US3563064A - Pressure sealing apparatus for processing of fibers in tow form - Google Patents

Abstract

APPARATUS FOR SEALING A HIGH PRESSURE CONTINUOUS PROCESSING CHAMBER FOR FIBERS OR YARNS IN TOW-FORM, FROM THE OUTSIDE ATMOSPHERE, THE PRINCIPAL APRT OF WHICH IS A TUBE CONNECTED TO SAID HIGH PRESSURE PROCESSING CHAMBER, MADE OF A PRACTICALLY ELASTIC MATERIAL AND INSTALLED IN A PROTECTING PRESSURE CHAMBER AND THE CROSS-SECTIONAL AREA OF SAID TUBE RELATIVE TO THE TOTAL CROSS-SECTIONAL AREA OF FIBERS PASSING SAID TUBE BEING REDUCIBLE BY CONTROLLING THE GAP OF A SET OF TWO PLATES WHICH ARE POSITIONED ALONG SAID SMALL TUBE SO AS TO CLAMP SAID SMALL TUBNE, WHEREBY LEAKAGE RESISTANCE OF PRESSURIZED GAS FROM THE HIGH PRESSURE

PROCESSING CHAMBER IS INCREASED WITHOUT AFFORDING ANY HARMFUL EFFECT TO THE FIBERS OR YARNS, SAID PROCESSING IS STRETCHING, RELAXATION, SCOURING, BLEACHING, DYEING, CHEMICAL TREATMENT OR THE LIKE UNDER EVELATED TEMPERATURE AND PRESSURE.

Description

Feb. 16,1971

PRESSURE SEALING APPARATUS FOR PROCESSING OF FIBERS IN TOW FORM Filed April 30, 1969 2 Sheets-Sheet 1 MASAHIDE YAZAWA 3,563,064

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Feb. 16, 1971 MASAHIDE YAZ AWA 3,563,064

PRESSURE SEALING APPARATUS FOR PROCESSING OF FIBERS IN TOW FORM Filed April .30, 1969 2 Sheets-Sheet 2 3,563,064 PRESSURE SEALING APPARATUS FOR PROCESS- ING OF FIBERS IN TOW FORM Masahide Yazawa, Tokyo, Japan, assignor to Polymer Processing Research Institute Ltd., Tokyo, Japan, an organization of Japan Filed Apr. 30, 1969, Ser. No. 820,416 Claims priority, application Japan, Jan. 24, 1969, 44/5,380 Int. Cl. D06f 37/00 US. Cl. 68-5 10 Claims ABSTRACT OF THE DISCLOSURE Apparatus for sealing a high pressure continuous processing chamber for fibers or yarns in tow-form, from the outside atmosphere, the principal part of which is a tube connected to said high pressure processing chamber, made of a practically elastic material and installed in a protecting pressure chamber and the cross-sectional area of said tube relative to the total cross-sectional area of fibers passing said tube being reducible by controlling the gap of a set of two plates which are positioned along said small tube so as to clamp said small tube, whereby leakage resistance of pressurized gas from the high pressure processing chamber is increased without affording any harmful effect to the fibers or yarns, said processing is stretching, relaxation, scouring, bleaching, dyeing, chemical treatment or the like under elevated temperature and pressure.

DESCRIPTION OF THE DISCLOSURE This invention relates to a pressure sealing apparatus suitable for sealing a continuous high pressure processing chamber for bundles of fibers or yarns arranged in tow form so as not to leak pressurized medium to the outside atmosphere and also relates to a processing apparatus equipped with the same. More particularly, this invention relates to a pressure sealing apparatus used in introducing fibers to a high pressure processing chamber from the outside atmosphere or in taking out them from the former to the latter for the purpose of continuous processing of bundles of fibers or yarns in tow-form collected and arranged in parallel from a number of groups of filaments or yarns especially of artificial fibers or tows thereof (throughout in this specification these will be referred to simply as fibers"), the order and arrangement of which are prefixed by e.g. adhesive tapes, yarns, or threads at several points near both the ends of warped fibers, in such continuous processings carried out under a temperature higher than 100 C. and a pressure higher than 1 atm. in steam atmosphere as scouring, bleaching, dyeing carried out by a pad-steaming process, stretching, relaxation, annealing, heat treatment or the like.

With regard to the pressure sealing at the inlet and the outlet of a high pressure processing chamber for tow form filaments, filament yarns or spun-yarns, there are known two US. patents to the present inventor; US. Pat. No. 2,954,687, entitled Continuous Treatment of Textile Material Under Pressure and U.S. Pat. No. 3,213,470 entitled Method for the Continuous Treatment of Textile Bundles With Pressure Steam.

The invention of US. Pat. No. 2,954,687 disclosed a process for feeding tows into a processing chamber and taking them out from said chamber to the outside atmosphere through a small tubular passage equipped with a valve or cock.

However, the cross-sectional area of fibers varies during heat processing. When fibers, particularly artificial fibers, are heated at as high a temperature as possible United States Patent 3,563,064 Patented Feb. 16, 1971 lCC within their softening temperature range where their molecular orientation is not substantially relaxed so as to process them effectively within one minute, such a phenomenon occurs in the fibers that their fine structures become more compact and consequently, their cross-sectional area is reduced by about l520% by the effect of heat applied.

