AT520236A1 - Continuous fiber non-woven sheet - Google Patents

Abstract

The invention relates to a method for producing a continuous fiber nonwoven sheet (2), wherein an endless fiber fleece (1), in particular synthetic fibers, formed by punctiform joining of the fibers (3) at connection points (4) comprising polypropylene fibers or polyethylene terephthalate fibers, is guided and compacted by a calender with smooth rolls such that the fibers (3) of the continuous fiber web (1) are at least partially fused to form a film (5) and an endless fiber web produced by this process Film (2).

Description

Summary

The invention relates to a method for producing a continuous fiber fleece film (2), wherein a continuous fiber fleece (1), which is formed from uniform fibers (3), in particular synthetic fibers, and is produced by punctually connecting the fibers (3) at connection points (4), in particular comprising polypropylene fibers or polyethylene terephthalate fibers, is guided and compressed by a calender with smooth rollers in such a way that the fibers (3) of the continuous fiber fleece (1) are at least partially melted into a film (5), and an endless fiber fleece produced by this method Film (2).

3b / 16

- 54043 / PE / MB

BCA Vertriebsgesellschaft m.b.H., Eitzenberger Straße 8, 2544 Leobersdorf (AT)

Continuous fiber non-woven sheet

The invention relates to a method for producing an endless fiber fleece film. Furthermore, the invention relates to an endless fiber fleece film produced by the method according to the invention.

In particular for the production of sausage casings, other food packaging or the like, it is essential that on the one hand a corresponding one

Vapor permeability and, on the other hand, a corresponding passage of oxygen and smoke permeability is made possible. This requirement also applies to wrapping or covering other edible products such as meat, cheese, chocolate and the like.

So far, sausages have either been filled in natural casings or synthetic casings made from collagen and possibly cellulose fibers have been used. Regarding the use of natural casings, it should be noted that these are only available in certain dimensions and quantities. The artificial casings made of collagen and possibly cellulose fibers, on the other hand, require an additional special treatment, specifically on the one hand in the production of the artificial casings and on the other hand in their preservation and storage.

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- 54043 / PE / MB

BCA Vertriebsgesellschaft m.b.H., Eitzenberger Straße 8, 2544 Leobersdorf (AT)

As an alternative, nonwoven products, in particular continuous fiber nonwoven products, can be used to wrap the food. However, this has the disadvantage that fleece does not have optimal tear behavior and tends to fray when the sausage casing is torn open. In addition, the oxygen permeability is too high for most food products.

The object of the invention is to overcome the disadvantages of the prior art and to provide a method for producing a nonwoven material which reduces fraying of the sausage casing when it is torn open. Furthermore, the oxygen and water vapor permeability of the material produced should be in an acceptable range for sausage production.

These and other objects of the invention are achieved in that a continuous fiber fleece formed from uniform fibers, in particular synthetic fibers, produced by punctually connecting the fibers at connection points is guided and compacted by a calender with smooth rollers, so that the fibers of the continuous fiber fleece are at least partially closed be melted into a foil.

In the method according to the invention, the upstanding webs are melted on the edge of the connection points, pressed wide and partially thermobonded in the surface like a film.

In particular, the continuous non-woven fabric which is used as the starting material can comprise polypropylene fibers or polyethylene terephthalate fibers. The starting material can in particular comprise pure PP / PE as well as PP / PE bicoconvlies as well as continuous polyester nonwovens.

By partially fusing the fibers, the properties of a film are mixed with those of a nonwoven and a hybrid material is produced. The interruption of the continuous fiber structure by partially formed film areas creates an almost paper-like tear behavior. There is no fraying and the direction of tearing is essentially isotropic.

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- 54043 / PE / MB

BCA Vertriebsgesellschaft m.b.H., Eitzenberger Straße 8, 2544 Leobersdorf (AT)

The strength is also increased by up to 20% and the elongation is reduced to up to 35% compared to the original values.

In addition, the oxygen and water vapor permeability is reduced compared to a pure continuous fiber fleece. However, since individual areas without unmelted fibers in turn have a very high permeability to oxygen and water vapor, the average permeability is still higher than with a pure film material.

According to the invention, the oxygen and water vapor permeability can be changed by different degrees of fusion.

The formation of a film structure also reduces the adhesion of the continuous nonwoven film according to the invention to the food product, which, for example, enables the sausage to be peeled more easily.

According to a further feature according to the invention it can be provided that the rolls are kept at an essentially constant temperature. An essentially constant degree of fusion of the fibers is thereby achieved.

According to a further feature according to the invention, it can be provided that the surface temperature of the rolls for processing the continuous fiber fleece is between 100 ° C and 250 ° C, for processing polypropylene fleece between 145 ° C and 170 ° C, for PE between 100 ° C and 125 ° C, and in the processing of polyethylene terephthalate fleece is between 200 ° C and 240 ° C.

