US3099907A - Process for obtaining textile end products using discontinuous fibers - Google Patents

Description

Aug. 6, 1963 M. MASUREL ETAL 3,099,907

PROCESS FOR OBTAINING TEXTILE END PRODUCTS USING DISCONTINUOUS FIBERS Filed Dec. 4, 1961 2 Sheets-Sheet l A TTO/FNEKS Aug. 6, 1963 M. MASUREL ETAL 3,099,907

PROCESS FOR OBTAINING TEXTILE END PRODUCTS USING DISCONTINUOUS FIBERS Filed Dec. 4, 1961 2 Sheets-Sheet 2 g- 4 INVEN TOPS A TT'ORNEYS United States Patent Claims priority, application Great Britain Dec. 8, 1960 7 Claims. (Cl. 57-156) Hitherto in order to obtain from discontinuous fibers textile products ready for use, termed generally end products, such as knitted wear and fabrics, there was used as the starting material yarn spun on continuous spinning frames, "or much more rarely on spinning mules.

The only exceptions to this general practice are nonwoven fabrics; for example felts or hinder impregnated card webs.

The conventional procedure is as follows:

To obtain the yarn one starts from a sliver or roving of discontinuous fibres obtained from the last spinning stage (finishers or roving frames) and this sliver or roving is subjected in the order set out below to the following processes which are independent of each other and are carried out on separate machines.

First of all the silver or roving is drawn by a drawing process in order to thin it and bring it down to the required fineness or count for the yarn to be obtained. It is then twisted to give strength to the yarn and at the same time the yarn thus obtained is wound onto a bobbin.

This work is carried out either in a continuous manner (continuous spinning frame) or in a discontinuous manner (mule), the operations of drawing and twisting then being separate from the mule winding operations.

The yarn thus obtained by continuous spinning is then taken up by bobbins in an amount limited by weight (generally 100 to 200 grams of yarn per bobbin). It is then generally rewound on winding machines which permit the yarn to be supplied on large bobbins, generally conical in form (normally weighing l-Z kilograms) so that it can then be used at a better production rate on the make-up machines.

The customary procedures may also provide for a certain number of ancillary operations such as retwisting (uptwisting or downtwisting) or doubling which consists in twisting together the single threads obtained on spinning frames in order to give them greater strength and better appearance.

It is the large bobbins aforesaid that are used for the manufacture of end products ready for use such as knitted wear, fabrics, etc.

This customary procedure possesses the following main disadvantages: slow speed of the continuous spinning frame and the impossibility of guaranteeing continuity of various operations, i.e. their complete automation.

In particular it is known that the speed of the spinning frame is limited by the following factors:

To ensure strength in the sliver or roving obtained after drawing, it is permanently twisted, i.e. in such a manner that the yarn obtained retains its degree of twist permanently, even after the winding.

For this purpose the fine sliver or roving coming from the rolling unit is passed through a traveller displaceable on a ring and is wound by a vertical spindle, rotating at a great speed, which by virtue of the presence of the traveller imparts torsion to the thread while winding it.

The rate of production of the yarn is limited by the high rate of torsion, or rather by factors which are closely related therewith:

Speed of rotation of the spindle (of the *order of 10,000 r.p.m.) limited by the weight of the bobbin;

3,099,907 Patented Aug. 6, 1963 Speed of displacement of the traveller which depends on the rotation of the spindle and high rate of torsion to be given to the yarn, but which is limited to 32-35 metres per second for technical reasons: undue heating of the metal of the traveller.

Generally the speed of the yarn, and thereby its production is thus limited to 2025 metres/minutes at the maximum.

The low rate of production of yarn by continuous spindle spinning machines which is thus occasioned has as a consequence that the quantity of yarn produced is too small for an extensive captial investment.

At [this stage it may be pointed out that uptwisting machines for continuous yarns (silk or man-made fibres) which do not need a preliminary drawing eliminate the bobbin, obviously cutting out the disadvantages of the traveller by rotating the feed bobbin instead of the receiver traveller, but still retaining the disadvantages due to the limitations on the speed of the spindle.

