DE2353558A1 - Process for the production of non-twist yarn from staple fibers - Google Patents

Description

.-Pi; te ?: ^e u.iw.S! TePI; '. F, »ng. W. Scherrmnnn Dr.-lng. R. Riigsr

7300 Esslingen (Neckar), Fabrikstrasse 24, PO Box 348

October 24, 1973 Telephone

τ. * - ■ "ι ι-r 'Stuttgart (0711) 356539

PA 117 nana. - -. - _35g3l9

Telegrams patent protection Esslingenneckar

Holland.se Signalaalapparaten EV, Kengelo (Q), 'Mieder lan d e, Zuidelijke Ha ^TT enweg 40 . '' -.

Method for the production of rotation-free yarn from

S tapeIfase rn

The invention relates to a method for producing rotation-free yarn from slivers and rovings made of staple fibers.

Because of the limited speed with which even the most modern spinning machines can produce yarns from staple fibers, efforts have recently been made to find other and faster processes for producing yarns. These studies have therefore in which apart on Spinnvorrichtungenerstreckt _e thereof to supply the yarn to rotate, and instead a binder is used, in order to gain the necessary cohesion between the fibers of the yarn herzusteller * and a sufficient strength as for the subsequent processing of the yarns into fabrics is required »" -. "" .-

For example, a process has become known in which a

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warped fiber strand is impregnated with the solution of a binder, the moist fiber strand is then solidified by mechanical rolling and then the solidified fiber strand is continuously dried so that the fibers adhere to one another and form a twist-free yarn (US Pat. No. 2,689,813). This method has the disadvantage that the binder solution largely comes into contact with machine parts, which leads to extraordinary contamination of the machine, which becomes sticky, so that difficulties arise in the transport of the fiber strand. In addition ^{, it is} very difficult with this known spinning process to piece a broken yarn end.

It has also become known a method in which the binder in an ineffective state, e.g. in the form of starch granules, a completely moistened, warped one Fiber strand is added, the fiber strand impregnated in this way for its consolidation a Is subjected to a false twist and is then wound into a lap while it is still moist. «The lap is then placed in an oven, in which the ineffective binder can be effectively removed and that excess water is dried out. This known method suffers from the Kachteil that it is extremely difficult under normal manufacturing conditions to supply a chemical in a reproducible manner to a moist, moving fiber streak /, which is why the produced yarn has very different concentrations of the binder over its length. Leading too weak spots that the subsequent processing of the twist-free yarn into fabrics. In addition, this known method has the disadvantage that it it is impossible to piece a broken yarn end on the spinning machine, because the moist fiber strand on the lap · '

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no strength has, furthermore, the fact that the binder is made effective at the winding in the presence of big quantities of water, in addition that the binder during drying by ¹ travels a certain ti ate. This reduces the size of the nickel, and a considerable waste of yarn can also be disfigured as a result of the migration of the binding agent in the. Coil can no longer be wound or has become too weak (US Pat. No. 1,186,233).

It has also become known to produce twist-free yarns by mixing different types of fibers, at least one type of fiber consisting of a potential binder, then moistening a strand of such a fiber mixture, then drawing it to solidify it is subjected to a false twist and the moist, warped fiber strand is then wound into a bobbin. The bobbin is then placed in an oven to make the binder effective and to dry out the excess water. Although this method alleviates the problem of uniform penetration of the ineffective binder the problems of aggregation and migration of the activated binder remain undiminished (Dutch patent application 71.13624).

Another known method is a fiber strand formed from contiguous fibers composed of at least two different types of fibers, of which the fibers of one kind through a potential binder are formed and the fiber strand is subjected to a treatment that activates the potential binder (U.S. Patent 3,49,482,2). This procedure mainly serves for the consolidation of yarns made from continuous filaments,

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^to make it easier to process them into fabrics and, for example, to prevent the yarn from becoming entangled and frayed. Finally, the known method also aims to make it superfluous that your continuous yarn has to be given a twist. However, the aim of the known method is not to spin staple fibers into coherent, twist-free yarns.

