions of the space 22, the substance contained in the container closed by the lid 201 could be contaminated in an undesirable manner by particles or foreign bodies that could enter the container from the outside through the space 22.

[0134] The transverse cut 21 joins the two cutting lines 17b, 17a between two consecutive flaps 18 and allows a piece of material between the two cutting lines 17b, 17a and the transverse cut 21 to be separated from the cup-shaped part 2. This piece of material can thus be removed from the cover.

[0135] Due to the space 22, overlapping of the folded flap 18 inside the cover 201 can be avoided.

[0136] The transverse cuts 21 may be made simultaneously with the cutting lines 17a, 17b, for example by a cutting blade or by laser cutting.

[0137] The position of the transverse cut 21, in particular its distance from the breakable line 5, may be different from Figure 6 The positions and distances shown in , so that the axial dimensions of the intermediate element 23 may vary compared to what is shown.

[0138] In all the embodiments of the lid described so far, the flap 18 may have a predetermined folding line arranged in the position along which the flap 18 is designed to be folded inwardly towards the interior of the cup-shaped part 2 .

[0139] The predetermined folding line may be a line along which the thickness of the annular band 7 is thinner than the thickness of the surrounding area. In this way, it is easier to fold the flap 18.

[0140] The predetermined folding line may be a cut formed in the endless band 7 after the cover has been formed, for example after the cover has been removed from the mould or while the cover is still in the mould. Alternatively, the predetermined folding line may be formed during moulding of the cover in the mould.

[0141] The desired number of cutting lines 17, 17a, 17b can be selected so as to obtain the desired number of flaps 18. It is also possible to select only two cutting lines so as to obtain a cover having only two flaps 18, or three cutting lines, in which case the cover comprises three folding flaps 18.

[0142] In an alternative embodiment not shown, there may be no cutting lines 17, 17a, 17b. In this case, the cap comprises a single flap, i.e. a single portion of the annular band, which may be circumferentially continuous and folded inwardly towards the interior of the cup-shaped part to prevent the tamper-evident ring from being pulled down from the neck of the container.

[0143] Figure 7 A cover 301 according to an alternative embodiment is shown.

[0144] The cover 301 is made from a cellulose containing material, has the same features as described with reference to the previous covers, and uses the same compression moulding technique.

[0145] The cap 301 includes a tamper-evident ring 324 which is intended to remain engaged to the neck of the container. The tamper-evident ring 324 may be a reference Figures 1 to 6 The type described, i.e., provided with flaps 18 separated by a cutting line 17 and folded inwardly. Alternatively, the tamper-evident ring 324 may include one or more retaining elements of a type other than the folded flaps 18, which are adapted to prevent the tamper-evident ring 324 from being pulled off the neck of the container.

[0146] The cover 301 also includes a closure body 306 which can be in a closed position (not shown) and an open position (such as Figure 7 ) to close or, alternatively, open an opening defined by the neck of the container.

[0147] The closure body 306 is hinged to the tamper-evident ring 324 , ie the closure body is fixed to the tamper-evident ring 324 by means of the hinge structure 28 .

[0148] Thus, the closing body 306 is substantially movable between an open position and a closed position by means of a rotational movement about an axis of articulation perpendicular to the axis Z.

[0149] The closed body 306 comprises an end wall 304 which may be substantially flat. The end wall 304 extends transversely to the axis Z, in particular perpendicularly to the axis Z.

[0150] The closed body 306 also has a side wall 308 which extends around the axis Z and is closed at one end by the end wall 304 .

[0151] From the side wall 308 there may extend a protrusion 29, which is located in a position diametrically opposite to the hinge structure 28, in order to facilitate opening of a container closed by the lid 301. In fact, when the user wants to place the closure body 306 in the open position, he / she can place one finger under the protrusion 29 in order to more easily rotate the closure element 306 around the hinge axis.

[0152] The closure body 306 may include internal securing structures to enable the closure body 306 to be removably secured to the neck of a container.

[0153] In the example shown, the internal fixing structure is configured to allow the closed body 306 to engage with the neck of the container in a snap-fit ​​manner. For this purpose, the internal fixing structure can include one or more protrusions that extend inwardly toward the interior of the closed body 306 to engage with corresponding protrusions formed on the neck.

[0154] Before the lid 301 is opened for the first time, a breakable line 305 is defined between the closure body 306 and the tamper-evident ring 324. The closure body 306 is initially joined to the tamper-evident ring 324 along the breakable line 305.

[0155] The breakable line 305 may extend in a plane arranged transversely to (particularly perpendicular to) the axis Z.

[0156] The breakable line 305 has a circumferential extent of less than 360° around the axis Z, since the closure body 306 is joined to the tamper-evident ring 324 at least along the hinge structure 28 .

