US3791132A - Process for sizing textile fibres - Google Patents

Abstract

Process for sizing slivers or rovings of textile fibres in which the slivers or rovings are unwound from a supply thereof and are accelerated progressively and smoothly to a given speed by a pulling force which is always less than the cohesion force between the fibres constituting the slivers or rovings. The slivers or rovings are then flattened by passing between a first pair of pressure rollers, before dipping into a bath of size and then passing through a second pair of pressure rollers to be forwarded onto a drier for drying the size whereafter they are wound up on a bobbin. The size has the effect of gluing the fibres of slivers or rovings together and imparts sufficient cohesion for the slivers or rovings to be worked as such in a loom or knitting machine. The size may subsequently be removed after manufacture of a textile article from the slivers or rovings.

Description

United States Patent 1191 Schutz et al.

[ Feb. 12, 1974 PROCESS FOR SIZING TEXTILE FIBRES [75] Inventors: Richard Adrien Schutz; Pierre Elisee Exbrayat, both of Mulhouse, France [73] Assignee: Centre Technique Industriel: lnstitut Textile De France, Boulogne Sur Seine, France {22] Filed: Dec. 1, 1971 [21] Appl. No.: 203,720

3,093,504 6/1963 Bode 28/72.6 X

3,154,908 11/1964 Cilker et a1. 57/2.5 X

Primary Examiner-Louis K. Rimrodt 5 7] ABSTRACT Process for sizing slivers or rovings of textile fibres in which the slivers or rovings are unwound from a supply thereof and are accelerated progressively and smoothly to a given speed by a pulling force which is always less than the cohesion force between the fibres constituting the slivers or rovings. The slivers or rovings are then flattened by passing between a first pair of pressure rollers, before dipping into a bath of size and then passing through a second pair of pressure rollers to be forwarded onto a drier for drying the size whereafter they are wound up on a bobbin. The size has the effect of gluing the fibres of slivers or rovings together and imparts sufficient cohesion for the slivers or rovings to be worked as such in a loom or knitting machine. The size may subsequently be removed after manufacture of a textile article from the slivers or rovmgs.

8 Claims, 3 Drawing Figures PATENTEDFEB 12 1974 SHEET 1 OF 2 Inventor Kmhard Hdnsn Schu tz Dvsvre Ehs ea Exbraqar PROCESS FOR SIZING TEXTILE FIBRES The present invention relates to a process and an apparatus for sizing textile fibres, more particularly to a process and apparatus for sizing textile fibres in the form of slivers or rovings, and to textile articles formed therefrom.

Conventionally, articles such as fabrics, knitwear etc., are formed with the aid of textile fibres in the form of a yarn. This yarn should have a suppleness, an elasticity and resistance sufficient to enable it to be subjected, without damage, to the diverse constraints occasioned by its manipulation during the course of the operations of weaving or of knitting.

For this purpose, the conventional yarn, obtained by spinning a textile raw material, is more or less twisted, in order to improve the cohesion between the fibres constituting the yarn, then, in this state is subjected to sizing, when it is intended to form the warp of a fabric.

This spinning can, in general, be divided into two successive stages in which, in a number of cases present the same importance and substantially the same cost price. During the first stage, called preparation, the textile material in the form of bales is treated by heating and then by carding to give a web, the textile fibres being distributed in a homogeneous fashion and oriented preferentially in the sense of advance of the web, the latter being eventually subdivided to form slivers. These are subjected to doubling and drawing to give rovings. The slivers generally have hundreds of thousands of fibres to the section, such that the roving comprises thousands of fibres to the section; but it is possible to obtain a roving of desired fineness by suitable drawing.

During the second stage of the spinning proper, the rovings are made finer by successive drawing, until one obtains a yarn in which the number of fibres to the section can fall to less than 50. The fibres then receive a number of turns of twist to form a yarn giving the required resistance and elasticity. The yarns are then fed to a loom or knitting machine to produce the textile article.

This conventional technique of fabrication of textile articles is long and costly. Moreover, the twist of the fibres looses a large part of the ability to cover the fibres constituting the yarn.

It has already been proposed to omit the operation of the twisting of the yarn, effected usually during the second stage of the treatment of the yarn and to replace this twisting by a sizing operation.