Accordingly, in starting the processing by the method of the above mentioned invention, the fibers are led through an inlet side small tubular passage into a processing chamber and taken out through an outlet side small tubular passage to the outside atmosphere without heating and then pressurized steam is introduced into the processing chamber while controlling the ratio of the total cross-sectional area of fibers to that of the small tubular passage (hereinafter referred to filling up ratio of fibers) by adjusting the opening degree of the valve or cock installed so as not to cause a large amount of the leakage of steam out of the chamber and after an appropriate temperature is attained and processing operation is started, the leakage of pressurized fiuid, particularly pressurized steam, at the outlet is apt to vary and increase gradually. This phenomenon is often observed particularly in case of processing of artificial fibers, because the fine structure of artificial fibers becomes more compact due to the heat applied, causing shrinkage of cross-sectional area and reduces the filling up ratio of fibers in said small tubular passage.

In case of the method of US. Pat. No. 2,954,687 above-mentioned, the small tubular passage will take the state almost incapable of sealing the pressurized fiuid, unless the leakage of pressure fluid is reduced by controlling the opening degree of a valve or cock equipped with at the outlet side of the processing chamber in the course of processing.

Such a pressure sealing may be useful when the pressurize'd fluid for processing is liquid, but it is impossible to realize effective pressure sealing with only one valve or cock attached to the small tubular passage in the abovementioned invention without injuring fibers when the pressure fluid is steam which has extremely low viscosity. In this regard, in the method of U.S. Pat. No. 3,213,470, where saturated steam is used as a processing pressurzed fluid, there are provided valves or cocks in multiple stages, successively along a small tubular passage by which the cross-sectional area of it can be controlled only at places where valves or cocks are inserted and a controlled amount of steam is vented to the atmosphere at each stage between valves or cocks to adjust the steam pressure at each stage. By such arrangement, particularly, continuous operation is feasible under so high a pressure as 510 kg./cm. gauge, even when pressurized fluid is steam. However, the method has a drawback in the points that the product processed is damaged to some extent and the leakage of a certain quantity of steam cannot be avoided in this apparatus at the outlet side of the processing chamber.

An object of the present invention is to provide an apparatus to overcome the drawbacks of the apparatus of two preceding inventions above-mentioned. Such an object can be attained by the apparatus of the present invention.

The present invention consists in an apparatus for sealing a high pressure continuous processing chamber at its inlet or outlet, through which; fibers are introduced into said chamber from the outside atmosphere and taken out therefrom without receiving any damage, which comprises a small deformable tubular passage having a length sufficient to produce a desired pressure drop, made of practically elastic material, installed in a protecting pressure chamber and directly attached to the outlet or inlet of the processing chamber; the cross-sectional area of the small tubular passage being adjustable to such an extent that filling up ratio of fibers passing through the small tubular passage is maintained at a value between 25- 50% of the adjusted area of the small tubular passage by controlling, from the outside atmosphere, the gap of at least a set of two plates throughout their entire length which are placed along the small tubular passage so as to clamp it, whereby the leakage resistance of the pressurized fluid from the pressure processing chamber on both the ends is increased so as to keep the filling up ratio of fibers between 2550% by strengthening the clamping of the two plates at one time or decreased by loosening the clamping of the two plates at another time in order not to afford harmful effects on the fibers; for the inlet side sealing apparatus, one end of the small tubular passage being connected tightly to the narrower end of a feed guide pipe, the other end of which opens divergently to the outside atmosphere, and the other end of the small tubular passage, being open to the processing chamber; for the outlet side sealing apparatus, one end of the small tubular passage being connected tightly to the narrow end of a converging guide pipe, the wider end of which is connected divergently to the outlet of the processing chamber and the other end of the small tubular passage being open to the outside atmosphere after passing through a pressure-tight means provided in the wall of the protecting pressure chamber; the inside pressure of the protecting pressure chamber being balanced directly with that of the high pressure processing chamber when a non-corrosive fluid is used in the high pressure processing chamber and indirectly when a corrosive fluid is used.

Further the present invention consists in, an apparatus equipped with at least one above-mentioned pressure sealing apparatus useful for such a processing as scouring, bleaching, dyeing, chemical treatment, stretching, relaxation, annealing, heat treatment or the like, all carried out under a high pressure and a high temperature.

The apparatus of the present invention is different from and more advantageous than that of US. Pat. No. 2,954,687 in the points that a small tubular passage used for pressure sealing is installed in a protecting pressure chamber and its cross-sectional area can be controlled almost throughout its entire length within said chamber by the operation carried out from the outside atmosphere even in the course of processing and more advantageous than that of US. Pat. No. 3,213,470 in the points that it does not require valves or cocks in multiple stages as is the case with the above-mentioned patent in which they are used for controlling the opening degree of each valve or cock equipment. Further it is also an advantage of the apparatus of the present invention that the operation can be carried out with extremely small amount of steam leakage without accompanying any trouble even in case of pressure scaling for such a fluid as steam which is deemed to have substantially zero viscosity, only by freely controlling the inside cross-sectional area of the small tubular passage installed in a protecting pressure chamber almost throughout its entire length from the outside atmosphere.