[0157] Along the breakable line 305, a plurality of breakable bridges (not shown) may be provided which are adapted to break when the closure body 306 is first placed in the open position, thereby signaling to the user whether the container closed by the lid 301 has been opened.

[0158] exist Figure 7 , the breakable line 305 is shown as a separation line between the closure body 306 and the tamper-evident ring 324 after the closure body 306 has been placed in the open position.

[0159] The hinge structure 28 comprises at least one connecting band 31 arranged to connect the tamper-evident ring 324 to the closure body 306. The connecting band 31 keeps the closure body 306 engaged to the tamper-evident ring 324 even when the closure body 306 is in the open position.

[0160] In the example shown, there are two connecting strips 31 .

[0161] The mechanical properties of the cellulose-containing material used to make the lid 301 (and specifically, the elastic modulus of the material is between 200MPa and 2000MPa, the tensile strength is between 15MPa and 70MPa, and the deformation degree under maximum tensile stress is between 3% and 30%) allow the hinge structure 28 to be repeatedly bent to open or close the container closed by the lid 301 without being damaged.

[0162] Figure 8 and Fig. 9 A cover 401 according to an alternative embodiment is shown. The cover 401 comprises a closed body 406, which is connected to the closed body 406. Figures 1 to 6 The closed body 6 of the cover shown in FIG. Figures 1 to 6 What has been said applies to the closed body 406 and therefore it will not be described in detail.

[0163] The cap 401 further comprises a tamper-evident ring 424 comprising a plurality of retaining elements such that the tamper-evident ring 424 remains engaged to the neck of the container even after the container has been opened by removing the closure body 406. Figures 1 to 6 As described, the retaining element may comprise respective folding flaps 18 .

[0164] exist Figure 8 In the example shown in FIG. 1 , the folded flap 18 is Figure 4 The folding flaps shown in FIG. 1 are similar, wherein the folding flaps 18 slightly overlap each other. However, it is also possible to use Figure 5 or Figure 6 Alternatively, a folding flap 18 of the type shown in FIG. 1 may be used, or a retaining element having a structure different from that of a folding flap may be used.

[0165] A breakable line 405 is provided. Figures 1 to 6 The breakable line 5 shown in FIG. 4 is similar and engages the tamper-evident ring 424 and the closure body 406 prior to the first opening. Figure 8 and Fig. 9 In FIG. 4 , the closure body 406 has been separated from the tamper-evident ring 424 along the breakable line 405 by breaking the breakable bridges 410 , wherein the breakable bridges are visible as protruding from the breakable line 405 .

[0166] The breakable line 405 extends less than 360° around the axis Z, so that the engagement portion 33 where the closure body 406 is engaged with the tamper-evident ring 424 remains intact after the closure body 406 and the tamper-evident ring 424 are separated along the breakable line 405. The engagement portion 33 keeps the closure body 406 engaged with the tamper-evident ring 424 and thus anchored to the neck of the container even after the first opening.

[0167] A discontinuity line 34 is formed on the tamper-evident ring 424 , which discontinuity line interrupts the continuity of the material of the tamper-evident ring 424 .

[0168] The interruption line 34 may be parallel to the breakable line 405. The interruption line 34 may be formed by performing a cutting operation on the tamper-evident ring 424.

[0169] Along the interruption line 34, a plurality of breakable bridges (not shown) may be provided which are intended to break when the closure body 406 is first placed in the open position.

[0170] The interruption line 34 is axially aligned with the engagement portion 33 and is arranged at a position centrally located relative to the engagement portion 33. The angular dimension of the interruption line 34 around the axis of the cap 401 is greater than the angular dimension of the engagement portion 33. In this way, two connection bands 35, 36 are defined between the interruption line 34 and the breakable line 405, which connect the tamper-evident ring 424 to the closure body 406.

[0171] More specifically, the connecting bands 35 , 36 join the tamper-evident ring 424 to the joining portion 33 .

[0172] The connecting strips 35, 36 and the engaging portion 33 define a hinge structure that allows the closure body 406 to rotate relative to the tamper-evident ring 424 to move between an open position and a closed position.

[0173] Thanks to the connecting strips 35, 36, even in the open position, the closure body 406 remains engaged to the tamper-evident ring 424 and is therefore anchored to the neck of the container, which prevents the possibility of the closure body 406 being separated from the container to which the cap 401 is applied and accidentally discarded in the environment.

[0174] When the closure body 406 is placed in the open position, the connecting strips 35, 36 are moved away from the tamper-evident ring 424 along the interruption line 34, which enables the closure body 406 to be detached from the neck of the container, for example by unscrewing it from the neck.