This enables the roller temperature to be adapted to the softening temperature of the fibers to be processed. A change in the degree of fusion can be achieved by changing the temperature, as a result of which properties such as tensile strength, permeability to oxygen and water vapor can be controlled.

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- 54043 / PE / MB

BCA Vertriebsgesellschaft m.b.H., Eitzenberger Straße 8, 2544 Leobersdorf (AT)

According to a further feature according to the invention it can be provided that the thickness of the continuous fiber fleece during calendering is reduced by 10% to 40%, preferably by 14% to 21%.

In addition to the partial formation of a film, the thickness is also reduced in comparison to the continuous fiber fleece. Nevertheless, the nub structure formed by the connection points is retained, as a result of which, for example, spices adhere well to the continuous fiber fleece film.

According to a further feature according to the invention it can be provided that the distance between the rollers is between 0.1 mm and 0.2 mm. The thickness of the continuous fiber fleece used as the starting material can be approximately 1.5 mm.

According to a further feature according to the invention, it can be provided that the pressure acting on the continuous fiber fleece introduced into the calender is between 5 bar and 30 bar.

According to a further feature according to the invention it can be provided that the speed of rotation of the calender rolls is between 5 m / min and 25 m / min.

The variation of the process conditions, such as the distance between the rolls, the contact pressure or the rotation speed of the rolls during calendering, determines the properties of the continuous fiber fleece film produced. This ensures optimal control over the parameters of the end product.

According to a further feature according to the invention, it can be provided that the roller combination is in the form of steel / steel or steel / plastic, in particular rubber. Other materials can also be provided for the rollers. The material of the roller determines, among other things, the pressure conditions acting on the continuous fiber fleece. By varying the material of the rollers, for example, a different shape of the knob structure defined by the connection points can be achieved. It is also possible to smooth the surface of the continuous fiber fleece film with steel rollers, for example.

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- 54043 / PE / MB

BCA Vertriebsgesellschaft m.b.H., Eitzenberger Straße 8, 2544 Leobersdorf (AT)

Another object of the invention is to provide a material which can replace known packaging materials for food products and does not have the disadvantageous properties of nonwoven products used in the prior art, for example.

These and other objects according to the invention are achieved by an endless fiber fleece film which is produced by the method according to the invention.

According to a further feature according to the invention it can be provided that the continuous fiber fleece film has a water vapor permeability of 1 to 200 g / m 2 per day.

The water vapor permeability determines, for example, the drying rate of a packaged sausage. The combination of film and continuous fiber fleece leads to optimal properties for the food industry. Furthermore, the water vapor permeability also determines the diffusion rate of, for example, aromatic substances, such as, for example, essential oils of spices or smoke aroma.

According to a further feature according to the invention, it can be provided that, after calendering, approximately 90% of the total area of the continuous fiber nonwoven film consists of the film formed by fused fibers. This film has definable oxygen permeability in order to optimize the drying process of the packaged product.

Further features according to the invention result from the patent claims, the exemplary embodiments and the figures.

The invention is explained in more detail below using an exemplary embodiment. Show:

Fig. 1: A schematic side view of an endless fiber fleece;

Fig. 2: A schematic side view of an embodiment of a continuous nonwoven film according to the invention;

3a: A schematic top view of an endless fiber fleece;

3b: A schematic top view of a continuous fiber nonwoven film according to the invention.

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- 54043 / PE / MB

BCA Vertriebsgesellschaft m.b.H., Eitzenberger Straße 8, 2544 Leobersdorf (AT)

1 shows an endless fiber fleece 4 which is used as the starting material for the method according to the invention. The side view shows a schematic fiber 2 or a plurality of fibers 2 superimposed on one another. The fibers 2 are compacted selectively at connection points 3 in the production process of the continuous fiber fleece 4. This keeps the fibers together. The result is a funnel-shaped depression with a flank 6.

Typically, the fibers are made of plastic such as polyethylene, polypropylene or polyethylene terephthalate. Such a continuous fiber fleece 4 has a high permeability to water vapor and gases. It also shows anisotropic properties when torn, because it tears preferentially along the grain.

Both aspects are disadvantageous when, for example, sausage products are to be packaged in fleece: the sausage dries out quickly and the fleece frays when torn open.

