FI90717B - Cellulose-based packaging casing, especially sausage casing, with improved handling properties - Google Patents

Abstract

The tube-shaped packaging casing, especially an artificial sausage casing, is composed of fibre-reinforced cellulose in which at least the exterior of the fibre reinforcement is coated with a cellulose layer, and of a surface layer on the cellulose layer. The surface layer comprises a water-insoluble cationic resin and, in addition, plastic or cellulose particles or fibres, in particular plastic particles made of vinyl chloride homopolymers or vinyl chloride copolymers.

Description

90717

Cellulose-based packaging casing, especially sausage casing, with improved handling properties

The invention relates to a packaging shell as mentioned in the preamble of claim 1 and to a method for manufacturing the same, in which method the fibrous carrier hose is coated at least on its outer surface with a cellulose layer according to a viscose method.

Have tubular artificial sausage casings consisting of fiber-reinforced cellulose carrier tubes 10 been known for a long time; in these shells, the fibrous jet is coated with a layer of regenerated cellulose on at least one surface. It has also already been proposed to improve the adhesion of dyes, fungicidal salts 15 and synthetic resin layers to the outer cellulosic layer of fiber-reinforced hose shells by means of an outer coating layer or an adhesion-enhancing intermediate layer consisting of cationic resins (U.S. Pat. Nos. 4,695; 426).

It is further prior art that these cellulosic shells are filled with a filler moistened with water. The water then acts as a cellulose plasticizer and gives the shell the necessary flexibility and extensibility. However, when these soft and flexible shells are pushed at one end into bonded pieces 25 to the filling tube of the filling machine, they are difficult to grip and hold by hand.

The object of the invention is thus to improve these packaging shells in terms of their handling properties, whereby the shells must be modified so that they can be easily pushed onto the filling tube when wet, but on the other hand its optical appearance, in particular its surface gloss, remains unimpaired.

This object is solved by a packaging casing, in particular a sausage casing, which has the features set out in claim 2 1. Preferred embodiments of the shell are set out in the dependent claims. The invention further relates to a method according to claim 9.

The solution to this problem is thus achieved in combination, in which the thermosetting resin and the plastic or cellulose fibers, in particular the plastic or cellulose particles, are each of the two main components of the surface layer. The outer surface of the packaging shell has a clear roughness. Therefore, the shell 10 has improved handling properties, in particular it can be taken to the filling pipe of the filling machines without any problems when broken. There is virtually no change in the surface gloss or transparency of the shell. The hoses can also be folded flat without damaging the relatively soft and easily scratched cellulosic surface. The particles of lice, respectively, the fibers are permanently attached to the surface of the shell. The resin layer completely surrounds the fibers or the fibers, respectively, or at least to the extent that they adhere firmly to the surface. 20 The particles or fibers embedded in the outer resin layer consist of cellulose or plastic, the plastic being selected according to the following criteria. The material used must not, at the end of the dry process, when the resin changes to its water-insoluble form, form a film 25 and dissolve in the resin, but must retain its particulate structure as well as possible. The plastic or cellulose particles, respectively, should also have, as closely as possible, a specific gravity that corresponds approximately to the density of the cationic resin-containing coating dispersion so that they remain floating in this dispersion and do not tend to rise or sediment.

Particularly suitable are plastic particles based on homopolymers or copolymers containing vinyl chloride units, in particular polyvinyl particles 90717 3 with a particle size of more than 0.1. These relatively coarse particles are formed as a by-product upon separation by centrifugation of PVC dispersions which are intended for coating paper and which therefore have to exclude particles larger than 0.1 .mu.m in size. Thus, a particularly inexpensive starting material is available for the preparation of the shell according to the invention.

Particles with a size of less than 0.2 μm have a relatively small target effect, with particles 10 larger than 5 μm there is a risk that they will not adhere sufficiently firmly to the resin layer. In general, particles with a diameter in the range of 0.2 to 2 μm are preferred. When using fibers, fibers with a relatively small length, i.e. less than 10 pm, especially 15 less than 5 pm. Fibers with an average length of 0.1 to 1 μm are usually used.