[0175] The cover 401 can be made of the same material containing cellulose (more specifically, having a cellulose matrix) as described above with reference to the cover 1. The mechanical properties of this material (and specifically, the elastic modulus of the material is between 20MPa and 2000MPa, the tensile strength is between 15MPa and 70MPa, and the degree of deformation under the maximum tensile stress is between 3% and 30%) allow the hinge structure including the connecting bands 35, 36 and the joint portion 33 to deform to selectively place the closed body 306 in the closed position or the open position without damaging the cover 301.

[0176] In all the embodiments of the cap described above, the closure body may be provided with one or more sealing members arranged to enable the closure body to engage with the neck of the container in a sealing manner.

[0177] For example, there may be one or more annular sealing lips on the inner surface of the end wall, which project inwardly toward the interior of the closure body to engage with the inner and / or outer and / or front surface of the neck of the container to which the cap is applied. The one or more annular sealing lips are made when the cap is manufactured in the same mold that forms the cap itself.

[0178] Alternatively, a gasket may be applied on the inner surface of the end wall, the gasket being shaped like an annular element or a solid disk (e.g. circular) adapted to engage with the edge region of the neck of the container for closing the container in a sealed manner. The gasket may be made of a natural fiber-based material, in particular a cellulose-containing material, in order to obtain a cap made entirely of environmentally friendly material.

[0179] In this case, the result is a cover that has a particularly low environmental impact.

[0180] In all embodiments disclosed so far, the annular band may have a substantially constant thickness. In this case, one or more retaining elements formed by folding at least a portion of the annular band toward the interior of the cup-shaped component have a substantially constant thickness.

[0181] This makes it easier to manufacture the cap, as it can be manufactured in a relatively simple mould. In addition, there is no need to provide flanges, protrusions, thin sections or other thickness variations on the endless band. These thickness variations may be difficult to achieve with cellulose-based materials.

Claims

1. A method for manufacturing a cover (1; 101; 201; 301; 401) for a container, comprising the following steps: - inserting a material in the form of a solid or a solid dispersed in a liquid into a mold, the material comprising at least 70% by weight of cellulose; - pressing said material in said mould so as to obtain a cup-shaped part (2) having a skirt (3) extending around an axis (Z) and an end wall (4; 304) closing said skirt at one end thereof; - at least one breakable line (5; 305; 405) is formed on the skirt (3), at least one breakable line at least partially surrounding the axis (Z) so as to define a closed body (6; 306; 406) and an annular band (7) on the cup-shaped part (2); - Folding a portion (18) of the annular band (7) inwards towards the inside of the cup-shaped part (2) to obtain at least one retaining element (26) protruding inwards towards the inside of the annular band (7), thereby retaining the annular band (7) associated with the neck of the container.

2. The method according to claim 1, further comprising the steps of: In the end region of the skirt (3) opposite to the end wall (4; 304), a plurality of cutting lines (17, 17a, 17b) extending transversely to the free edge (9) of the skirt (3) are formed, and wherein the portion of the annular band (7) folded inwardly toward the interior of the cup-shaped part (2) to obtain the retaining element (26) is a wing (18) defined between two consecutive cutting lines (17, 17a, 17b).

3. The method according to claim 2, wherein: Each cutting line (17, 17a, 17b) is located on the endless belt (7), and a first end of each cutting line is at a distance from the breakable line (5; 405; 505), and a second end of each cutting line is arranged at the free edge (9).

4. The method according to claim 2 or 3, wherein: The cutting lines (17, 17a, 17b) are formed by cutting the cup-shaped part (2) with a cutting blade or by laser cutting.

5. The method according to any one of claims 2 to 4, wherein: Two adjacent flaps (18) are separated by a common cutting line (17), which defines corresponding side portions (27) on the two adjacent flaps (18), and wherein, after the flaps (18) are folded inwardly toward the interior of the cup-shaped part (2), the side portions (27) at least partially overlap or interfere with each other.

6. The method according to any one of claims 2 to 4, wherein: Two adjacent flaps (18) are separated by two consecutive different cutting lines (17a, 17b), so that when the two adjacent flaps (18) are folded inwardly toward the inside of the cup-shaped part (2), a space (22) is defined between the two adjacent flaps (18).

7. The method according to claim 6, further comprising the steps of: A piece of material of the skirt (3) is removed between two consecutive different cutting lines (17a, 17b), and wherein the piece of material of the skirt (3) is removed by forming a transverse cut (21) between the two consecutive different cutting lines (17a, 17b).

8. The method according to claim 7, wherein: The transverse cut (21) joins the corresponding inner points of the two consecutive distinct cutting lines (17a, 17b) to form an intermediate element (23) extending between two adjacent folded flaps (18) as an extension of the skirt (3).