According to a known process of manufacture, of a yarn without twist, the slivers and rovings of the textile fibres are drawn until one obtains a very thin band which is impregnated with size; then the sized fibres of this band are re-grouped in such a manner as to form a yarn of substantially circular section which is then dried.

A known sizing apparatus for the purpose of putting into operation this process comprises in particular: a first drawing train for the slivers or rovings of textile fibres unwound from a bobbin; an endless conveyor belt for feeding the textile fibres leaving the first drawing train in the form of a very thin band to the point where they are sized; two parallel coating rollers defining between them a space sufiicient to receive the size and deposit it on the walls of the band of fibres; at least one forming roller defining with one of the coating rollers a space situated on the path of the band of fibres downstream of the coating space, the said forming rollers being given an axial reciprocating motion; two guiding rollers and a second drawing train disposed on the path of the sized textile fibres downstream from the point of contact with the forming roller with the said textile fibres.

Another known installation comprises, in particular, an endless conveyor belt furnished with a layer of size and of which the upper face is put in contact with the textile fibres leaving the drawing train.

In these installations, the textile fibres are coated with size by contact with a guide surface of the fibres, this surface being covered with size.

This method of sizing has the disadvantage of transferring to the fibres an excessive quantity of size distributed in a hetrogeneous fashion. Moreover, the forming rollers of these apparatuses exercise on the thin band of fibres an alternating force which can create partial or total rupture of the band of fibres and also produce irregularities in the thickness of the yarn obtained or in the distribution of the long and short fibres in the yarn.

Furthermore, the known procedure takes away from the rovings their initial character and of necessity transforms them, by thinning, into yarns in which the fibres are glued to one another along their length.

According to one aspect of the invention, there is provided a process for sizing slivers or rovings of textile fibres, such process comprising the steps of unwinding the slivers or rovings from a supply thereof, applying a pulling force to the slivers or rovings progressively and smoothly to accelerate the slivers or rovings to a given speed, said pulling force always being slivers than the cohesion force between the fibres constituting the silvers or rovings; thereafter flattening the slivers or rovings; dipping the slivers or rovings into a bath of size; drying the sized slivers or rovings and winding up the sized slivers or rovings on a bobbin.

With such a process it is possible to form slivers or rovings which lead themselves to the manufacture of textile articles of all sorts, such as net or mesh articles, knitted articles, laps, carpets or tufted articles, or interlaced articles such as fabrics, without the necessity to transform the rovings into yarns.

Thus, the slivers or rovings are constituted by fibres glued partially to one another to acquire the necessary cohesion to be worked without substantial deformation. Moreover, such slivers or rovings lend themselves without difficulty to the operations of weaving or knitting. The qualities of the textile article formed from the slivers or rovings temporarily consolidated are fully evident after elimination of the size once the article is manufactured.

These articles present then an exceptionally soft touch, a great suppleness, apparent increased volume and can be thermally insulating and have a brilliance considerably superior to textile articles formed from a conventional yarn.

Because the sized slivers or rovings can be utilized directly on looms or knitting machines, one saves, for a textile article formed from rovings according to the invention, at least the cost price of the transformation of the rovings into a twisted yarn or cable.

The invention also provides apparatus for forming sized slivers or rovings, such apparatus comprising a frame having a feed bobbin for slivers or rovings mounted for free rotation substantially without friction therein; a vat of size, a first pair of pressure rollers mounted between said feed bobbin and said vat, a second pair of pressure rollers mounted downstream of said vat of size, a drier mounted downstream of said second pair of rollers, a windup bobbin positioned to receive slivers or rovings from said dryer and drive means to drive at least one of the rollers of each of said pairs of pressure rollers at a controlled speed. Thus, the slivers or rovings can be accelerated progressively and smoothly and the pulling force does not exceed the natural cohesion force of the fibres and can be dipped into the bath of size without the fibres being pressed one against the other and without the initial regularity of the rovings being destroyed.

Finally, the invention provides a textile article formed from slivers or rovings, which may be produced by the process or using the apparatus of the invention, and the slivers or rovings having fibres which are not heckled and have very little or no twist.