The aim of the present invention is to provide a method for producing internal cohesion, indicate twist-free yarns that do not have the disadvantages of the known methods. In particular lies The invention is based on the object of using large amounts of water in a method of the aforementioned type or other solvents to avoid making the binding agent effective and drying out the To enable water in a continuous manner, so that a special activation and drying process is superfluous will continue to exclude the annoying wandering of the binder and finally the possibility to create to produce a solid yarn directly by spinning, so that a piece of the yarn to the Spinning machine is possible.

To achieve the above object, water is added to the fiber strand according to the invention in a predetermined amount, which is not significantly larger than is necessary to make the water-soluble binder effective. It is evident that that this reduces the pollution of the machine to a minimum and an ongoing one Drying is made possible, which extends over a practically relatively short length of the fiber strand, working at a relatively high speed.

Instead of water, another solution can of course be used

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ORIGINAL

or swelling agents can be used. The required Solvents or swelling agents can be used before, during or after be added to a drawing process to which the fiber strand is optionally subjected. is being expected-, that there is enough time for the penetration of Solvent or swelling agent in the potential binding agent before the fiber strand gets into the area, in which the binder is made effective.

The solvent or swelling agent is preferably water. It can but also from acetone, formic acid or acetic acid exist, depending on the type of binder. On the other hand, this is preferably one that is in hot Water, but not soluble in cold water. -

The potential binding agent can be made effective, for example, by using dielectric heat, radiant heat or heated steam. When steam is a solvent for the binder, the process is preferably carried out such that the steam gelatinizes the binder but does not dissolve it to such an extent that the resulting solution is so thin that it becomes larger during subsequent drying Dimensions can hike. ' ^:

The for the asserting ^of: time erforderliehe binder depends on the degree of penetration of Läsungs- or swelling agent from continuing from the source · - and / or dissolution characteristics of the binder and of the time between dem'EindrIngen of the solvent or swelling agent and is the beginning of the making of the binding agent;

The lingering time required for the binder to take effect is preferably at least as long as the time for making it effective> so that the activated binding agent can cool down and / or partially harden and / or the remaining solvent or swelling agent.

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can evaporate wisely.

Any remaining vaporizable solution or Swelling agent is removed before the fiber yarn is wound up, at least at the stage at which the yarn is no longer tacky and firm enough to, in the case of the Fraction to be able to be put together.

According to a further invention, the method comprises for producing a twist-free yarn from a fiber strand the following steps from staple fibers:

a) The fiber strand in which a potential binder. is introduced, a predetermined amount of a Solvents or swelling agents added for the binder.

b) During a dwell time, the solvent or swelling agent penetrates into the binder.

c) The binder is made effective.

d) During a further dwell time, the activated binder partially hardens.

e) The fiber strand is dried, and

f) the fiber strand is wound up.

under the term "fiber strand" are in the above Slivers, "rovings and yarns understood.

Before the binder is made effective, the fiber strand is preferably drawn, either in the dry State or in the presence of the solvent and swelling agent. The fiber strand is preferably twisted incorrectly. That can

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before and / or at the same time as aera effective matters of the binder and / or done afterwards. the False rotation device preferably consists of such a device of the pneumatic type and performs the following functions;

a) · It holds the fibers together when they come out of the Delivery rollers emerge and diminished in this way wrapping the rollers. - ■ -...

b) It gives the fiber strand a temporary one Strength during the time before the binder takes effect is made, in which the fiber strand is otherwise extremely weak and difficult to work with without support.

c) It has an additional drying effect by it blows air currents onto the fiber strand at a relatively high speed. IM this drying effect To increase still further, the air supplied to the false rotation device can be heated.

d) It contributes to the fact that the end product is given a round cross-section.

e) It solidifies the fiber strand at the time it becomes effective of the binder, so that a good contact from fiber to fiber and an optimal binding effect of the Binder status office. Even if the yarn is small Contains capillary spaces in its interior, the binder is influenced to the effect that it during its Effective spreads along the fibers.

f) It is a non-adjacent, self-cleaning ■ "guide for the fiber strand, so that the Maintain operational safety of the spinning device

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BATH

remain. This is difficult to achieve with a standard fixed guide because of the pollution problem.

