MXPA99001822A - Method to slowly regenerate cellulosic sausage casing - Google Patents

Abstract

The present invention relates to an improved method for regenerating cellulosic sausage casings which includes the steps of extruding viscose through an annular extrusion die (44) submerged in an aquarium (46) to form a tubular product (64) and partially gelling and coagulating the gel tubing (64) in the aquarium (46), supporting the partially gelled and coagulated tubing (64) on at least two upwardly moving inclined belts (52) such that different sides of the casing are disposed in an upward facing orientation on the different belts (52) and applying an intermediate regenerating solution to the tubing (64) supported by the belts (52) until it is partially cured, and conveying the partially cured tubing (64) into at least one coagulation/regeneration bath (80) which completes regeneration of the tubing (64).

Description

METHOD TO REGENERATE SLOWLY CELLULOSIC TRIPLE FOR SAUSAGES FIELD OF THE INVENTION This invention relates to the provision of a new and unique regeneration method for the precise extrusion, at high speeds, of regenerated, tubular, non-fibrous, unreinforced cellulose casing, commonly known as skinless sausage casings. STATE OF THE ART Tubular cellulose casing is well known, and has been widely used for many years by numerous manufacturers. The basic process for manufacturing regenerated cellulose casings is carried out by means of the well-known viscous process that creates a liquefied colloidal dispersion of cellulose fibers in an alkaline liquid vehicle. Viscose is described in British Patent No. 8700, Cross, Bevan and Beadle. Patents such as the U.S. no. 1,036,282 Lilienfield, redefine the compositions. The U.S. Patent no. No. 1,070,776, U.S. Pat. no. 1,158,400, and the U.S. Patent no. 1,163,740, by Cohoe and Fox, describe the use of viscose to make a tubular cellulose casing. Henderson provides basic technology for manufacturing viscose tubular casings with regeneration baths that come in contact with the internal and external surfaces of the tub: U.S. no. 1,601,686; U.S. Patent no. 1,612,508; U.S. Patent no. 1,645,050; U.S. Patent no. 1,654,253. Specific details for the manufacture of casings updated from viscose to regenerated cellulose are well known in the art and have been described in references such as U.S. Pat. num. 2,999,756 and 2,999,757 to Shiner; U.S. Pat. no. 3,835,113 to Burke; U.S. Pat. no. 4,590,107 of Bridgeford; U.S. Pat. no. 4,778,639 to Jon; and U.S. Pat. no. 5,358,765 Markulin.

These references describe the basic process of viscose extrusion (sodium cellulose xanthate, sodium hydroxide, water), by means of an annular die, to a coagulation and regeneration bath that regenerates the extruded viscose to produce a tubular cellulose casing. A critical aspect in the manufacture of cellulose casing is the speed of conversion of the liquefied viscose back into regenerated cellulose, using such coagulation and regeneration baths. A very detailed chemical discussion of viscose regeneration is included in the document Physics and Chemistry of Cellulose Fibers, by Hendrik Petrus Hermans, Elsevier Publishing Company, 1949. Hermans describes the use of a regeneration bath of 9% H2SO4 (sulfuric acid ), 22% Na 2 SO 4 (sodium sulfate salt), in which the viscose is melted to regenerate it back to cellulose. The need for a correct salt concentration is critical, since the salt allows the viscose to first gelatinize before the NaOH (sodium hydroxide) in the viscose can react with the sulfuric acid to break down the xanthan molecule again in cellulose and water. Sodium sulphate delays the penetration of the H ion of sulfuric acid into the viscose, delaying the acid reaction. The degree of regeneration of viscose back to cellulose, can be visually determined through the regeneration process according to the following: (1) inside the aquarium, the viscose / gut is brown and is still a weak, fresh gel, and it is characterized by a pH above 7; (2) at the exit of the aquarium, the viscose / gut becomes yellow and is characterized by an increased resistance and a pH below 7; (3) with the subsequent regeneration, after the exit of the acid wash tanks, the casing turns white, indicating a pH comprised between 2 and 4, and that all the NaOH of the viscose has been extracted, being now in the gut the CS2 and sodium; (4) After the exit of the washing tanks but prior to the glycerination, the casing becomes transparent, which indicates that all the CS2 has been extracted by washing the casing, and the pH returns to the range of 6.5 at 7.0. Hermans also provides a detailed description of the means to raise the resistance of the regenerated cellulose product, including the elevation of the final degree of polymerization of the product, and the elevation of the cellulose composition of the viscose. Both options, however, will increase the viscosity of the viscose, making it more difficult to extrude and manipulate. Patents such as Henderson no. 1,601,686, clearly describe a viscose of higher viscosity (i.e., a higher degree of polymerization of the viscose), as critical to the