Cap made of moulded fibre material, packaging unit comprising the cap and manufacturing method

Abstract

This invention relates to a cap made of molded fiber material, a packaging unit including such a cap, and a method of manufacturing the cap. The cap according to the invention comprises: - a covering member having one or more clamping elements and configured to cover the packaging unit, and having a covering density; and - a venting element disposed in the covering member, wherein the venting element is configured to allow vapor to pass through and exit the packaging unit, and wherein the venting element has a smaller venting density compared to the density of the covering member.

Description

[0001] This invention relates to a lid made of molded fiber material. These lids are used in packaging units (e.g., cups), and other packaging units for containing, storing, transporting, and / or displaying a range of products (e.g., food containing beverages). Lids are typically used to cover cups used to hold (hot) beverages. Lids can also be used in other packaging units such as containers, holders, caps, dishes, boxes, trays, etc. Molded fiber lids can be manufactured using a dry-laid process using a "fluffy" slurry matrix.

[0002] For example, traditional lids are used in practice to cover cups and trays. Traditional lids can be made of plastic materials. To provide a more sustainable solution for covering packaging units containing products, traditional lids can also be made of moldable fiber materials.

[0003] One problem with traditional lids is their use in conjunction with hot products, such as hot drinks in a cup. These hot products can create steam within the packaging unit, and consumers may be exposed to this steam. This can be unpleasant and could even be harmful to consumers.

[0004] The purpose of this invention is to eliminate or at least reduce one or more of the aforementioned problems of conventional covers.

[0005] Therefore, the present invention provides a cap made of molded fiber material, wherein the cap according to the present invention comprises: - A covering component having one or more clamping elements and configured to cover a packaging unit, and having a covering density; and - A venting element disposed in the covering component, wherein the venting element is configured to allow vapor to pass through and exit the packaging unit, and wherein the venting element has a smaller venting density compared to the covering density.

[0006] The lid according to the invention includes a covering member that can cover the opening of a packaging unit. Such packaging units typically relate to cups for containing (hot) beverages. It should be understood that the lid can also be used for other packaging units that can contain products. The covering member is provided with a clamping element that can clamp the lid to the packaging unit. More specifically, the clamping element is capable of releasably clamping the lid to the packaging unit and typically involves a clamping ring element engaged with the rim of the cup.

[0007] The invention also includes a venting element disposed in the cover component. The venting element allows steam to escape from the interior of the packaging unit (e.g., a cup) to the external environment. This prevents unpleasant experiences for consumers and can even prevent harm from hot steam trapped in the cup under the lid. Therefore, the lid of the present invention provides a safety measure that is particularly convenient when applied to packaging units (e.g., cups) containing hot drinks or other hot products.

[0008] According to the invention, the venting element is provided with a venting density that is smaller than the coverage density. The coverage density is the average density of the covering components excluding the venting element. The venting density is the average density of the venting element. Providing a venting element with a lower density allows vapor to pass through the venting element and exit the packaging unit. In a currently preferred embodiment of the invention, the coverage density is higher than 800 kg / m³. 3 And preferably at 800 kg / m 3 Up to 1200 kg / m 3 Within a certain range. The ventilation density is preferably below 800 kg / m³. 3 More preferably below 650 kg / m 3 or even more preferably below 550 kg / m 3 or even more preferably below 425 kg / m 3 or even more preferably below 350 kg / m 3 And most preferably below 300 kg / m 3 .

[0009] As another effect of the lid according to the invention, it prevents the contents of the packaging unit (e.g., a cup) from spilling. This also helps to provide a safety measure so that consumers are not injured by spilled hot product.

[0010] The thickness of the venting element of the lid is currently preferably in the range of 0.45 mm to 2.5 mm. Providing a venting element with a certain thickness prevents undesirable spillage of the contents of the packaging unit on the one hand, and allows vapor to pass through the venting element on the other.

[0011] Compared to a conventional drinking opening optionally provided in the lid, the venting element in the lid according to the invention has thickness, while the drinking opening has no thickness and may cause the contents of the packaging unit to spill out. Furthermore, a conventional drinking opening cannot provide controlled release of vapors that can form beneath the lid of the packaging unit. In a presently preferred embodiment of the invention, the venting element is provided in a lid without a drinking opening, and the consumer removes the entire lid to access the contents of the packaging unit.

