AT520230B1 - Food wrapping - Google Patents

Abstract

The invention relates to a method for producing a temporary food coating (1), in particular for sausages, meat, cheese or chocolate, wherein a web of continuous fiber fleece (4) is provided and the continuous fiber fleece (4) consists of uniform fibers which are connected to one another at connection points (2) (3), in particular synthetic fibers, preferably comprising polypropylene fibers or polyethylene terephthalate fibers, is formed, and a film (5) made of plastic is provided, and the continuous fiber fleece (4) is connected to the film (5) at certain points or areas, in particular welded or glued. The invention further relates to a food casing (1) produced by the method according to the invention, in particular in flat form or in tubular form.

Description

FOOD COATING The invention relates to a method for producing a temporary food coating, in particular for sausages, meat, cheese or chocolate. The invention further relates to a food casing, which is produced in particular in flat form or in tubular form by the method according to the invention.

Different materials are used in the coating of food products. Natural casings or artificial sausage casings made of cellulose, for example, are typically used for sausage skins. Natural casings have the disadvantage that they are only available to a limited extent. Plastic casings, in particular those made of cellulose, have to undergo various chemical pretreatment steps before they are filled with food products in order to have sufficient tensile strength and lubricity.

[0003] As an alternative to the above-mentioned food casings, food casings made of nonwoven material are known in the prior art, for example from EP 1 872 663 B1. Compared to synthetic casings made from cellulose, these have the advantage that chemical pretreatment is not necessary.

However, the tear properties, which are anisotropic due to the presence of so-called continuous fibers, are problematic. Therefore, when the packaged food products are torn open, there is an undesirable fraying of the material and often also an uncontrolled tearing. Furthermore, the water vapor and oxygen permeability of nonwoven material is significantly higher than that of cellulose films, which can be undesirable in some applications. This is particularly important if the food product is not to be dried out.

[0004] DE 10 2004 048 057 A1 discloses a multi-layer food casing which comprises a film layer and a non-woven layer. The film layer and the fleece layer are connected to one another in a planar manner. A further food casing, which comprises a film layer and a non-woven layer, is known from WO 03/086087 A1, the partial layers here not being connected to one another in a planar manner.

The object of the present invention is to provide a production method for a food casing, with which an improved food casing can be produced compared to the prior art. In particular, the food casing produced should enable a lower water vapor and oxygen permeability in comparison to nonwoven material. Furthermore, the negative tear properties of nonwoven materials are to be overcome. Nevertheless, the processing of the food coatings should be possible without extensive pretreatment steps.

These and other objects of the invention are achieved in that a web of continuous fiber fleece and a film made of plastic are provided in the manufacturing process. The continuous fiber fleece is formed from uniform fibers, in particular synthetic fibers, preferably comprising polypropylene fibers or polyethylene terephthalate fibers, which are connected to one another at points of connection. The continuous fiber fleece is welded or glued to the film in the process according to the invention.

By connecting an endless fiber fleece with a film, the properties of the fleece material and film material are combined and a hybrid material is created. Compared to pure non-woven material as a food casing, the water vapor and oxygen permeability is significantly reduced, since the food casing produced by the method according to the invention has a continuous film layer as a barrier.

[0008] While a continuous fiber fleece comprising individual fibers is permeable to both oxygen and water vapor by direct air flow, gas exchange is by / 8

AT 520 230 B1 2020-02-15 Austrian patent office a film is only possible by diffusion - a much slower exchange process than the direct air flow.

[0009] Furthermore, the tear properties are optimized by the presence of a film. The anisotropic tearing of the continuous fiber fleece is held back by the film, which leads to a better usability of the food casing. In particular, the welding of continuous fiber fleece and film improves the tear properties, since a firm melt connection is made between the two parts of the food casing.

According to a further feature of the invention it can be provided that the film and the continuous fiber fleece are formed at least on their contact surfaces from the same material.

