RU2529727C2 - Glossy multilayered casing for food products, permeable to water vapours and smoke - Google Patents

Abstract

FIELD: packaging industry.

SUBSTANCE: invention relates to a package, namely to glossy multilayer tubular biaxially oriented casing for food products, mainly for use as a casing for frankfurters, sausages and boiled-smoked, air-dried and uncooked smoked sausages, and smoked processed cheese, and so on. The casing has at least two layers which comprise from 15% to 70% polyamide material and from 30% to 85% of at least one water-soluble polymeric material selected from the list comprising polyvinyl alcohol, vinyl alcohol copolymers, polyvinyl pyrrolidone, copolymers of vinylpyrrolidone, polyoxazoline, cellulose ether; and the value of the transmission rate of water vapour by the casing, measured according to DIN 53122 at 23°C and a relative humidity of 85%, is more than 200 g/m²·per day.

EFFECT: casing has increased mechanical reliability combined with high permeability with respect to the smoke fume and water vapour, and can be manufactured at high-performance industrial plants.

12 cl, 3 tbl, 6 ex

Description

Field of Invention

The present invention relates to a multilayer casing for food products, permeable to water vapor and smoke substances of smoke and intended mainly for use as a casing for sausages, sausages and cooked smoked, dried and smoked sausages, as well as processed cheeses and etc.

Description of the level of technology achieved

Over the past decade, melt-extruded films based on synthetic polymers, mainly polyamides, permeable to water vapor and smoke and used as casings for smoked sausages and sausages have appeared on the packaging market.

In the application WO 02054878, publ. 07/18/2002, a film was disclosed from a mixture of a block copolymer of polyamide and simple polyester (hereinafter referred to as polyester-block amide or PEBA) with polyamides (hereinafter referred to as PA), proposed for use as a vapor and smoke-permeable casing for sausages, suggesting smoking. The sausage casing comprises 15-85% polyamide or a mixture of polyamides and 15-85% PEBA. In a preferred embodiment, the shell consists of 50-70% polyamide or mixtures of polyamides and 30-50% PEBA.

Steam and smoke-permeable film, which is made of the same components and, in addition, polyvinyl alcohol (hereinafter - PVA), is described in RF patent 2333652, publ. September 20, 2008. A thermoplastic mixture consists of 40-80% PA, 5-40% PVA and 20-30% PEBA. The film may be single-layer or multi-layer. The preferred content of the components in the mixture is: 50-65% PA, 24-26% PEBA and 15-25% PVA.

It should be noted that PEBA is an elastomer with a very low mechanical modulus. Therefore, single-layer shells containing PEBA, as well as multilayer shells, where PEBA is present in all layers, although they have high vapor permeability, are characterized by excessive elasticity. This can lead to deformation of sausages in such casings under their own weight, which limits the applicability of these casings to extremely small calibers.

A smoked film from a mixture of a block copolymer of an ether and an ester with an aliphatic polyamide in an amount of from 50 to 99.9% is disclosed in WO 02082913, publ. 10.24.2002 g.

The high content of polyamide in these mixtures is due to the fact that the used block copolymers themselves, as well as the compositions in which they prevail in the mass fraction, give mechanically very fragile films. They cannot be used as, for example, sausage casings, which must withstand high mechanical loads when stuffing with minced meat. In addition, such block copolymers are quite expensive, which affects the cost and price of the films containing them.

A single-layer sleeve smoke and vapor permeable film containing polyamide, for example PA 6, PA 6/66, and from 4 to 50% hydrophilic compounds, including water-soluble polymers such as polyvinylpyrrolidone or polyvinyl alcohol, forming a highly dispersed phase with a linear size (thickness in polyamide) ) the domain of 0.1-3.0 μm, is disclosed in the patent of the Russian Federation 2182107, publ. 05/10/2002

This film is made using the “triple bubble” technology to give it the properties necessary for the sausage casing. extruded as so-called the primary sleeve (bubble), which is then heated in a hot water bath to about 70-80 ° C and biaxially stretched by blowing and simultaneous longitudinal drawing to obtain a secondary sleeve. The secondary sleeve is then subjected to heat setting to obtain a finished (tertiary) sleeve. Such a shell allows the production of sausages and sausages with a pronounced smoking effect, but the formation of a sufficiently distinct characteristic crust on the surface of the product still does not occur.