There should also be noted the permanent twist devices which apply the principle of the hollow spindle and double twist. These devices are only just coming into use commercially and are complicated and costly.

' It has also been proposed to overcome the costliness of the operation of continuous spinning by one of the devices mentioned above, by replacement of a spinning operation without twist called false twist.

Following this known method the thinned sliver or roving brought down to the required size for the yarn to be made, passes through a device such as a rotating disc with an eccentric hole through which the yarn being formed passes, Without a subsequent winding device, and which twists the sliver or roving while transforming it into yarn, but only in a temporary manner.

This operation is currently described as false twist; in this case the twist thus applied is only temporary and the yarn tends to return to the sliver state, so that the twist has to be retained by impregnating the fibres making 'up the yarn with a binder.

'by the convention process, by rendering the false twist permanent and also increasing the resistance to breakage of the fine sliver as it is being formed into a thread.

This known process where true twist is replaced by false twist made permanent by means of a binder, re-

quires as in the conventional process, winding of the yarn obtained and its use at a later stage on a machine for making end products ready for use. The speed of false twist operation is not limited by the same technical conditions as that of true twist by the traveller but it does generally call for a drying process for the yarn to which the binder has been applied in the wet state.

Since the rate of feed of the yarn is high, these drying operations are a delicate process if a perfectly dry yarn is to be obtained, operating costs are thus being increased while at the same time losing some of the advantages of the high production speed (of the order of metres/minute).

The presence of a binder in the yarn tends moreover to limit its field of application, since the yarn no longer has a fibrous touch and lacks flexibility.

3 manent, the yarn to which this provisional twist is applied being used directly in the machine for manufacturing the end product.

By reason of this immediate usage, the provisional twist is retained long enough for the manufacture of the end product, and it is the retention of the fibres within the end product which afterwards .maintains the cohesion of the yarn reverting to a fine sliver and a variable fraction of the twist.

This twist retention is achieved by means of the tying made by the machine: stitches and overlapping in the case of knitting machines, tying of the warp and of the weft by simple crossing as on a weaving loom, or even eventually tying by chain stitches.

It will be noted here that the term provisional twist has been used rather than .the term false twist. In eifect the term false twist is normally applied not only to the present case and that previously recalled, where the yarn is mobile, i.e. displaces itself all the way through the device applying the false twist, but also in the case where the yarn is immobilised at both ends. Thus when the yarn is fixed, the false twist is permanent, while in the present case it is only provisional, as pointed out in the case of the known process, implying thereby the use of a binder for the manufacture of this twist.

As has been explained this process gives the advantage that the provisional twist device permits much greater speeds to be attained (it being possible to attain, if needed, many tens of thousands of rpm.) and in any case to supply yarn with provisional twist at a speed .at least equal to the feeding speed of the most speedy knitting and weaving machines. Consequently sucha machine can be directly fed from a drawing head and provisional twist device, without the intermediary of the customary spindles for the finished yarn and the feed bobbins for the make-up machine, with a much cheaper apparatus and with a considerable saving of time.

In addition, contrary to what .one would at first expect, the quality of the end product, far from being inferior, is found to be improved.

The end product has a much more even appearance; the provisional twist evens out the arrangement of the fibres, so that in the case of a mixture of fibres of differing colours, the product presents a more uniform colour.

The product has less defects in view of the absence of knots which commonly arise at the ends of the yarn on each bobbin.

In addition, there are practically no yarn breakages as has been pointed out above. In any case, the provisional twist twists the fibres immediately as they come from the drawing device, and since the rate of twist is not limited, .the strength of the yarn can be sufiicient to prevent any breakage and to trap any floating fibres, which is not always the case in conventional continuous spinning.

Finally the end product has a very much better feel, since the fibres are no longer twisted and have not been impregnated with any chemical agent before use on the make-up machine, unless this is done deliberately for special purposes.

