JP2568156C - - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a cellulosic product, and more particularly to a tubular cellulose food casing and a method and apparatus for producing the same. BACKGROUND OF THE INVENTION Cellulose food casings are well known and are widely used to make casing stuffed foods such as sausages. Cellulose food casings are generally seamless tubes made of regenerated cellulose and contain water and / or plasticizers such as polyols such as glycerin. Cellulose tubes need to be plasticized because if they are not plasticized, they are fragile and difficult to handle and are not suitable for commercial use. Cellulose food casings are generally divided into two types. A first type of casing is made from a tubular film of pure regenerated cellulose having a wall thickness of about 0.025 mm to about 0.076 mm from a diameter of about 14.5 mm to about 203.2.
It was manufactured as a mm tube. The second type of casing is a reinforced casing reinforced by bonding a paper web to regenerated cellulose. Such reinforced casings are commonly referred to as "fibre-filled" casings to distinguish them from non-reinforced casings. The fibrous casing has a wall thickness of about 0.050 mm to about 0.102 mm, and a thickness of about 40.50 mm.
It has a diameter from 6 mm to about 193 mm or more. Cellulose, which is a material for both types of casings, is generally referred to as a so-called "
It is manufactured by the viscose method. In the viscose method, viscose, a soluble cellulose derivative, is extruded through an annular die as a tubular film into a coagulation / regeneration bath to form a tube of regenerated cellulose. The tube is washed, plasticized with glycerin or other polyol and dried. Drying is usually
This is done while maintaining the diameter of the tube constant and expanding the tube with air at a pressure sufficient to stretch orient the film. Viscose processes for producing cellulose are well known in the art. Briefly, in the viscose method, natural cellulose, such as wood pulp or cotton linter, can first be allowed to derivatize the natural cellulose and extract certain alkali-soluble fractions from the natural cellulose. Treat with a caustic solution to activate the cellulose as described above. The obtained alkali cellulose is cut, aged, and treated with carbon disulfide to produce cellulose xanthate, which is a derivative of cellulose. This cellulose xanthate is dissolved in a weak caustic solution, and the resulting solution, "viscose", is aged, filtered, degassed (removing air bubbles) and extruded. The type of pulp source and the length of time to ripen the alkali cellulose are selected depending on whether the viscose is used to make a fibrous casing or a non-reinforced casing. When fabricating a fiber-filled casing, the choice is dictated by the viscose solution having a relatively low viscosity. The viscose solution having a low viscosity completely penetrates into the reinforcing paper web by capillary action, and can establish strong intercellulose bonds. Conversely, when manufacturing a non-reinforced casing, the above choice is dictated by the relatively viscous viscose solution obtained. The viscose is extruded as a tube through an annular die around a self-centering mandrel into a coagulation and regeneration bath. coagulation·
The regeneration bath is a solution containing salt and sulfuric acid. In such an acidic bath, cellulose xanthate, such as viscose, is converted back to cellulose. Specifically, the acidic bath degrades the cellulose xanthate, resulting in the coagulation and regeneration of the pure form of cellulose. This coagulated and regenerated cellulose is initially in a gel state. In this gel state, the cellulose tube is first passed through a series of rinse water tanks to remove by-products generated in the regeneration step. The gelled cellulose tube is then treated with a humectant, such as glycerin, and dried to about 10% moisture based on the total weight of the cellulose tube. As described above, during this drying step, the gelled cellulose tube is expanded to a pressure sufficient to give it a certain degree of stretching. Except for extruding the viscose into the coagulation / regeneration bath in the case of a fiber-containing casing before it is extruded onto a tube of reinforced paper web, the unreinforced cellulose casing is also
The fiber-containing casing is manufactured in a similar manner as described above. During the process of regenerating cellulose from xanthates, sulfur products are liberated and gases such as hydrogen sulfide, carbon disulfide and carbon dioxide are released through both the inner and outer surfaces of the gelled cellulose tube. Because such gases generated as by-products during the regeneration process are harmful and toxic, the containment and recovery of those gases imposes a significant burden on the cellulose manufacturing process. Moreover, the gas released through the inner surface of the gelled cellulose tube or casing results in a special problem because it accumulates in the tubular casing. That is, since the tubular casing is inflatable while in the gel state, an increase in pressure due to the gas accumulated in the gel casing will cause undesirable diameter fluctuations of the casing. In order to prevent this, a piercing hole for venting is formed at regular intervals in the gel-like casing. This hole forming process involves drilling holes, venting gases, and then sealing the holes, forcing an undesirable interruption to the manufacturing process. Further, the gas generated in the wall of the casing stays in the wall as it is and generates air bubbles. As a result, the casing is weakened and the food filling performance is deteriorated. Also, the casing, which is in a certain gel state, retains a small residual amount of sulfur compounds generated during the regeneration process. Care is taken to remove all residual sulfur compounds by rinsing the gel tube or casing before drying, but the dried casing still contains traces of residual sulfur compounds. The viscose method has inherent problems as described above, but nevertheless is, to date, the most common method for producing cellulose casings for the food processing industry. It is known that the viscose method can be modified in various ways to increase the strength of the cellulosic material produced therefrom. For example, a modifier can be introduced into viscose or into a spin bath to obtain regenerated cellulose having high strength. However, the cellulose material thus strengthened has been found to have a low elongation at break, which is disadvantageous as a flexible casing composed of a seamless cellulose tube for use as a food casing. Is known. It is therefore an object of the present invention to overcome the above-mentioned drawbacks of the prior art cellulose food casings and the method and apparatus for producing the same. DISCLOSURE OF THE INVENTION The present inventors have surprisingly found that underivatized cellulose solutions are suitable for use in both the production of unreinforced cellulose food casings and the production of fibrous (reinforced) cellulose food casings. I found that. The underivatized cellulose in the molten state can be extruded as a tubular film into a non-solvent liquid such as a water bath. As used herein, the term "underivatized cellulose" refers to a cellulose dissolved not by a covalent bond with a solvent or a reactant but by association with the solvent or the reactant by van der Waals forces such as a hydrogen bond. means. "Non-solvent" means a liquid that is not a cellulose solvent. For example, the dissolution of natural cellulose is based on N-methylmorpholine-N-oxide (N
(MMO) can be carried out by using a tertiary amine oxide.
