Use of a dispersion glue as a barrier coating of a plastic-free, fiber-containing substrate for producing supd-compliant packagings

Abstract

The invention relates to the use of a dispersion adhesive as a coating (40) of an otherwise plastic-free, fiber-containing substrate (20). According to the invention, the dispersion adhesive forms a barrier against water and / or water vapor and / or aroma and / or oxygen and / or oil and / or grease after setting. In addition, the dispersion adhesive can be sealable.

Description

TECHNICAL AREA

[0001] The invention relates to the use of a dispersion adhesive as a barrier coating on a plastic-free, fiber-containing substrate for the production of SUPD-compliant packaging. Such a plastic-free, fiber-containing substrate can be, for example, paper, cardboard, corrugated board, or corrugated board. Such products are suitable for a range of applications and can be used, in particular, as a replacement for plastics or composite materials.

[0002] Examples of applications for these products include trays and bowls. Pre-cut portions or pouches with freshness-preserving properties, for example for sausage, cheese, fish, and meat, can also be produced using appropriately coated products. Furthermore, such products are also suitable as transport packaging for fresh foods such as fish or fruit. STATE OF THE ART

[0003] Dispersion adhesives are usually applied in the thinnest possible layers and serve to bond different substrates together.

[0004] Functional packaging with a barrier effect and / or heat-sealability currently usually consists of: A) Pure plastic packaging B) Composite packaging C) Packaging that is partially coated with a thin layer of plastic (a so-called dispersion barrier) to make it more resistant to liquids and greases during use.

[0005] Composite packaging refers to a combination of several materials, for example the combination of paper, cardboard, carton or corrugated board with other materials including plastic and / or aluminum.

[0006] Due to legal regulations, in particular the guidelines of the Single-Use Plastics Directive (EU) 2019 / 904 (SUPD), the use of plastics for single-use packaging is becoming increasingly regulated and more expensive, as it is subject to additional taxes and fees. Therefore, there are growing efforts to avoid or at least reduce the use of plastics in packaging.

[0007] Both pure plastic packaging and composite packaging, as well as packaging coated with a so-called dispersion barrier, can fall under this directive and consequently be subject to financial levies and prohibitions or restrictions. PRESENTATION OF THE INVENTION

[0008] Based on this prior art, the invention aims to provide an improved packaging that can be manufactured as cost-effectively as possible, is exempt from the prohibitions and restrictions of the Single-Use Plastics Directive and is still environmentally friendly.

[0009] The food packaging according to the invention is defined by the features of main claim 1. Further developments of the invention are the subject of subsequent claims.

[0010] According to the invention, a dispersion adhesive is used in a greater layer thickness as a coating on an otherwise plastic-free, fiber-containing substrate. After setting, the dispersion adhesive forms a homogeneous, closed film that does not permit further bonding. This film is particularly suitable as a barrier against water and / or water vapor and / or aroma and / or oxygen and / or oil and / or grease.

[0011] Such dispersion adhesives are available in particular from the company Polybond LTD under article number 2907 and the name "dispersion adhesive".

[0012] The invention takes advantage of the fact that adhesives are expressly exempt from the current version of the Single-Use Plastics Directive. Therefore, products made from an otherwise plastic-free, fiber-containing substrate coated with an adhesive are not subject to the prohibitions and restrictions of the Single-Use Plastics Directive, nor to the additional financial levies, allowing them to be manufactured economically. Furthermore, the dispersion adhesive is a sustainable alternative to conventional plastics or plastic coatings, is biodegradable and compostable, and does not hinder the recycling process of the end products.

[0013] In this way, for example bags for cement, pet food and cereals can be produced in a particularly environmentally friendly way.

[0014] The products obtained through the coating according to the invention are compostable and recyclable in conventional waste paper. Furthermore, the products can be manufactured economically in large quantities using conventional processing machines.

[0015] After the dispersion adhesive dries and sets, the substrate's strength is significantly increased, allowing for a lower substrate weight. This conserves resources right from the start when selecting the substrate thickness. Furthermore, the coating on the substrate increases the product's wet strength by creating a moisture-repellent barrier. It also provides a barrier against the penetration of liquids and gases, thus enhancing the substrate's functionality.

[0016] In a particularly preferred embodiment, the dispersion adhesive can be food-safe. This allows for the production of packaging for consumption or storage of food. Such products can be service and sales packaging, for example, packaging requiring a barrier against liquids, especially to-go packaging such as folding boxes, cups, lids, bowls, or trays. Alternatively, such products can be single-use or reusable food packaging, for example, pre-cut sheets with a freshness-preserving effect, such as wrapping paper at the deli counter. Alternatively, they can also be sales packaging, for example, for delicate foods such as fruit.