In order that the invention will more fully be understood, the following description is given, merely by way of example, reference being made to the accompanying drawings, in which:

FIG. 1 shows schematically one embodiment of apparatus according to the invention;

FIG. 2 represents schematically the drive device for the pressure rollers and for the rollers of the drier; and

FIG. 3 is a perspective view of the rollers of the drier of the apparatus.

In FIG. 1, the feed bobbin 1 on which are wound slivers orrovings 2, is mounted so as to be freely rotatable without friction on the lateral pointed andcoaxial ends 3. Theseends 3 are located in ball bearings 4, mounted on an intermediate support 5 disposed on a frame 6, which itself is capable of turning around an axis XX perpendicular to the axis of the bobbin 1 by means of a transmission formed by a pulley 7 associated with a drive belt 8.

The slivers orrovings 2 unwind from the bobbin 1 and pass successively between a first pair of pressure rollers 9 and 10 disposed upstream of asize bath 11, then into the latter between a second pair ofpressure rollers 12 and 13 disposed downstream of the saidvat 11 and then into ahot drier 14.

The lower pressure rollers 10, 13 have smooth steel surfaces, whereas theupper pressure rollers 9 and 12 can be covered with a substance having a high coefficient of friction for example rubber to ensure a positive drive to the fibres of the roving 2 between the pairs of rollers 9, l0 and 12, 13.

Thesize vat 11 contains a bath of size 11a and is provided with adip roller 15 adjustable in height to guide and totally immerse the slivers orrovings 2 in the bath 1 la.

The temperature of the bath of size 11a is maintained constant by means of a water bath 16 heated by a resistance 17 fed through athermostat 18 equipped with a contro thermometer 19.

Thepressure rollers 9 and 12 are each provided with a pressure regulator comprising alever 20 and 21, pivoted at oneend 22 and 23, and carrying respectively a bearing for theshafts 24 and 25 of therollers 9 and 12, and at theother end weights 26 and 27 adjustable in position.

After passage between thepressure rollers 12 and 13, the sized slivers or rovints 2' enter into thehot air drier 14 through an entry opening 28 arranged laterally in the saiddrier 14 near its upper end.

Within the cabinet of thedrier 14 are twoseries 29 and 30 ofreturn pulleys 29', 29" and 30', 30", the pulleys of each series being mounted on thesame shaft 31 or 32 respectively, the pulleys being so disposed that a pulley of the upper set is in the same vertical plane as the pulley on the lower set situated immediately downstream thereof.

At its lower part thedrier 14 is provided with an entry opening 33, for hot air of which the temperature is regulated by a thermostat, of which only a thermometer 34 is shown in FIG. 1.

The sized and dried slivers orrovings 2" leaves thedrier 14 through an outlet opening 35 provided at its lower end and is wound up on a wind-upbobbin 36, with afriction drive 37 to maintain a constant tension on the slivers orrovings 2" downstream from thedrier 14.

According to one embodiment of the invention, an oiling orwaxing apparatus 38 is disposed in the path of the slivers orrovings 2" between theexit 35 of thedrier 14 and the rewindingbobbin 36.

One can equally, with advantage, provide an oiling or waxing apparatus 38' between thedownstream pressure rollers 12, 13 between the entrance to the drier 28.

In certain cases, notably for the acceleration of the roving and when the roving is very fragile by virtue of the weak force of cohesion between its constituent fibres, it can be advantageous to provide a support and transport filament constituted preferably from a material different from that of the slivers or rovings.

In FIG. 1, this support andtransport filament 39 unwinds from abobbin 40 and is placed in contact with the slivers orrovings 2 unwinding from the bobbin 1 by means of a frusto-conical yarn guide 41, the larger base of which is directed towards bobbin 1.

The support andtransport filament 39 associated with the slivers orrovings 2 passes successively between the upstream pressure rollers 9 and 10, through the sizing bath 11a between thedownstream pressure rollers 12 and 13 and then into thedrier 14.

The support andtransport filament 39 and the sized slivers orrovings 2 are separated from one another, for example, at the moment where they reach thefirst pulley 30 of the lower series ofpulleys 30, that is to say before the sized rovings are completely dried.