The cellulose in the resulting solution remains underivatized before dissolution. The underivatized cellulose is precipitated in a water bath, and the resulting gelled cellulose tube is treated with water or a polyhydric alcohol such as glycerin, or another water-soluble softener such as polyalkylene oxide or polyalkylene glycol. And then dried. Examination of food casings extruded with underivatized cellulose solutions has shown that such casings, unexpectedly, have higher water permeability than casings of derivatized cellulose obtained by the viscose method. have. Water permeability is a significant factor for food casings. This is because the processing of food-stuffed casings often involves a cooking or curing step that must allow moisture and flavor to freely penetrate the casing walls and penetrate the foodstuffs inside. Furthermore, examination of underivatized cellulose casings has shown that such casings are tougher than derivatized cellulose casings obtained by the viscose method. Such a property of the non-derivatized cellulose casing that the water permeability is enhanced and the strength is maintained or enhanced is the same as the conventional attempts to increase the water permeability of the derivatized cellulose casing. This is unexpected, as it results in a decrease in the strength of Underivatized cellulose casing also has higher wet tear resistance than derivatized cellulose casing obtained by the viscose process. Wet tear resistance is an important property for food casings because it is a measure of the casing's ability to withstand the violently high stresses exerted during the process of pleating the casing and filling the casing with food. For example, it is not uncommon for poorly maintained filling equipment to scratch or otherwise damage the casing during the filling process, resulting in the casing not being able to withstand the filling pressure and tearing or breaking. Therefore, it is important that the casing have a force that can withstand some damage without breaking. Underivatized cellulose can be used to produce a fiber-filled casing by casting the NMMO-cellulose solution described above onto a reinforced paper web before precipitating the cellulose in the solution. This is because the NMMO-cellulose solution applied to the paper web does not cause any visible and obvious paper degradation, even if the NMMO component of the solution is a cellulose solvent (solvent that dissolves cellulose). In that respect, it is surprising and unexpected. As noted above, produced by a process that has improved wet tear resistance without loss of strength or water permeability, is sulfur-free, and does not generate harmful or toxic by-products The surprising benefits of cellulosic food casings are obtained by using underivatized cellulose as a material for producing food casings. Accordingly, the present invention provides a cellulose food casing comprising an extruded seamless tubular film containing a water-soluble softener, obtained by extruding underivatized cellulose precipitated from a cyclic amine oxide solution. The present invention also provides a tube wall having a water permeability of about 1.2 ml / min / m ² / mmHg at a temperature of 25 ° C. and having a wet tear strength of greater than about 20 mg / 0.1 mm wall thickness. Provided is a cellulose food casing having the same. In another aspect, the present invention is a method of forming a cellulose food casing, comprising: a) providing a solution comprising underivatized cellulose dissolved in an amine oxide solvent; b) directing the solution downward. C) lowering the extruded seamless tube of the solution down first through a void and then into a bath of non-solvent liquid; d) moving the solution down through the void E) derivatized cellulose is precipitated from said solution at said inner surface by flowing a stream of non-solvent liquid downward so as to directly contact said inner surface of said extruded seamless tube in a co-current relationship; The extruded seamless tube is maintained in the bath of non-solvent liquid such that its inner and outer surfaces are in direct contact with the non-solvent liquid, thereby maintaining the solution Precipitating the underivatized cellulose to form underivatized cellulose, and f) extracting the underivatized cellulose from the bath and contacting the underivatized cellulose with a water-soluble softener. A method of forming is provided. The invention, in yet another aspect, is an apparatus for forming a seamless tube of underivatized cellulose suitable for use as a food casing from a solution of underivatized cellulose and an amine oxide solvent, comprising: a. B.) A non-solvent bath for precipitating underivatized cellulose from the solution; and b) a non-solvent bath disposed above the liquid level so as to define a void between the liquid level in the bath. An extrusion nozzle having an annular extrusion outlet adapted to extrude the seamless tube downwardly into the bath; c) a hollow mandrel having an upper portion and a lower portion depending from the extrusion nozzle; The upper portion is surrounded by an extruded seamless tube which is surrounded by the annular extrusion outlet and extruded from the nozzle, and is formed by the extruded seamless tube. A) having an outer peripheral surface of a smaller diameter than the extrusion outlet so as to define an annular space between the inner peripheral surface and the outer peripheral surface having a port facing the annular space; A hollow mandrel having a larger diameter than the upper portion and having an inlet facing into the bath; and f) a non-solvent liquid ejecting a non-solvent liquid from the port flows downward to form the extruded seamless tube. A first conduit protruding into said hollow mandrel to direct said non-solvent liquid to said port such that said non-solvent liquid comes into direct contact with said inner peripheral surface of said extruded seamless tube; A second conduit extending through the hollow mandrel for discharge and communicating with the inlet. It has been found that the underivatized cellulose food casing of the present invention has all of the desirable attributes of food casings conventionally formed of derivatized cellulose. The non-derivatized cellulose food casing of the present invention absorbs water and is treated with glycerin or other softener to provide the flexibility required when processing the casing, and is packed in a casing. Has the water permeability required to process the filled food, is capable of filling the food, and contains the filled food during its cooking cycle without causing casing tearing It has elasticity that can be used. These attributes are obtained in addition to the fact that they have a higher tear resistance than conventional cellulose food casings and do not contain any sulfur compounds produced during the cellulose regeneration process.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram showing a configuration of an apparatus for extruding a food casing of the present invention.