The prior art is another approach to increasing the permeability of polymer films made on the basis of mixtures of aliphatic (co) polyamide and a water-soluble synthetic organic polymer. In the patent of the Russian Federation 2341090, publ. December 20, 2008, a shell with a rough surface and a natural (matte) appearance is disclosed, containing in addition to aliphatic (co) polyamide and a water-soluble synthetic organic polymer, at least one organic and / or inorganic filler, which may be a carbohydrate, organic synthetic fiber or organic synthetic powder with an average fiber length of 5-3000 microns, glass spheres with an average size of 5-3000 microns. This shell may be monolayer or multilayer. Moreover, the shell has a vapor permeability, determined according to DIN 53122, from 50 to 1500 g / m ² · day. The multiple increase in vapor permeability, the inventors explain the presence in the shell of the above-mentioned fillers.

Meanwhile, the introduction of such fillers in the composition of the thermoplastic composition requires additional technological operations that extend the production cycle, and the subsequent production of shells from these compositions, especially oriented, is a difficult technical problem due to their increased stiffness. In addition, the organic fillers included in the mixture under the conditions of extrusion of aliphatic (co) polyamides are prone to thermal decomposition, leading to contamination of the extrusion equipment and shell by products of this decomposition at all stages of its preparation. As for coarse inorganic fillers, they usually cause accelerated wear of extrusion and corrugating machines and, in addition, tend to crumble from the finished shell. If such a casing is used as a sausage casing and is intended for stuffing on high-speed stuffing machines, which require the use of a casing in the form of rigid corrugated "tracks", its uneven thickness prevents the production of such "tracks" made of known technology, for example, in accordance with with the patent of the Russian Federation No. 2131670, publ. 06/20/1999, In addition, the advantage of a “natural” appearance is absolutely irrelevant if the casing is intended for receiving sausages, which the manufacturer cleans from the casing and repackages, for example, in vacuum bags.

Closest to the present invention, the shell is described in RF patent 2345104, publ. January 27, 2009. This single-layer shell consists of an aliphatic (co) polyamide and a water-soluble synthetic organic polymer. The proportion of aliphatic (co) polyamide is 40-94%, particularly preferably 60-85%, the proportion of water-soluble polymer is 3-50%, particularly preferably 15-30%. It has a water vapor transmission rate (hereinafter referred to as SPV) or water vapor permeability, determined according to DIN 53122, from 40 to 200 g / m ² · day, at a temperature of 23 ° C and a relative humidity of 85 ° C. However, for the production of cooked smoked and raw smoked sausages, such permeability is insufficient.

In addition, as will be shown below, the upper value of the vapor permeability of the shell according to this patent is achieved when the content of the water-soluble polymer is approximately equal to the upper value of the preferred range (30%), and it is extremely difficult to produce an oriented single-layer shell with an industrial content of such a water-soluble polymer and higher.

It should be expected that in membranes made of aliphatic (co) polyamide and a water-soluble synthetic organic polymer, the permeability to water vapor and smoke should increase with an increase in the content of hydrophilic components in them.

However, the high-performance manufacture of a single-layer shell on an industrial scale as the content of the water-soluble polymer in it becomes more and more difficult due to the increasing tendency to breaks at the stage of orientation of the shell. The same tendency is observed with respect to ruptures of single-layer shells and when stuffed with sausage (sausage) stuffing.

Thus, the object of the present invention is to provide a glossy multilayer sleeve biaxially oriented synthetic food casing based on a mixture of polyamides with water-soluble polymers with improved smoke and vapor permeability, that is, the casing must have an SPVT above 200 g / m ² · day, without introduction additional coarse filler, increasing its smoke and vapor permeability, but creating problems in the manufacture and processing of shells. Moreover, it should also have improved mechanical characteristics at all stages of preparation and in finished form, i.e. both the finished shell and the technologically preceding primary and secondary sleeves should have improved mechanical reliability.

Here and in the further description, unless otherwise specified, the sign "%" means the mass percentage taken from the total weight of the composition or mixture. Also in the future, the words containing the prefix in parentheses are used to denote concepts that simultaneously include the concepts denoted by this word with this prefix and without it. For example, the word (co) polyamide means both polyamide (homopolymer) and copolyamide.