The present apparatus is diiferent from and advantageous over conventional apparatuses particularly when fibers are to be stretched under heating at a high temperature in the atmosphere of a high pressure steam.

For example, if a tow of polyacrylonitrile fiber having a tenacity of 4-5 g./d. is re-stretched by a high stretching ratio of 2.5-3.5 times on heating at 120-148" C. in the atmosphere of saturated steam by applying a method such as that of US. Pats. Nos. 2,954,687, 3,213,470 or the like in order to obtain a raw material for high tenacity carbonized fibers, an abrupt increase in filling up ratio of fibers occurs at portions where valves or cocks are installed, because the portion capable of regulating the filling p ra io of fib rs is only the p rtions where valves r cocks are installed. Accordingly, the filling up ratio of fibers must be increased extremely at the very portions of valves or cocks to decrease leakage, by which fibers passing through those portions are injured in most cases.

Contrary to the conventional apparatuses, according to the apparatus of the present invention, since the crosssectional area of the small tubular passage can be reduced gradually as explained later and pressurized steam must be passed to leak through a long range of constricted passageway where the filling up ratio of fibers is increased, the pressure in said small tube drops gradually and continuously and thus a high pressure is practically sealed ofl? without impairing fibers.

Particularly when a small tube made of TFEP (Tetrafluoroethylene polymer, a resin containing fluorine) is used, an excellent result can be attained, because it gives fibers smooth slipping and does not injure fibers at all.

Of course, it is possible to use, as a material for the small tubular passage, a small thin wall tube of phosphor bronze, steel, stainless steel or the like, having an elliptic cross-section and easily deformable by pressing it in the direction of the short axis of the illipse of the crosssection due to its elasticity, and also a flexible tube made of spring wound up in a tubular form and covered with TFEP and the like.

At any rate, when the small tubular passage, is for instance, of circular cross-section and pressed into a nearly elliptic form between two plates, the inside cross sectional area becomes smaller and thus the filling up ratio of fibers passing therethrough is increased.

The above-rnentioned descriptions are given relating to the cases where the initial cross-section of the small tubular passage are circular and elliptic, but it is possible to select a small tube of arbitrary shape so long as it practically satisfies the object of the present invention.

Further explanation will be given to illustrate the present invention by referring to the accompanying drawings.

FIG. 1 shows a birds eyeview of a pressure sealing apparatus of the present invention which is attached to a pressure processing chamber by means of flanges and through which fibers are led into or out of said pressure processing chamber. FIG. 2 shows a longitudinal crosssection of said pressure sealing apparatus furnished at the inlet of the pressure processing chamber and FIG. 2 shows a longitudinal cross-section of said pressure sealing apparatus furnished at the outlet of the pressure processing chamer. FIG. 3 shows a cross-sectional view taken along a line A-A of FIG. 2 which is perpendicular to longitudinal direction of the apparatus.

In FIG. 2', an apparatus having a diverging guide pipe 4' shown in a protecting chamber 30, is a pressure sealing apparatus for the outlet side of the processing chamber through which fibers are guided to the outside atmosphere after high temperature, and high pressure processing, while an apparatus having a converging guide pipe 4a shown partly in the outside of the protecting pressure chamber 30 is a pressure sealing apparatus for the inlet side of the pressure processing chamber 1, through which fibers are guided into the pressure processing chamber 1.

In case of outlet side sealing apparatus, the converging guide pipe 4' is fixed to the right end of the small tube 3 and placed within the protecting pressure chamber 30, and the wider end of said guide pipe is jointed to the opening of the outlet wall of a processing pressure chamber 1. The fibers which have been spread and processed as stated later in the processing pressure steam chamber 1, pass through the convergent pipe 4' in FIG. 2, and after being converged they pass through the small tube 3 which forms the principal outlet side sealing means and are led into the outside atmosphere.

A stafiing box 5, through which the small tube passes, is provided at the end of the protecting pressure chamber 30, toward the side of the outside atmosphere and serves to seal the protecting pressure chamber 30 from the outside atmosphere.

In case of inlet side sealing apparatus, the converging guide is provided whose wider end opens to the outside atmosphere and narrower end pipe 4 is attached to the right end part of the small tube 3, as shown in FIG. 2. The spread fibers which have been subjected to a preliminary treatment such as padding with a dyeing liquor in the outside atmosphere prior to the high temperature and high pressure processing as stated later, are converged in the converging guide pipe 4 as shown in FIG. 2, and introduced into the small tube 3 which forms the inlet Side principal sealing means.

In any cases in the present invention, the small tube 3 directly connected to the guide pipe 4 or 4, is held between two plates 6 and 7, as seen in FIG. 3.

