PACKING MATERIAL WITH A SEALING SEAM AREA

Abstract

 The invention relates to a packing material (2) comprising a substrate (20) with a sealing seam area (11). The substrate (20) comprises a paper base layer (21). Furthermore, the substrate (20) comprises two flat sides. The sealing seam area (11) is arranged on at least a part of at least one flat side of the substrate (20). In other words, the sealing seam area (11) is at least a part of the substrate (20). A sealing media (10) is arranged in the sealing seam area (11), wherein the sealing media (10) comprises a water-soluble polymer. The water-soluble polymer comprises PVOH.

Description

[0001] The invention relates to the field of packaging material and packaging as well as a method for producing a packaging as described in the preamble of the independent claims.

[0002] Commercially established packaging materials for high-barrier food-applications pose increasing challenges to recycling systems and end-of-life scenarios as sources of microplastics. Due to the high barrier requirements for packaging certain types of food materials, conventionally used solutions are mostly multilayer systems made up of non-biodegradable polymers.

[0003] Packaging, such as a pouch, has to be sealed in order to have the packed goods protected from environmental influence. The sealing should be conducted in the sealing seam area and has to be reliable.

[0004] It is therefore an object of the invention to create packaging material and packaging as well as a method for producing a packaging.

[0005] These objects are achieved by packaging material and packaging as well as a method for producing a packaging according to the independent claims.

[0006] The invention relates to a packing material comprising a substrate with a sealing seam area. The substrate comprises a paper base layer. Furthermore, the substrate comprises two flat sides. The sealing seam area is arranged on at least a part of at least one flat side of the substrate. In other words: the sealing seam area is at least a part of the substrate. The sealing media is applied at least partially on the substrate. Such a partial application of the sealing media allows for a reliable sealing of the packing material to form a packaging. A sealing seam is the joining seam between two (individual) parts of the sealing seam area.

[0007] A sealing media is arranged in the sealing seam area, wherein the sealing media comprises a water-soluble polymer. The water-soluble polymer comprises at least one of poly(vinyl alcohol) (PVOH), cellulose-ether polymer, Butenediol-Vinylalcohol-Copolymer (BVOH), and Ethylene-Vinylalcohol-Copolymers (EVOH).

[0008] In embodiments, the water-soluble polymer comprises PVOH (poly(vinyl alcohol)).

[0009] Additionally, the packing material is a high barrier material. High barrier material in this context means, to provide an oxygen transmission rate (ORT) and a water vapor and/or humidity barrier suitable to pack oxygen sensitive such as coffee.

[0010] In an embodiment, the packing material and/or the packaging can have an oxygen transmission rate of a maximum of 3 cm³/m² per day at room temperature (RT, room temperature = 23°C) and a relative humidity of 50% (relative humidity = r. h.), in particular the oxygen transmission rate can be maximal 1 cm³/m² per day at room temperature and a relative humidity of 50%, in particular maximal 0,2 cm³/m² per day at room temperature (23°C) and a relative humidity of 50%; in particular maximal 0,05 cm³/m² per day at room temperature (23°C) and a relative humidity of 50%.

[0011] The oxygen transmission rate (OTR) is the steady state rate at which oxygen gas permeates through a film at specified conditions of temperature and relative humidity. Values are expressed in cc/m²/24 hr in metric (or SI) units, with cc being cubic centimetre being cm³, m² being square metre, 24 hr being 24 hours being one day. The OTR in this text is determined according to ISO 15105-2 (as of April 2022).

[0012] In embodiments, the packing material and/or the packaging has a water vapor and/or humidity barrier of a maximum of 15 g/m² per day at 25°C and a relative humidity of 80%, in particular a maximum of 10 g/m² per day at 25°C and a relative humidity of 80%, in particular 3 g/m² per day at 25°C and a relative humidity of 80%, in particular 2 g/m² per day at 25°C and a relative humidity of 80%. This makes the packing material and/or the packaging suitable for packaging barrier-sensitive goods, such as coffee.

[0013] In embodiments, the sealing media is applied with a rather small layer thickness in order to prevent a spreading of the sealing media upon sealing.