This feature of the invention ensures that the layers of the food casing can be easily connected to one another. In particular when welding plastics, it is advantageous that the materials located at the interface are coordinated with one another. Since the welding typically takes place at temperatures which are above the melting point of the materials to be joined, liquid plastic is temporarily produced. For a firm connection, it is advantageous if the materials involved can be mixed with one another in the molten state. If there is no miscibility of the molten substances, a satisfactory connection cannot be made by welding. This can even lead to delamination of the material layers, which would be disadvantageous for the quality of the food casing produced.

According to a further feature according to the invention it can be provided that the film comprises at least two sheet layers that are connected to one another, in particular bonded, in particular. The first film layer is a weldable film, preferably a weldable polypropylene film, and the second film layer comprises polyethylene terephthalate, polypropylene or polyamide.

[0013] The use of a multilayer film ensures a great variability in the material properties. While a film layer can be adapted, for example, to the properties required for tight welding to the continuous fiber fleece, an increased or reduced oxygen permeability can be achieved by a further film layer. Furthermore, by adapting the melting points of the plastics, which comprise the film layers, it can be achieved that one film layer melts during welding, while the other remains firm.

According to a further feature according to the invention it can be provided that the film has a thickness of 20 μm to 40 μm, preferably 35 μm.

The water vapor permeability and the oxygen permeability of the multilayer food casing produced by the method according to the invention should advantageously be in an appropriate range for food products. This is achieved in particular through a very thin film layer.

According to a further feature of the invention it can be provided that the continuous fiber fleece has a thickness of up to 1.5 mm, preferably about 0.5 mm.

By adjusting the thickness of the continuous fiber fleece, a regulation of the water vapor and oxygen permeability can also be achieved. Furthermore, the tensile strength of the food casing is determined by the choice of the thickness of the continuous fiber fleece. The continuous fiber fleece is preferably substantially thicker than the film, for example by a factor of 1.5-15 thicker.

According to a further feature according to the invention it is provided that a food-safe adhesive is applied to the food casing, the application preferably being carried out on the side of the food casing which releases the continuous fiber fleece.

According to a further feature according to the invention it can be provided that by

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AT 520 230 B1 2020-02-15 Austrian patent office the adhesive food additives such as spices, herbs or other flavoring substances are applied to the food casing. In the food industry, food products are often flavored, for example with spices or smoke flavoring. The food casings used must allow the flavorings to penetrate to the food product. Naturally, the food casing produced by the process according to the invention is not only sufficiently permeable to water vapor and oxygen, but also the permeation of other gaseous substances, in particular flavoring substances, is possible.

For example, when smoking, the coated food product is completely introduced into an atmosphere containing the flavoring substance mixture. However, if the flavoring is to be carried out, for example, with spices such as pepper, paprika or garlic, the spice substance must be introduced to the food coating by other means and kept there for a long time. According to an advantageous feature of the method according to the invention, this can be done by means of a food-safe adhesive to which the flavorings are then glued.

If the application of the adhesive and the flavoring agents takes place on the side of the food casing that releases the continuous fiber fleece, the structure resulting from the spot welding of the continuous fiber fleece ensures optimal absorption and good adhesion of the food-safe adhesive.

Another object of the invention is to provide a food casing which overcomes the disadvantages of the food casing available in the prior art.

[0023] These and other objects are achieved in that a food casing is produced by means of the method according to the invention, which has the advantageous properties already described.

According to a further feature of the invention it can be provided that the basis weight of the continuous fiber fleece is between 20 g / m ² and 100 g / m ² and the basis weight of the food casing is between 40 g / m ² and 180 g / m ² , wherein the total thickness of the food casing is less than 3 mm.

According to a further feature of the invention it can be provided that the food casing has a water vapor permeability of 2 cm ³ / m ² to 20 cm ³ / m ² per day at 23 ° C and 85% relative humidity.

[0026] Further features according to the invention result from the description of the exemplary embodiments, the figures and from the patent claims.