The false twist device is preferably located at the end of the dwell zone that faces the zone of activation of the binder follows. The potential binder that is incorporated into the fibers can e.g. starch, modified starch or modified cellulose. On the other hand, the binder can also have the shape of a fiber, so that in this case a skeleton of fibers has to be treated, of which possesses at least one potential binding property and at least one is neither bindable nor potentially bindable.

The potentially bindable fiber can e.g. from the water-soluble form of polyvinyl alcohol (alginate, Cellulose diacetate or cellulose triacetate} consist. The fiber that is neither bindable nor potentially bindable can be made of cotton, for example.

The smallest amount of the potential binder that is contained in the fiber strand must be so great that after the binding agent has become effective, it has hardened and drying a sufficient binding of the fibers is achieved and the proper processing of the yarn to substances is enabled. In the case where the binder consists of the water-soluble form of polyvinyl alcohol exists, the minimum amount is about 4%. On the other hand, it is not desirable to to use large amounts of the binder because the fiber strand is stiffened thereby and in particular higher costs arise. From the water-soluble form of polyvinyl alcohol is preferably not more than

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use about 10%.

The binder is preferably of such a type that it can be removed / after the yarn becomes one Fabric has been processed. -

The solvent or swelling agent can, for example, be applied to the fiber strand with the aid of an application roller or by introducing a predetermined amount of the solvent or swelling agent in a stream, for example into a “compressor of suitable shape ¹ , through which the fiber strand passes however, any other of the known methods can also be used with the aid of which a constant, precisely measured flow of liquid can be introduced into a moving fiber strand, the amount of solvent or swelling agent which remains in the fiber strand before this is made effective , can also be limited by the fact that, for example, an additional pneumatic false rotating device is arranged immediately behind the device for introducing the solvent or swelling agent. The amount of the solvent or swelling agent is then determined by the speed of the air flowing from it The device is blown out Ittel can be heated and / or "can contain wetting agents in order to increase in this way the degree of penetration of the solvent or swelling agent into the binding agent. ,.

The amount of solvent or swelling agent to be added depends on the type of binder used. If, for example, a fiber tape of 250 tex is to be spun, which contains 90 % cotton fibers and 10% polyvinyl alcohol fibers, with one yarn of 25 tex and to make the binding agent effective. Steam is to be used, the end product has very little strength when the amount of water that is in front of the

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Zone of the wetting of the binding agent is added, is less than about 30 percent by weight. If the amount of water added is between 30 and 60 percent by weight, the strength of the end product increases very significantly in relation to the amount of water added. In contrast, amounts of water that are greater than 90 percent by weight do not result in any further substantial increase in strength. Rather, they put additional strain on the drying device and make it necessary to work at a lower speed.

It may be beneficial to add other chemicals to the water or solvent. If that Binder e.g. consists of the water-soluble form of polyvinyl alcohol, one has a relative effect small added amount of glycerine as a plasticizer for the binder. This results in a softer, more stretchable one Yarn that is easier to work with. For drying and winding up the fiber strand, any known devices are used for these purposes. However, there is the particular aspect of the invention that because of the limited small amount of the solvent or swelling agent to be used there is the possibility of within a space and time that is economically acceptable, the solvent or swelling agent to be eliminated to a sufficient extent. For example, when processing the above-mentioned mixture of Cotton and polyvinyl alcohol fibers, water as The swelling agent and steam used to make the binder effective is the remaining moisture content after the wrong turn that follows the relaxation zone, only on the order of 25-35 percent by weight. There is a moisture content of 10-15% in the end product is acceptable, only about 10-25% water needs to be evaporated in the dry zone. Even with one

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non-contact, tubular Erhitzer.geringer performance can, relatively over a distance of one meter _with: high speeds, for example, be 50 to 100 m / min accomplished. \

The fiber strand is preferably driven at a constant speed wound up. In this case, no tension should occur in the fiber strand, but rather the fiber strand with a Speed that "e.g. T up to 2% is greater than the winding speed.

In the aforementioned way it is possible to a certain extent To influence the extensibility of the end product. This is not possible with the ones described at the beginning known devices for rotationless spinning. However, it is an advantage of the present Invention, since twisted twist-free yarns in general tend to be quite stiff and lack extensibility. The additional stretch that the present method can be generated, facilitated the further processing of the yarn.