Hereinafter, the mechanical reliability of the casing is understood as the probability that an arbitrarily selected segment of this casing with a length of 33 m (casing length in the corrugated "caterpillar") will not break under loads, which usually develop when it is filled with automatic equipment.

Description of the invention

As a result of intensive research, it was unexpectedly discovered that the objective of the present invention is solved by a glossy multilayer sleeve biaxially oriented food coating containing a polyamide material and a water-soluble polymer material, and this coating has at least two layers containing from 15% to 70 % polyamide material and from 30% to 85% of at least one water-soluble polymer material selected from the list including polyvinyl alcohol, vinyl alcohol copolymers, polyvinyl alcohol ilpirrolidon, copolymers of vinylpyrrolidone, polyoxazoline, cellulose ether and the value of the water vapor transmission rate envelope, as measured by DIN 53122 at 23 ° C and relative humidity of 85%, is more than 200 g / m ² · day.

In the framework of the present invention, the polyamide material consists of at least one individual aliphatic (co) polyamide. The polyamide material may be any thermoplastic synthetic (co) polyamide (nylon), but in preferred embodiments it is a thermoplastic aliphatic polyamide or copolyamide selected from the group consisting of polyamide 46, polyamide 6, polyamide 66, copolyamide 46/6, copolyamide 6/66 , as well as any mixtures thereof.

Polyamide 46 is produced, for example, by Royal DSM (Netherlands) under the common brand name Stanyl®. Polyamide 6, polyamide 66, copolyamide 6/66 are manufactured, for example, by BASF SE (Germany), UBE Industries, Ltd. (Japan), Royal DSM (Netherlands) under the trademarks Ultramid®, Nylon® and Akulon®, respectively.

The water-soluble polymer material contains at least one water-soluble (co) polymer and, if necessary, a water-soluble plasticizer.

By water-soluble (co) polymer is meant a (co) polymer whose solubility in water heated to 80 ° C. is at least 20 g / l.

One of the preferred synthetic water-soluble polymers is polyvinyl alcohol, in particular with a weight average molecular weight M _w ranging from 10,000 to 50,000 and a saponification degree of acetate groups ranging from 70 to 98%, preferably from 75 to 85%.

Polyvinyl alcohol in the broad (technical) sense refers to water-soluble products of almost complete or incomplete saponification of vinyl acetate, which nominally can be considered as copolymers of vinyl alcohol and vinyl acetate. In the narrow, strictly chemical sense, polyvinyl alcohol is a homopolymer of residues of vinyl alcohol. As used herein, the term “polyvinyl alcohol” is used in a broad sense unless otherwise interpreted clearly from the context. Polyvinyl alcohol of various grades is produced, for example, by Japanese companies Kuraray Co., Ltd., The Nippon Synthetic Chemical Industry Co., Ltd. under the brands Mowiol®, Gohsenol® respectively and Taiwanese company ChangChun Petrochemical Co., Ltd. under the brands PVA BF, PVA BP and PVA BC.

Polyvinylpyrrolidone (hereinafter - PVP) and water-soluble copolymers of vinylpyrrolidone (for example, vinyl acetate) are manufactured, for example, by BASF SE (Germany) under the brand name Kollidon®.

Polyoxazolines of varying molecular weights are manufactured by Polymer Chemistry Innovations Inc. (USA) under the brand name Aquazol®.

As the cellulose ether, for example, thermoplastic methyl cellulose manufactured by The Dow Chemical Co. can be used. (CIHA) under the brand name Methoce®.

Water-soluble polymeric materials are mainly selected in accordance with the requirements of RF patent 2182107, i.e. those that form a highly dispersed phase in polyamide.

The content of water-soluble polymeric material in these at least two layers containing polyamide and water-soluble polymeric material can vary from 30 to 85%, depending on the structure of the shell and its purpose. Typically, the PVA content in the developed casing is in the range of 30-50%, however, if the casing is intended for undigested sausages, in the layer not in contact with wet minced meat, 50 to 85% of the PVA can be contained.