increase in the strength of the casing. The related Patent of Tachikawa no. 2,592,355 and Dyer no. No. 3,758,458, describe methods for making viscose with a high degree of polymerization (DP) increase resistance. Patents such as Hewitt's no. 1,937,225, describe the evolution of the gas during the conversion of the viscose into cellulose, in which the gas emitted is trapped inside the tubular casing and must be extracted by puncturing the casing for the release of the gas. Hewitt teaches the fact of increasing the height of the booths to distribute the gas for the puncture. Hewitt also teaches slow regeneration, in order to distribute the gas through the process, allowing a greater volume for a fixed amount of gas, and therefore longer times between the punctures of the gut. Hewitt suggests the use of lower concentrations of H2SO4 in the regeneration bath, to slow down the regeneration process. On the contrary, Freund in Patent no. 2.013.491, teaches that regeneration is accelerated, and that regeneration takes place in a long vertical tank. Such a tank allows easy escape of the internal gas through the drain of the extrusion nozzle attached to the vertical aquarium tank. Atkinson, in Patent no. 2.271.932, shows a longer residence time from the exit of the aquarium to the first tank after the aquarium. The residence time allows more gas and more liquid to return through the nozzle attached to the aquarium. In addition, this method allows the casing to cool. Atkinson indicates the convenience of imparting some stretching in machine direction after full regeneration, to strengthen the gut. Specifically, Atkinson teaches the fact of imparting a longitudinal stretch from 5% to 70%. Shiner in Patents nos. No. 2,999,756 and 2,999,757, describes the fact of imparting a transverse orientation after complete regeneration, to reinforce and guide the gut, with less orientation in the machine direction. Burke, in Patent no. 3,835,113, shows that the resistance of the tubular casing will be 20,000 to 25,000 psi dry, from 3,000 to 4,000 psi when it is completely wet. Bridgeford, in Patent no. 4,590,107, describes the use of slow regeneration. Typical methods of the prior art using "normal" regeneration rates, used regeneration bath temperatures (Muller's bath) from 40 ° C to 46 ° C, and sodium sulfate concentrations from 150 to 250 g / liter of water. sodium sulfate, and sulfuric acid concentrations from 50 g / liter to 135 g / liter. Such methods result in casings having a degree of polymerization (DP) of about 450 to 750.

In contrast, Bridgeford teaches "slow" regeneration using a regeneration bath temperature of 28 ° C 34 ° C, with a sulfuric acid concentration of 100 to 120 g / liter and an increased concentration of sodium sulfate of 250 g / liter at 280 g / liter. Each of these three changes made by Bridgeford dramatically reduces the rate of regeneration, which Bridgeford found to make a stronger gut. Resistance was achieved by increasing the density of the casing in the range of 1.46 to 1.53 grams per cubic centimeter (g / cc), compared to the prior art range of 1.37 g / cc to 1.40 g. /DC. Extrusion rates were described as between 34 and 46 meters per second (110 to 150 feet per minute). Casings produced by the Bridgeford method were presented as having equivalent or superior physical properties and tensile strength compared to those regenerated in the prior art at a regeneration rate "conventional". Similar alternatives were used in production of rayon viscose, as described in U.S. no. 3,139,467. However, the method described in U.S. Pat. no. 4,590,107 of Bridgeford, for the production of an increased resistance casing, was never marketed successfully. This is because conventional extrusion systems subject the partially regenerated casing, which has just exited the aquarium, to a long vertical travel trajectory (see Figure 1). The casing typically has a residence time of 20 to 30 seconds from the time it leaves the aquarium until it reaches the first tub in the final sequence of regeneration and washing. Bridgeford describes this first tank as a wash water tank, at 25 ° C, followed by regeneration bath tanks, and then, finally, a system of hot water tanks, countercurrent, from 35 ° C to 60 ° C. ° C. During the period between the time the gut leaves the aquarium outlet and enters the first tank, which is a wash tank with water, various stages can take place. The casing can be cooled and the internal liquids can be drained back to the aquarium, up to the top where the displacement path turns. After the upper position of change of direction, the liquid and gas can be collected in the downward displacement path, in order to extend the time between punctures. In this zone, acid sprays can be applied, to increase the regeneration of the casings as shown in U.K. Pat. no. 408,774 and U.S. Pat. num. 2,043,455, 2,070,247, 2,176,925 and 2,275,348. Figure 1 shows the predominant technology used in different embodiments by most producers of skinless cellulose casings. The gut must be sufficiently regenerated when leaving the aquarium as to be strong enough to withstand the stresses applied to it