In the following several embodiments of the Method according to the invention described.

Embodiment I.

There is produced a fiber ribbon, that of 90% of fibers of uncooked Lankart cotton and 10% fibers of polyvinyl alcohol having a solution temperature of 85 ⁰ C. The degree of fineness is about fs Ne and the original strength is 33g.

Samples of the above sliver are produced at speeds from 5 and 10 'm / min by one with steam

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filled room, what steaming times of about corresponds to one second or half a second. To Immediate cooling and drying, the specimens have a strength of 124Og and 23Og, respectively, which clearly shows What is made is that an extensive bond has occurred between the fibers, although the water is only in shape has been introduced by steam.

All strength tests were carried out at 100 mm / min with a measuring length of 10 cm.

Embodiment II

A sliver of 300 Tex is produced, which is made from 90% fibers from unwashed Lankart cotton and 10% fibers consist of polyvinyl alcohol. The fibers from 1.6 denier polyvinyl alcohol has a length of about 38 mm and dissolves in water at about 85 °. The strength of the sliver is 0.05 g / Tex. The sliver is drawn in a standard two-stage ■ two-belt drafting system, which is perpendicular.over the Steam room is arranged. The total draft is 1: 5, so that a fiber strand of 60 tex is produced. That Sliver is then passed through the steam chamber, which consists of an 8 cm long double-walled cylinder, one outside diameter of 2.5 cm and one. Has an inner diameter of 1.5 cm. At the top of the outer wall dry steam is introduced, which is drawn through a hole one centimeter in diameter at the bottom of the inner • The tube reaches the inside of the cylinder and then flows in the opposite direction to the direction of movement of the fiber strand. As a result, water hits the fiber strand

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down, -when this enters the pipe, whereby the size of the amount of water that precipitates on the temperature and moisture content of the Fiber strand depends, while its temperature rises to about 100 ° C at the same time .. Further back in the cylinder the fiber strand is dried. From the bottom of the steam chamber, the sliver arrives at a false twisting device of the pneumatic type and is then operated at a speed " speed of 10 m / min on the divided drum usual winding device wound up *

In the final stage, the yarn has a moisture content hold- of about five percent, a yarn tenacity of 3g / Tex and an elongation of nine percent ..

Embodiment III

The procedure is the same as in Äus Ausführungsbeispiel II, with the exception that in the fiber strand after leaving a known amount of water is introduced into the drafting system * This is done with the help of a special Roller that rotates with the front stretching roller and against which one is kept moist by a water tank The sponge is in contact * The amount of water introduced is 50 percent by weight.

The remaining moisture content after steaming and before winding is 10%. The tensile strength of the yarn is 7g / Tex and the elongation is 11%.

...-.; -.- .. ■■; Embodiment IV ■ -.> - ^; , -.- ■:

A sliver of 235 Tex is produced in which Slivers made of cotton fibers and polyvinyl alcohol fibers

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be mixed on the drafting system / .with a fuse out Polyvinyl alcohol fibers are added to nine slivers of cotton of equal weight. At the Streckv / Erk three passages are necessary in order to achieve a reasonably uniform distribution of the polyvinyl alcohol fibers in the mixture. *

The coming about. Sliver is drawn in a normal two-belt stretching machine, which is arranged vertically, a draft of 1: 9.4 being produced, so that the fiber strand produced has a weight of 25 tex per unit length owns.

Located on the lower front delivery roller of the drafting system a small roller, which is partly immersed in a water bath, so that it is in the clamping line of the stretching mechanism the narrow edge of a water film is continuously introduced. The water contains 0.5 percent by volume of the Wetting agent Sovatex CP (Standard Chemical Co,). The amount of that introduced into the fiber strand in this way Water is about 160 percent by weight. The moisture content is brought to the desired level by adding a pneumatic false turning device is arranged directly behind the stretching rollers. In this way The moisture content can be changed by changing the speed of the air flowing through the false rotation device passes through, be reduced to a manageable level. A diagram of the remaining moisture content as a function of the air flow is essentially linear over the range from 0 to 16 l / min, where ■ the water content drops by around 7% per l / min. The delivery speed of the fiber strand is 30 m / min. The air flow is maintained at 10.l / min, resulting in a Residual moisture content of about 90% leads.