The composition of the at least two layers mentioned may be different, close or the same. In some cases, it is preferred that different water-soluble polymers are present in different layers of the shell. For example, the use of a mixture of polyamide with PVA in the outer layer of the sleeve, and a mixture of polyamide with PVP in the inner layer of the multilayer shell adjacent to the contents, can be especially useful when a combination of high permeability and smokiness with increased adhesion of the shell to sausage meat is required.

In some cases, these layers may contain up to 10% of other polymeric materials, for example, insoluble cellulose ester, block copolymer of polyamide and polyester, block copolymer of polyester and polyester, block copolymer of polyurethane and polyester, polyethylene, copolymer ethylene and vinyl acetate, polysiloxane. The listed block copolymers can, for example, be introduced if it is desired to modify the elastic properties and transparency of the films. Small amounts (up to ≈2%) of polyethylene, a copolymer of ethylene and vinyl acetate or polysiloxane can, for example, be introduced into the layer in contact with the meat, if it is necessary to modify the adhesion of the shell to the meat.

In addition to the above-described layers, the inventive shell may have at least one additional layer that contains at least 90% polyamide material.

In addition to an additional layer made predominantly of such a (co) polymer as (co) polyamide, the multilayer shell may also contain at least one additional layer, mainly made of a mixture of from 70% to 95% polyamide material and from 5% to 30% water soluble polymer material.

The presence in the shell of an additional layer of pure polyamide material and / or a mixture of polyamide material with a reduced amount (up to 30%) of water-soluble polymer material is sometimes advisable from the point of view of improving the mechanical properties of the shell, especially designed for cooked smoked sausages of large caliber. Such a layer (s) is preferably made thin enough so that it does not lower the overall vapor permeability of the shell.

In addition to the above-described layers, the inventive shell may have layers that do not contain (co) polyamides at all, but contain such (co) polymers as soluble polyvinyl alcohol, insoluble vinyl alcohol copolymer (for example, vinyl alcohol-ethylene copolymer - SEVS), insoluble cellulose ester , a block copolymer of polyamide and polyether, a block copolymer of polyester and polyester, a block copolymer of polyurethane and polyester, or any mixture of the above (co) polymers. In particular, the inventive shell may have a layer or layers made of elastomeric PEBA or mixtures of PEBA with a water-soluble (co) polymer, such as PVA or PVP, with different quantitative composition. Such a layer, due to the extremely high moisture absorption capacity of its constituent materials, is especially useful as the outer layer of the casing for sausage-sausage products that are smoked by dipping into or spraying with liquid smoke.

It is impossible to obtain an oriented single-layer film from materials such as compositions with a quantitative predominance of PVA, PVP, or PEBA due to their insufficient mechanical strength and hygroscopicity, and in addition, for the same reason, it cannot be used as a food casing. However, it was unexpectedly discovered that such materials and compositions can be used as separate layers in multilayer structures.

Block copolymers of polyamide and polyether are commercially available, for example, by Arkema S.A. (France) under the common brand name Pebax®.

Polyester and block copolymers are commercially available from E.I. du Pont de Nemours and Co., (USA) under the Hytrel® brand and Royal DSM under the Arnitel® brand.

Thermoplastic polyurethanes with polyester blocks are commercially available, for example, by Lubrizol Corp. (USA) under the Estane® brand.

The aforementioned at least two layers comprising a polyamide material and a water-soluble polymeric material may be adjacent or separated by other layers.

The total number of layers in the shell is preferably from 2 to 7. In addition, each of the layers may additionally contain at least one additive selected from the list including pigment, dye, a finely divided filler, a plasticizer, an additive that facilitates drawing, an additive that regulates adhesion of the shell to the contents, an additive that regulates the coefficient of friction of the shell, or any mixture thereof.

At least one substance selected from the list including polyhydric alcohol, polyglycol, polyhydric ester, substituted or unsubstituted aliphatic carboxylic acid amide, substituted or unsubstituted aliphatic sulfamide is used as a plasticizer.

The total shell thickness is preferably from 15 to 70 microns, i.e. the thickness of the multilayer shell is comparable to the thickness of a single layer shell. The total thickness of the layers containing polyamide and water-soluble polymeric material, preferably can be from 10 to 100% of the total thickness of the shell.

