CZ293020B6 - Method of applying print onto a plastic tube, as well as coiled tube printed in such a manner and use thereof - Google Patents

Abstract

The invented method is characterized in that a plastic tube (1) is first printed and is then heat-shrunk into a circular shape and filled. The plastic tube (1) is first provided with flat print (3) symmetrically with the tube (1) centerline (m) before the tube (1) is bent into a ring. The initial printed image (3) applied is distorted in comparison with the unfolded image. The distortion of the printed image (3) is equal to the change in shape of the tube (1) because of subsequent tube-shrink. A pre-print distortion factor is calculated which is related to the ring geometry and the heat-shrink characteristics of the plastics tube. The distortion factor relates to the centerline of the product in the filled ring and is positive, and is added to the longitudinal dimension of the printed image (3). The tube can be used as a means for wrapping foods, in particular as a sausage casing.

Description

Method of applying print on a plastic hose, printed according to the method, coiled hose and using this hose

Technical field

The invention relates to a method of applying a print to a plastic hose which, after shrink-printing, is folded into a collar, further into a collar of a coiled hose printed according to the method and use of such a hose.

BACKGROUND OF THE INVENTION

Almost all conventional printing methods are themselves suitable for printing plastic hoses used as sausage wrappers. In practice, two methods have prevailed, namely flexographic printing and gravure printing, the latter being used primarily for large printing. Plastic hoses are generally imprinted on the outside because hygiene regulations do not allow direct contact between the ink and the sausage surface. In the case of sausage packages made of multilayer plastic strips with a seam, it is possible to apply printing between two layers. The printing of the plastic hoses must be carried out in such a way that the print image changes either during the storage and processing of the plastic hoses or the distribution of the sausages wrapped with such plastic hoses or in the distribution of sausages. sausages.

In the state of the art, as described, for example, in Fleischforschung und Praxis, 2nd edition 1991, Hans Holzmann Verlag GmbH & KG, Bad Worishofen, pp. 41 - 48, the following requirements must be met:

neutral behavior against sausage wrapping itself and against sausage, stability to fat, water, salt, brine, spices and flavorings, heat resistance, inert to flue gases, resistance to aging and light fastness, abrasion resistance, dimensional change strength, ie. movement of print image during drawing and shrinking processes along with sausage wrap.

At the same time, the last requirement means that the print image changes during the drawing and shrinking processes; it has different dimensions from the print image prior to such drawing and shrinking processes and is thereby deformed.

The flexographic printing process is predominantly worked from roller to roller, whereby the plastic hose passed from the roller is guided above the roller on which the rubber printing plate is placed. The raised portions of the block are wetted with ink that is transferred to the surface of the plastic hose. In addition to normal flexographic inks, the so-called reaction inks, which consist of two components, namely paint and hardener, are used as printing inks. Both components are mixed in a certain ratio just before printing begins and must be printed at a predetermined time to allow the crosslinking reaction to occur on the surface of the packaging hose.

Flexographic inks are solvent-based inks (and also water-soluble inks) with relatively low solids content, which can be adjusted the lower the higher the printing speed. For multicolour printing, the printed plastic hose must pass through as many coloring stations as the number of colors to be applied. The printed plastic hose is reeled and ready-made.

-1 CZ 293020 B6

Printed sausage packages or. plastic hoses contribute as a promotional packaging to the creation of branded goods, but they can also only describe and classify the product as such. In addition, food-relevant declarations can be printed.

Nowadays, printed plastic hoses are increasingly being used as sausage casings. This makes it possible to include all the information of interest to the consumer in the print image, such as details of the type of sausage and its quality level, references to decorations, trade marks and other signs, as well as the name and address of the sausage manufacturer. In addition, special instructions for storage, preparation and consumption may be placed.

I 10

In the production of a curl of coiled plastic hoses used for sausages, there is a problem that the printing applied to the first flat straight plastic hose shrinks during curling into the ring, and therefore there may be difficulties reading, for example, barcodes, texts, logo or other markings.

SUMMARY OF THE INVENTION

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for applying a print to a plastic hose which is folded into a shrink after printing 20 and a hose twisted into a shroud and printed according to a method filled with food.

This object is achieved according to the invention by a method of applying a print to a plastic hose, which after shrink printing is curled into a collar, in accordance with the invention the printing is printed symmetrically 25 to the hose axis before curling into the collar. and the deformation of the printing is chosen to be as great as the deformation of the hose resulting from the shrinking of the hose into the ring.

An advantageous embodiment of the method according to the invention is characterized in that a deformation factor of the printing is selected along the hose axis, depending on the dimensions of the rim and the shrinkage behavior of the hose, for deforming the surface print.