Other objects, features and advantages of the invention will be apparent from the following specification, when taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a schematic sectional view and illustrates an apparatus constructed and assembled in accordance with the teachings of the present invention;

FIG. 2 is a schematic plan view of the apparatus illustrated in FIG. 1;

FIG. 3 is a view similar to FIG. 1 illustrating a second embodiment of the invention; and

FIG. 4 is a schematic plan view similar to FIG. 1 but illustrating the embodiment of FIG. 3.

The apparatus shown in FIGURES 1 and 2 comprises for each thread or yarn to be supplied to the make-up machine 1 (knitting machine or loom) a drawing device on conventional lines as indicated generally by the numeral 2 and a temporary twist device. This twist device can, for instance, be made up of a disc or pulley 3 rotating about an axis 4 disposed in an extension of the drawing frame and pierced with an eccentric hole 5, through which pass the fibres 6 as they come from the drawing frame, whereby these are temporarily twisted, as at 7. In a modification the fibres may be passed around the periphery of a rubber-covered cone (not shown).

The disc may rotate in a continuous or intermittent manner in one or other direction but always giving a temporary twist which completely or partly disappears when the yarn is made up in the make-up machine.

The speed of rotation and thereby the twisting speed of this device is correlated with the feed speed of the yarn. When the drawing device stops the twisting device must also stop.

The make-up machine 1 can be 'of any type so long as it ensures the tying of a thread with other threads to make up a product ready for use. For illustrative purposes this rcan be for example, a knitting machine of any type: rectilinear knitting machines (including full-fashioned knitting machines), knitting machines, tricot machines (including Raschel machines). In such cases the tying is ensured by the interlacing of the stitches.

A loom in which the tying is ensured in the normal manner by the crossing of the warp threads with the weft threads and/ or according to a new method of chainstitches for tying together the warp threads or the weft threads, or solely the warp threads.

It will be noted that the apparatus which has just been described forms in actual fact a single machine, comprising as many drawing devices and at least as many temporary twist devices as there are threads fed into the make-up machine. It is characterised in that the speed of yarns or threads as they leave the drawing frame must be the same as their feed speed to the make-up machine.

On the other hand the threads enter the makeup machine continuously :or intermittently according to the type of machine. In the latter case the drawing and temporary twist devices also work intermittently.

The embodiment illustrated in FIGURES 3 and 4, illustrates a modification wherein it is possible to .bring together sliver fibres NN issuing from the double drawing device which have already been separately twisted .in the same direction or in opposite directions by two temporary twist devices 3 and 3'; the threads 6-6 are then twisted in a second false twist device '8 (identical or not to the preceding ones) but common to the temporary thread twist device 6 and 6. Thus it vw'll be seen that when twist devices 3 and .3 are rotated in the same direction, a temporary twist in the same direction Will be imparted to all of the threads and that when the twist devices 3 and 3 are rotatedin opposite directions, one-half of the threads will have imparted thereto a temporary twist in one direction and the other of the threads a temporary twist in the other direction. The twist device 8 may be rotated in either direction to obtain with the twist devices 3 land 3' the desired results in the end product.

In such a case one obtains a finished article 7a with threads showing several plies or ends and not made up of a single thread. This allows the elimination of twist or doubling operations in separate machines.

.Another modification consists in using a single yarn or ends obtained from a little tow of continuous yarn which has been broken.

In this case the feed slivers are no longer discontinuous slivers, but little tows of continuous yarn or filament which are broken up into discontinuous fibres through tensioning and cracking during the stretching in a special drawing device 2.

A compound thread can also be used, either single or multi-ended obtained from slivers of discontinuous fibres and one or more continuous threads, textured or otherwise. The continuous threads are then fed directly to the take-off cylinders of the drawing frame but without going via the feed cylinder and stretching device.

The following examples are given which, however, are to be regarded as non-limiting.