At this'moment, the sized slivers or rovings 2' makes a turn around this first pulley 30' and rises towards the followingupper pulley 29 while thesupport filament 39 leaves thedrier 14 through a lower exit opening 42 and is rolled up on a rewind bobbin 43.

According to another embodiment of apparatus, the support and transport filament can be constituted by an endless filament. As shown in the drawings in dashed lines in FIG. 1, the endless support andtransport filament 39 leaves thedrier 14 through an exit 42 and passes successively on a drive roller 44 and on atensioning roller 45 before joining the slivers orrovings 2 in the yarn guide 41 and continues on its path in common with the slivers orrovings 2 until the drier, where its separation with the said slivers or rovings is effected in the same manner as in the preceding embodiment.

In FIG. 2, the upstream pressure roller 9 anddownstream pressure roller 12 as well as theshaft 31 of theupper series 29 of pulleys of thedrier 14 are rotated by a transmission system having a relative adjustment, by

adrive motor 46 having a fly wheel coupled to its rotor, the saidmotor 46 being, moreover, coupled to aspeed variator 47 and provided withreduction gear 48.

This transmission system includes adrive belt 49 connecting theoutput shaft 50 on the reduction gear to theshaft 25 of thepressure roller 12. This shaft 51 is coupled firstly to theshaft 31 by a V-belt 52, which passes around pulleys 53 and 54 of which one is fixed to theshaft 25 and the other to theshaft 31, and, secondly, to the pressure roller 9 by a V-belt 55 and passing around pulleys 56 and 57 of which one is fixed to theshaft 24 and the other to theshaft 25 of thepressure roller 12. The discs of thepulleys 53, S4, 57 and 56 are of adjustable separation and define, between their bevelled peripheral faces grooves having a depth adjustable as a function of the spacing between the discs.

According to FIG. 3, each of the series of theupper pulleys 29 andlower pulleys 30 of thedryer 14 is constituted by a roller of which the first disc has a very small coefficient of friction and is anti-adhesive, the roller comprising a series of coaxialannular grooves 29', 29" and 30, 30".

The support andtransport filament 39 associated with the sized slivers orrovings 2 passes on the first upper pulley 29' and separates from the sized slivers or rovings 2', for example at the moment when the said sized slivers orrovings 2 reaches the firstlower pulley 30.

ln operation, the slivers orrovings 2 are progressively and smoothly accelerated by the drivenrollers 9 and 12, cooperation with rollers and 13, and by the series of drivenpulleys 29 of the drier 1. The force applied for this purpose on the slivers orrovings 2 is such that it remains always below the natural cohesion force of the fibres constituting the slivers orrovings 2. The pulling force is preferably below 5 to 20 cN. The application of a weak pulling force on the slivers orrovings 2 is possible due to the motor-reduction-gear 46, 48 provided with aspeed changer 47 and by virtue of the very small frictional forces exercised on the supply bobbin 1. These friction forces are, in general, less than several cN by virtue of the mounting of the bobbin 1 between thepoints 3 located in the ball bearings 4.

The slivers orrovings 2 are thus accelerated progressively until they reach the predetermined feed speed through the apparatus which can reach 30 m/minute or even more.

The mounting of the bobbin 1 on the rotatable frame 5 permits removal of several turns of twist from the slivers orrovings 2. This is, for example, necessary when the slivers or rovings have been rolled on the bobbin with several turns of twist to give to the fibres of the slivers a better hold, making them suitable for initial winding. It should be understood, when one talks of a small twist, one must understand a twist of several turns per meter but this is not comparable with a normal twist comprising hundreds or even thousands of turns per meter.

The upstream pair of pressure rollers 9 and 10 flattens the slivers orrovings 2 before they are immersed in the bath of size 11a by thedip roller 15. Thus, it is possible to force air between the fibres to increase the surface of contact between the slivers orrovings 2 and the size.

The downstream pair ofpressure rollers 12 and 13 compresses the sized slivers orrovings 2 after their soaking in the bath of size 11a, thus improving the distribution of the size into the interior of the said slivers or rovings and to reject any excess size. It is possible to regulate the degree of flattening of the slivers or rovings by variation of the pressure on the rollers and to regulate the quantity of size expressed from the sized slivers orrovings 2 by an adjustment of the pressure applied by therollers 12 and 13.