FIG. 2 shows a side view of a continuous fiber fleece film 1 produced by the method according to the invention by calendering the continuous fiber fleece 4 shown in FIG. 1. The schematic view also shows a fiber 2 or more fibers 2 superimposed on one another a film 5 was formed by calendering. These areas are located in particular on the flanks 6 of the connection points 3. During calendering, the knobs formed by the connection points 3 are pressed together in the continuous fiber fleece 4 and the fibers 2 are melted together to form a film 5 by the preferably increased temperature of the rollers of the calender. In addition, as can be seen from a comparison of FIGS. 1 and 2, the height of the knobs formed by the connection points 3 is reduced, which also leads to a reduction in the overall height of the continuous fiber fleece film 1 compared to the continuous fiber fleece 4.

In this exemplary embodiment, smooth rolls made of steel were used for the production of the continuous fiber fleece film 1 by the method according to the invention. These were kept at a constant temperature of about 150 ° C. An endless fiber fleece 4 with polypropylene fibers was used as the starting material.

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- 54043 / PE / MB

BCA Vertriebsgesellschaft m.b.H., Eitzenberger Straße 8, 2544 Leobersdorf (AT)

In addition to the paper-like isotropic tear properties of the continuous fiber fleece film 1, the water vapor permeability of the continuous fiber fleece film 1 with 30 g / m 2 and day is in an optimal range for sausages. If other continuous fiber nonwovens 4 are used as starting material and other calendering conditions, continuous fiber nonwoven films with different properties can be produced.

3a shows a schematic top view of a continuous fiber fleece 4 as used for the production of a continuous fiber fleece film 1. The fibers 2 comprise polypropylene and are held together at connection points 3. The connection points have a shape similar to that shown in FIG. 1, that is to say they are essentially funnel-shaped with flanks 6.

In this schematic representation, the deepest areas of the connection points are illustrated with a dashed line. The flanks 6 of the connection points 3 extend around these deepest areas analogously to the lateral view in FIG. 1.

3b shows a schematic top view of a continuous fiber fleece film 1 according to the invention after the continuous fiber fleece 4 shown in FIG. 3a has been calendered. The fibers 2 are largely melted together to form a film 5. In particular, a film has formed in the area of the flanks 6 of the connection points 3. This achieves the same advantageous properties as already described in the exemplary embodiment in FIG. 2.

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- 54043 / PE / MB

BCA Vertriebsgesellschaft m.b.H., Eitzenberger Straße 8, 2544 Leobersdorf (AT)

LIST OF REFERENCE NUMBERS

Continuous fiber non-woven sheet

fiber

junction

Continuous fiber fleece

foil

Flank / 16

- 54043 / PE / MB

BCA Vertriebsgesellschaft m.b.H., Eitzenberger Straße 8, 2544 Leobersdorf (AT)

Claims (13)

claims 1. A method for producing an endless fiber fleece film (1), characterized in that a continuous fiber fleece (4), formed from uniform fibers (2), in particular synthetic fibers, is produced by connecting the fibers (2) at points of connection (3), in particular comprising polypropylene fibers or polyethylene terephthalate fibers, is guided and compacted by a calender with smooth rollers in such a way that the fibers (2) of the continuous fiber fleece (4) are at least partially melted into a film (5). 2. The method according to claim 1, characterized in that the rollers are kept at a substantially constant temperature. 3. The method according to claim 1 or 2, characterized in that the surface temperature of the rollers for processing the continuous fiber fleece (4) is between 100 ° C and 250 ° C, in particular when processing polypropylene fleece between 145 ° C and 170 ° C, for PE between 100 ° C and 125 ° C and for processing polyethylene terephthalate fleece between 200 ° C and 240 ° C. 4. The method according to any one of claims 1 to 3, characterized in that the thickness of the continuous fiber fleece (4) during calendering is reduced by 10% to 40%, preferably by 14% to 21%. 5. The method according to any one of claims 1 to 4, characterized in that the distance between the rollers is between 0.1mm and 0.2mm. 6. The method according to any one of claims 1 to 5, characterized in that the pressure acting on the continuous fiber fleece (4) introduced into the calender is between 5 bar and 30 bar. 7. The method according to any one of claims 1 to 6, characterized in that the rotational speed of the calender rolls is between 5 m / min and 25 m / min. 10/16 10 - 54043 / PE / MB BCA Vertriebsgesellschaft m.b.H., Eitzenberger Straße 8, 2544 Leobersdorf (AT) 8. The method according to any one of claims 1 to 7, characterized in that the roller combinations comprise steel / steel or steel / plastic, in particular rubber. 9. continuous fiber fleece film (1), produced by a method according to any one of claims 1 to 8. 10. continuous fiber fleece film (1) according to claim 9, characterized in that it has a water vapor permeability of 1 to 200 g / m2 per day. 11. Continuous nonwoven film (1) according to claim 9 or 10, characterized in that after calendering, about 90% of the total area of the continuous nonwoven film (1) consists of the film (5) formed by fused fibers (2). 11/16 1.2 12/16 2.2 13/16 Austrian Patent Office