[0012] In a further preferred embodiment of the invention, the thickness of the venting element is in the range of 0.5 mm to 2.35 mm, more preferably in the range of 1.0 mm to 2.15 mm, and most preferably in the range of 1.5 mm to 2.05 mm. These further ranges have been shown to prevent spillage and allow vapor to pass through the venting element and exit the packaging unit, enabling consumers to use the packaging unit and lid safely.

[0013] The cap of the present invention can be manufactured by a dry-laying process. In this process, the slurry matrix can be supplied in sheets or rolls, which can be fed into a hammer mill or similar device (also known as a fiber separator) that separates the compressed slurry rolls or sheets into individual loose fibers, which are then conveyed to the forming system that forms the cap.

[0014] The preparation and provision of moldable fibrous materials typically involves providing a quantity of fibrous material. This fibrous material can have various sources, such as wood and / or non-wood fibrous materials, optionally derived from recycling processes, such as recycled paper materials. Alternatively, or in addition to such paper materials, the fibrous material may also include a quantity of non-wood fibrous materials, also referred to as natural fibers and / or alternative fibers. Such fibers may involve biomass fibers from plant sources, examples of which are described in WO 2021 / 145764 A1. After the preparation of the moldable fibrous material, a primary cap is formed in a mold. This molding involves shaping the material into the desired shape of the primary cap. After the molding process, the primary cap is typically dried, optionally involving an in-mold drying step.

[0015] In a currently preferred embodiment of the invention, the moldable slurry material comprises a fibrous material, which optionally includes a certain amount of non-wood fiber material. Non-wood fiber materials are also referred to as natural and / or alternative fiber materials. Providing a certain amount of these fibers gives the lid a natural feel and / or improves the overall strength and stability of the lid. Such non-wood fibers can include fibers from various sources, particularly biomass fibers from plant sources. Examples of such plant-derived biomass are described in WO 2021 / 145764 A1 above.

[0016] In the currently preferred embodiment of the lid, the non-wood fiber material accounts for at least 5 wt% of the fibrous material of the lid, preferably at least 10 wt%, preferably at least 50 wt%, even more preferably at least 80 wt%, even more preferably at least 85 wt%, and most preferably at least 92.5 wt%. The results show that the lid can be efficiently manufactured from a non-wood fiber material having such a large amount of non-wood fiber material.

[0017] In a currently preferred embodiment of the invention, the moldable fiber material comprises a certain amount of non-wood fibers, wherein at least 80% of the fibers have a length of 1.1 mm or more, preferably 1.2 mm or more. This results in a significant increase in the fiber length provided in the molding paste material compared to most conventional caps. This increases the strength-to-weight ratio of the cap.

[0018] In a currently preferred embodiment of the invention, the moldable fiber material comprises a certain amount of microfibrillated cellulose (MFC). In the context of the invention, this may also include nanofibrillated cellulose, cellulose nanofibers, or nanocellulose. The MFC is preferably derived from plant-derived cellulose raw materials. The use of MFC enhances fiber-fiber bond strength and further improves the reinforcing effect in the matrix. In this embodiment of the invention, MFC provides improved barrier properties. Furthermore, MFC can fill the gaps between fibers, thus possessing gas barrier properties, such as enhanced oxygen barrier properties. When MFC is modified, for example, by replacing carboxyl groups with hydrophobic groups, modified MFC can also enhance water vapor barrier properties. As another advantage, a surface layer can provide or improve the paper-like appearance and / or paper-like feel. This paper-like appearance and / or paper-like feel surface layer contributes to consumer acceptance of the lid.

[0019] In yet another preferred embodiment of the invention, the moldable fiber material comprises a certain amount of biodegradable polyester. Preferably, the biodegradable polyester in the cap has dimensional constancy or dimensional stability.

[0020] In another preferred embodiment of the invention, the biodegradable polyester in the moldable fiber material comprises fibers preferably having a length of 1.2 mm or more. The provision of biodegradable polyester fibers creates a network of molded fibers and biodegradable polyester fibers in the molded fiber product. This further improves the strength of the cap.