In the following, the invention is discussed in detail using a non-exhaustive exemplary embodiment.

[0028] The figures show:

Fig. 1a: A schematic representation of an embodiment of a manufacturing method of a food casing according to the invention;

Fig. 1b: A schematic representation of the food casing according to the invention after the application of a layer of food-safe adhesive and spices;

1c: A schematic view of the food casing according to the invention after casing of a food product.

It should be noted in advance that the thicknesses of the individual layers are shown partially exaggerated for better illustration and thus do not correspond to the actual proportions.

1a shows a schematic representation of the manufacturing steps of an invention 3/8

AT 520 230 B1 2020-02-15 Austrian patent office food coating 1. An endless fiber fleece 4 formed from uniform fibers 3, in which the fibers are connected to one another at points of connection 2, is welded to a two-layer film 5.

In this embodiment, the two-layer film 5 consists of a first film layer 6 and a second film layer 7. The continuous fiber fleece 4 is connected to the film 5 over a wide area by thermal action 11.

In this embodiment, the continuous fiber fleece 4 consists of uniform polypropylene fibers. The continuous fiber fleece is about 1.5 mm thick. In other exemplary embodiments, the fibers can also comprise, for example, polyethylene, polyamide or other plastics than which fibers 3 can be produced; the continuous fiber fleece 4 can also have different thicknesses. In this exemplary embodiment, the film 5 comprises a first film layer 6 made of polypropylene.

Advantageously, the material of the side of the film 5 which forms an interface with the continuous fiber fleece 4 is essentially the same as the material of the continuous fiber fleece 4. Thus, when the film 5 is welded to the continuous fiber fleece 4, a permanent connection is established. Since the plastic material is at least partially melted during welding, a miscibility of the liquid plastics is advantageous for an optimal connection of the continuous fiber fleece 4 and the film 5. In this exemplary embodiment, this is achieved in that the first film layer 6 and the fibers 3 of the continuous fiber fleece 4 are made of the same plastic, namely polypropylene. Of course, the use of other plastics is also provided in other exemplary embodiments.

In this exemplary embodiment, the second film layer 7 comprises polyamide. The first film layer 6 made of polypropylene has a thickness of approximately 10 μm, while the second film layer 7 has a thickness of approximately 20 μm. The film 5 to be welded to the continuous fiber fleece 4 thus has a total thickness of approximately 30 μm. The water vapor or oxygen permeability can be determined by adjusting the film thickness. Furthermore, regulation of the tear strength of the food casing 1 is possible.

In this embodiment, the first film layer 6 and the second film layer 7 are glued together, since welding of the two materials is essentially not possible.

By thermal action 11 of about 180 ° C, a temperature just above the melting point of polypropylene, a fusing of the first film layer 6 with parts of the continuous fiber fleece 4 is achieved. The thermal action 11 comes from the side of the film 5 during welding in order to avoid a complete melting of the fibers 3 of the continuous fiber fleece 4. During the welding process, the first film layer 6 is permanently connected to part of the continuous fiber fleece 4. The integrity of the second film layer 7, which in this exemplary embodiment consists of polyamide, is retained, since the melting point of the polyamide used here is higher than the melting point of the polypropylene.

Fig. 1b shows a schematic representation of the food casing 1 according to the invention after the application of a layer of food-safe adhesive 8 and of spices 9. The food casing 1 shown in Fig. 1b is the same, the production of which was illustrated in Fig. 1a. The continuous fiber fleece 4 can be seen, which was connected to the second film layer 7. The first film layer 6 is no longer recognizable, since it was fused to the continuous fiber fleece 4 in the welding process. A food-safe adhesive 8 was applied to the side of the food casing 1 that released the continuous fiber fleece 4. Particularly good adhesion of the adhesive is achieved, since it can also penetrate into the structure of the continuous fiber fleece 4 produced by the connection points 2. The spices 9 were sprinkled on the layer formed by the adhesive 8. In this embodiment, the spice 9 comprises dried and coarsely ground red peppers. In other exemplary embodiments, other spices 9 such as dried garlic, rosemary or spice mixtures of several different spices 9 can also be used

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AT 520 230 B1 2020-02-15 Austrian patent office.