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The distance between the delivery rollers and the area in which the binding agent is activated is approximately ^; 20 cm, leaving a penetration time of about 0.04 seconds. '"

In the area where the binding agent is made effective is an insulated glass tube with a diameter of about 3 cm and a length of about 30 cm which ■ steam at low speed is initiated, and in an amount that is currently sufficient to keep the glass tube filled at all times. The time for the binder to take effect is accordingly about 0.6 seconds. About 15 cm behind the. The area in which the binder becomes effective is one second false rotation device arranged so that for relaxation or a time of about 0.3 seconds remains for partial hardening. The air flow in this second wrong turning device is about 16 l / min.

The remaining water in the fiber strand is dried out, by blowing hot air from a 3 KW / fan heater to the Fiber strand is inflated. The dry yarn is wound into a cross winding, including a customary one Used winder with a split drum will. This is modified in that - to reduce the changes in the take-up tension in front of the take-up device a curved guide rail, from is arranged in a suitable shape.

The yarn produced has a tensile strength of about 8 g / Tex and a tensile strength of about 4.5% and .- is suitable to be processed into an active ingredient »

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Embodiment V

A fiber band is produced from a fiber mixture in the same way as in Embodiment IV, except that the air flow in the first false.

rotating device is 16 1 / inin, which has the consequence that the water content before making the binder effective is only about 50%.

The final product has a tensile strength of about 6.5 kg / Tex and an elongation at break of about 4%.

Execution example VI

The sliver is produced in the same way and treated as in embodiment IV, with the exception that the time to his relaxation or to partial hardening is increased to about 0.6 seconds after the binding agent has taken effect.

The final product has a tensile strength of about 10 g / Tex and an elongation of about 5% at break.

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Claims (4)

Claims Method for producing a twist-free yarn from a sliver or a roving A fiber strand consisting of staple fibers, in which the fiber strand has a potential binder added and the fiber strand then is that. the binder is made effective, characterized in that water is introduced into the fiber strand in a predetermined amount which is not substantially greater than is necessary to make the water-soluble binder effective. ■ _ ' 2. The method according to claim 1, characterized in that that the potential binder in the form of fibers is used and the binder with the help of steam is made effective. 3. The method according to claim 2, characterized in that that the fiber strand is passed through a chamber, through which steam is passed opposite to the direction of movement of the fiber strand. 4. "Continuous process for the production of yarn, consisting of the following steps: a) The fiber strand in which a potential binder is introduced, a predetermined amount of a solvent or swelling agent for the binder is added. * - 409818 / 111A - 18 - b) During a dwell time, the solvent or swelling agent penetrates into the binder. c) The binder is made effective. d) This hardens during a further dwell time activated binders partially. e) The fiber strand is dried and f) the fiber strand is wound up. '5. Method according to claim 4, characterized in that that the potential binder in the form of fibers verv / ends v / ird. 6. The method according to claim 5, characterized in that that the fibers consist of water-soluble polyvinyl alcohol. 7. The method according to claim 4, 5 and 6, characterized. that the swelling agent consists of water. 8. The method according to claim 7, characterized in that the amount of water in the fiber strand immediately before making the binder effective is 60 to 90 percent by weight. 9. The method according to claim 4,5,6,7 or 8, characterized in that in connection with the solution or swelling agent, a plasticizer for the binder is introduced. - 19th 409.818 / 1 1 U 10. The method according to any one of the preceding claims, characterized in that your fiber stiff on the tinde
the dwell time, - which follows the effectiveness of the binding agent, is given a false twist. . 11. The method according to any one of the preceding claims, characterized in that for influencing the
Amount of solvent or swelling agent in the
Fiber strand remains, a pneumatic false twist device is used. 12. The method according to any one of the preceding claims, characterized in that the binding agent becomes effective is brought about by steam, 13. The method according to any one of the preceding claims, characterized in that the residence time that the
Effectiveness of the binder follows, at least equal to the duration of the making of the binding agent
is. 14. The method according to one of the preceding claims, characterized in that the binder is removable after the yarn has been fabricated. 4 03818/1114