during its upward movement through the tower. The first roller found on leaving the aquarium is commonly known as the main roller (18), which is typically 1 to 3 meters above the aquarium, to allow a sufficient residence time for the solidification of the gut beforehand. its entrance in contact with the roller. However, if the viscose / casing leaving the aquarium has not been sufficiently regenerated, the casing is too weak and fragile, and the casing can not adequately overcome the vertical displacement in the tower. Also, it is desirable that the gases that are emitted from the casing during regeneration, especially CS2 and H2S, are readily released in the regeneration step, so that they can be extracted again through the nozzle and the drain, thus lengthening the puncture interval. Slow regeneration converts much of the viscose into CS later in the displacement path, and if the conversion is carried out past the upper point (22) of Figure 1, these gases will be trapped by the gut, causing the need to puncture more frequently, to promote the extraction of the gases. Bridgeford forces these gases to be subsequently regenerated in the process, thereby reducing the time between punctures. For these reasons, the slow regeneration method described by Bridgeford has limited commercial utility. The use of tapes to support the viscose during its regeneration is well known in the art, especially in the manufacture of cellophane. H. by Leewin W. Sois Artificielles, Librairie Polytechnique Ch. Beranget, Paris, 1932, and French Patent no. 463.402 describe the regeneration of viscose on ribbons that pass through one or more regeneration baths. The U.K Patent No. 408,774, describes a method for regenerating cellulose tubes, using a belt initially driven to contact the tubing as it leaves the regeneration bath, and then applying gentle sprays of regeneration fluid thereto, to regenerate it, moving through a first duct which is a trajectory slightly inclined upwards, towards a second duct slightly inclined upwards in which the casing is sprayed with water, washing also the casing. The patent teaches that the casing moves in a straight line, without curves, through both regeneration and washing lines. Similar methods have been practiced in the art, such as those in which the casing left the aquarium with a pH between 8 and 9, and was deposited on a belt in which it was subjected to treatment by spraying (or dripping). , first with regeneration fluid, and then, with hot water to regenerate the viscose to a pH of around 5. Such methods did not have curves in the path of displacement of the casing and applied regeneration fluid only to one side of the gut. SUMMARY OF THE INVENTION The present invention provides an improved method for the slow regeneration of viscose casings for sausages from a pH higher than 7, in which the viscose is liquefied, and its formation is reversible to a pH below 7. , where the viscose coagulates irreversibly. While conventional methods rapidly regenerate viscose casings such that viscose extruded in aquariums at pHs greater than 7 is cured at pHs below 7 in about thirty seconds or less, the methods of the invention are capable of delaying regeneration. of the viscose extruded from a pH of more than 7 to a pH of less than 7 in more than one minute, and for as long as two or three minutes. Slow regeneration of the viscose according to the methods of the invention provides casings which are characterized by increased strength and density. Specifically, the present invention provides an improvement in the methods for the production of tubular casings for sausages, of regenerated cellulose, in which the viscose is extruded through an annular extrusion nozzle immersed in an aquarium to form a tubular product, and the coagulation and regeneration of the tubular product starts in said aquarium and is completed in one or more coagulation / regeneration baths, the refinement comprising gelifying and partially coagulating the tubing of gel extracted in the aquarium up to an initial level of regeneration characterized by a pH greater than 7, and preferably a pH of 8.0 at a pH of 9.5, with a pH of about 9.0 being most preferred.; supporting the partially gelled and coagulated tubing on at least two ascendingly inclined ribbons, in such a way that the different sides of the casing are arranged with an upward orientation on the different tapes mentioned, and applying an intermediate regeneration solution to said tubing while it is supported by said ribbons, until it is cured at an intermediate level of regeneration characterized by a pH higher than 7, and preferably from a pH of 7.0 to a pH of 8.5, being most preferred is a pH of about 7.5, prior to completion of regeneration in said coagulation / regeneration bath in which the viscose is cured to a regeneration level characterized by a pH of less than 7. The bath final that completes the tubing regeneration, according to this method, is typically maintained at 35 ° C, and has a sulfuric acid concentration of around 3 gm / 100 m i, although you can also use multiple baths with different concentrations of sulfuric acid. The method of