IL278564B1

IL278564B1 - Packaging material and method for the production thereof

Info

Publication number: IL278564B1
Application number: IL278564A
Authority: IL
Inventors: Karatzis Antonios
Original assignee: Karatzis S A Ind & Hotelier Enterprises
Priority date: 2018-05-09
Filing date: 2019-04-10
Publication date: 2024-03-01
Also published as: DE102018111118B4; IL278564A; ES2859666T3; EP3566864A1; WO2019214893A1; EP3566864B1; PL3566864T3; DE102018111118A1; CA3099606A1; JP2021523067A; IL278564B2; DK3566864T3; UA126420C2; PT3566864T; JP7527974B2

Description

Packaging material and method for its production The invention relates to a packaging material according to the preamble of claim 1. Furthermore, the invention relates to a method for the production of the packaging material according to the invention. A packaging material with a first film and a woven fabric, which are arranged one above the other and are connected together, is known from the applicant's WO 2017/080609. Here, the first film comprises first areas in which the first film is locally stretched and second areas in which the first film is not locally stretched; the first areas are each arranged between two second areas and run in a first direction, wherein the woven fabric comprises a thread and wherein a part of the thread runs in a direction which intersects the first direction. In the case of certain applications in which heavy goods are to be packaged, however, the known packaging material can disadvantageously tear at certain points on account of the different high tensile stress between the film and the woven fabric. Such packaging materials are used to package pallets, agricultural products, refuse etc., so that a high tear strength and protection against weather influences is required. Furthermore, such packaging materials should contain as little plastic as possible, which on the one hand reduces the environmental burden and on the other hand results in more favourable prices for consumers. The problem of the present invention is to specify a packaging material with low weight relative to its dimensioning and high tear strength in the presence of high tensile stresses. Furthermore, a method for the production of the packaging material according to the invention is to be specified. This problem is solved by the features of claim 1. A method for the production of the packaging material according to the invention is the subject-matter of claim 8. Further embodiments according to the invention and advantages emerge from the corresponding sub-claims.

Accordingly, a packaging material is proposed, which comprises a pre-stretched and heat-stabilised elastic film and an elastic plastic net arranged flat on the film, in particular a plastic net constituted as a Raschel net, wherein the plastic net is connected to the film by means of an adhesive layer applied on the film, in such a way that a relative movement of the film and the plastic net in relation to one another is permitted in the event of high tensile stresses. As a result of the pre-stretching of the elastic film, the packaging material advantageously becomes thinner and lighter relative to a predefined length, wherein the effect of the heat stabilisation of the pre-stretched film is that the film does not exhibit any remaining surface stresses. As a result of the concept according to the invention, local excess stresses, which arise at different points of the packaging material, can be uniformly distributed by a relative movement of the net and the film in relation to one another in the event of high tensile stresses, so that tearing of the packaging material is advantageously prevented. This is made possible by the fact that the adhesive is a water-soluble adhesive, for example a food-grade adhesive, which has a low adhesive strength. Furthermore, as a result of the prevention of local excess stresses, the packaging material can be wound around lightweight and thin winding cores instead of heavy winding cylinders made of pressboard. For the production of the packaging material according to the invention, the elastic film is pre-stretched to a defined, predetermined degree and then heat-stabilised, wherein an adhesive layer, for example a water-soluble adhesive having a low adhesive strength, is then applied on the pre-stretched film, for example by means of cylinder axes or high-pressure jets. After the pre-stretching of the film, the latter has a residual elasticity of 20%. In a subsequent step, the film and the plastic net are pressed together by means of rollers, so that a packaging material arises, one side of which is constituted as a self-adhesive film covered by a plastic net without necking points. The self-adhesive embodiment also gives rise to the advantage that closing of the packaging material after receiving the goods is simplified.

The elastic film can be pre-stretched for example to a thickness of 5 μm, wherein the width can be arbitrary, and for example can lie in a range between 40 cm and 3cm. The elastic film can be produced from LLDPE (linear polyethylene of low density), LDPE (polyethylene of low density), HDPE (polyethylene of high density), VC (polyvinyl chloride), EVA (ethylene vinyl acetate) or from a similar plastic, in particular from any polyolefin, or can comprise the latter. The plastic net can be produced from polyolefins such as for example LLDPE (linear polyethylene of low density), LDPE (polyethylene of low density), HDPE (polyethylene of high density), PVC (polyvinylchloride), EVA (ethylene vinyl acetate) or from a similar plastic or can comprise the latter. Its weight can for example be 2 to g/running metre, wherein the net density can lie for example in a range between needles/inch to 2 inches needle spacing. The width of the net essentially corresponds to the width of the elastic film. The net can consist of fringes extending in the flow direction of the net (also called warp threads) and weft threads, which connect the fringes thereby forming a zigzag pattern to form a net, which according to the prior art are interwoven with one another, wherein the fringes are each formed from a thread. Furthermore, provision can be made such that all or part of the fringes, in particular the outer fringes, are each formed from two or more threads to increase the strength. The distance between the fringes can be arbitrary and for example lie in a range between 4.2 and 50.8 mm. The plastic threads used for the fringes can have a thickness from 10 – 60 μm or less. Furthermore, at least the outer or any fringes can each comprise two or more partial fringes to increase the strength, which are connected to one another by means of at least one weft thread running in a zigzag manner, in such a way that the partial fringes run directly adjacent parallel to one another. In the case of fringes comprising two partial fringes, the partial fringes are linked with one another in pairs by means of at least one weft thread.