You. FIG. 2 is a partially cut-away sectional view of an extrusion nozzle used in the apparatus of FIG. FIG. 3 is a view similar to FIG. 2 showing an extrusion nozzle of a modified embodiment. Example Use of underivatized cellulose to form cellulose food casings
To demonstrate the rationality of food casings made of underivatized cellulose.
Several tests were performed to measure. For such a test, the NMMO solution from Coatles, UK was used. this
The test solution (hereinafter also referred to as “dope”) has a yellow-brown color having a melting point of 60 to 70 ° C.
Is a solid solution of This dope, according to its Material Safety Data Certificate, is 70-8
0 wt% NMMO, 10-20 wt% cellulose, 5-15 wt% water
It contains. This dope, supplied by Coulters, is described in U.S. Pat.
Nos. 145,532, 4,196,282 and 4,255,300.
Generated by the process. This dope obtained in the form of a slab was put into a refrigerator to increase the brittleness of the dope
. Next, the dope is broken into small pieces with a hammer, and the diameter is less than about 1.58 mm.
Crushed to a particle size of. The particles are extruded with "Brabender" 100 screw type
And extruded through a die as a tube of dope about 25.4 mm in diameter.
Was. The extruder and die temperatures were maintained at about 105 ° C. Extruded extruded dope
60 mesh, 200 mesh, 325 mesh, 200 mesh between machine and die
Screen and a 60 mesh screen were sequentially passed through the screen set. This screen set is
Prevents semi-molten dope and other contaminants from being extruded through the die,
To increase the residence time in the extruder,
Is completely melted before being extruded from the extruder. The die is a dope tube or extruded tubular food casing ("extruded
"Tubular casing" or simply "tube") to a temperature of about 15 ° C.
It was arranged to extrude downward into a held water bath. Between the die and the surface of the water bath
A gap of about 50 mm was provided. With this configuration, the extruder is operated at a rotation speed of about 50 rpm.
To feed the dope to the extruder at a feed rate of about 1.13 to 1.36 kg / hr.
Was. The residence time of the extruded tube in the water bath is about 1 minute,
The tube was pulled out through a nip roller and wound on a spindle. FIG. 1 shows the test apparatus used in the experimental pilot process. Shown in FIG.
As described above, the extruder 12 includes a hopper for supplying the ground dope into the extruder 12.
14 is provided. The screen set 16 described above is provided between the extruder 12 and the die 18.
Are located. A band heater 20 provided around the die 18 raises the die up.
Maintain at a temperature of about 105 ° C. as described. The die 18 is then
The tube of the loop is arranged to pass downward into the water bath 24. From the die
The extruded tube was opened so that when it entered the water bath 24, the bore of the tube was filled with water.
It is kept in a state and is passed around rollers 26, 26 provided in a water bath. H
The water in the inner hole of the tube is passed through the tube around the rollers 26, 26 and becomes flat.
To prevent sticking (ie, self-adhesion) when performed. The die 18 has an outer portion having a central bore 30 as best seen in the cross-sectional view of FIG.
It has a material 28 and a plug 32 inserted into the inner hole 30. Outer circumference of plug 32
An annular space 34 is defined between the surface and the inner peripheral surface of the inner hole 30. The annular space 34
A gap of about 0.508 mm wide and 25.4 mm in diameter at the exit 38 of the die.
Set. The molten dope introduced into the annular space 34 from the extruder through the inlet 36 is
It flows downwardly around plug 32 and is extruded as a tube from outlet 38. Dope tube (extruded tubular casing) water thus extruded
Washing with water in bath 24 (FIG. 1) removed all NMMO. Obtained in this way
Some tubes or casings (test samples) were dissolved in 10% glycerin.
It was immersed in the solution for 10 minutes. The tube was then inflated with air and dried
. The pressure of the inflation air is sufficient to keep the tubing open during the drying process.
Pressure. For example, the wall thickness of the extruded tube in this experimental process is
It was not as uniform as the wall thickness of extruded viscose in industry-based conventional casing production. For example, the underivatized cellulose
In one test sample of the sourcing, measurement was taken at several points around the circumference.
Its wall thickness ranged from 0.06 mm to 0.11 mm. In contrast,
The derivatized viscose casing has a leather-like uniform thickness of 0.06 mm.
ing. In any case, this test reduces the amount of underivatized dope (NMMO solution).
It can be extruded as a tube with a thickness as thin as at least 0.06 mm.