[0021] In a currently preferred embodiment of the invention, the ventilation element includes a plurality of openings.

[0022] Multiple openings are provided to allow steam to exit the packaging unit, enabling hot beverages to be served to consumers in a safe manner.

[0023] The number of openings is preferably in the range of 5 to 30, more preferably in the range of 10 to 25, and most preferably in the range of 15 to 20. It should be understood that the number of openings can be adapted to the size of the packaging unit and the type of beverage or product in the packaging unit covered by the lid.

[0024] In this embodiment of the invention, the opening is preferably configured as a mesh or wire mesh. This mesh or wire mesh provides structure for the opening and further improves the controlled release of vapors generated within the packaging unit. This further enhances the overall security of the lid and the packaging unit equipped with such a lid.

[0025] In the presently preferred embodiment of the invention, the width or diameter of the opening is in the range of 0.2 mm to 1.0 mm, preferably in the range of 0.3 mm to 0.75 mm, and most preferably in the range of 0.45 mm to 0.6 mm.

[0026] Experiments have shown that the size of the opening of the venting element within the above range prevents the contents of the packaging unit from overflowing, while allowing the vapor formed inside the packaging unit to leave the packaging unit.

[0027] In yet another preferred embodiment of the invention, the cover is made of dry molding fiber material.

[0028] The lids made from dry-molded fiber materials enable an efficient and effective manufacturing process, resulting in more sustainable lids compared to conventional lids produced by other manufacturing processes.

[0029] In yet another preferred embodiment of the invention, the ventilation element includes a high-density portion and one or more low-density portions.

[0030] High-density portions provide structural and stability for the ventilation elements. Low-density portions allow vapor to pass through these portions and exit the packaging unit. In the currently preferred embodiment of the invention, the density of the high-density portions is greater than 600 kg / m³. 3 Preferably, it is higher than 900 kg / m 3 More preferably higher than 1050 kg / m 3 And most preferably, it is higher than 1150 kg / m 3 Preferably, the density of one or more low-density portions is less than 600 kg / m³. 3 Preferably below 425 kg / m 3 More preferably below 350 kg / m 3 And most preferably below 300 kg / m 3 .

[0031] Experiments have shown that the density combination of the high-density and low-density portions within the aforementioned range effectively prevents overflow while allowing vapor to pass through the venting element and exit the packaging unit.

[0032] The present invention also relates to a packaging unit that includes a lid as described in one embodiment of the invention.

[0033] This packaging unit provides the same or similar effects and / or advantages as described regarding the lid. The packaging unit advantageously relates to a drinking cup for hot beverages that can be fitted with a lid.

[0034] The present invention also relates to a method for manufacturing a cap from a molded fiber material, wherein the method includes the following steps: - Preparation of moldable fiber materials; - Molding a moldable fibrous material into a lid in a mold, the lid comprising; - A covering component having one or more clamping elements and configured to cover a packaging unit, wherein the covering component has a covering density; and - A venting element disposed in the covering component, wherein the venting element is configured to allow vapor to pass through and exit the packaging unit, and wherein the venting element has a smaller venting density compared to the covering density.

[0035] This method provides the same or similar effects and / or advantages as described with respect to lids and / or packaging units with lids.

[0036] Optionally, the manufacturing method includes providing a moldable fiber material, which relates to one or more of the optional materials mentioned with respect to the cover. The method may further include the steps of providing one or more features mentioned with respect to the cover, optionally including providing a plurality of openings in the venting element and / or providing the moldable fiber material from a dry moldable fiber material.

[0037] Other advantages, features, and details of the invention are described based on preferred embodiments thereof, with reference to the accompanying drawings, wherein: - Figures 1A-1C A view of the cover according to a first embodiment of the present invention is shown; - Figures 2A-2C A view is shown of an alternative embodiment of the lid according to the invention; - Figures 3A-3C A view of yet another alternative embodiment of the cover according to the invention is shown; - Figure 4 A covered packaging unit according to the present invention is shown; - Figure 5 A method for manufacturing the cap according to the invention is shown; and - Figure 6 The following is shown for molding according to Figures 1A-1C The structure of the mold for the lid.