In such a case, it is further proposed according to the invention that the deformation factor of the printing decreases with increasing inner diameter of the rim and with a constant rim of the curved hose. In such a case, it is preferably provided according to the invention that the print deformation factor for the inner diameter of the rim 4 to 24 cm is 5 to 30 percent of the length of the print axis after shrinking the hose, and / or

caliber wreaths

-----------------------------------------------. 100% inner ring diameter + 2x ring caliber

According to the invention, it is advantageously provided that the deformation factor of the printing along the hose axis is positive.

In other words, in the modification of the printing deformation method, a deformation factor along the axis of the hose is selected depending on the geometry of the rim and the shrinkage behavior of the hose. At the same time, the deformation factor decreases with an increasing inner diameter of the shroud with a constant caliber of the shroud of the curved hose. In an embodiment, the deformation factor of the printing along the hose axis causes a positive.

In the hose formed by the method described above, according to the invention, the printing is applied to the food-filled hose along the axis of the hose compared to the predetermined size of the printing without deformation.

-2GB 293020 B6

Preferably, according to the invention, the ring caliber is in the range of 24 to 64 mm.

A variant advantageous embodiment of the hose consists in that the inner diameter of the rim is 4 to 24 cm.

Another advantageous variant of the hose is that the hose material is a heat-shrinkable monolayer or multilayer hose package, in particular based on cellulose hydrate, regenerated cellulose, non-derivatized cellulose, polyamide, polyester and / or polyolefins.

A last variant advantageous embodiment of the hose is that the printing is a combination of words and images, text, barcode, logo, trademark, image, word, label or other marking.

According to the invention, such a hose can be used as a food wrapping means, in particular as a sausage wrap.

BRIEF DESCRIPTION OF THE DRAWINGS

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a top view of a schematically indicated rectangular printing on a flat laid plastic hose not twisted into a ring; FIG. 2 is a top view of the plastic hose of FIG. 1 with distorted printing; Fig. 3 is a top plan view of a schematically depicted trapezoidal print on a flat laid plastic hose not twisted into the shroud; and Fig. 4 is a plan view of the plastic hose of Fig. 3 with undeformed printing in the longitudinal direction of the hose. curl up and fill with food.

DETAILED DESCRIPTION OF THE INVENTION

In the manufacture of plastic hoses 1 coiled into a ring on which a flat printing 3 is applied prior to the curling into the ring, shrinkage of the flat printing occurs during the shrinking process

1 and 2, the deformation of the printing 3 is explained by way of example. FIG. 1 shows a straight plastic hose 1 having a flat width 2 of, for example, 50 mm. A flat printing 3, which forms, for example, a rectangle or a square, is applied symmetrically to the axis m of the surface of the plastic hose 1 laid. In the present case, the printing is 3 square with a side length a. After printing in a known manner by thermal shrinkage, the plastic hose 1 is folded into a collar and subsequently filled with food or wound onto a roll and stored until further processing.

Giant. 2 shows a top view of a coiled, food, such as sausage, filled plastic hose 1 having a caliper 5 of the ring, for example 32 mm, in a top view. The printing 3, which is a square according to FIG. 1, has been transformed into a deformed flat printing 3, which is similar to a trapezoid, due to the curvature of the rim of the filled plastic hose L

The upper side b and the lower side c are curved, while the side edges d, d extend straight but are inclined towards each other. Printing 3 is also arranged symmetrically to the curved axis m of the hose. The inner radius of the collar is, for example, 4 cm. It can be seen that the print 3 conditioned by the curvature of the rim is distorted compared to the original print 3. Obviously, when printing 3, which consists, for example, of a bar code, deformation can cause problems when reading the bar code. In this case, the trapezoidal deformation due to the shrinkage of the ring geometry from the inside is caused in the longitudinal direction.

-3 CZ 293020 B6

Referring to Figures 3 and 4, a method according to the invention for preventing such deformation of the printing 3 is described.