And proved. Water permeability A tube of the above underivatized cellulose of fixed length to analyze water permeability
Immersed in water at a temperature of 25 ° C. for about 5 minutes, and then from the immersed tube
It was cut as a disk having a diameter of 8 mm. Obtained immersion disk (test sample)
Was charged into a 52 type ultrafiltration cell made by Amicon Corporation, and the polyethylene of the cell was charged.
On the plate. 500 m of water at a temperature of 25 ° C. is applied to one surface of the ultrafiltration cell.
It was introduced with a pressure of mHg. With a pipette attached to the other side of the ultrafiltration cell
The water that permeated the test sample of the casing was collected. Use the obtained data
Then, the water permeability of the test sample was calculated. The result of the calculation is the applied unit pressure
Water per unit area, ie, ultrafiltration rate, per ml / min / m ^Two / MmHg unit
Represent. Thus, three samples of underivatized cellulose were analyzed. For comparison, only the case of NOJAX casing from Viscase Corporation was
Of derivatized cellulose by the conventional viscose method from a commercial production line
A soaking test piece (sample) was collected. This control sample was
It has been rinsed with phosphorus but is in a gel state before drying.
Was. This gel-like casing sample is inflated with air and dried in the open state.
And then subjected to the same water permeability test as described above. The calculation results are shown in the table below.
I. As can be seen from the analysis results in Table I, the treatment formed with underivatized cellulose
The water permeability of the pretreated casing is comparable to that of the treated casing made of derivatized cellulose.
Bigger than that of Ning. Burst strength The strength of the underivatized cellulose casing is determined by the so-called "burst strength" test.
And analyzed. In this test, a test sample of the casing was immersed in water at room temperature for 30 minutes.
To re-wet. In this rewet condition,
One end was ligated, and the sample was air blown at a rate of pressure increase of about 44.52 mmHg / sec.
Inflated until burst. The diameter increase of the casing sample during inflation and the
The diameter of the was recorded. The underivatized cellulose casing samples tested were:
The expansion increased the diameter by about 48.0 mm and burst at an internal pressure of 203 mmHg.
. For comparison of burst pressures, a gelled derivatized cellulose diet was prepared from a commercial production line.
After the control test sample of the product casing has been treated with glycerin and collected before drying.
I took it. This gel-like casing was supplied by VISCASE CORPORATION as "N
A conventional frankfurter sold as "Ojax casing" size 25N
For the manufacture of casings for Place this gel casing sample on top
Treated in the same manner as the underivatized cellulose casing described above. That is,
The sample is simply dried, not for the purpose of stretching orienting by expansion.
Inflate with air for ease, then use the underivatized cellulose
Re-wet in the same manner as for the single sample. Three controls in rewet condition
The average folding diameter of the sample was 35.47 mm (the diameter was 22.6 mm). The average burst pressure was 271.33 mmHg, and the average
The diameter was 37.33 mm. This burst pressure is the value of underivatized cellulose casing.
It was higher than that of the sample. However, keep all other coefficients the same
If so, the burst pressure depends in part on the size of the casing diameter. Immediately
That is, a casing having a smaller diameter has a higher burst pressure. Therefore, this derivatized cell
The increase in burst pressure of a sample of Lulose is due, at least in part, to its derivatized cellulose.
The average diameter of the base sample was smaller than that of the underivatized cellulose sample.
And As a further attempt to compare burst pressures, the formation of derivatized cellulose
Re-wet two stretch-oriented casings from Viscase Corporation
Selected for burst pressure comparison at One control sample is Viscase Corp.
Sold as "NOJAX Casing" size 40G by RACEON
This was chosen because the casing is made of underivatized cellulose.
It has a specification folding diameter (48.77-52.33 mm) comparable to that of the Sing sample
Because it is. This "NOJAX casing" size 40G screw case
According to the Corporation specifications, the minimum value measured in the same way as described above
The ultimate burst pressure is said to be 173 mmHg. One other control sample is sold by Viscase Corporation as "NOJAX casing" size HS65.
Therefore, it has a larger specification folding diameter (55.37-65.02 mm).
"NOJAX casing" size HS65 viscase corporation
According to the specification, the minimum burst pressure is 171 mmHg. these
The minimum burst pressure of the two control samples is the same as the underivatized cellulose according to the invention.
Bursting pressure less than 203 mmHg obtained by testing
. In addition, the casing made of derivatized cellulose has a higher
(By drying while the casing is expanded sufficiently to stretch it)
It is known that the burst pressure is higher when facing. Used for the above burst test
The resulting underivatized cellulose casing was not oriented.
On the other hand, the above-mentioned burst pressures of the above-mentioned Viscase Corporation are
For the finished casing. Therefore, the casein of underivatized cellulose
Are, if oriented, comparable to equivalent casings made of derivatized cellulose.
All will show even higher burst pressures. In view of the results of the above tests, the underivatized cellulose casing
Specification of the derivatized cellulose casing closest to the minimum burst pressure higher than the burst pressure
It is clear that it has a tear pressure. Tear strength The machine direction (MD direction) and transverse direction (TD direction) of the casing of underivatized cellulose
Direction) was examined for tear strength in both directions. The sample to be tested is
Extruded non-derivatized cellulose casing and "NOJAX case
NG "cut out of a 25N gel-like casing into a rectangular shape.
In a first group of three samples, one side (A) of each sample is in the MD direction.
Cut at right angles. A second group of three samples contains one sample of each sample.