9. The method according to any preceding claim, further comprising the steps of: A predetermined folding line is formed in a position along which the portion (18) of the endless band is intended to be folded so as to facilitate the portion (18) of the endless band to be folded inwardly toward the interior of the cup-shaped member (2).

10. A method according to any preceding claim, wherein: The material in solid state is inserted into the mold in a form selected from the following forms: powder, granules, solid film, fluff, air-laid structure.

11. The method according to any one of claims 1 to 9, wherein: The material in the form of a solid dispersed in a liquid is in a paste-like state when inserted into the mold.

12. A cap according to any preceding claim, wherein: At least one of the retaining elements (26) has a substantially constant thickness.

13. A cover for a container, comprising a cup-shaped member (2), the cup-shaped member being made of a material comprising a cellulose matrix, wherein: The cover is made of a material of which at least 70% by weight is cellulose, the cup-shaped part (2) having a skirt (3) extending around an axis (Z) and an end wall (4; 304) closing the skirt at one end of the skirt, wherein at least one breakable line (5; 305; 405) is provided on the skirt (3), at least one breakable line (5; 305; 405) at least partially surrounding the axis (Z) to allow the cup-shaped part (2) to be broken. ) is defined on a closed body (6; 306; 406) and an anti-tampering ring (24; 324; 424), and wherein the anti-tampering ring (24; 324; 424) includes an annular band (7), a portion (18) of which is folded inwardly toward the interior of the cup-shaped body (2) to define a retaining element (26) extending inwardly toward the interior of the anti-tampering ring (24; 324; 424), thereby retaining the anti-tampering ring (24; 324; 424); 424) is associated with the neck of the container.

14. The cover according to claim 13, wherein The annular band (7) comprises a plurality of retaining elements (26), which are defined by corresponding flaps (18) folded inwardly towards the interior of the cup-shaped part (2), each flap (18) extending from an end region of the anti-tampering ring (24; 324; 424) opposite to the breakable line (5; 305; 405).

15. The cover according to claim 14, wherein Two adjacent flaps (18) folded inwardly toward the interior of the cup-shaped part (2) are in contact with each other inside the cup-shaped part (2).

16. The cover according to claim 14 or 15, wherein Two adjacent flaps (18) folded inwardly towards the interior of the cup-shaped part (2) have respective side portions (27) that at least partially overlap.

17. The cover according to claim 14, wherein: Two adjacent flaps (18) folded inwardly toward the interior of the cup-shaped member (2) are spaced apart from each other.

18. The cover according to claim 14 or 17, wherein Between two adjacent flaps (18) folded inwardly toward the interior of the cup-shaped part (2), an intermediate element (23) is provided, the intermediate element (23) extending between the adjacent flaps (18) as an extension of the skirt (3).

19. A cover according to any one of claims 13 to 18, wherein The material used to make the cover has an elastic modulus between 200 MPa and 2000 MPa, a tensile strength between 15 MPa and 70 MPa, and a deformation degree under maximum tensile stress between 3% and 30%.

20. A cover according to any one of claims 13 to 19, wherein At least one of the retaining elements (26) has a substantially constant thickness.

21. A cover for a container, comprising: A closure body (306; 406) having an internal fixing structure for removably fixing the closure body to the neck of the container; an anti-tampering ring (324; 424) intended to remain anchored to the neck of the container; at least one connecting band (31; 35; 36) which keeps the closure body (306; 406) in place even after the closure body (306; 406) has been removed from the neck. 406) remains anchored to the tamper-evident ring (324; 424), wherein the cover (301; 401) is made of a material containing at least 70% by weight of cellulose, the elastic modulus of the material being between 200 MPa and 2000 MPa, the tensile strength being between 15 MPa and 70 MPa, and the degree of deformation under maximum tensile stress being between 3% and 30%.

22. The cover according to claim 21, wherein The internal fixing structure is configured to allow the closure body (306) to be snap-fitted into engagement with the neck of the container.

23. The cover of claim 21, wherein: The internal fixing structure comprises at least one helical thread so as to be able to screw the closure body (406) onto the neck of the container.

24. A cover according to any one of claims 21 to 23, wherein The tamper-evident sealing ring (424) has an interruption section (32) which interrupts the continuity of the tamper-evident sealing ring (424) and is arranged parallel to the breakable line (405) so that two connecting bands (35, 36) are defined between the breakable line (405) and the interruption section (32).

25. A cover according to any one of claims 13 to 24, wherein The material used to make the cover, which contains at least 70% by weight of cellulose, has a viscosity between 0.75 g / cm 3 Up to 1.3g / cm 3 The density between.

26. A cover according to any one of claims 13 to 25, wherein The material used to make the cover comprises cellulose fibers, at least 50% of which have a length between 0.2 mm and 3.0 mm and a transverse dimension between 0.01 mm and 0.05 mm.

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