Certain textile fibres undergo, during their dampening by the size, a modification of their length in general, less than 2 percent. To take into account any such increase or decrease, the spacing between the discs of at least one of thepulleys 56, 57 can be regulated in the appropriate sense such that the upstream rollers 9 and 10 turn with a peripheral speed less than or greater than that of the downstream pulleys l2, 13. In a similar fashion, the control of the spacing of the discs of at least one of thepulleys 53, 54 permits control of the speed of movement of the sized slivers orrovings 2 betweendownstream pressure rollers 12, 13 and the drier 14. The temperature of the drying air in the drier 14 is in general between 40C and 150C.

The size bath 11a is of a composition adapted to the nature of the filaments of therovings 2 and can contain a plasticising substance, the purpose of which is to give to the sized and dried slivers orrovings 2 the necessary suppleness to permit the use of the said slivers or rovings on a loom or on a knitting machine. The temperature of the size bath 11a is maintained constant and is, according to the particular size used, between 20C and C.

At the outlet to the bath of size 11a and/or of thedryer 14, the slivers or rovings are oiled or waxed, to lubricate the surface of the sized slivers or rovings. According to the particular case, this oiling operation is effected, either when the sized slivers are still wet and- /or when the sized slivers are already dry.

The support andtransport filament 39 or 39 is sometimes necessary to support the silvers orrovings 2, at least during the beginning of the unrolling of the slivers or rovings. Nevertheless, one can, in general, interrupt the support andtransport filament 39 or 39' after the unwinding of a dozen or so meters ofslivers 2, unrolling which is sufficient to obtain the speed of passage through the apparatus.

Thesupport filament 39 is separated from thesized slivers 2 preferably, when the latter is still wet. This separation is effected, for example, in theheater 14 at the moment the sized slivers or rovings 2' and thesupport filament 39 pass around thesecond pulley 30 of theheater 14, the pulley 30' being positioned, in the sense of movement of the slivers orrovings 2, immediately after the entry 28 into the drier 14. At the exit of the drier 14, the dried slivers orrovings 2" are rolled up under regulated tension on thewindup bobbin 36 driven by thefriction drive 37.

By way of example, there is indicated here below, the conditions in which the slivers or rovings of polyamide, and or polyester, according to the invention, can be formed.

1. Material-polyamide fibres of 1.7 dtex Length of fibres40 mm Count of the unsized rovings-200 tex Twistseveral turns per meter, therefore practically no twist Upstream pressure roller force-l daN/cm Temperature of the size bath-50C Sizing substance5 percent aqueous solution or pure polyvinyl alcohol, of which the degree of polymerisation is between 1,700 and 1,800

Normal speed through the apparatusl meters/minute Pressure force of the downstream rubber pressure roller 9 on the steel roller 10-2.5 daN/cm. per generatrix Drying air heated to 90C Rewinding tensioncN/roving This polyamide roving has been worked with success by knitting at a setting of l and 1 on a gauge E8 (needles to the inch) machine at a tightness of 12.

cent of a wax known commercially as TRUNAU 914.

The roving of polyester has been worked with success by knitting at a setting of 1 and l on a gauge E8 (needles to the inch) machine at a tightness of 10.

3. MaterialWool of which the fibres have a mean diameter of 10 to 20 um Count of the sized rovingsl tex Upstream pressure force-IdaN/cm Temperature of the size bath-50C Sizing substance-aqueous solution of 5 percent of pure polyvinyl alcohol of which the degree of 40 polymerisation is between 1,700 and 1,800

Sizing substance also comprises a solution of 1/ 100 of anti-forming agent, known under the commercial name NOPCO 1497V Downstream pressure roller force-2.5 daN/cm Spped of passage through the apparatus20 m/minute Drying air at a temperature between 80C and 90C.

This roving of wool has been worked with success by return stitch knitting, on gauge E6, tightness 7, 8 or 9.

Textile articles thus obtained can be treated in a bath to eliminate the size such that the fibres of the rovings recover their initial characteristics.