As a result of the studies, it was found that, in contrast to the prior art single-layer films based on mixtures of (co) polyamide with water-soluble polymers, the multilayer sleeve biaxially oriented sheath of the present invention has improved smoke and vapor permeability, that is, has an SPV above 200 g / m ² · day, while the shell does not contain coarse-grained fillers, roughening it and further increasing its vapor permeability, such as, for example, starch or cellulose. In addition, none of the layers of the invented shell does not contain a mixture of (co) polyamide, PEBA and PVA according to RF patent 2333652, publ. September 20, 2008, which combines high vapor permeability and smokeability with more or less satisfactory mechanics. In the manufacture of smoked sausage and sausage products in this shell, a characteristic crust forms on the surface of the product, while they have a pronounced aroma of smoking.

It was also found that high-performance manufacturing of permeable membranes with a high content of water-soluble polymer became possible only when switching from single-layer to multilayer shells with their comparable thickness.

The developed shell, both in dry and in wet form, has improved mechanical reliability, which is manifested in a sharp decrease in the number of shell breaks during packing compared to single-layer analogues. In addition, due to the improvement of the mechanical properties of the primary and secondary hoses, it became possible to manufacture the sheath in a highly productive way on an industrial scale.

It was also found that with an increase in the content of polyvinyl alcohol in the layer in contact with the contents, the adhesion of the shells to the minced meat decreases, which facilitates their cleaning from sausage-sausages on an automatic piller.

A preferred method for producing a shell in accordance with the present invention is the triple bubble technique.

Typically, in the manufacture of the shell of the present invention, extrusion plants (machines) with several extruders and one multilayer head are used, however, if the composition of several layers is the same, one extruder can be used to form the extrudate into the corresponding zones of the multilayer head.

The fabricated shell can be used as such or cut along one or both edges of a folded sleeve to produce a half sleeve or two extended flat films, respectively. It can be straight, curved or ring-shaped or made in the form of a corrugated doll.

The shell of the present invention can be used in the manufacture of sausages, sausages, pastes and cheeses in the shell, preferably those that involve smoking and / or curing. Smoking technology may include smoking operations with natural smoke obtained by decaying hardwood, as well as sprayed or sprayed “liquid smoke”. In addition, smoking can be carried out by dipping the shells filled with minced meat in a solution of "liquid smoke" with subsequent heat treatment.

Preferred but not exhaustive embodiments of the present invention will be illustrated in the following examples.

Examples.

Test methods.

1. Assessment of the rate of transmission of water vapor

The evaluation is carried out in accordance with DIN 53122 at 23 ° C and a relative humidity of 85%.

2. Evaluation of the effects of smoking

Evaluation is carried out by 10 experts who individually evaluate the effects of smoking (aroma, crust color) achieved on sausage samples in different casings under the same smoking regimes on a scale where “10” corresponds to the effect achieved in the commercially available NOJAX® cellulose casing manufactured by Viskase Co., (Darin, Illinois, USA), the same diameter and thickness as the shells under study, and “0” - the effect achieved in the shell made only from PA 6/66, after which the average score is calculated .

3. Evaluation of the proportion of weight loss in the process of cooking sausages

Weight loss in the manufacture of sausages occurs mainly at the stage of smoking / roasting / drying (65-75 ° C, a total time of about 50 minutes) due to the evaporation of water through a vapor-permeable shell. Thus, this parameter characterizes the ability of the casing to pass water vapor in real conditions of the technological process of preparing sausage products.

Weight loss (kg) is calculated as the difference between the mass of the sausage ligament after stuffing and the mass of the same sausage ligament after final preparation. Percentage of weight loss is the ratio of weight loss to the weight of the sausage ligament after stuffing, expressed as a percentage.

4. Determination of the mechanical reliability of the shell

In the process of filling a standard amount of casing on standard stuffing equipment, determined by its length L (m), but not less than 500 m, the number of breaks (N) is calculated, on average per corrugated "track" containing 33 m of casing. The reliability of the shell R (%) is calculated by the following formula

$$R=\mathrm{one\; hundred}\left(\mathrm{one}-\frac{33N}{L}\right)$$

List of used symbols and materials:

PVA - brand Mowiol 5-88®, manufacturer Kuraray Co., Ltd., Japan;

PA 6/66 - brand Ultramid C33®, manufacturer BASF SE, Germany;

PA 6 - brand Ultramid B33L®, manufacturer BASF SE, Germany;

PEBA - brand Pebax®3000 MV, manufacturer Arkema S.A., (France).