the invention provides a denser, stronger casing characterized by a higher degree of cellulose polymerization of the casing, and a higher viscose concentration in the extruded viscose. The method provides a slower regeneration of the viscose, in which the initial regeneration bath in the aquarium is characterized by a lower concentration of sulfuric acid than typical of prior art methods. The initial regeneration bath is also characterized by a lower temperature and a higher regeneration salt concentration than that used in the conventional regeneration baths of the prior art. According to the invention, the extruded viscose is characterized by the ability to accommodate increases in NaOH concentration, if desired. While the viscose produced by means of conventional systems is generally characterized by a NaOH concentration of 6.0 to 6.3%, the method of the invention provides a viscose having an NaOH concentration of 6.3 to 6, 7% Thus, the higher NaOH content of the viscose used according to the methods of the invention, acts to retard the regeneration reaction by consuming more H2SO4 from the regeneration bath prior to allowing the xanthan molecule to decompose. The method of the invention also provides an increase in the in-line viscose index (a higher Hottemoth index, which means a higher gamma number, in which the gamma number is the industry standard for the degree of CS emission). The Hottemoth Test is an industry-recognized standard that uses NHC1 titration of viscose to determine its reactivity, thereby predicting ease of regeneration. While conventional methods produce viscose characterized by Hottenroth in-line numbers of 7 to 9, the methods of the present invention provide viscose characterized by hottemoth index numbers of on-line index of 11 or 12. The method of the invention further provides the reduced use of CS2, which also results in a reduction in the total sulfur content of the viscose. In addition, the method provides casings having a tensile strength in the transverse direction exceeding 25,000 psi as measured by a voltage resistance tester such as that manufactured by Instron. In addition, the slow regeneration method allows higher line and extrusion speeds, which exceed 55 and even 60 meters per minute. According to the preferred methods of implementation of the invention, the aquarium contains regeneration fluid characterized by a sulfuric acid concentration of 50 to 100 grams per liter, with 80 grams per liter being the most preferred, and a concentration of Sodium sulfate of approximately 200 to 300 grams per liter, a value of 250 grams per liter being most preferred. Furthermore, according to the preferred methods, the intermediate regeneration solution is characterized by a sulfuric acid concentration of about 35 to 70 grams per liter, with 50 grams per liter being the most preferred, and a sodium sulfate concentration of 50 grams per liter. about 150 to 250 grams per liter, with 200 grams per liter being the most preferred. The invention provides support for the weakly regenerated tubing, on two or more inclined strips that move upward, which are arranged in such a way that the different sides of the casing are arranged with an orientation directed upwards on the different ribbons. In this way, the regeneration tubing can be even better placed in contact with the intermediate regeneration spraying. According to a preferred embodiment of the invention, three belts are used to support the regeneration tubing in a manner such that the exposure time upward of the two opposite sides of the flattened casing is the same. However, it is understood that those skilled in the art provided by the present disclosure are qualified to use a different number of tapes. According to a preferred aspect of the invention, the orientation in the machine direction can be imparted to the casing by stretching in the machine direction before the casing reaches the cold water tank. A particularly preferred means of doing this consists of a double-S wrapping trawl roller system, such as that described in U.S. Pat. no. 2,291,932 to Atkinson, the disclosure of which is incorporated herein by reference. The casing in double S that is given to the casing a final tension in machine direction (MD) to counteract the high contraction that occurs with the slow regeneration on the tapes, which results in a resistance to the tension in machine direction that exceeds of 35,000 psi.