[0017] Preferably, the dispersion adhesive can be sealable. This allows the corresponding products to be used for sealable packaging, for example, for lids of milk product cups or paper bags for cereals or cement. Furthermore, no additional sealable coating needs to be applied, which is economically advantageous and saves material.

[0018] The dispersion adhesive can be reactivated at elevated temperatures, especially above 100°C, so that the adhesive effect can be restored.

[0019] The adhesive layer, at least one of which is preferably applied across the entire surface of at least one side of the substrate, prevents unintentional moisture penetration of the substrate when moist products come into contact with the packaging. Furthermore, a full-surface coating is generally easier to apply than a partial coating. For example, the coating can be applied by immersion, spraying, or by roller or squeegee application.

[0020] Dyes are also not included in the definition of plastics according to the current version of the Single-Use Plastics Directive. Therefore, the products can be additionally coated with a colored layer. The colored layer can be applied to the entire surface or only to specific sections. It is possible to coat only one side of the substrate with a colored layer; however, it is also possible to coat both sides. The colored layer is preferably located between the substrate and the coating. This prevents the colored layer from coming into direct contact with the product, such as food, even accidentally. Furthermore, the coating acts as a barrier against the migration of the colored layer into the product, thus further enhancing food safety.

[0021] Preferably, a coating can be provided on both sides of the substrate. This prevents the packaging from being accidentally misused and the food from coming into direct contact with the substrate. This could lead to undesirable adhesion of the substrate to the food, especially with moist foods.

[0022] Depending on the desired application, the substrate can be paper, cardboard, or corrugated board. This allows for different stability requirements to be met without having to change the fundamental structure of the product.

[0023] Since single-use packaging is a mass-produced item with only short-term use, the raw materials used should be easily reproducible. Ideally, the substrate should therefore consist of recycled fibers or a rapidly renewable raw material, or at least contain such a sustainable raw material. By eliminating or at least reducing the use of wood as a raw material for the substrate, up to 90% of water can be saved during production. Such a substrate is therefore particularly environmentally friendly.

[0024] For example, suitable packaging could be wrapping paper for food. In this case, the substrate can be relatively thin, as the packaging does not need to be particularly sturdy.

[0025] Alternatively, the packaging can be designed as a container. Such a container could be, for example, a cup or a bowl. These cups can be used both for takeaway, for example, for hot or cold drinks, and as retail packaging for dairy products. Similar trays can also be used for both takeaway and retail packaging. Furthermore, a suitable container could also be designed in the form of a beverage carton.

[0026] Such food packaging can also include a lid that can be attached to a container. For example, this lid might be a flat lid that is sealed to a container with a tamper-evident seal. Because the adhesive used is sealable, this type of attachment can be done easily without any further measures. These lids are commonly used, for instance, to seal milk product cups. Alternatively, the lid could also be a slip-on lid, which is particularly common for to-go containers.

[0027] The invention is based on the finding that such dispersion adhesives are suitable as a coating for packaging that requires a barrier. The use of such a dispersion adhesive for these purposes is therefore of independent inventive significance.

[0028] In a first embodiment, the coating can be applied to packaging, as already described. In a second embodiment, the coating can be applied to a food product, in particular to disposable tableware and / or disposable cutlery.

[0029] Further advantages and features of the invention can be seen in the features further specified in the claims and in the exemplary embodiments below. BRIEF DESCRIPTION OF THE DRAWING

[0030] The invention is described and explained in more detail below with reference to the exemplary embodiments shown in the drawing. The drawing shows: Fig. 1 a cross-section through a first embodiment of a packaging according to the invention, Fig. 2 a cross-section through a second embodiment of the packaging according to the invention, Fig. 3 a cross-section through a third embodiment of the packaging according to the invention, Fig. 4 a cross-section through a fourth embodiment of the packaging according to the invention, Fig. 5 a cross-section through a fifth embodiment of the packaging according to the invention, Fig. 6 a cross-section through a sixth embodiment of the packaging according to the invention, Fig. 7 a cross-section through a seventh embodiment of the packaging according to the invention, Fig. 8 a cross-section through an eighth embodiment of the packaging according to the invention. WAYS TO IMPLEMENT THE INVENTION

[0031] A first embodiment of the packaging 10 according to the invention is in Fig. 1 schematically represented. Packaging 10 could, for example, be wrapping paper in which a food item 12 is to be packaged.

[0032] The wrapping paper 10 for food according to the invention has a substrate 20, which in this example is a paper layer 20. The coating 40 is present over the entire surface of one side and consists of a dispersion adhesive that forms a barrier, particularly against liquids and gases, is food-safe, and can be reactivated at elevated temperatures. The dispersion adhesive forms a homogeneous layer, so that the substrate 20 is completely covered by the coating 40.

[0033] A food item 12 to be packaged, for example a piece of meat, a portion of fresh sausage, or a piece of cheese, can generally be placed on either side of the wrapping paper 10. In this example, the food item 12 has been placed on the coated side of the substrate 40. In contrast, the food item 12 could also be placed on the uncoated side 20.