[0014] In an embodiment, the packing material is foldable and/or cuttable such that in a folded state at least a part of the sealing seam area is arranged on top of another part of the sealing seam area. This allows for a reliable sealing of the folded packaging.

[0015] In an embodiment, the sealing seam area comprises a longitudinal seam, in particular two longitudinal seams, a top seam and a bottom seam. The top seam can also be called head seam. The longitudinal seam, also called side seam, is a lengthwise seal which is directed along the hights of the packaging.

[0016] In an embodiment, the top seam and the bottom seam are separated from each other. Separated in this context means, that the top seam and the bottom seam do not touch each other.

[0017] In an embodiment the longitudinal seam, the top seam and/or the bottom seam can be arranged as at least one of

• an essentially circumferential sealing seam, for example for a seal pouch;
• essentially individual sealing seam areas, as the top seam, the bottom seam and the longitudinal seam, do not necessarily contact each other.

[0018] In an embodiment, the longitudinal seam is arranged essentially at the longitudinal side areas of the substrate. The bottom seam can be arranged essentially perpendicular to the longitudinal seam. The top seam can be arranged essentially parallel to bottom seam. This enables an efficient folding of the packing material to provide packaging essentially shaped as a rectangular cuboid.

[0019] In an embodiment, the substrate is on a roll to be processed. The rolled up substate can be fixed in a machine for processing the packing material to produce a packaging, for example an FFS machine (Form Fill and Seal machine). In an embodiment, several sealing seam areas for several packagings could be arranged on one roll. The top seam can be separated from the previous and/or subsequent bottom seam.

[0020] In an embodiment, the substrate has a customized size. This makes it possible to produce custom sized packaging, in particular a custom sized pouch.

[0021] In an embodiment, in case of a continuous substrate e.g. on a roll the bottom seam of a first bottom seam area of a first packaging is not separated from a second top seam area of a second packaging. In such a case the sealing media is applied in a larger area spanning the first bottom seam and the second top seam. This allows for a single application of the sealing media simultaneously on the bottom and top seam. While cutting the substrate in individual packaging sheets for folding and/or sealing the large area is divided and each separate packaging sheet comprises a part of the large area forming either the top seam area or the bottom seam area. In such the case the cutter runs through the sealing media.

[0022] In an embodiment, the packing material is recyclable in a paper recycling process, in particular in paper recycling process according to DIN EN 13430 (as of the end of 2021). DIN being a European standard.

[0023] In an embodiment, the sealing media is essentially only applied in the sealing seam area. Accordingly, no excess of sealing media is used. This makes it possible to reduce the amount of sealing media.

[0024] In an embodiment, the packing material comprises at least 50 wt% paper, in particular at least 70 wt% paper. This allows for a good recycling yield in the paper recycling process.

[0025] The invention also concerns a packaging, in particular a pouch, for packing food, in particular for packing coffee. The packaging comprises a packing material as described in this text. The sealing media in the sealing seam area is designed as a sealing layer and the sealing layer is arranged between two portions of the sealing seam area of the substrate.

[0026] In an embodiment, the sealing media is arranged on the flat side of the substrate facing the product to be packed. The inside of the packaging is the side facing the product to be packed and/or sealed. The outside of the packaging is facing away from the product towards the customer.

[0027] The invention also concerns a method for producing a packaging, in particular the packaging as described in this text, in particular a pouch. The method comprises the steps of:

• providing a substrate with two flat sides;
• applying a sealing media on a sealing seam area on at least one flat side of the substrate;
• folding the substrate to form the packaging;
• aligning at least two parts of the sealing seam areas on top of each other;
• applying at least one of pressure, heat and/or ultrasound in the region of the sealing seam area and
• sealing the packaging at least in the sealing seam area.

[0028] In an embodiment, both parts of the sealing seam area applied on top each other have the sealing media arranged and/or applied. Accordingly, sealing media of one part of the sealing seam area is touching and/or contacting the sealing media of another part of the sealing seam area. This is in particular the case for the top seam and/or the bottom seam.