The side (B) was cut so as to be perpendicular to the TD direction. A slit was formed in each sample to initiate tearing. Each slit is
A cut was made in the direction to be tested from the midpoint of one side (A) or (B) of the sample. these
Sample was immersed in demineralized water for 30 minutes, and the thickness was measured.
It was fixed on a crack tester. When this tear tester releases its pendulum, it swings
The sample was torn in two due to the weight of. The tear cuts into one side of the sample
Started from the slit. The scale of the tester is required to tear the sample
Record the value that represents the tear force in gm-cm. Using this value, the film (case
)) Was calculated. Derivatized cellulose casings were tested in the same manner. Derivative
The results of the tear test of the casing samples of activated cellulose are shown in Table II,
The results of the tear test on the casing sample of underivatized cellulose are shown in Table III.
You. Comparing the above results, on average, the tear strength per 0.1 mm wall thickness is MD
Tube formed of underivatized cellulose in both the TD and TD directions
It can be seen that the casing is considerably larger. Specifically, tearing in the MD direction
The strength is 2.5 times larger on average, and the tear strength in the TD direction is 1.5 times larger on average.
Good. This means that, as explained above, the wet tear strength is a measure of the casing's ability to withstand the violently high stresses exerted during the filling process.
So it's important. The tear strength is also determined by processing the casing before the filling process.
It is also important in the process. For example, it is used to process frankfurta, etc.
Food casings are usually pleated (ie, the casing is shirred)
From a long casing to a relatively short tube
It is a casing stick (rod-like body) with folds. For pleating, 60m
It is rare to compress a casing that is longer than this into a stick that is only 76 cm long
Unfortunately, the pleating process itself is performed at speeds up to 360 meters per minute. Therefore
The casing maintains physical integrity during crimping and is strong enough not to split
It is important to have Therefore, the casing is
In addition, it is desirable to have high tear strength even from the filling step. Whether casings made of underivatized cellulose are suitable for food processing
A filling test was performed to confirm. Formed as above, with glycerin
One end of several treated and dried casings is ligated and a high core is placed inside the casing.
Lagen's Frankfurter emulsion was manually filled. Some casein
During filling, a weakening point was created by pinholes or bubbles in the casing wall
It was torn. Samples successfully filled (emulsion filling)
The filled casing was filled at a temperature of 82 ° C. and a relative humidity of 40% to simulate commercial processing conditions.
Cooked for 75 minutes. The non-derivatized cellulose thus filled and processed
The casing shall not break during cooking or break in any way,
Proved to be suitable for use as In place of the die used to manufacture the casings from the tests described above,
Used to make cellulose frankfurter casings from courses.
A nozzle arrangement that was partially similar to a conventional nozzle was used. Cellulose food case
A typical viscose extrusion nozzle for making shings protrudes from the body of the nozzle.
Equipped with self-aligning mandrel. Viscose extrusion nozzle is made of cellulose
Viscose extruded from the nozzle placed below the liquid level in the regeneration bath
Ascending upwards along the mandrel and coming out of the liquid level in the regeneration bath
. To extrude the melt dope described above, the more viscous of underivatized cellulose
The following are added to a conventional viscose extrusion nozzle to be suitable for extruding a thermoplastic dope.
Such modifications were made. This modified nozzle device does not
, Configured to extrude downward into a non-solvent bath. FIG. 3 shows such a modified nozzle device. The nozzle device has an extrusion outlet 44
And an outer member 40 having a center hole 42 tapered toward. In the hole 42
A tapered plug 46 is mounted so as to be aligned. Outer peripheral surface of plug 46 and hole
An annular extrusion passage 48 is defined between the wall and the wall of the cylinder 42. The outlet or push of this extrusion passage
The outlet 44 is about 0.25 mm wide and about 23.6 mm in diameter. The molten dope extruded from the extruder (FIG. 1) is supplied to the inlet port of the nozzle device shown in FIG.
50 into the extrusion passage 48 and around the plug 46 along the extrusion outlet
Flow to 44. On the outer peripheral surface of the plug 46, a molten dope flowing around the plug is provided.
Helical channels 51 are formed to promote uniform distribution and passage. A hollow mandrel 52 projects from the plug 46 to the outside of the hole 42 in the axial direction.
In use, the lowermost end portion 54 of the mandrel 52 is used as a nonsolvent liquid for precipitation (non-induction).
Submerged below the liquid level 56 of the bath 82
Can be The lowermost portion 54 of the mandrel 52 has a diameter approximately equal to the diameter of the extrusion outlet 44.
A portion of the mandrel 52 between the extrusion outlet 44 and the lowermost portion 54
The outer peripheral surface is made thinner, thereby forming the seat portion 57. This seat 57
In addition, it is made of relatively low friction material such as polytetrafluoroethylene (PTFE).
The formed sleeve 58 is held. The sleeve 58 is close to the extrusion outlet 44
From the small diameter end to the large diameter end that matches the outer diameter of the lowermost portion 54 of the mandrel 52
It is tapered. This tapered low friction surface of the sleeve 58
A non-solvent liquid for sedimentation (hereinafter simply referred to as “sedimentation liquid”)
Or "non-solvent liquid"). A central conduit 60 is provided which extends completely axially through the mandrel 52 and plug 46 and is concentric with the central or second conduit 60.
A second conduit 62 surrounding the plug 46 and projecting upward through the plug 46.