According to a preferred method, the double-S casing system helps ensure that the casing is characterized by a machine-direction stretching of about 7% between the aquarium and the first regeneration tub, in order to provide the properties Convenient mechanics for meat filling, and avoid undesirable characteristics such as the production of Vienna sausage in the form of a bullet. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 represents a generalized casing regeneration apparatus, according to the prior art; Figure 2 represents in general a side view of an apparatus according to the invention, for the regeneration of cellulose casing; Figure 3 represents a detailed side view of an inclined belt according to the invention, and Figure 4 shows a front view of a battery of aquariums and inclined belts, according to the invention. DETAILED DESCRIPTION Preferred viscose solutions for use according to the invention, are characterized by a cellulose concentration from about 7.3% to about 8.0%, and by a concentration of NaOH from about 6.3 % up to about 6.7%, and preferably, have a total sulfur content of about 2%. The viscose is extruded through an annular nozzle according to conventional methods, but is extruded in an aquarium containing a coagulation / regeneration fluid at 36 ° C, characterized by a concentration of sulfuric acid of 50 to 100 grams per liter, the most preferred being 80 grams per liter, and a sodium sulfate concentration of about 200 to 300 grams per liter, with 250 grams per liter being most preferred. The aquarium bath is capable of inducing an initial level of regeneration in the viscose which is characterized by a pH greater than 7, with a pH of 8.0 to 9.5 being preferred, and a pH of 9.0 being particularly preferred. favorite. This level of regeneration is lower than conventional methods of the prior art, which typically regenerate the bright product to a lower pH, close to a pH of 7, and result in a partially curdled and regenerated casing, characterized by a lower tensile strength and diminished physical properties compared to the casings that come out of the aquarium according to other conventional methods. This level of regeneration is critical to the provision of the improved properties of the present invention, since it has been found that conventional, faster viscose regeneration produces larger gas bubbles CS2 and? ^. Such large bubbles that leave the gut while the viscose is coagulating in gel, result in permanent voids and interstitial openings. This hinders the future cross-linking of the cellulose hydrogen bond, thereby permanently reducing the density and strength of the casing. Previously, when concentrations or lower temperatures of the aquarium bath have been proven, the resistance and density of the viscose have increased, due to the reduced gas emission. However, in the cases of the prior art, when gas is subsequently emitted in the process, the time between the puncture of the gut is greatly reduced, thus limiting the practical utility of these methods. The slow regeneration method of the invention provides additional advantages since it allows a viscose of high viscosity to be used. While the normal viscose have a viscosity of about 200 seconds of downward ball measured with a ball of a diameter of 3.2 mm (1/8 inch) at 20 ° C, with a distance of 20 cm between measuring lines (around 20,000 to 25,000 centipoise) in extrusion, you can use a viscose of 300 seconds of downward ball (about 30,000 centipoises). Accordingly, a casing can be made in a manner consistent with a degree of polymerization comprised between 700 and 750. Alternatively, a higher cellulose content in the viscose can be used to obtain also higher strengths. According to the methods of the prior art, cellulose contents for skinless gut viscose above the normal range of 7.3% to 7.7% cellulose content tended to be characterized by properties of casing . Surprisingly, the invention provides for the use of cellulose contents of 8% and greater, with increases in both viscosity and strength, without imparting the undesired characteristics typically produced by the high cellulose compositions of the prior art. The method of the present invention allows the casing to be weakly regenerated upon leaving the aquarium, such that it is characterized by a dark brown color and a pH greater than 7, and preferably a pH of around 9.0, and gradual It turns yellow in a path of approximately 36 meters, or twice the normal trajectory of conventional systems. As a result, speeds above 55 and even 60 meters per minute can be obtained, while casings with physical properties comparable to those produced in conventional casings produced at lower linear speeds are produced. According to the implementation of the methods of the invention, the casing does not acquire a "permanent" crystalline form in the aquarium, with emission of gases, leaving large gaps and a lower density. Specifically, the casing leaves the aquarium as an amorphous brown semi-solid gel, and in this fragile state, it is conducted smoothly through the tower section on conveyors, these carriers remaining until the regeneration is slowly completed. While the gut is then regenerated slowly on the conveyors, the gases are emitted very slowly, as small microbubbles. The interstices of the casing are opened for the bubbles to pass, but can then shrink and close again since sufficient crystallinity was imparted in the aquarium to allow the cellulose to have a strong crosslinking. The casing is therefore not subjected to a violent emission of gas, and the density is considerably higher than with previous technology, above 1.6 g / cc. The gut is extremely strong and thin. It is much cheaper to manufacture and allows the use of lower thicknesses. The casing is more tolerant of subsequent mechanical damage during cooking and stuffing with meat paste.