[0034] In Fig. 2 An alternative wrapping paper 10.2 is shown. In contrast to the wrapping paper 10, the substrate 20 has been coated on both sides with a coating 40. The foodstuff 12 comes into contact with the coating 40 of the wrapping paper 10.2.

[0035] In Fig. 3 An alternative wrapping paper 10.3 is shown. In contrast to the wrapping paper 10, the substrate 20 has a coating 30 applied to one side, which is usually only present in sections. The coating 40 is present on the other side of the substrate 20. The foodstuff 12 comes into contact with the coating 40 of the wrapping paper 10.3.

[0036] In Fig. 4 An alternative wrapping paper 10.4 is shown. In contrast to the wrapping paper 10.3, the substrate 20 has been coated on both sides with a layer of color 30. In this example, one of the two layers of color 30 is covered by a coating 40. The foodstuff 12 comes into contact with the coating 40 of the wrapping paper 10.4.

[0037] In Fig. 5 An alternative wrapping paper 10.5 is shown. In contrast to the wrapping paper 10.3, the substrate 20 has a coating 40 on both sides. Furthermore, a color layer 30 is present on one side of the substrate 20, which is usually only present in sections. In this example, the color layer 30 is covered by the coating 40. The food item 12 thus comes into contact with the coating 40 of the wrapping paper 10.5.

[0038] In Fig. 6 An alternative wrapping paper 10.6 is shown. In contrast to the wrapping paper 10.5, the substrate 20 has been coated on both sides with a layer of color 30. In this example, both layers of color 30 are covered by a coating 40. The foodstuff 12 comes into contact with the coating 40 of the wrapping paper 10.6.

[0039] In Fig. 7 An alternative wrapping paper 10.7 is shown. In contrast to the wrapping paper 10.3, the colored layer 30 is covered by an associated varnish 50. The varnish layer 50 serves to protect the colored layer 30 and is therefore also excluded from the Single-Use Plastics Directive. The other side of the substrate 20 has the coating 40 according to the invention. The foodstuff 12 thus comes into contact with the coating 40 of the wrapping paper 10.7.

[0040] In Fig. 8 An alternative wrapping paper 10.8 is shown. On one side of the substrate 20, a layer of color 30 has first been applied, which is covered by a varnish 50. The varnish layer 50 serves to protect the color layer 30 and is therefore also excluded from the Single-Use Plastics Directive. On the opposite side of the substrate 20, another layer of color 30 has been applied, which is covered by the coating 40.

[0041] The packaging according to the invention can be any type of packaging that may come into contact with food. The basic structure of the packaging can correspond to the structure shown in the drawings. The structure and stability of the substrate 20 can be adapted to the respective applications.

Claims

1. Use of a dispersion adhesive as a coating (40) of an otherwise plastic-free, fibrous substrate (20), - characterized by the fact that - the dispersion adhesive forms a barrier against water, water vapor, aroma, oxygen, oil, or grease after setting.

2. Use according to claim 1, - characterized by the fact that - the dispersion adhesive forms a barrier against water, water vapor, aroma, oxygen, oil and grease after setting.

3. Use according to one of claims 1 or 2, - characterized by the fact that - the dispersion adhesive is food-safe.

4. Use according to claim one of claims 1 to 3, - characterized by the fact that - the coated substrate is a food cling paper.

5. Use according to any one of claims 1 to 3, - characterized by the fact that - the dispersion adhesive can be sealed.

6. Use according to claim 5, - characterized by the fact that- the coated substrate consists of sealed bags or sacks.

7. Use according to claim 5, - characterized by the fact that - the coated substrate (20) consists of sealed cups, bowls or trays.

8. Use according to any of the preceding claims, - characterized by the fact that - the dispersion adhesive can be reactivated at elevated temperatures.

9. Use according to any of the preceding claims, - characterized by the fact that - the products coated with the dispersion adhesive (10, 10.2, 10.3, 10.4, 10.5, 10.6, 10.7, 10.8) are used for consumption or for the storage of food (12).

10. Use according to any of the preceding claims, - characterized by the fact that - the coating (40) is applied over the entire surface of at least one side of the substrate (20).

11. Use according to any of the preceding claims, - characterized by the fact that- a color layer (30) is present at least in sections between the substrate (20) and the coating (40).

12. Use according to any of the preceding claims, - characterized by the fact that - a coating (40) is present on both sides of the substrate (20).

13. Use according to any of the preceding claims, - characterized by the fact that - the substrate (20) contains paper, paperboard, cardboard or corrugated board.

14. Use according to claim 13, - characterized by the fact that - the substrate (20) consists of recycled fibers or of a rapidly renewable raw material, for example grass, straw or hemp, or at least contains such a raw material.

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