[0038] Cover 2 ( Figures 1A-1C The device includes a cover component 4 and a clamping edge or clamping rim 6. The cover component 4 also includes a venting element 8. In the illustrated embodiment, the venting element 8 includes a mesh or mesh 10 with a relatively high density and a thickness d2. The venting element 8 also includes a plurality of low-density portions 12 with a thickness d1, wherein the thickness d1 is substantially greater than the thickness d2 of the high-density portions 10 with greater compression.

[0039] In the illustrated embodiment, the mesh or mesh 10 has a density greater than 800 kg / m³ and a thickness d2 of approximately 0.5 mm. The low-density portion 12 has a density less than 400 kg / m³ and a thickness d1 of at least 1.5 mm, more preferably approximately 2 mm. Optionally, the high-density portion 10 can be manufactured using an additional compression step and / or this compression can be integrated into the actual molding. In this embodiment, the clamping element 14 is configured as an annular element capable of engaging the edge 66 of the cup 64. Figure 4 ).

[0040] In an alternative embodiment, cover 22 includes cover member 24 and clamping element 26. Figures 2A-2C The venting element 28 includes a bottom 30, which, in the illustrated embodiment, substantially fills the entire venting element 28. The bottom 30 is provided with a thickness d3. The bottom 30 with thickness d3 remains slightly “fluffy” to allow vapor to pass through the venting element 28 and also to prevent overflow. In the illustrated embodiment, the thickness d3 is in the range of 1.5 mm to 3.0 mm. It should be understood that the thickness d3 will preferably be designed relative to a particular packaging unit, lid material, and / or product type.

[0041] In yet another alternative implementation, cover 42 ( Figures 3A-3C The package includes a cover member 44 having a clamping element 46 shaped as a clamping ring. The cover member 44 includes a venting element 48 having a plurality of openings 50. The openings 50 are relatively small, having a diameter D. In the illustrated embodiment, approximately 15 openings 50 are provided, each with a diameter of approximately 0.5 mm. These small openings prevent overflow and allow vapor to exit the packaging unit. It should be understood that, in this case, the exact diameter D of the openings 50 may also depend on the material properties, the type of packaging unit, and the product type.

[0042] Lids 2, 22, and 42 can be applied to cup 64 with a rim 66 ( Figure 4 The packaging unit 64 having lids 2, 22, and 42 forms an assembly 62 having lids 2, 22, and 42.

[0043] Manufacturing process 102 ( Figure 5The process includes a preparation step 104, in which a fibrous material is prepared. Preparation step 104 may involve applying and / or mixing wood fiber materials and / or non-wood materials (e.g., alternative fibers). For example, the wood material may involve so-called virgin fibers and / or fibers from recycled paper materials. The prepared fibrous material 106 is then provided to a molding step 108, in which caps 2, 22, and 42 are molded / shaped, preferably including ventilation elements 8, 28, and 48. Optionally, a separate step for providing ventilation elements 8, 28, and 48 may be included. Caps 2, 22, and 42 may then be further processed in another processing step 112 to obtain the final products 2, 22, and 42.

[0044] Then, in application step 114, the lids 2, 22, and 42 are applied to the packaging unit, such as a cup filled with beverages or other products.

[0045] Optionally, packaging units 2, 22 are provided with an alternative fiber material having fibers that are preferably visible to the consumer. This fiber material can involve wood fibers and non-wood fibers (such as the aforementioned alternative fibers). In some embodiments, the illustrated caps 2, 22, 42 comprise a molded fiber material containing a certain amount of MFC and / or biodegradable aliphatic polyesters, such as PLA and / or PHBT. Optionally, a certain amount of calcium carbonate is applied.

[0046] Alternatively, other additional materials may be used, such as Xerolex (or BIM DS2801 as an example of a dry strength agent) and / or AKD.