The cationic resin is, for example, a condensation product consisting of a protein of animal or vegetable origin, such as gelatin, soy protein, peanut protein or wheat protein, in particular casein, and an aldehyde, such as malonaldehyde or glutaraldehyde, or glutaraldehyde. the proportion of aldehyde is from 5 to 15% by weight, in particular from 6 to 10% by weight; a condensation product of urea and formaldehyde (US-A-2,616,874) or a condensation product of melamine and formaldehyde (US-A-2,796,362, US-A-2,345,543). Preferred are the condensation products of epichlorohydrin and polyamine, polyamide and polyamine polyamide (US-A-2 573 956, US-A-2 926 154, US-30 A-3 378 379). Suitable polyamines for use in the reaction with epichlorohydrin are simple alkylenediamines or polyalkylene polyamines, such as, for example, diethylenetriamine, triethylenetetramine, tetraethylenepentamine and the corresponding polypropylene and polybutyleneamines.

4

Polyamide polyamines are condensation products of a saturated, aliphatic, dibasic acid having from 3 to 8 carbon atoms in the molecule with one of the aforementioned polyamines having at least one secondary and two primary 5 amino groups.

The coating on the outer surface of the hose comprises a total of 40 to 200 mg, preferably 60 to 150 mg of water-insoluble cationic resin per square meter of support surface. These values were determined as follows: 200 mg of surface material is scraped on the outer surface over an area of 10,500 cm2 and the nitrogen content of the scraped material is determined, for example, by combustion analysis. For comparison, the nitrogen content of the outer surface of a hose of the same carrier material without a coating is examined. For this purpose, 200 mg of surface material are scraped in an analogous manner over an area of 500 cm2 in each case and the nitrogen content is determined in the same way. When calculating the difference between the nitrogen values of the coated and uncoated hose surface, the nitrogen value of the outer coating and the concentration of the cationic resin 20 on the outer surface of the hose are obtained from this value.

The outer surface coating - due to the aqueous plastic dispersion used in the manufacturing process - contains the chemical emulsifier in small amounts so that they do not affect the desired properties of the coating or the coated hose 25, respectively.

The main use of the sausage casing is the production of unheated cooked sausages, such as salami or sausages. It then has a typical inner surface coating on these sausages to improve the adhesion between the sausage mass 30 and the cellulosic shell or to improve the peelability of the shell from the sausage mass.

The humidity of the hose shell is conventional, e.g. 5-15% by weight of water, or its water content is very high, 25% by weight or more, so that it does not need to be moistened before filling.

90717 5

The manufacture of cellulose hydrate-based fiber-reinforced hose shells is known and is not the subject of the present invention. They are usually prepared by coagulating a viscous solution applied to the outer surface 5 of a tubular fiber reinforcement with an acidic precipitating liquid and regenerating cellulose, and contain plasticizers such as glycerol.

The surface weight of the fiber reinforcement is usually 17 to 28 g / m 2 and is preferably a paper carrier or a nonwoven fabric made of hemp fibers 10. Preferably, it is impregnated and coated only with a viscous outer surface. If, in addition to the inner surface of the fiber hose, it is coated with viscose, then the proportion of viscose on the inner surface of the total amount of viscose is at most 30% by weight. The regenerated cellulose is distributed in a similar manner, i. the cellulose is 70 to 100% on the outer surface.

Methods for coating the outer surface of cellulose hydrate hoses have also been described previously, for example in EP 0 037 025 and in the literature cited therein, and are not per se an object of the present invention.

The invention is further illustrated by the following examples. The starting material in each case is a fibrous jet hose having a cellulose hydrate-25 gel layer on the outer surface and prepared by coating the outer surface of the fibrous hose with viscose, coagulating and regenerating the viscous layer on the outer surface with an acidic precipitating and regenerating liquid. The resulting fiber-reinforced cellulose hydrate-30 gel tube is coated on the outer surface with a dispersion according to the invention and blown dried in a drying tunnel at 120-150 ° C, whereby the cationic resin hardens and adheres in its water-insoluble form together with the particles to the cellulose surface. The humidity of the hose is then adjusted to the desired value.