Fig. 1c shows a schematic view of the food casing 1 according to the invention after the casing of a food product 10. Fig. 1c shows the same food casing as Fig. 1b. The food product 10, which is a piece of cheese in this exemplary embodiment, was encased with the food casing 1 according to the invention. The side with the spices 9 is in direct contact with the surface of the food product 10.

The second film layer 7 is located on the outside and protects the food product 10 from excessive contact with oxygen from the ambient air and in particular from bacteria and other contaminants.

In another exemplary embodiment, the second film layer 7 can also be in direct contact with the food product 10, as a result of which a milder flavoring is achieved since the spice 9 and the food product 10 do not come into direct contact with one another. According to the invention, other food products 10, such as sausages or chocolate, can also be coated with the food casing 1.

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AT 520 230 B1 2020-02-15 Austrian patent office

LIST OF REFERENCE NUMBERS

Food wrapping

junction

fiber

Continuous fiber fleece

Film first film layer second film layer

adhesive

seasoning

Food product thermal exposure

Claims (9)

1. A method for producing a temporary food coating (1), in particular for sausages, meat, cheese or chocolate, wherein a. a web of continuous fiber fleece (4) is provided, the continuous fiber fleece (4) being formed from uniform fibers (3), in particular synthetic fibers, preferably comprising polypropylene fibers or polyethylene terephthalate fibers, which are connected at points (2), b. a film (5) made of plastic is provided, and c. the continuous fiber fleece (4) is welded or adhesively bonded to the film (5), characterized in that a food-safe adhesive (8) is applied to the food casing (1), the application preferably being carried out on the side of the continuous fiber fleece (4) Food coating (1) takes place. 2. The method according to claim 1, characterized in that the film (5) and the continuous fiber fleece (4) are formed at least on their contact surfaces from the same material. 3. The method according to claim 1 or 2, characterized in that the film (5) comprises at least two sheet-like, in particular glued, film layers, wherein a. the first film layer (6) is a weldable film, preferably a weldable polypropylene film, and b. the second film layer (7) comprises polyethylene terephthalate, polypropylene or polyamide. 4. The method according to any one of claims 1 to 3, characterized in that the film (5) has a thickness of 20 microns to 40 microns, preferably 35 microns. 5. The method according to any one of claims 1 to 4, characterized in that the continuous fiber fleece (5) has a thickness of up to 1.5 mm, preferably about 0.5 mm. 6. The method according to any one of claims 1 to 5, characterized in that food additives such as spices (9), herbs or other flavoring substances are applied to the food casing (1) by the adhesive (8). 7. Food casing (1), in particular for sausages, meat, cheese or chocolate, comprising a. a web of continuous fiber fleece (4), the continuous fiber fleece (4) being formed from uniform fibers (3), in particular synthetic fibers, preferably comprising polypropylene fibers or polyethylene terephthalate fibers, which are connected at points (2), b. a film (5) made of plastic, the continuous fiber fleece (4) being welded or glued to the surface of the film (5), and a food-safe adhesive (8) on the food casing (1), preferably on the one releasing the continuous fiber fleece (4) Side of the food casing (1) is arranged. 8. Food casing (1) according to claim 7, characterized in that the basis weight of the continuous fiber fleece (4) is between 20 g / m ² and 100 g / m ² and the basis weight of the food casing (1) between 40 g / m ² and 180 is g / m ² , the total thickness of the food casing (1) being less than 3 mm. 9. Food casing (1) according to claim 7 or 8, characterized in that it has a water vapor permeability of 2 cm ³ / m ² to 20 cm ³ / m ² per day at 23 ° C and 85% relative humidity.