We claim 1. A process for sizing slivers or rovings of textile fibres while maintaining said fibres substantially in their initial state as slivers or rovings whereby said fibres may be worked without substantial deformation, said process comprising the steps of:

a. unwinding the slivers or rovings from a feed bobbin by applying a pulling force to the slivers or rovings progressively and smoothly to accelerate the slivers or rovings to a given speed, said pulling force always being less than the cohesion force between the fibres constituting the slivers or rovings;

b. flattening the silvers or rovings;

c. guiding the slivers or rovings in their flattened state through a bath of size;

d. drying the sized slivers or rovings; and

e. winding up the sized and dried slivers or rovings on a rewind bobbin.

2. A process as claimed in claim 1, wherein the pulling force is less than 50 cN.

3. A process as claimed in claim 1 and further comprising the step of turning the slivers or rovings around their axis at several turns per meter during said unwinding thereof, said turning being to the extent effective for removal of twists existing in said slivers or rovings prior to said unwinding.

4. A process as claimed in claim 1 and further comprising the step of oiling the slivers or rovings.

5. A process as claimed in claim 1 and further comprising the step of supporting the slivers or'rovings before said flattening step on a support and transport filament and separating the slivers or rovings from said filament before the end of the drying step.

6. A process as claimed in claim 1, wherein the size is selected from the group consisting of a solution of pure polyvinyl alcohol, a solution of polyvinyl alcohol wherein the polyvinyl alcohol contains acetyl and sulphate groups, and a solution of acrylic copolymer.

7. A process as claimed in claim 6, wherein said size contains a plasticizer.

8. A process as claimed in claim 1, wherein the size is capable of being dissolved from the sized slivers or rovings when in the dry state.

' UNITED STATES PATENT OFFICE CERTIFICATE OFCORRECTION Patent 3,79 3 Dated February 12 197 4 InVefitOflB) Richard Adrien Schucz et al It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

.Column 2, line 33, after "being" delete "slivers" and insert in place thereof --less--.Column 2,line 20, "produce" should read --produces-.Column 2, line &0, "lead" should read lend--.Column 3,, line 58, "contro" should read -control-. Column 4,line 26, after "13" insert -and-. Column 5,line 31, "cooperation" should read -cooperating--. Column 5,line 32, "drier 1" should read drier l l-. Column 7, line 1", "or" should read -of-. Column 7,line 21, "plymer" should read "polymer"; Column 7, line 42, 1/100" should read- --1/lOO0--.

Signed and sealed this 30th day of July 1974.

(SEAL) Attest: V

MCCOY M. GIBSON; JR. I C. MARSHALL DANN Attes'ting Officer Commissioner of Patents

Claims (8)

1. A process for sizing slivers or rovings of textile fibres while maintaining said fibres substantially in their initial state as slivers or rovings whereby said fibres may be worked without substantial deformation, said process comprising the steps of: a. unwinding the slivers or rovings from a feed bobbin by applying a pulling force to the slivers or rovings progressively and smoothly to accelerate the slivers or rovings to a given speed, said pulling force always being less than the cohesion force between the fibres constituting the slivers or rovings; b. flattening the silvers or rovings; c. guiding the slivers or rovings in their flattened state through a bath of size; d. drying the sized slivers or rovings; and e. winding up the sized and dried slivers or rovings on a rewind bobbin.

2. A process as claimed in claim 1, wherein the pulling force is less than 50 cN.

3. A process as claimed in claim 1 and further comprising the step of turning the slivers or rovings around their axis at several turns per meter during said unwinding thereof, said turning being to the extent effective for removal of twists existing in said slivers or rovings prior to said unwinding.

4. A process as claimed in claim 1 and further comprising the step of oiling the slivers or rovings.

5. A process as claimed in claim 1 and further comprising the step of supporting the slivers or rovings before said flattening step on a support and transport filament and separating the slivers or rovings from said filament before the end of the drying step.

6. A process as claimed in claim 1, wherein the size is selected from the group consisting of a solution of pure polyvinyl alcohol, a solution of polyvinyl alcohol wherein the polyvinyl alcohol contains acetyl and sulphate groups, and a solution of acrylic copolymer.

7. A process as claimed in claim 6, wherein said size contains a plasticizer.

8. A process as claimed in claim 1, wherein the size is capable of being dissolved from the sized slivers or rovings when in the dry state.

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