You. The second conduit 62 has a closed lower end 64 and an open upper end 66. No.
2 between the outer peripheral surface of the conduit 62 and the inner wall 68 of the hollow mandrel 52
A channel 70 is defined. An annular space immediately between the concentric first conduit 60 and the second conduit 62
That is, a channel 74 is defined. The annular channels 70 and 74 are connected to a second conduit
The first port 72 formed on the side wall 62 communicates with the first port 72. Mandrel 5
The second port 80 is formed through the side wall of the sleeve 2 and the sleeve 58. 2nd port
The plate 80 is located above the liquid level 56 of the nonsolvent liquid for precipitation and near the small-diameter end of the sleeve 58.
It is provided in place. Concentric conduits 60 and 62 are tubes of underivatized cellulose extruded from the precipitation liquid.
(Hereinafter simply referred to as “tube”). In more detail, the precipitation liquid
, A pump (not shown) from the bath 82 to the conduit 62 as shown by arrow 84.
Introduced through the open upper end 66 into the annular space 74 between the concentric conduits 60 and 62
, Through port 72 to space 70 and out through port 80. this
The liquid discharged in this manner is supplied to the sleeve 58 and the lower end portion 54 of the mandrel 52.
Flows down along the outer peripheral surface of the to perform several functions. First, this liquid is extruded
The underivatized cellulose tube performs a lubricating function to facilitate descending along the mandrel into bath 82. Also this
The liquid fills the extruded underivatized cellulose tube so that the tube
Works to promote the precipitation of cellulose on the inner peripheral surface of the polymer. This extruded tube
Liquid from the interior of the central conduit 60 is pumped through the conduit from the lower end of the central conduit 60
Sucked up and returned to the bath 82 from the top of the central conduit as indicated by arrow 86
. Under the same doping conditions and the same extrusion conditions as described above, the extrusion nozzle of FIG.
Tubes of MMO cellulose solution were placed in 30% NMMO and 70% water by volume.
The resulting non-solvent liquid was extruded into a 25 ° C. bath. The mixture of water and NMMO is
To a degree, it is a non-solvent for cellulose. The residence time of the extruded tube in the bath was about 1 minute. This residence time
Is sufficient to precipitate underivatized cellulose from the NMMO cellulose solution.
It was time. Next, the extruded tube is taken out of the bath 82 and washed with water.
Then, it was immersed in a 10% glycerin solution for 10 minutes. Then the tube
Was inflated with air and dried to produce casing samples for testing. This
The casing sample manufactured as described above is based on the dry weight of cellulose.
Containing 38% by weight of glycerin, after rewetting of this casing sample.
The folding diameter was about 30.7 mm (the diameter was 19.57 mm). These casing samples were tested for water permeability and burst strength as described above.
They were tested for hardness and tear strength. As a control for this test, a conventional gelled casing of derivatized cellulose was used.
Using. The gelled casing of this derivatized cellulose is manufactured by Viscase Corporation.
Extracted from the production line for NOJAX casings of size 25N from Chillon
did. Because the casing of this size uses the modified extrusion nozzle device described above.
Diameter and diameter of the underivatized cellulose casing of the present invention produced
Because it is near. The gelled casing of this derivatized cellulose is converted to glycerin.
After contact, they were collected during the manufacturing stage before drying. The casing at this stage is
, 13-14% glycerin. Then the casing was opened
Air was dried by inflating to maintain the condition. The induction obtained in this way
The casing of the embodied cellulose has a folded diameter after rewetting of about 30.7 mm (diameter of 1
9.57 mm), thus providing a support for the casing of underivatized cellulose.
It still had a slightly smaller diameter than the sample. The non-derivatized cellulose of the present invention produced using the modified extrusion nozzle device of FIG.
The thickness of the case casing (also referred to simply as “underivatized casing”) is shown in FIG.
From the previous sample of underivatized cellulose casing made using
Thin and uniform. Table IV shows meat measured at three points around the diameter of eight rewet casing samples.
Indicates the thickness. As shown in Table IV, the average wall thickness of these casings was 0.050 mm
The case of non-derivatized cellulose produced using the die of FIG.
It has better uniformity than the thickness of the ring. On average, these eight casings
The thickness of the sample was in the range of 0.050 mm to 0.084 mm,
The thickness of the casing sample manufactured using the die of FIG.
The range was 0.11 mm. The water permeability, burst strength and water resistance of these eight casing samples
The results of the tensile and tear strength tests are shown in Table V. Table V shows the modified extrusion nozzle arrangement of FIG. 3 compared to the derivatized cellulose casing.
The underivatized cellulose casing produced using the filter is water permeable (ultrafiltration).
%) Is high, but the burst and tear strengths are low. As shown in Table V
The low burst strength and tear strength of underivatized cellulose casing
High ultrafiltration (1.66 vs 0.72) and high glycerin content (
(38% vs. 13-14%). High filtration rate
High serine content can also have a negative effect on casing strength.
Because it is known. Therefore, the strength of the underivatized cellulose casing is
Glycerin content is higher when compared to the same derivatized cellulose casing.
It is thought that there is no doubt. Drop test Underivatized cellulose for use in producing fiber reinforced casing
A withdrawal test was performed to assess the suitability of the test. The withdrawal test is for fiber reinforced case
To screen paper and viscose solutions to assess their suitability for manufacturing
Used for In the drop-down test, it is used to manufacture fiber-reinforced casing.