When the prior art practiced spraying the regeneration tubing, it was done to increase the regeneration that had already occurred substantially in the aquarium, as evidenced by the pH of the outgoing tripe, and that regeneration was completed as quickly as possible. . The technique taught rapid regeneration in order to quickly provide a strong casing that could withstand the efforts of displacement on the trajectory of the casing. Contrary to such methods of the prior art, the method of the invention implements to equally pulverize the upper and lower part, but causes complete regeneration not to occur until the casing enters a series of regeneration tanks in which the viscose is cured to a pH of less than 7. After the exit from the aquarium, the partially regenerated casing is transported vertically to a main roller, and then to a three-level tape system, which completes the casing transfer conveyor. Specifically, the casing is placed on a first upwardly moving tape, which supports the fragile, partially regenerated casing as it transports it upward in a manner that allows internal gases and fluids to drain down into the aquarium. At the same time, an intermediate regenerative solution is applied to the casing supported by the belt by means of sprays arranged above the inclined belt, so that the regeneration process continues slowly and the casing is cooled. The intermediate regeneration fluid is generally characterized by concentrations of H2SO4 and Na2SO4 that are lower than those of the aquarium regeneration bath. Specifically, as it travels on the belt, it is sprayed with a cold regenerator bath, approximately 50 g / liter of H2SO4 and 200 g / liter of Na2S? 4- The casing completes the regeneration with a yellow color, requiring a total of 30 seconds to generate a yellow color (low pH) in the invention, compared to the prior art in which the gut had a yellow color at the exit of the aquarium, which required 4 seconds to develop. The intermediate regenerating solution is preferably applied at a temperature between 30 ° C and 50 ° C, a temperature of about 40 ° C being most preferred. The intermediate regenerating solution is preferably applied according to a volume of around 100 cubic centimeters per gut (ie about 8 linear meters). According to a preferred aspect of the invention, the conveyors are completely enclosed in separable fiberglass panels. Inside the conveyors, batteries of spray nozzles are found to spray regenerative acid on the casing. Additionally, automatically every few hours, the rooms are watered with hot water to detach the salt crystals that have been collected on the tapes. The intermediate regenerating solution is preferably directed to the aquarium bath after it has been applied to the casings on the inclined ribbons. Specifically, it is collected, preferably, in recovery containers as it drains from the tapes, and is combined with the regeneration bath in the aquarium. According to an embodiment of the invention, the aquarium regeneration bath can be diluted with water to produce the spray of intermediate regeneration solution. According to the preferred methods of implementation of the invention, each portion of the gut surface receives equal contact by spraying intermediate regeneration solution by alternating the sides of the gut exposed to the spray on two or more inclined belts. Specifically, the casing that extends flat on a first tape inclined, turns on its opposite side when it is transferred to the second tape. This alternative process can continue along successive tapes to ensure that the surface is treated uniformly with the intermediate regeneration solution. For example, when an odd number of tape is used, the length of tape (s) that holds the casings in one direction can be designed to be equal to the length of the tape (s). ) disposing (n) the casings in the opposite direction to provide the same exposure of all sides of the casings to the intermediate regeneration solution.

After the exit of the most superior regeneration tape, the casing is transported downwards along a long vertical trajectory, towards one or more coagulation / regeneration baths, which act to complete the regeneration.

During this downward movement, gases and liquids that have been emitted during regeneration can be collected in a large volume. Also, optionally during the downward trajectory, the casing can have a machine direction orientation imparted prior to the final regeneration baths, by means of a double-S wrap-up roller system, such as that described in U.S. Pat. of Atkinson no. No. 2,271,931, which stretches the viscose of the casing to cause excess shrinkage to occur on the tape portion of the regeneration apparatus. According to the invention, the complete regeneration of the casing does not occur until its entry into a cold water tank, in a series of additional tanks containing regenerating fluid. The initial cold water tank contains, preferably, about 0.5% of H2SO4 derived from the transient discharge of the regeneration fluids. According to one embodiment, six consecutive regeneration tanks contain, preferably, regeneration fluid having sulfuric acid concentrations as follows: Cuba 1, 1-3 g / 100 ml; Cuba 2, 5-7 g / 100 ml; Cuba 3, 8-11 g / 100 ml; Cuba 4, 5-7 g / 100 ml; Cuba 5, 1-3 g / 100 ml; and Cuba 6, 0.5-1 g / 100 ml. Figure 1 represents a general view of a casing regeneration apparatus according to the methods of the prior art. The prior art section, like that of the invention, is generally arranged as batteries of identical equipment arranged in multiple rows and even in two or more columns, in order to efficiently use resources and personnel , and to optimize the output. In general, therefore, the description that follows will be directed to a single line of viscose casing production, even though the figures represent multiple groups of production equipment, as used commercially. Figure 1 depicts a generalized viscous gut regeneration apparatus (10), according to the prior art, comprising a viscous pump (12) for extruding viscous solution through an annular mold (14) in the lower part of an aquarium (16), to form a cylindrical gut. The viscose is regenerated inside the aquarium (16), and is guided vertically to a main roller (18), which