Here, it is assumed that in the case of a predetermined rim geometry, i. With the inner diameter d of the rim and the caliber 5 of the rim, as well as the known plastic hose material 1, the deformation of the print 3 is determined earlier than the size of the so-called deformation factor. This deformation factor in percent of the initial length will be explained in more detail below. It relates to the m-axis of the unformed straight plastic hose 1 as shown in FIG. it is added to the predetermined final dimension of one section after twisting into the collar, so that the preformed section AA on the m-axis of the plastic hose 1 is obtained. The deformed section AA is also the middle printing section 11o 3 in Fig. 3. 2, for example, 50 mm, and after twisting into the collar, the caliber 5 of the collar, for example 32 mm, as shown in FIG. 4. The flat pre-deformed printing 3 has a trapezoid shape with a base side e, cover side f and inclined sides g, g. converge upwards. By axis m is meant the axis of the surface of the laid plastic hose 1 in the longitudinal direction, which forms an elongated rectangular strip. If the plastic hose 7 is filled with food, the axis m can lie in the central plane, but also above or below the central plane in the ring of the twisted, filled plastic hose L

In Fig. 4, a curled, filled plastic hose 1 is shown which has a flat printing 3 in the longitudinal direction without deformation. The printing 3 has two parallel straight sides 1, 1, whose 20 shortest distance BB from one another coincides with the desired final dimension of the printing 3 after being curled into the rim in the longitudinal direction. The two remaining sides h, h are curved according to the curvature of the rim, parallel to each other and of equal length. By specifying the deformation factor, the deformation of the printing 3 is chosen as great as the deformation of the hose 1 resulting from the curl of the plastic hose 1, so that the deformation of the printing 3 with the deformation of the hose 1 is compensated. 1 without deformation.

The deformation factor is calculated as follows:

diameter of the m axis of the rim deformation factor = (1 ----------------------------------------) . 100% outer ring diameter 5 ring = =--------------------------------------- -------------------. 100% internal diameter d _K i wreaths + 2x caliber 5 wreaths

If, under certain conditions, the coiling process is performed with a hose material having undergone a pre-stretching, this pre-stretching value shall be subtracted in the aforementioned deformation factor formula.

If the material for the plastic hose 1 is a single-layer or multilayer polymer hose 1 capable of shrinking, its shrinkage capability in 80 ° C hot water for about 5 minutes is generally about 8%. However, this value may vary widely in special applications.

Possible hose materials are any heat-shrinkable tubing, in particular based on cellulose hydrate, regenerated cellulose, non-derivatized cellulose, polyamide, polyester and / or polyolefins.

When printing, it can be a combination of words and images, text, bar code, logo, brand of goods, the image itself, the word itself, a label or other marking.

The following table shows the deformation factors in percent, which were calculated according to the preceding formula, for the common 5-gauge ring diameters from 24 to 64 mm and the respective inner diameters d κι of the ring from 4 to 24 cm. The deformation factor is that with increasing inner diameter dsi

The crown at a constant caliber 5 of the crown of the curved hose 1 decreases the deformation factor. If, on the other hand, the inner diameter dj of the rim is kept constant, the deformation factor becomes larger with the increasing caliber of the rim.

Table

BI ΒΠ ΒΙΠ B IV BV BVI Caliber 5 wreaths (mm) 30 24 40 45 51 64 Inner diameter dm of rim (cm) 4 5 10 15 Dec 20 May 24 Deformation factor (%) 30 24.5 22.2 18.8 16.9 17.4

Based on the aforementioned ring geometries and known hose material, deformation factors can be determined according to the preceding formula. Their purpose is to position the print 3 on the m-axis of the product curled into a ring. The deformation factor for the m-axis of the product twisted into the rim is thus considered to be characteristic of the entire print 3. As shown in the above table, for example, when printing B Π on the packaging hose axis, the deformation factor of 24.5% must be taken into account. for BV printing, a deformation factor of 16.9% to obtain undeformed printing 3, i. zero deformation of the print 3 on the product twisted into the ring. In printing VI, the deformation factor is 17.4% and can be reduced to 5%, for example, if printing 3 is not symmetrically aligned with the product curled in the rim, but protrudes with its outer edge against the outer edge of the rim.

Claims (5)

PATENT CLAIMS A method of applying a print to a plastic hose (1) which, after shrink printing, is twisted into a collar, characterized in that the printing (3) is printed symmetrically to the axis (m) of the hose (1) before being folded into the collar, the print (3) is distorted from the shape after the hose (1) is twisted into the shroud and the deformation of the print (3) is as great as the deformation of the hose (1) caused by the shrinking of the hose (1). Method according to claim 1, characterized in that a deformation factor is selected for the deformation of the printing (3) along the axis (m) of the hose (1), depending on the dimensions of the rim and the shrinkage behavior of the hose (1). Method according to claim 2, characterized in that the deformation factor decreases with increasing rim inside diameter (dxi) at a constant rim (5) of the curved hose (1). Method according to claim 2, characterized in that the deformation factor along the axis (m) of the hose (1) is positive. Method according to claim 3, characterized in that the deformation factor of the printing (3) for the inner diameter (dui) of the rim in the range of 4 to 24 cm is 5 to 30 percent of the length of the printing axis (m). ).