[0029] In an embodiment, only part of the sealing seam area is covered with the sealing media before sealing. Accordingly, the when aligning at least two parts of the sealing seam areas on top of each other only one part of the sealing seam area has the sealing media arranged and/or applied. This enables the reduction of the used sealing media. The sealing media arranged on one part of the sealing seam area is touching and/or contacting another part of the sealing seam area without any sealing media applied before sealing. During and/or after sealing both parts of the sealing seam area are arranged next to the sealing media as after aligning the two parts of the sealing seal area are contacting the sealing media of the one part applied with the sealing media.

[0030] The sealing media comprises a water-soluble polymer, wherein the water-soluble polymer comprises at least one of poly(vinyl alcohol) (PVOH), cellulose-ether polymer, Butenediol-Vinylalcohol-Copolymer (BVOH), and Ethylene-Vinylalcohol-Copolymers (EVOH), in particular the water soluble polymer comprises PVOH. The substrate comprises a paper base layer.

[0031] After filling the packaging, in particular the pouches, a sealing process is generally carried out in which a so-called sealing seam is created between two parts of the substrate by applying heat, time and/or pressure by means of a sealing device. The aim of the sealing process is to weld two packing material. Heat sealing has become important in the packaging industry because of their high cost-effectiveness. Alternatively, ultrasound can be used for carry out the sealing.

[0032] In an embodiment, the sealing temperature is 120°C to 220°C. The sealing temperature is the temperature at which the sealing takes place. At such a sealing temperature the substrate stays intact and the sealing is reliable.

[0033] In an embodiment, the sealing is facilitated by at least one of thermal conduction and ultrasound.

[0034] In an embodiment, the sealing media is applied at least at one of the following conditions:

• hot and or liquid sealing media applied to the substrate;
• water dissolved sealing media is applied to the substrate, in particular the water dissolved sealing media is dried on the substrate after application in the sealing seam area.

[0035] In an embodiment, the hot and/or liquid sealing media is applied by a slot-die and/or in a point-by-point manner. In other embodiments the water dissolved sealing media is applied to the substrate by an anilox roller, as a mayer-bar coating and/or it is sprayed onto the substrate.

[0036] In an embodiment, the packaging is produced with at least one of a form, fill and seal packaging machine, an automatic folding box machine and a pressure machine. This enables the automated production of the packaging.

[0037] Further preferred embodiments are evident from the dependent patent claims. Features of the method claims may be combined with features of the device claims and vice versa.

[0038] The subject matter of the invention will be explained in more detail in the following text with reference to exemplary embodiments which are illustrated in the attached drawings, in which:

Figure 1

schematically shows a packing material on a roll.

[0039] The reference symbols used in the drawings, and their meanings, are listed in summary form in the list of reference symbols. In principle, identical parts are provided with the same reference symbols in the figures.

[0040] Figure 1 schematically shows a packing material 2 on a roll. The packing material 2 is driven over couple of rolls and processed to a packaging 6, in particular a pouch 60.

[0041] The packing material 2 comprises a substrate 20 with a sealing seam area 11. The sealing seam area 11 can comprise a top seam 12, a bottom seam 13 and/or a longitudinal seam 14.

[0042] The substrate 20 comprises a paper base layer 21. The sealing seam area 11 is arranged at least on one flat side of the substrate 20.

[0043] A sealing media 10 is arranged in the sealing seam area 11, wherein the sealing media 10 comprises a water-soluble polymer 31. The water-soluble polymer 31 comprises PVOH.

[0044] The longitudinal seam 14, the top seam 12 and the bottom seam 13 are separated from each other. Meaning those sealing seam areas do not touch each other but are arranged next to each other.

[0045] For the production of the packaging 6 the substrate 20 is provide and the sealing media 10 is applied on the sealing seam area 11. The substrate 20 is folded to form the packaging 6 and at least two sealing seam areas are aligned on top of each other. Pressure and/or ultrasound is applied in the sealing seam area 11 and the packaging 6 is sealed.

[0046] In embodiment, before the final sealing the product to be packed is filled into the packaging 6 and after filling the packaging 6 is filled.