The clamping with the two plates is carried out by pushing said two plates with one or more rods which exerts vertical force upon the plates. Explanation will be given in case of two rods. The end parts 10 and 11 of the two rods 8 and 9 which are movable upward and downward, are placed in respective sockets 12 and 13 fixed on the plate 6, similarly, the end parts of two rods 25 and 26 which are movable also upward and downward, are placed in respective sockets 12 and 13 fixed on the plate 7, and further each of these end parts of the rods is secured to the plates 6 or 7 by means of bolts 14 or 14 as seen in FIG. 3.

The plate 6 is so constructed that it takes parallel positions relative to the plate 7 and the small tube 3 is clamped between the two plates 6 and 7 throughout its entire length by the vertical movement of the rods. The movement of rods can be carried out from the outside atmosphere by any one of various mechanism. One embodiment will be illustrated by a case where two rods are shafts of two screw presses having respective chain wheels in order to exert uniform pushing force upon the plates. A handle 15, and a chain wheel 18 are fixed to a rotatable bushing 17, having female thread on its inner wall 17, and the male thread 16 on a shaft 8 engages with the female thread of the bushing 17.

A chain 19 which is moved by the rotation of the chain wheel 18, rotates another chain wheel 22 fixed to a bushing 21 having the female thread on its inner wall which engages with a male thread on an adjacent shaft 9. Thus, the shafts 8 and 9 move up and down concurrently with the revolution of the handle 15. The shafts 8 and 9 pass through staffing boxes 23 and 24, respectively in order to prevent the leakage of a pressure medium from the protecting pressure chamber 30. The branched pipes 32 and 33 as seen in FIG. I serve as inspecting holes from which the inside of the protecting chamber is accessible for setting or repairing and through which the two upper and lower plates are fixed to the shafts by means of bolts 14 and 14 as seen in FIG. 3. Particularly, when the lower plate 7 is to be fixed at a proper horizontal position, it is adjusted at such a position by moving it up or downward by revolving the shafts 25 and 26, followed by fixing air tightly, with lock- nuts 27 and 28 and packings, respectively as shown in FIG. 3. Thereafter the plate 7 is set by means of a bolt 14 to the shaft 25 or 26 through the above mentioned holes 32 and 33.

Subsequently, the holes are closed by blank flanges 34 and 35 in assembling the apparatus.

The plate 7 may not always be of a structure movable up and down. It may be possible to predetermine, for practical use, the position of the plate 7 lying at a short distance apart from and along the centerline of said small tube and set it by means of shafts 25 and 26 as abovementioned and thus the upper plate 6 alone is moved up or downward in order to adjust the gap between the plates 6 and 7.

Both the right and left ends of the plates 6 and 7 are made in such a slant form like a forward end of a ski as shown in FIG. 2 to attain a smooth conveying movement of fibers because abrupt contraction of the small tube can 6 be avoided and the passing of the fibers through the small tube 3 becomes easier.

When holes 29, through which a pressure fluid, particularly, pressure steam can be led into the protecting pressure chamber surrounding the small tube from the processing pressure chamber, are provided on the guide pipe 4' as seen in FIG. 2, the pressure within the chamber 30' is maintained approximately the same with that in the processing pressure chamber 1, and the drain accumulated in the bottom of the chamber 30' is always withdrawn through a discharging pipe 31 at the bottom of the chamber and a trap or cock.

The pressure within the small tube 3 is generally lower than that of the pressure in the protecting chamber 30. Accordingly, even when a thin TFEP tube is used as a small tube, its inside cross-sectional area is not reduced down to a certain limit, since fibers filling it, are passing through it.

Although the explanation is given to a case where a set of plates and two shafts are used for controlling the crosssectional area of the small tube as shown in the accompanying drawings hereinbefore, two or more sets of two clamping plates and at least one pressing shaft per a set of two plates can be used according to the length of the small tube necessary for controlling and altering the crosssectional area of the tube.

Recently, NaClO from which evolves a corrosive gas during bleaching, has often been used in the bleaching of fibers, and in this case, highly expensive titanium has been used as a corrosion-resistant metal. However, if, for example, after sealing holes 29' which are the means to balance the pressure in the protecting pressure chamber 30' with that in the processing chamber 1 as seen in FIG. 2' on the guide pipe 4, air having the same pressure with that in the processing pressure chamber 1 is introduced into the protecting pressure chamber 30 in which the small tube is installed, through an attached branched pipe (not shown) to the pipe 31. Thus a corrosive gas generated from the processing liquor passes through only the inside of the TFEP tube without entering the protecting pressure chamber 30' and goes out into the atmosphere and there is no need of using highly expensive corrosionresistant material such as titanium for constructing the parts of the present apparatus such as shafts and plates installed in the protecting pressure chamber, including the wall of it. This is an advantageous point of the pres ent apparatus because the cost of the apparatus for bleaching can be made cheaper.

In the above explanation or description is mainly directed to a pressure sealing apparatus provided on the outlet side of the processing pressure chamber. In case of inlet side pressure sealing, the converging guide pipe 4 is placed to open in the outer atmosphere, and the pressure sealing is easier compared with that of the outlet side, when fibers are introduced into the processing pressure chamber at high speed through the small tube which is directly connected to the narrower end of said converging guide pipe and placed in the protecting pressure chamber.