The invention is explained in greater detail below by way of example with the aid of the appended figures. In the figures: Figure 1a shows a diagrammatic cross-sectional view of a packaging material constituted according to a first embodiment of the invention; Figure 1b shows a diagrammatic plan view of the packaging material according to figure 1a; Figure 2 shows a detail view from figure 1b; Figure 3a shows a diagrammatic cross-sectional view of a packaging material constituted according to a second embodiment of the invention; Figure 3b shows a diagrammatic plan view of the packaging material according to figure 3a; and Figure 4 shows a detail view from figure 3a. In the figures 1b and 2b, MD denotes the machine direction, i.e. the flow direction of the plastic net during production or of the packaging material during winding; TD denotes the transverse direction, i.e. the direction at right angles to the machine direction or flow direction. According to the invention and by reference to the example of embodiment according to figures 1a and 1b, the packaging material comprises a stretched and heat-stabilised elastic film 1 and an elastic plastic net of essentially identical width arranged flat on film 1, which is connected to film 1 by means of an adhesive layer applied on film 1, in such a way that a relative movement of film 1 and the plastic net in relation to one another is permitted in the event of high tensile stresses. The plastic net constantly remains in contact with adhesive layer 2. The plastic net arranged on film 1 and connected to film 1 can be constituted as a Raschel net according to the prior art, comprising fringes 3 extending in the flow direction of the net and weft threads 4 which connect the fringes thereby forming a zigzag pattern to form a net. The distance between adjacent fringes 3 can lie for example in a range between 4.2 mm and 50.8 mm The example of embodiment shown in figures 3a, 3b and 4 differs from the example of embodiment according to figures 1a, 1b and 2 in that all fringes 3 each comprise two partial fringes 3a and 3b for increasing the strength, which are connected to a one another by means of a weft thread 4 running in a zigzag manner, in such a way that partial fringes 3a, 3b run directly adjacent parallel to one another. The distance between partial fringe 3a, 3b of a fringe 3, i.e. the distance between the virtual central longitudinal lines of the partial fringes from one another can lie for example in a range between 2 mm and 10 mm, preferably in a range between 2 mm and 5 mm. With such small distances, partial fringes 3a, 3b can come into contact with one another. The plastic net can be produced by a Raschel machine, which in each case comprises at least two guide needles for guiding in each case a plastic thread for knitting a fringe in each case, wherein the in each case two guide needles are supported by a common guide needle support and wherein two needles supported by a common needle support can be assigned to the in each case two guide needles. The distance between two adjacent guide needles and/or between two directly adjacent needles can lie here in a range between 2 and 10 mm, in particular between and 5 mm, as a result of which straightforward production of the fringes is enabled in the normal operation of the Raschel machine.

Claims

1.CLAIMS 1. A packaging material, comprising a pre-stretched and heat-stabilised elastic film and an elastic plastic net arranged flat on the film, characterised in that the plastic net is connected to the film by means of an adhesive layer applied on the film, wherein the adhesive is a water-soluble adhesive having a low adhesive strength, in such a way that a relative movement of the film and the plastic net in relation to one another is permitted in the event of high tensile stresses.

2. The packaging material according to claim 1, characterised in that the elastic film can be pre-stretched up to a thickness of 5 μm and has a residual elasticity of at least 20%.

3. The packaging material according to claim 1, characterised in that it has a width of 40 cm to 3cm.

4. The packaging material according to any one of claims 1-3, characterised in that the elastic film (1) is produced from LLDPE, LDPE, HDPE, VC, EVA or from a similar plastic or comprises the latter.

5. The packaging material according to any one of claims 1-4, characterised in that the plastic net is produced from LLDPE, LDPE, HDPE, PVC, EVA or from a similar plastic or comprises the latter.

6. The packaging material according to any one of claims 1-5, characterised in that the plastic net consists of fringes extending in the flow direction of the net and weft threads, which connect the fringes thereby forming a zigzag pattern to form a net, wherein the fringes are each formed from a thread or wherein all or part of the fringes are each formed from two or more threads to increase the strength.

7. The packaging material according to claim 6, characterised in that at least the outer fringes each comprised two or more partial fringes to increase the strength, which are connected to one another by means of at least one weft thread running in a zigzag manner, in such a way that the partial fringes run directly adjacent parallel to one another.

8. A method for producing a packaging material executed according to any one of claims 1-7, characterised in that an elastic film is pre-stretched to a defined, predetermined degree and then heat-stabilised, wherein an adhesive layer is then applied on the pre-stretched film, wherein the adhesive is a water-soluble adhesive having a low adhesive strength, wherein in a subsequent step the film and the plastic net are pressed together by means of rollers, so that a packaging material arises, one side of which is constituted as a self-adhesive film covered by a plastic net without necking points, wherein a relative movement of the film and the plastic net in relation to one another is permitted in the event of high tensile stresses.

9. The method according to claim 8, characterised in that the adhesive is applied by means of high-pressure jets or cylindrical axes. Webb+Co. Patent Attorneys