is typically one to three meters above the aquarium, to allow a sufficient residence time for solidification of the casing before it comes into contact with the roller. The casing is then guided to additional rollers (20) prior to reaching the upper roller (22). Optional cooling sprays (24) and / or regeneration can be directed to the casing during its upward movement. During the course of the upward trajectory of the casing and before it reaches the upper roller (22), the liquids are able to flow downwards, towards the aquarium, in the direction of the arrow (A). When it reaches the upper roller (22), the casing is then guided downwards, on one or more optional rollers (26), to the cold water bath (28), and from there to one or more baths (30) of acid regeneration. During the course of the downward movement of the casing, after reaching the upper roller (22), the gases and liquids are able to flow downwards, towards the cold water bath (28), in the direction of the arrow (B) ). In order for these liquids and gases to be released from the interior of the casing, the operators periodically puncture the casing in position (32). Figure 2 presents a general representation of an apparatus useful for the implementation of the methods of the invention. In this system, the gut is regenerated in the aquarium slowly using temperatures and bath compositions similar to those of Bridgeford, according to U.S. Pat. no. 4,590,107. Figure 2 depicts a generalized viscous regeneration apparatus (40) according to the invention, comprising a viscous pump (42) for extruding viscous solution through an annular mold (44) in the lower part of an aquarium (46). ), to form a cylindrical gut. The viscose is regenerated inside the aquarium (46), and vertically guided to a main roller (48) that is spaced a sufficient distance from the aquarium to allow a minimum of regeneration, sufficient for the casing to tolerate contact with the roller principal. The casing is then directed to the casing transfer conveyor (50), which comprises three upwardly moving inclined tapes (52), each supported by drive rollers (54) and by rollers (56) of rotation in empty. The tapes are preferably formed from open-loop plastic, such as polypropylene, which supports the regeneration of the casing but allows the regeneration fluids to pass therethrough. Preferred tapes have screens with openings of about 12.7 mm (one-half inch), such as the 50 Series polypropylene transmission belts manufactured by Falcon Belting Co. (Oklahoma City, Oklahoma). The tapes themselves may be designed to support a simple regenerative casing, but are preferably designed to support a wide plurality of regenerative casings produced from multiple aquariums. For example, as many as 18 or even 36 or more casings can be regenerated simultaneously on the tapes of the invention. The inclined ribbons (52) are preferably arranged with an inclination of between 14 ° and 22 °, and are preferably inclined with the same inclination. The casing transfer conveyor is surrounded by a cover (58), open to an exhaust (60), which protects the casing against contamination and reduces the emissions of the intermediate regenerating solution that is applied to the casing. Figure 3 provides a more detailed representation of an inclined belt of the casing transfer conveyor according to the invention. As shown in this Figure, the inclined belt (52) moving upwardly is supported by a drive roller (54) and by a vacuum roll (56), as well as by rollers (62) of platforms arranged in an intermediate way between the drive and idle rollers. The partially regenerated casing (64) is guided on the lowermost portion of the belt (52) inclined by means of the anterior sloping belt or the main roller (48), and is transported upwardly on the belt while being sprayed with a solution of intermediate regeneration from sprayers (66) arranged in a spray manifold (68), fed via the spray manifold feed conduit (70). While Figure 3 only represents a cross-section of the inclined belt of the casing transfer conveyor, it is typically preferred that numerous casing regeneration lines according to the invention are processed. According to an embodiment of the invention, a production line could comprise as many as 36 lines of casings being extracted and regenerated simultaneously on one or more inclined belts extending in parallel. The casings are extracted from two batteries of 18 aquariums (46) each, in which the aquariums are slightly displaced, so that when transported either to the main roller (48) or has shown in Figure 2, until the first tape (52) inclined, the casings from the two aquarium batteries alternately extend side-by-side on the tape (52), for its treatment through the intermediate regeneration solution. See, for example, Figure 4, which provides a side view of a battery of 18 aquariums (46) that extrude casings (64) that are intermixed in the main roller (48). Alternatively, the casings can be intermixed above the idle roll (56) in the first tape (52) inclined. In this way, while the manifold (68) could have only 6 spray nozzles that apply intermediate regenerative solution to a particular casing, the collector can supply regenerating solution to as many as 36 casings, and therefore to 216 (6 x 36) nozzles sprayers simultaneously. Accordingly, any of a variety of spray configurations may be useful, and may be apparent to those skilled in the art. The intermediate regenerating solution is applied to the casing (64) by means of spray nozzles (66), and after coming into contact with the casing to be regenerated, it is drained through the casing and the tape (52) inclined until it is collected by the recovery container (70). The regenerating solution is then directed to the drainage duct (72), and the solution is recycled either for use in the casing transfer conveyor, either in the aquarium, or in the regeneration baths. . After reaching the uppermost portion of the belt (52) inclined, the casing (64) is removed from the belt, which returns to the bottom of the conveyor, and turns to its opposite side and is deposited on the next inclined belt. higher, above the roller (56) of rotation in vacuum. The casing is thus subjected to regeneration on multiple inclined belts according to the