[0047] Mold group 202 ( Figure 6The assembly includes an upper mold 204 and a lower mold 206. The mold assembly 202 is preferably used for molding step 108 of manufacturing process 102. In the illustrated embodiment, in molding step 108, the volume 208 between molds 204 and 206 is filled with the prepared fibrous material 106 to form a cover 2. It should be understood that other shapes are also conceivable according to the invention. The mold assembly 202 can be used to manufacture covers 2, 22, and 42. Molding step 208 is optionally performed at a molding temperature in the range of 90°C to 220°C, preferably in the range of 110°C to 180°C, even more preferably in the range of 125°C to 165°C, and most preferably about 150°C. Molding pressure can be in the range of 0.5 MPa to 150 MPa, more preferably in the range of 0.8 MPa to 25 MPa, and even more preferably in the range of 0.95 MPa to 10 MPa. The molding time using the closed mold assembly 202 is optionally in the range of 0.1 seconds to 10 seconds, more preferably in the range of 0.25 seconds to 4.5 seconds, and most preferably in the range of 0.45 seconds to 2.5 seconds. For example, the mold assembly 202 or any other suitable mold assembly can be used in the manufacturing process at a molding temperature of 155°C, a molding pressure of 4.5 MPa, and a holding time of 1.0 second. It should be understood that other combinations of process conditions are also possible, for example, depending on the specific material and / or cap design applied.

[0048] This invention is by no means limited to the preferred embodiments described above. The sought rights are defined by the following claims, and many modifications may be contemplated within their scope.

Claims

1. A cap made of molded fiber material, comprising: - A covering component having one or more clamping elements and configured to cover a packaging unit, and having a covering density; and - A venting element disposed in the covering member, wherein the venting element is configured to allow vapor to pass through and exit the packaging unit, and wherein the venting element has a smaller venting density compared to the covering density.

2. The cap of claim 1, wherein, said ventilation density is lower than 800 kg / m 3 , preferably lower than 650 kg / m 3 , more preferably lower than 550 kg / m 3 , even more preferably lower than 425 kg / m 3 , even more preferably lower than 350 kg / m 3 , and most preferably lower than 300 kg / m 3 .

3. The cap of claim 1 or 2, wherein, The thickness of the ventilation element is in the range of 0.45 mm to 2.5 mm, preferably in the range of 0.5 mm to 2.35 mm, more preferably in the range of 1.0 mm to 2.15 mm, and most preferably in the range of 1.5 mm to 2.05 mm.

4. The cap of claim 1, 2, or 3, wherein, The ventilation element includes multiple openings.

5. The cap of the preceding claim, wherein, The number of openings is in the range of 5 to 30, preferably in the range of 10 to 25, and most preferably in the range of 15 to 20.

6. The cap according to the preceding claim 4 or 5, wherein, The opening is constructed as a grid or mesh.

7. The cap of claim 4, 5, or 6, wherein, The width or diameter of the opening is in the range of 0.2 mm to 1.0 mm, preferably in the range of 0.3 mm to 0.75 mm, and most preferably in the range of 0.45 mm to 0.6 mm.

8. The cover according to any one of the preceding claims, wherein, The cover is made of dry-molded fiber material.

9. The cover according to any one of the preceding claims, wherein, The ventilation element includes a high-density portion and one or more low-density portions.

10. The cover according to the preceding claim, wherein, the density of the high density fraction is higher than 600 kg / m 3 , preferably higher than 900 kg / m 3 , more preferably higher than 1050 kg / m 3 , and most preferably higher than 1150 kg / m 3 .

11. The cover according to claim 9 or 10, wherein, the density of the one or more low density parts is below 600 kg / m 3 , preferably below 425 kg / m 3 , more preferably below 350 kg / m 3 , and most preferably below 300 kg / m 3 .

12. The cover according to any one of the preceding claims, wherein, The coverage density is the average density of the covering components excluding the ventilation element, and wherein the ventilation density is the average density of the ventilation element.

13. A packaging unit comprising a lid according to any one of the preceding claims.

14. A method for manufacturing a cap from a molded fiber material, wherein, The method includes the following steps: - Preparation of moldable fiber materials; - The moldable fiber material is molded into a cover in a mold, the cover comprising; - A covering component having one or more clamping elements and configured to cover a packaging unit, and having a covering density; and - A venting element disposed in the covering member, wherein the venting element is configured to allow vapor to pass through and exit the packaging unit, and wherein the venting element has a smaller venting density compared to the covering density.

15. The method according to the preceding claim, wherein, The moldable fiber material is provided by dry molding fiber material.

16. The method according to claim 14 or 15, further comprising the step of providing a plurality of openings in the venting element.

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