Example 1

A. Preparation of water-soluble material

PVA (according to the designation) is pre-mixed with 14% glycerol in a mixer for dry and highly viscous materials, then passed through a twin-screw extruder equipped with a vacuum degassing zone, and plasticized PVA is obtained in the form of cream-colored granules.

B. Shell Production

A mixture of 35% PVA granules obtained according to Section A of this example is loaded into the hoppers of two extruders operating at the same capacity (≈8 kg / h) of a two-layer extrusion plant, and 65% of PA 6/66 granules are melted and mixed in the extruders. Further, the melts enter a two-layer head, where a molten two-layer extrudate is formed, which exits through the annular die in the form of a sleeve blank, which is sharply cooled with cold water to a temperature of 13-15 ° C. The result is a hardened primary sleeve with an average thickness of 128 microns and an average diameter of 7.5 mm. Using a system of shafts, a flat-folded primary sleeve is fed into the action area of a planar infrared emitter, heated to a temperature of 80 ° C, and then fed to the exhaust zone. In this zone, the primary sleeve is subjected to longitudinal and transverse extraction with coefficients of 2.7 and 3.6, respectively, using air blown into it under an overpressure of about 2 atm and two pairs of active clamping shafts holding this air and moving at different speeds. The resulting biaxially elongated sleeve in the form of a slightly inflated bubble is fed into the zone of action of a tubular infrared emitter, where it is heated to 150 ° C and held at this temperature for 5 seconds. At this stage, called the curing of the shell, it is simultaneously shrinked in the longitudinal direction by 15% and in the transverse by 23%. The result is a two-layer sleeve casing with a diameter of 21-22 mm and an average thickness of 20 μm, suitable for use as a casing for sausages, which are wound into a roll at a speed of ≈300 m / min.

The production of 5,000 linear meters of shell took place without any problems.

The shell was corrugated to produce stable dolls, as described in RF patent No. 2131670 (publ. 06/20/1999), and used in the manufacture of sausages of the variety "Dairy". Here and in the following examples, a meat emulsion made in accordance with GOST 52196-2003 was used to make sausages of the Dairy variety. The manufacturing technology of these sausages includes high-speed stuffing on the Handtmann apparatus, cooking and smoking.

SPPV shell, its behavior during packing and the properties of the final product are shown in Table 3.

Example 2

The following mixtures are loaded into the hoppers of three extruders operating with the same capacity in a three-layer extrusion plant:

- into the extruder A, the forming layer adjacent to the inner surface of the sleeve - 45% of the granules of PVA according to example 1 (section A) and 55% of granules PA 6,

- into the extruder B, forming an intermediate (heart-shaped) layer - 40% of the granules of PVA according to example 1 (section A) and 60% of granules PA 6/66,

- into the extruder C, the forming layer adjacent to the outer surface of the sleeve - 40% of the granules of PVA according to example 1 (section A) and 60% of granules PA 6/66,

which are then melted and mixed in these three extruders. After this, the melts enter the three-layer head, where a molten three-layer extrudate is formed, which exits through the annular die in the form of a primary sleeve. Further, in accordance with the technology described in example 1, a sleeve film is made with three layers of equal thickness.

The production of 5,000 linear meters of this tubular casing proceeded with virtually no problems.

The casing was also corrugated into stable dolls and used in the manufacture of dairy sausages.

SPPV shell, its behavior during packing and the properties of the final product are shown in Table 3.

Example 3

In the bins of three extruders operating at different capacities of a three-layer extrusion plant, three compositions are shown, shown in Table 1.

Table 1 Extruder The share of the extruder productivity of the total installation productivity,% Structure A twenty Pebax® 3000 MV pellets B 40 45% of the granules of PVA according to example 1 (section A) and 55% of granules PA 6/66 C 40 40% of the granules of PVA according to example 1 (section A) and 60% of granules PA 6/66

Further, in accordance with the technology described in example 1, a sleeve film is made in which its three layers with thicknesses proportional to the capacities of the respective extruders are located from the inner surface of the sleeve to the outer one and have the composition as in compositions in extruders A to C respectively.

The production of 5,000 linear meters of this tubular casing proceeded with virtually no problems.