Place the paper to be tested on a flat plate and place the liquid to be tested (usually
Solution) and pull the paper under the weighing bar. Weighing bar coated on paper
The liquid is scraped to a uniform thickness. Roll the liquid-coated paper over the hoop
Length, immerse in coagulation / regeneration solution, rinse, and then bathe in glycerin solution
Immerse. Next, whether the coating (coating) liquid has permeated the paper and bound it
Inspect to determine All of these properties (penetration and binding)
It is an essential element for the production of a good fiber-reinforced casing. Good penetration
If bonding is observed, the material is suitable for producing fiber-reinforced casing
It can be said. To test underivatized cellulose, use the NMMO cellulose dough described above.
Melt (105 ° C.) and dilute with 78% aqueous NMMO solution to about 5% by weight cell
A solution containing the loin was prepared. Used in the manufacture of commercial fibre-reinforced casing.
US C.I. H. Long fiber hemp paper combined with conventional viscose sold by Dexter Company
(A weight of 4.98 kg per unit) is placed on a flat plate at 105 ° C.
Until heated. Pour the solution onto the paper and place the paper on the plate for 1.0
Pull the solution 1 mm below the paper by pulling it under a horizontal bar 2 mm apart.
Coated slightly thinner. After a few seconds, the hoop is immersed in running water for about 10 minutes.
Lulose was allowed to settle. The hoop was then placed in a 10% glycerin solution for 15 hours.
The sample was immersed for 5 minutes and dried in an oven (105 ° C.). When the surface of the above paper, which was not coated with the solution, was observed with the naked eye,
It was confirmed that the activated cellulose permeated the paper well and was bonded to the paper. Mentioned above
As such, these properties (permeability and binding) are
Is an essential factor for the manufacture of As can be seen from this withdrawal test,
Cellulose is suitable for producing fiber-reinforced casings. Also surprising
From the visual observation, no visible deterioration was observed in the paper substrate. this is
The solution coated on paper did not contain NMMO, a cellulose solvent.
This was unexpected. Formed from 7.3% underivatized cellulose (cellulose xanthate) solution
The resulting second casing sample was weighed 4.98 k per run as described above.
g of paper was subjected to a drawdown test. The bar was set at a height of 0.762 mm. Although the thickness of the coating solution was reduced, the concentration of the solution was increased.
The total amount of cellulose coated on the paper was the same as in the previous sample.
Was. The coating solution of the second sample is immersed in a bath in which salt and sulfuric acid have been invited.
Therefore, coagulate, regenerate, then rinse with water, treat with glycerin, dry
Was. Both the above samples and paper that has just been treated with a 10% glycerin solution and dried
A tensile strength test was carried out on the comparative control composed of these. 25.4mm each
The results of tests performed on samples of the following widths are shown in Table VI. As the results of this test show, paper samples coated with underivatized cellulose
1 and the paper sample 2 coated with viscose have an increased load-carrying capacity as compared to paper on uncoated paper.
I have. However, the load carrying capacity of paper sample 1 coated with underivatized cellulose
Was lower than that of paper sample 2 coated with viscose. That is,
The load at break of paper sample 1 coated with underivatized cellulose was viscose.
About 70% of that of the coated paper sample 2. Nevertheless, its above
The improved permeation and binding properties of commercially available fibers with underivatized cellulose
This shows that a reinforced casing containing fibers can be manufactured. Because non
Derivatized cellulose improves the strength of the base paper, allowing the user to enter fibers
This is because the strength required for the reinforced casing is sufficiently satisfied. As can be seen from the above description, the food produced with the underivatized cellulose of the present invention.
Article casings represent a major advance in the art. This case
Since sulfur and sulfur compounds are not used and do not generate in forming the ring,
The resulting casing does not contain sulfur. The tear strength, water permeability and burst strength of underivatized cellulose food casing
For example, by regenerating cellulose from cellulose xanthate,
Superior to conventional food casings formed from derivatized cellulose formed by
Have been. In addition, no harmful or toxic by-products are generated in the production of the non-derivatized cellulose casing of the present invention.
Without burdening, it is a big company in the field of manufacturing technology of cellulose food casing.
Bring progress.