The inside cross-sectional area of the small tube is controlled by clamping it between two plates as stated formerly.

At the inlet side the leakage of pressure fluid from the protecting pressure chamber can be prevented, by merely welding the outer wall of the converging guide pipe 4 to the opening of the protecting pressure chamber through which said guide pipe is inserted.

At the inlet side, the temperature of fibers is usually equal to that of the outside atmosphere and is below C. even in case where there is a need for heating them, for instance, in case of padding of a dyeing liquor, and even when the filling up ratio of fibers in the small tube at the inlet side is lower than that at the outlet side, the leakage of pressure steam or the like scarcely occurs, or is extremely little, because direction of leaking fluid is diametrically opposite to the traveling direction of the fibers introduced and moreover, in case of steam heating, the heat of leaking steam is absorbed in the cold entering fibers and the condensate is carried away in the small tube together with the fibers in high speed operation. However, until the temperature of the processing pressure chamber is elevated to reach a predetermined point after starting the processing operation, it is necessary to press the small tube to prevent the pressure fluid from leaking through the small tube and just before the starting of normal processing operation, the distance of gap between the two plates is controlled so as to increase the inside cross-sectional area of the small tube to such an extent that fibers may not be injured by abrassion and the leakage of the pressure fluid, such as steam, is as slight as possible.

At the outlet side, the operation is almost the same with that in the inlet side in principle, but it is often necessary to recontrol the clamping grade of the small tube especially soon after the beginning of the normal operation in such a way that the gap between the two plates becomes narrower. It is, particularly, so in case of artificial of synthetic fibers whose cross-sectional area is liable to become smaller by the shrinkage during processing.

Particularly, when fibers are stretched on heating in the atmosphere of pressurized steam, they become thinner depending upon the stretching ratio, hence the cross-sectional area of the small tube at the outlet side must be readjusted so as to become smaller, by narrowing the gap between the two plates.

At any rate, the use of TFEP tube makes the slipping of fibers better, without fear of injury thereupon and also is preferable in the point of corrosion-resistance.

Of course, another thin, elastic metallic of flexible tube can also be used, but their corrosion-resistance may often be a problem in bleaching, dyeing, chemical treating or the like.

When a metal tube is used, it is often more convenient to use, from the beginning, a tube having an elliptic section in such a way that the direction of its shorter axis is clamped almost throughout the entire length of the tube by two plates rather than a tube of circular form in controlling its inside cross-sectional area, because the deformation of the former is easier than that of the latter. In case of usual steam treatment which is operable without accompanying any problem of corrosion, a thin metal tube easily available in the market can often be used without using the one made of an expensive material.

When a TFEP tube is connected to the narrower end of a converging guide pipe, it is preferable that one end of the tube is expanded at first by heating, before being inserting in the narrower end of the guide pipe and the inserted part is tied with wire tightly.

According to the experimental result carried out by the present inventor, a pressure scaling, in case of high pressure steam processing, requires a length of about cm. of the small tube per difference of one atm. between the pressure in the processing chamber and that of the outside atmosphere when the filling up ratio of fibers is in the range of -35%. Accordingly, when a pressure in the inside of the chamber is ten atm., it is suitable to use a small tube whose inside sectional area is controllable over a length of about one meter for carrying out the processing without causing leakage of steam and affording any harmful effect on fibers. Of course, when the filling up ratio is increased up to 40%, the necessary length of the small tube to be controlled becomes shorter and even a length of about cm. will be sulficient for the sealing of 10 kg./cm. steam. But, considering the possible change in thickness of fibers during pressing, it is practical to carry out the pressure sealing by using a long small tube having a filling up ratio of approximately 30%.

As mentioned above, at the inlet side, the heat of the leakage steam is absorbed in cold entering fibers, the temperature of which is thus elevated and the condensate is carried away with the fibers, hence the steam leakage scarcely occurs or is extremely little, even if the filling up ratio of fibers is low. However, when stopping of operation is requested at starting of or during the operation for some reasons or other, fibers are often injured owing to the violent leaking jet of steam particularly at the inlet, unless the small tube is immediately clamped tightly. In such cases, the small tube must be, quickly and without delay, clamped by rotating the handle 15 shown in FIGS. 1 and 2 after stopping the operation.

The apparatus of the present invention is effective when it is furnished to the outlet or the inlet or the boh of a high pressure processing chamber of any structure equipped with necessary feed-in and taking-out rollers, guide bars, turning rollers etc., where a continuous processing is carried out under a pressure for a necessary processing period of time. Further, the present apparatus can be applied for processing fibers in tow form having a thickness within a wide range of from about 20,000 to several million denier by properly selecting the size and length of the small tube.

Further in place of using the apparatus according to the present invention at either side of inlet or outlet of a processing pressure chamber, it is possible to seal the processing chamber by using the apparatus of the present invention at one end of the chamber, preferably at the outlet end and a conventional sealing apparatus, for example one of those disclosed in the above mentioned two patents, at the other end of the chamber.