The casing was also corrugated into stable dolls and used in the manufacture of dairy sausages.

SPPV shell, its behavior during packing and the properties of the final product are shown in Table 3.

Example 4

In the bins of the three extruders forming the layers in accordance with Example 3, the following 3 compositions are loaded, shown in Table 2.

table 2 Extruder The share of the extruder productivity of the total installation productivity,% Structure A twenty 45% of the granules of PVA according to example 1 (section A) and 55% of granules PA 6/66 B 40 55% of the granules of PVA according to example 1 (section A) and 45% of the granules Pebax®3000 MV C 40 40% of the granules of PVA according to example 1 (section A) and 60% of granules PA 6/66

Next, the shell is made according to example 3 except that the primary sleeve is extruded with a thickness of 153 μm and a diameter of 15.3 mm, from which then a finished sleeve film with a thickness of 24 μm and a diameter of 45 mm is obtained.

The production of 5,000 linear meters of this tubular casing proceeded with virtually no problems.

The shell in the form of a roll was used in the manufacture of uncooked smoked sausages of the Cervelat variety, the sausage stuffing for which was made according to GOST 16290-86. The sausage stuffed into this shell was precipitated at a relative humidity of 90% and a temperature of 4 ° C for 6 days, cold smoked at 20-22 ° C for 2 days and dried for 7 days at a temperature of 13-15 ° C and relative humidity 82% and for another 20-23 days at 10-12 ° C and relative humidity 76%.

SPPV shell, its behavior during packing and the properties of the final product are shown in Table 3.

Comparative Example 1

The polymer composition of example 1 (section B) is loaded into the hopper of a single-layer extrusion machine (manufactured by Ankele Kunststoffmaschinenbau GbR, Germany), with a nominal capacity of the same total capacity of the three extruders from example 1, is melted and mixed in an extruder, then fed into a single-layer die, from where extruded through an annular die in the form of a primary sleeve. Further, in accordance with the technology described in example 1, at the same speed conditions, they try to produce a single-layer sleeve film. It is not possible to produce a single-layer sleeve film due to continuous tearing of the sleeve film at the stage of orientation drawing.

Further, the productivity of the extruder and, accordingly, the lines as a whole are reduced three times. However, even after this, in the manufacture of a single-layer sleeve film, frequent breaks occurred. Having consumed the same amount of raw materials as in Example 1, it was possible to produce only about 500 linear meters of this sleeve film.

The casing was also corrugated into stable dolls and used in the manufacture of dairy sausages.

SPPV shell, its behavior during packing and the properties of the final product are shown in Table 3.

Reference Example 2

A single-layer sleeve film is made in accordance with comparative example 1 and at the same speed mode except that 40% of the PVA granules obtained according to Section A of Example 1 and 60% of PA 6/66 granules are loaded into the hopper of a single-layer extrusion machine. Due to continuous tearing of the tubular film at the stage of orientational drawing, the shell cannot be obtained. For this reason, its properties are not shown in Table 3.

An analysis of comparative examples 1 and 2 shows that a single-layer permeable shell with a water-soluble polymer material content of more than 30% either cannot be obtained at all, or can only be manufactured if the line productivity and the level of raw materials and working hours are unacceptable for industrial production.

Reference Example 3

A single-layer sleeve film is made in accordance with comparative example 1 and at the same speed mode except that 25% of the PVA granules obtained according to Section A of Example 1 and 75% of PA 6/66 granules are loaded into the hopper of a single-layer extrusion machine.

The production of 5,000 linear meters of this tubular casing proceeded satisfactorily. Due to infrequent breaks at the drawing stage, approximately 5% more raw material was consumed than in Example 1.

The casing was also corrugated into stable dolls and used in the manufacture of dairy sausages.

SPPV shell, its behavior during packing and the properties of the final product are shown in Table 3.

Reference Example 4

A single-layer sleeve film is made in accordance with comparative example 1 except that 100% PA 6/66 granules are loaded into the hopper of a single-layer extrusion machine.

The casing was also corrugated into stable dolls and used in the manufacture of dairy sausages.

SPPV shell, its behavior during packing and the properties of the final product are shown in Table 3.

Reference Example 5

Sausage cellulose casing NOJAX® with a diameter of 22 mm in the form of dolls was used in the manufacture of sausages sort "Dairy" as in example 1.