6

The manufactured hose is further processed as a hose shell tied at one end. A string or braid and possibly an additional metal connector are used to tie the end of the hose.

5 Example 1

The composition of the aqueous coating dispersion is as follows: 2% by weight of a thermosetting, still water-soluble polymer of ethylenediamine, diethylenetriamine, adipic acid and p10 epichlorohydrin (Resamin HW 601, manufactured by Cassella) as a cationic resin, 6% by weight of 50% by weight corresponds to 3% by weight of a PVC solid with a dispersion particle size of 0.1 to 1.6 μπι (R Hostalit E 1069/072, manufactured by Hoechst), 10% by weight of glycerol.

The outer surface of the finished hose has a layer of 80 mg of cationic resin and 120 mg of PVC particles per square meter of surface.

20 The outer surface of the coated hose (diameter 65 mm) is used to make pieces tied at one end. After wetting, they can be easily pulled over the filling tube of the sausage filling machine; their handling properties have been substantially improved. Despite the surface layer, the ready-made sausage has the desired high surface gloss and good crust transparency.

Example 2

The composition of the aqueous coating dispersion is as follows: 2% by weight of the cationic resin of Example 1 4% by weight of the 50% by weight PVC dispersion of Example 1, 10% by weight of glycerol.

The outer surface of the finished hose (diameter 85 mm) has 35 layers with 65 mg of cationic resin and 65 mg of PVC

B

90717> ----------- 7

At one end, the bound and moistened parts of the broken hose can be easily pulled over the filling tube of the filling machine when making lightning-type sausages.

Due to the increased surface roughness, they have better operating properties than before. The finished sausages have the desired surface gloss and good translucency of the sausage casings made from this material.

Claims (9)

A tubular packaging shell, in particular an artificial sausage casing, formed of a fiber-reinforced cellulose carrier hose, the fiber reinforcement being at least completely coated on its outer surface with a cellulose layer, and the outer surface layer of the outer cellulosic layer of the outer surface resin, characterized in that the outer surface layer further contains particles or fibers which are plastic or cellulose. Shell according to Claim 1, characterized in that the plastic particles consist of vinyl chloride homopolymers or copolymers. Shell according to Claim 1 or 2, characterized in that the particle size of the particles is less than 5 μπι and is in particular in the range from 0.2 to 2 μπι. Shell according to Claim 1, characterized in that the fibers have a length of less than 10 μπι, preferably less than 5 μιη, and have an average of, in particular, 0.1 to 1 μπι. Shell according to one of Claims 1 to 4, characterized in that the cationic resin is a protein, melamine, phenol or urea compound crosslinked with an aldehyde, in particular formaldehyde or glyoxal, preferably with a crosslinked hydrochloride of bifunctional halohydrins or their derivatives, in particular epichlorohydrin. aliphatic polyamine or polyamide resin, especially polyamine polyamide resin. Shell according to one of Claims 1 to 5, characterized in that the weight ratio of cationic resin to particles or fibers is in the range from 1: 5 to 5: 1, in particular from 1: 3 to 2: 1. 90717 Shell according to one of Claims 1 to 6, characterized in that the concentration of cationic resin in the surface layer corresponds to a basis weight of 40 to 200 mg / m 2, in particular 60 to 150 mg / m 2. Composition according to one of Claims 1 to 7, characterized in that when it has a moisture content of 5 to 15% by weight and a glycerol content of 18 to 22% by weight, each based on the total weight of the shell, it has a basis weight of 70 to 130 g / m 2. especially 80 to 120 g / m2. A method of making a packaging shell according to any one of claims 1 to 8, wherein the tubular fibrous material is impregnated and coated with viscose at least on the outer surface and the viscose is precipitated, the and changes to its water-insoluble form, characterized in that the aqueous dispersion contains 0.5 to 20% by weight, preferably 1 to 5% by weight of particles or fiber and, in particular 2 to 4% by weight, of PVC particles, and 1 to 5% by weight. %, preferably 2 to 4% by weight of a crosslinkable cationic resin, in particular a crosslinkable epichlorohydrin-polyamine polyamide resin.