EXAMPLE 1 A filament yarn of about 5,000 denier consisting of 600 filaments of 8-8.5 denier, having a tenacity of 3.5 g./d. and an elongation of 36%, solely made of pure polyacrylonitrile, was subjected to twisting of 10 times per meter after being treated with an oiling agent for stretching (a kind of surfactant) so as to pick up 0.7% by weight.

While 25 yarns thus obtained were warped, and wound on a beam up to 25 kg., they were stitched obliquely by 4 weft yarns with some distance apart at the positions to both the beginning and the terminating ends of the warped yarns in order to fix the order of the parallel arrangement of yarns.

From two beams, warped and winded, the two groups of warped yarns whose parallel arrangement are fixed in advance as above-mentioned, were taken out in parallel and put together into tow of 250,000 denier and subjected to stretching in a high pressure steam processing chamber at 75 mm. in diameter and 6 meters long, equipped with the pressure sealing apparatus of the present invention shown in the accompanying drawings on both the ends, having long small TFEP tubes of 9 mm. inner diameter and 0.5 mm. wall thickness respectively, through which the tow was allowed to pass. The length of 50 cm. of the small tube situated in a protecting pressure chamber was so made that it is clamped between two plates in order to control the filling up ratio of the tow in the small tube.

One unit of the stretching equipment used was composed of a group of feed pinching rollers placed in front of the high pressure steam processing chamber; the processing chamber itself having the pressure sealing ap paratus of the present invention at both the inlet and outlet side and further several fixed bars installed near the inlet in zig zag arrangement in order to spread and flatten the tow introduced; a group of taking up pinching rollers, and a winder arranged in this order in series.

At the start, before assembling each part of the equipment, a guiding thread was passed through the whole equipment in the same way as the tow was processed therethrough.

After assembling the whole equipment, the tow already put together into 250,000 denier was jointed to the end of the guiding thread at the feeding side of the feeding pinching rollers and then pulled together with the thread by means of taking up pinching rollers. Thus the tow was gradually introduced into the processing chamber and came out of it.

The tow, after passing through the inlet side pressure sealing apparatus, was spread and flattened by passing over the fixed bars installed in the processing chamber in zig-zag arrangement. During this period, before stretching was begun, the small tubes were still kept round on both the inlet and the outlet sides and the filling up ratio of tows in the small tubes was estimated to be about 39% by calculation.

The stretching of the tow started by introducing pres surized steam into the pressing chamber till the temperature in the chamber rose up to 120 C. under a saturated steam pressure and the stretching ratio was gradually raised by controlling both the speeds of the inlet side and outlet side pinching rollers till it reached up to 2.5 times stretching. As the stretching ratio was raised and became close to the predetermined ratio, the small tubes of the sealing apparatus on both the inlet and the outlet side were pressed by clamping two plates till the tubes became elliptic in order to decrease leaking steam. Then 50 kg. of the stretched tow of about 100,000 denier was obtained by taking it up at a rate of about 12 meters per minute.

The once stretched tow was then subjected to relaxation and simultaneous annealing giving 20% contraction in length under a saturated steam pressure at 165 C. using the same unit of the equipment to get 125,000 denier tow, followed by re-stretching by 2 times the relaxed and annealed tow at 140 in the atmosphere of a saturated steam, using also the same unit of the equipment, excepting that a small TFEP tube of 6.5 mm. inside diameter and 0.5 mm. wall thickness was used in place of the previous one having the 9 mm. inside diameter and 0.5 mm. wall thickness in the pressure sealing apparatuses on both the inlet and outlet side.

And then over-all stretching by 4 times of the original tow could be carried out by two step stretching while putting in a relaxation annealing step between the two stretching steps.

The restretched tow was then divided into two warped yarns originally composed of and winded on two beams, respectively, each of which was separated successively into 25 original yarns in parallel by the guidance of the weft yarns which had been inserted at both the beginning and the terminating ends of the warped yarn by passing through a comb installed at one end of a spindle type twisting machine, while giving effective vibrations transversely to the whole yarns in order to disentangle the yarns which might have become out of order during the processing and each yarn was wound on a bobbin with simultaneous twisting up to 50 turns per meter.

The yarns thus obtained, after cutting off both the end parts thereof which had been unevenly stretched during the processing, had a tenacity of lll2 g./d., elongation of 67% and thickness of l,200l,300 denier and were of superior quality as raw materials for producing carbonized yarns having high tenacity and high Youngs modulas after carbonizing.

EXAMPLE 2 To obtain a tow of 500,000 denier, an acrylic polymer, prepared from 95% by weight of acrylonitrile and 5% by weight of methyl methacrylate by redox-polymerization, was subjected to wet spinning using a dope containing 14% by weight of said polymer in 67% HNO aqueous solution and, using 33% HNO aqueous solution at 2 C. as a coagulating bath; complete washing with water, primary stretching 2.5 times the original length before stretching in a water bath maintained at 70 C.; secondary stretching 6 times the length before stretching in a water bath at about C.; tertiary stretching 8.5 times the original length in a bath of -98 C., and drying successively.