Reference Example 6

Cellulose-reinforced casing “Fibrous with a diameter of 22 mm in the form of a roll was used in the manufacture of uncooked smoked sausages of the sort“ Cervelat ”according to the manufacturing technology described in example 4.

Table 3 Example No. SPPV, g / m ² · day Stuffing (mechanical reliability) Smoke flavor Crust color and density The proportion of mass loss,% one 205 No breaks (≈100%) 5.9 4.7 9.5 2 225 No breaks (≈100%) 8.2 6.9 11.3 3 256 No breaks (≈100%) 8.5 7.4 12.1 four 520 No breaks (≈100%) 8.9 9.5 8.8 Comparative 1 198 Frequent tears (≈21%) 5.9 3.9 9.0 Comparative 2 Sample not received Comparative 3 150 Almost without gaps (≈80%) 3,5 1,2 7.3 Comparative 4 85 No breaks (≈100%) 0 0 5.1 Comparative 5 724 No breaks (≈100%) 10 10 13.5 Comparative 6 550 No breaks (≈100%) 10 10 9.0

The data in the table confirm the conclusion that the task of the invention has been successfully solved.

Claims (12)

1. A glossy multilayer sleeve biaxial oriented food casing containing a polyamide material and a water-soluble polymer material, characterized in that it has at least two layers containing from 15% to 70% polyamide material and from 30% to 85 % of at least one water-soluble polymer material selected from the list including polyvinyl alcohol, vinyl alcohol copolymers, polyvinylpyrrolidone, vinylpyrrolidone copolymers, polyoxazoline, cellulose ether and a pr the lowering of water vapor by a shell measured according to DIN 53122 at 23 ° C and a relative humidity of 85% is more than 200 g / m ² · day. 2. The glossy multilayer sleeve biaxial oriented shell according to claim 1, characterized in that the polyamide material is at least one aliphatic (co) polyamide selected from the group consisting of polyamide 46, polyamide 6, polyamide 66, copolyamide 46 / 6, copolyamide 6/66 or a mixture thereof. 3. The glossy multilayer sleeve biaxial oriented shell according to claim 1, characterized in that the polyvinyl alcohol is characterized by a weight average molecular weight M _w ranging from 10,000 to 50,000 and a degree of saponification of acetate groups ranging from 70 to 98%, preferably from 75 to 85% . 4. A glossy multilayer sleeve biaxially oriented shell according to claims 1 to 3, characterized in that it additionally has layers different in composition from the said at least two layers. 5. A glossy multilayer sleeve biaxially oriented shell according to claim 4, characterized in that at least one of the additional layers contains at least 90% polyamide material. 6. The glossy multilayer sleeve biaxially oriented sheath according to claim 4, characterized in that at least one of the additional layers is preferably made of a mixture of from 70% to 95% polyamide material and from 5% to 30% water-soluble polymeric material. 7. The glossy multilayer sleeve biaxially oriented shell according to claim 4, characterized in that at least one additional layer does not contain polyamide. 8. The glossy multilayer sleeve biaxial oriented shell according to claim 7, characterized in that the additional layer mainly contains at least one polymer material selected from the list including water-soluble polyvinyl alcohol, insoluble vinyl alcohol copolymer, insoluble cellulose ester, a block copolymer of polyamide and polyether, a block copolymer of polyester and polyester, a block copolymer of polyurethane and polyester, or any mixture thereof. 9. The glossy multilayer sleeve biaxially oriented shell according to claim 1, characterized in that any of its layers contains at least one additive selected from the list including pigment, dye, a finely divided filler, a plasticizer, an additive that facilitates drawing, an additive that regulates the adhesion of the shell to the contents, an additive that regulates the coefficient of friction of the shell, or any mixture thereof. 10. The glossy multilayer sleeve biaxially oriented shell according to claim 9, characterized in that it has a total number of layers from 2 to 7. 11. The glossy multilayer sleeve biaxial-oriented casing for food products of claim 10, characterized in that its total thickness is in the range from 15 to 70 microns. 12. The glossy multilayer sleeve biaxially oriented shell according to claim 11, characterized in that the total thickness of at least two layers containing a polyamide material and a water-soluble polymer material is in the range from 10 to 100% of the total shell thickness.