particular methodology desired, but in which the viscose is cured to a level of intermediate regeneration characterized by a pH greater than 7 (preferably between a pH of 7 and a pH of 8.5, and more preferably a pH of about 7.5). After reaching the uppermost regeneration belt, the casing is then transported to an upper roller (74) as shown in Figure 2. The casing then begins a downward trajectory during which it optionally passes through a roller system of double S wrap, such as that described by US Pat. no. 2.271.932 of Atkinson, which comprises two pairs of three rollers (76), which causes a final tension to be imparted in machine direction (MD) on the casing, to counteract the high contraction that occurs by slow regeneration on the tapes After passing through the double-S wrapping trawl roller system, the casing is transported to a cold water bath (78), and from here to one or more of the acid regeneration baths (80), in which its pH falls below 7.0, making the regeneration irreversible. According to a preferred embodiment of the invention, six separate acid regeneration baths (80) are used, each with different specific concentrations of regenerating solution. As in the case of conventional regeneration systems, during the course of the downward movement of the casing after reaching the upper roller (74), the gases and liquids are capable of flowing down to the cold water bath (78) in the direction of the arrow (C). In order for these liquids and gases to be released from the interior of the casing, the operators periodically puncture the casing at position (82). An advantage of the methods of the present invention is, however, that substantially less gas is emitted during the slow regeneration process, which results in a need to puncture the casing to release the emitted gas much less frequently than according to the conventional methods. According to the method of the invention, the intervals between punctures in the tubing can be lengthened. While the normal puncture frequency is once for every 800 to 1,600 meters of gut, the puncture frequency is expected to be substantially increased for casings produced according to the methods of the invention, so that the frequency is expected to be about once for every 4,000 to 5,000 meters of casing, or approximately one every 90 minutes Another advantage of the slower gas bubble emission rate is that the interior skin surface of the casing is softer, allowing for easier peeling ability later during the customer's processing. It is envisioned that numerous variations and modifications of the embodiments that have been described above may come to the mind of those skilled in the art upon assessing the teachings of the present disclosure. Accordingly, only those appearing in the appended claims should be considered as limitations.

Claims (13)

NO YEAR OF THE INVENTION Having described the present invention, it is considered as a novelty and, therefore, claimed as property contained in the following claims: 1. A method to produce tubular casings for sausages of regenerated cellulose, where viscous structure through an annular extrusion nozzle submerged in an aquarium to form a tubular product, and wherein the coagulation and regeneration of the tubular product are initiated in said aquarium and completed in one or more coagulation / regeneration baths, characterized in that it comprises gel and partially coagulate the tubing of gel extracted in the aquarium, up to an initial level of regeneration characterized by a pH greater than 7, supporting the partially gelled tubing and coagulating on at least two inclined strips that move upwards of such so that the different sides of the casing are arranged with an orientation facing upwards on the different ribbons mentioned, and applying an intermediate regeneration solution to said tubing while it is supported by said ribbons until it is cured at an intermediate regeneration level characterized by a pH higher than 7 prior to the regeneration being completed in the cited coagulation / regeneration bath in which the viscose is cured to a level of regeneration characterized by a pH of less than 7. 2. The method according to claim 1, characterized in that the initial level of regeneration is characterized by a pH comprised between 8.0 and 9.5. 3. The method according to claim 2, characterized in that the initial level of regeneration is characterized by a pH of around 9.0. 4. The method according to claim 1, characterized in that the intermediate level of regeneration is characterized by a pH comprised between 7.0 and 8.5. 5 - The method according to claim 1, characterized in that the intermediate level of regeneration is characterized by a pH of about 7.5. 6. The method according to claim 1, characterized in that the aquarium contains regeneration fluid characterized by a concentration of sulfuric acid comprised between 50 and 100 grams per liter, and a concentration of sodium sulfate comprised between 200 and 300 grams per liter. 7. The method according to claim 6, characterized in that the aquarium contains regeneration fluid characterized by a concentration of sulfuric acid of about 75 grams per liter, and a concentration of sodium sulfate of about 250 grams per liter. 8. The method according to claim 1, characterized in that the intermediate regenerating solution is characterized by a concentration of sulfuric acid comprised between 35 and 70 grams per liter, and by a concentration of sodium sulfate comprised between 150 and 250 grams per liter. 9. The method according to claim 8, characterized in that said intermediate regeneration solution is characterized by a concentration of sulfuric acid of about 50 grams per liter, and by a concentration of sodium sulfate of about 200 grams per liter. 10. The method according to claim 1, characterized in that said tubing is supported by three belts. 11. The method according to claim 1, characterized in that the casing is extruded at a speed of 55 meters per minute or greater. 12. The method according to claim 11, characterized in that the casing is extruded at a speed of 60 meters per minute or greater. 13. The method according to claim 1, characterized in that said casing is characterized by a density greater than

1.6 grams per cubic centimeter.