[0047] The sealing temperature 7 is 120°C to 220°C.

[0048] While the invention has been described in present preferred embodiments of the invention, it is distinctly understood that the invention is not limited thereto, but may be otherwise variously embodied and practised within the scope of the claims.

Claims

1. Packing material (2) comprising a substrate (20) with a sealing seam area (11), wherein the substrate (20) comprises a paper base layer (21); and

wherein the substrate (20) comprises two flat sides; and

wherein the sealing seam area (11) is arranged on at least a part of at least one flat side of the substrate (20); and

wherein a sealing media (10) is arranged in the sealing seam area (11);

wherein the sealing media (10) comprises a water-soluble polymer, wherein the water-soluble polymer (31) comprises at least one of poly(vinyl alcohol) (PVOH), cellulose-ether polymer, Butenediol-Vinylalcohol-Copolymer (BVOH), and Ethylene-Vinylalcohol-Copolymers (EVOH).

2. Packing material (2) according to claim 1, wherein the packing material (2) is foldable and/or cuttable such that in a folded state at least a part of the sealing seam area (11) is arranged on top of another part of the sealing seam area (11).

3. Packing material (2) according of any one of claims 1-2, wherein the sealing seam area (11) comprises a longitudinal seam (14), in particular two longitudinal seams (14), a top seam (12) and a bottom seam (13).

4. Packing material (2) according to claim 3, wherein the top seam (12) and the bottom seam (13) are separated from each other.

5. Packing material (2) according to any one of claims 3-4, wherein the longitudinal seam (14) is arranged essentially at the longitudinal side areas of the substrate (20);

wherein the bottom seam (13) is arranged essentially perpendicular to the longitudinal seam (14);

wherein the top seam (12) is arranged essentially parallel to bottom seam (13).

6. Packing material (2) according to any one of claims 1-4, wherein the packing material (2) is recyclable in a paper recycling process, in particular in paper recycling process according to DIN EN 13430 (as of the end of 2021).

7. Packaging (6), in particular a pouch (60), for packing food, in particular for packing coffee, comprising a packing material (2) according to any one of claims 1-6,

wherein the sealing media (10) in the sealing seam area (11) is designed as a sealing layer (16);

the sealing layer (16) is arranged between two portions of the sealing seam area (11) of the substrate (20).

8. Packaging (6) according to claim 7 wherein the sealing media (10) is arranged on the flat side of the substrate (20) facing the product to be packed.

9. Method for producing a packaging (6), in particular the packaging according to any one of claims 7-8, in particular a pouch (60), the method comprises the steps of:

- providing a substrate (20) with two flat sides;

- applying a sealing media (10) on a sealing seam area (11) on at least one flat side of the substrate (20);

- folding the substrate (20) to form the packaging (6);

- aligning at least two parts of the sealing seam areas (11) on top of each other;

- applying at least one of pressure, heat and/or ultrasound in the region of the sealing seam area (11) and sealing the packaging (6) at least in the sealing seam area (11);

wherein the sealing media (10) comprises a water-soluble polymer (31), wherein the water-soluble polymer (31) comprises at least one of poly(vinyl alcohol) (PVOH), cellulose-ether polymer, Butenediol-Vinylalcohol-Copolymer (BVOH), and Ethylene-Vinylalcohol-Copolymers (EVOH).;

wherein the substrate (20) comprises a paper base layer (21).

10. Method according to claim 9, wherein the sealing temperature (7) is 120°C to 220°C.

11. Method according to any one of claims 9-10, wherein the sealing is facilitated by at least one of thermal conduction and ultrasound.

12. Method according to any one of claims 9-11, wherein the sealing media (10) is applied at least at one of the following conditions:

- hot and or liquid sealing media (10) applied to the substrate (20);

- water dissolved sealing media (10) is applied to the substrate (20), in particular the water dissolved sealing media (10) is dried on the substrate (20) after application in the sealing seam area (11).

13. Method according to any one of claims 9-12, wherein the packaging (6) is produced with at least one of a form, fill and seal packaging machine, an automatic folding box machine and a pressure machine.

Drawing