Claims (1)

[Claims] 1. A method for forming a seamless tube made of underivatized cellulose suitable for use as a food casing, comprising: a) providing a solution comprising underivatized cellulose dissolved in an amine oxide solvent; and b) extruding. Concentrically located inside the seamless tube to be (i)
An upper portion having a diameter smaller than that of the seamless tube to be extruded and disposed above the liquid level in the bath of the non-solvent liquid; and (ii) having a diameter larger than the upper portion and disposed below the liquid level in the bath. Providing an extrusion nozzle having a hollow mandrel including a lower portion,
The solution is extruded downward from the extrusion nozzle in the form of a seamless tube, and the extruded seamless tube of the solution is introduced into the bath of the non-solvent liquid through a gap, whereby the outer peripheral surface of the extruded seamless tube of the solution is extruded. Contacting said non-solvent; c) circulating a non-solvent liquid through a first conduit provided in said hollow mandrel and through an outlet port provided in said upper part of said mandrel spaced below said nozzle; d) causing a non-solvent liquid to flow over the outer peripheral surface of the lower portion of the mandrel in a co-current flow with the extruded seamless tube of the solution moving downwardly from the outlet port, thereby causing the tube to fall. Contacting the inner surface with the non-solvent liquid and filling the tube with the non-solvent liquid at least to the lowest end of the mandrel; Second communicating with the inlet opening of the lowermost end of the mandrel into the hollow mandrel
Providing a conduit and discharging upwardly from within the extruded seamless tube of the solution through the inlet opening and the second conduit concurrently with the non-solvent liquid falling from the outlet port; f) extruding the solution Leaving the isolated seamless tube in the bath for a time sufficient to precipitate the underivatized cellulose from the solution to form a seamless tube of underivatized cellulose; g) removing the seamless tube of underivatized cellulose. Withdrawing from the bath; h) contacting the seamless tube of underivatized cellulose with a water-soluble softener. 2. A method for forming a seamless tube made of underivatized cellulose suitable for use as a food casing, comprising: a) providing a solution comprising underivatized cellulose dissolved in an amine oxide solvent; Extruding downwards to form a seamless tube; c) moving the extruded seamless tube of the solution down first through a void and then into a bath of non-solvent liquid; d) traveling downward through said void Flowing a stream of non-solvent liquid downward so as to directly contact the inner surface of the extruded seamless tube of the solution in a co-current relationship to precipitate underivatized cellulose from the solution at the inner surface, e. ) Maintaining the extruded seamless tube of the solution in the bath of non-solvent liquid such that both inner and outer surfaces thereof are in direct contact with the non-solvent liquid Thereby precipitating underivatized cellulose from said solution to form underivatized cellulose; and f) withdrawing said underivatized cellulose from said bath and contacting said underivatized cellulose with a water-soluble softener. How to become. 3. 2. The method according to claim 1, wherein the water-soluble softener is glycerin.
The method described in the section. 4. 3. The method of claim 2, wherein the non-solvent liquid comprises a mixture of water and N-methylmorpholine-N-oxide. 5. The method of claim 1, comprising rinsing the seamless tube of underivatized cellulose withdrawn from the bath with water prior to contacting with the water-soluble softener. 6. An apparatus for forming a seamless tube of underivatized cellulose suitable for use as a food casing from a solution of underivatized cellulose and an amine oxide solvent, comprising: a) precipitating underivatized cellulose from said solution. B) disposed above the liquid level so as to define a gap between the liquid level in the bath and the liquid level in the bath, and pressing the seamless tube of the solution downward into the bath. An extrusion nozzle having an annular extrusion outlet adapted to exit; c) a hollow mandrel having an upper portion and a lower portion depending from said extrusion nozzle, d) said upper portion being surrounded by said annular extrusion outlet. And is surrounded by an extruded seamless tube extruded from the nozzle, and defines an annular space between the extruded seamless tube and an inner peripheral surface of the extruded seamless tube. E) the outer surface has a port facing the annular space, e) the lower portion has a larger diameter than the upper portion, and A) a hollow mandrel having an inlet facing inward; and f) a non-solvent liquid ejecting the non-solvent liquid from the port flows downward and directly contacts the inner peripheral surface of the extruded seamless tube in a co-current relationship. A first conduit projecting into said hollow mandrel to direct non-solvent liquid to said port; and g) extending through said hollow mandrel to discharge non-solvent liquid from within said extruded seamless tube. And a second conduit communicating with the inlet. 7. At least the lowermost end of the lower part of the mandrel is located below the level of the non-solvent liquid in the bath, and the inlet is provided at the lowermost end face of the lower part of the mandrel. The apparatus according to claim 6, wherein 8. 7. The mandrel according to claim 6, wherein the mandrel has a transition portion that expands outward from a small diameter portion of the upper portion to a large diameter portion of the lower portion of the mandrel. Equipment. 9. 7. The apparatus of claim 6, wherein the diameter of the lower portion of the mandrel is at least as large as the diameter of the annular extrusion outlet. 10. The extrusion nozzle has a hole tapered toward the annular extrusion outlet,
An inlet for the solution, which is in communication with the hole at a position longitudinally separated from the annular extrusion outlet, and a tapered plug is inserted into the hole, and a wall surface of the hole and an outer peripheral surface of the plug are provided; 7. The apparatus according to claim 6, wherein an extrusion passage for said solution terminating at said annular extrusion outlet is defined between said extrusion outlet and said extrusion outlet. 11. 11. The system of claim 10, wherein the mandrel extends axially from the plug, and wherein the first and second conduits extend upwardly from the mandrel through the plug. An apparatus according to claim 1. 12. A spiral groove for conveying the solution and uniformly distributing the solution throughout the extrusion passage is formed on an outer peripheral surface of the mandrel.
The apparatus according to item 0. 13. Non precipitated from solution with a non-derivatized cellulose and amine oxide solvent
Derivatized cellulose obtained by extruding, Ri consists extruded seamless tubular film of nonderivatized cellulose containing a water-soluble softeners, 0.025Mm～0.
It has a wall thickness of 102mm, at least cellulosic food casings that have a diameter of 14.5mm. 14． 14. The cellulose food casing according to claim 13, wherein a paper web is contained in a wall of the extruded seamless tubular film. 15. 14. The cellulose food casing according to claim 13, wherein the solution comprises pulp cellulose dissolved in NMMO. 16. 14. Cellulose food casing according to claim 13, wherein the solution comprises 70-80% by weight of NMMO, 10-20% by weight of cellulose and 5-15% by weight of water. 17． 14. The cellulose food casing according to claim 13, wherein the water-soluble softener is glycerin.