The tow thus obtained, was introduced into a pipe autoclave of 160 mm. in diameter, 80 meters in total length, arranged in U-shape and maintained at 134 with saturated steam, through a pressure-sealing apparatus of the present invention. At a place 2 meters from its inlet opening in the inside of the autoclave, there was installed a group of pinching rollers by means of which the tow was pulled into the autoclave at a speed of 90 meters per minute and the tow travelled over two driven turning rollers of mm. diameter at the turning corners of the U-shaped autoclave, sliding over ladder-like inside bars of 3 mm, diameter positioned every 1 meter throughout the effective length of said pipe autoclave and then came out through a outlet side pressure sealing apparatus of the present invention by means of taking up pinching rollers installed at the outside of the autoclave at a speed of 70 meters per minute.

Thus, the tow was subjected to relation-annealing, allowing contraction of about 23% of its length during passing through the autoclave in 1 minute.

In this example, two TFEP tubes of 12 mm. diameter and 60 cm. long were used as small tubes for pressure sealing apparatuses on both the ends, respectively and there was no need of using small tubes of different size for each end, because the total denier of the tow after this heat-treatment was expected to become 23% thicker, but remained almost the same in denier as the filament before said treatment, owing to the contraction of 15- 20% during said treatment.

The more the filaments were relaxed, the more the decrease in their tenacity and the increase in their elongation took place, and especially, remarkable was the increase in their knot and bending strength.

The filaments, after subjected to this heat treatment, were homogeneous in their physicochemical properties, resistant to fibrilation, highly stabilized in dimension, and of superior practical value.

Further, with the apparatus stated above, acrylic fibers prepared according to a wet-spinning process using an organic solvent such as dimethylformarnide, dimethylacetamide, dimethylsulfoxide or the like, or an inorganic solution such as concentrated solution of rhodanates or zinc-chloride as a solvent for the polymer could be treated after once dried up, affording superior effects as fibers.

In this case, it was necessary to take into consideration that the more the content of co-monomer in the polymer was, or the less the over-all stretching ratio was, the lower the temperature of the treatment should have been, and in case of fibers made of a homopolyrner of acrylonitrile and further in case over-all stretching was done by 9 times the original length before stretching, the appropriate relaxation-annealing temperature was about C. and the higher the stretching ratio of the fiber according to the method stated in Example 1 was, the higher the relaxation-annealing temperature should have been.

EXAMPLE 3 A crimped polyester tow of 300,000 denier, packed in a box every 50 kg., and available in the market, was spread up to about 200 mm. wide and stretched by 13% till its crimps disappeared completely during the processing in a steam chamber maintained at 95 C.

After stretching, the tow was introduced into a padding vessel of a dye-liquor containing 2 g./l. of a dispersing agent and then, the tow was squeezed by a mangle so as to pick up 38% by weight of the dye liquor, the concentration of which had been so adjusted that the squeezed tow might pick up 2% of dispersed dye Dianix red brown, 1% of Dianix blue RN and 0.4% of Dianix yellow Y-L (all made by Mitsubishi Kasei Co., Ltd.) by O.W.F.

Before squeezing by the mangle, the dye liquor was al- 1 l lowed to sufficiently permeate into the tow during the passage of the tow through the dye vessel and over zigzag bars equipped between the dyeing liquor vessel and the mangle in the padding apparatus, while calculated volume of the dye liquor carried away by picking up was continuously supplied into the vessel.

After picking up the predetermined quantities of dyeing liquor on fibers, the tow was introduced into a high pressure steamer 45 meter long and 120 mm. in diameter, maintained at 160 C. by introducing saturated live steam into it, through a pressure sealing apparatus by pulling in with pinch rollers installed in the inside of said steamer close to the inlet opening, at a speed of 45 meter per minute.

The tow was evenly dyed in deep brown by absorbing almost completely the dyestuffs on fibers, when drawn out at a speed of 42 meter per minute from the steamer through an outlet side pressure sealing apparatus of the present invention, without contacting with drain in the bottom of the steamer, by means of taking up picking rollers installed in the outside atmosphere.

In this operation, the outlet side pressure sealing apparatus was satisfactory, needless to say of the inlet side one, and the fibers of the tow was scarcely damaged, when the small tube of said apparatus was adjusted to become narrower so that only a slightest amount of steam leaks through it together with the leaving tow.

Then the dyed tow was passed through a reducing agent bath, and a soaping bath and dried after washing with water, whereby an evenly dyed tow having brilliant gloss was obtained.

Further, a tow dyed evenly in deep blue was obtained by using the said apparatus as abovementioned, when the amount of picked up dyeing liquor on the tow was adjusted to be 5% Resorein blue FBL and 0.3% Amacron orange LS. by O.W:F., using 2 g./l. of :Resper TL as a dispersing agent.

What is claimed is:

1. An apparatus for sealing an elevated pressure and elevated-temperature-processing-chamber, in the state of collected fibers arranged in tow form being introduced into said processing chamber and withdrawn therefrom without affording injury to said fibers during the passage of this apparatus which comprises a small deformable tube having an effective length for affording a desired resistance to a leaking pressure fluid, made of a practically elastic material, installed in a protecting pressure chamber whose inside pressure is balanced with that of said processing chamber and one end of said small tube is connected to a guide pipe which is convergent toward the I entering direction of the fibers into said small tube and wider end of which opens to the outside atmosphere when said small tube is installed in the inlet side end, and opens to the pressure processing chamber when said small tube is installed in the outlet side; at least one set of two plates installed in said protecting pressure chamber and capable of clamping said small tube by changing the gap therebetween thereby to adjust the cross-sectional area of said small tube almost throughout its entire length, at least one rod extending from a point fixed to one of said two plates to the outside atmosphere through a conventional pressure sealing device which is installed on the wall of the protecting pressure chamber to prevent the leakage of pressurized fluid from the protecting pressure chamber to the outside atmosphere, which rod is movable so as to control the gap of the two plates and clamping grade of said small tube; the leakage of pressure fluid from said pressure processing chamber to the outside atmosphere being prevented by controlling the cross-sectional area of said small tube at a given length thereof to keep the ratio of the total cross-sectional area of fibers passing said small tube to the cross-sectional area of said small tube in the range of 25-50%.

2. An apparatus according to claim 1 wherein said small tube penetrates the end wall of the protecting pres- 12. sure chamber at the outlet side and a stufling box is provided at the penetrating part of said end wall in order to pass said small tube through said end wall while allowing the free expansion or contraction of the small tube but preventing the leakage of the pressurized fluid from said protecting pressure chamber.

3. An apparatus for processing collected fibers arranged in tow form under an elevated pressure and temperature comprising at least one set of inlet side pinching means for feeding said fibers, a pressure processing chamber having pressure sealing apparatuses at both the outlet and inlet sides and at least one set of outside pinching means for taking out said fibers arranged for passing said fibers in this order, at least one of said pressure sealing apparatus comprising a small deformable tube having an effective length for affording a desired resist ance to a leaking pressure fluid, made of a practically elastic material, installed in a protecting pressure chamber whose inside pressure is balanced with that of said processing chamber and one end of said small tube is connected to a guide pipe which is convergent toward the entering direction of the fibers into said small tube and wider end of which opens to the outside atmosphere when said small tube is installed in the inlet side end, and opens to the pressure processing chamber when said small tube is installed in the outlet side; at least one set of two plates installed in said protecting pressure chamber and capable of clamping said small tube by changing the gap therebetween thereby to adjust the cross-sectional area of said small tube almost throughout it entire length, at least one rod extending from a point fixed to one of said two plates to the outside atmosphere through a conventional pressure sealing device which is installed on the wall of the protecting pressure chamber to prevent the leakage of pressurized fluid from the protecting pressure chamber to the outside atmosphere, which rod is movable so as to control the gap of the two plates and clamping grade of said small tube; the leakage of pressure fluid from said pressure processing chamber to the outside atmosphere being prevented by controlling the cross-sectional area of said small tube at a given length thereof to keep the ratio of the total cross-sectional area of fibers passing said small tube to the cross-sectional area of said small tube in the range of 2550%.

4. An apparatu according to claim 3 wherein the peripheral speed of the inlet side pinching means is greater than that of the outlet side pinching means in order to effect relaxation and annealing of the fibers under an elevated pressure and temperature.

5. -An apparatus according to claim 3 wherein the peripheral speed of the outlet side pinching mean is greater than that of the inlet side pinching means in order to effect stretching of the fibers under an elevated temperature and pressure.

6. An apparatus according to claim 3 wherein the apparatus is combined with an annexed means to make the fibers fed towards the inlet of the processing chamber, pad with a processing liquor for fibers in order to process fibers under an elevated pressure and an elevated temperature.

7. An apparatus according to claim 6, wherein the annexed means is an apparatus for making the fibers pad with a scouring liquor to scour fibers under an elevated pressure and an elevated temperature.

8. An apparatus according to claim 6, wherein the annexed means is an apparatus for making the fibers pad with a bleaching liquor to bleach fibers under an elevated pressure and an elevated temperature.

9. \An apparatus according to claim 6, wherein the annexed means is an apparatus for making the fibers pad with a dyeing liquor to dye fibers under an elevated pressure and an elevated temperature.

10. An apparatus according to claim 6, wherein the annexed means is an apparatus for making fibers pad 13 14 with a liquid for chemical treating of the fibers to treat 2,708,843 5/ 1955 Gibson et a1. 68--5-5 the fibers chemically under an elevated pressure and 2,954,687 10/1960 Yazawa et a1. 685-5 an elevated temperature. 2,974,512 3/ 1961 Carter 68-5-5 3,175,375 3/1965 Yazawa et a1. 685-5 NITE E SQ YFI ES I Z TENTS 5 FOREIGN PATENTS U 1,284,928 12/1968 Germany 68-4-5 2,367,174 1/1945 Renk'n 68-'5-5 2, 54,010 12 1953 Emerxson 5 MARION PARSONS, JR., Primary Examiner

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