Example 1 A sliver of wool of metric number 0.7 (or 700 metres to the kilogram) is employed which is prepared for use in the mechanisms represented by the FIGURES l and 2. This sliver is drawn by the feed rolls of the drawing frame which subjects it to a drawing rate of 20. In this manner it is delivered by the delivery rolls of the said drawing frame with a metric number of 14. The speed of the delivery rolls is in the neighbourhood of 50 metres a minute whereas that of the feed rolls is of 50/20 metres a minute that is in the neighbourhood of 2.50 metres a minute. This sliver -fined to number 14, is temporarily twisted by a temporary twisting apparatus for example an eccentric hole in a pulley turning at 5000 rpm. Thus this sliver becomes a temporarily twisted thread of number 14 which is fed directly into a circular machine of diameter of 94 millimetres, of gauge 9 corresponding to the drawing gauge of the thread employed.

This machine seen on small scale only uses the thread at a speed of about 50 m./minute equal to the speed of the delivery rolls of the drawing frame. Thus knitwear is obtained where the simple thread employed loses little by little its twist according to the rate of knitting. This allows knitwear to be obtained with a soft touch and of great evenness.

Example 2 Two wool slivers of metric number 1.4 (or 1.4 kilometres to the kilogram) are employed which are caused to enter in the mechanism represented by the FIGURES 3 and 4. These two slivers are drawn separately by the feed rolls of the drawing frame which submits them for example to a drawing rate of 20. These slivers are delivered by the delivery rolls with a metric number of 28. The speed of the delivery rolls is about 70 metres/minute whereas that of the feed rolls is of 70/ 20 millimetres a minute that is about 3 .50 metres/ minute.

These two slivers fined to number 28 are temporarily twisted separately in the same direction or in opposite directions in the temporary twisting apparatus 3 and 3' turning at 6000 rpm.

Thus they become temporarily twisted threads of number 28 which are joined side by side in a temporary twisting apparatus 8 common to the two threads turning at 3000 rpm. When the twisting apparatus 3 and 3' are turning in the same direction, twisting apparatus 8 is generally turning in the reverse direction. Thus there is obtained a temporary twisted and re-twisted thread of drawing number 2/28=14 which is fed directly to the circular machine of 94 millimetres and of gauge 9 corresponding to the draw of thread utilised.

The speed of utilisation of the thread in the knitting machine is about 70 metres a minute equal to the speed of the delivery rolls.

The knitting obtained has a good touch because the temporary twisted thread loses little by little its twist at the rate at which it is knitted and has a greater even- 6 ness in appearance (because use is made of twisted thread).

What we claim is:

1. A process for manufacturing textile end products in a make-up machine comprising the steps of drawing slivers of discontinuous fibres into threads of the fineness of said end product, imparting a temporary twist to said threads, feeding said temporary twisted threads directly to the make-up machine, forming said threads into said end product in said make-up machine while permitting said temporary twisted threads to untwist, and recovering said end product from said make-up machine.

:2. A process as in claim 1 in which the temporary twist is applied by passing the thread through an eccentric hole moving in a rotating path.

3. A process as in claim 1 in which said temporary twisted threads retain a variable fraction of said temporary twist in said end product.

4. A process as in claim 1 in which said temporary twisted threads revert to substantially completely untwisted threads in said end product.

5. A process for manufacturing textile end products in a make-up machine comprising the steps of drawing slivers of discontinuous fibres into threads of the fineness of said end product, imparting a temporary twist to said threads, joining said temporary twisted threads into pairs disposed in side by side relationship, imparting a temporary twist to said pairs of threads to form a temporary twisted assembly, feeding said temporary twisted assembly directly to the make-up machine, forming said temporary twisted assemblies of pairs of threads into said end product in said make-up machine while permitting said temporary twisted threads to untwist, and recovering said end product from said make-up machine.

6. A process as in claim 5 in which said temporary twist imparted to said threads is in one direction and said temporary twist imparted to said temporary twisted assemblies of pairs of threads is in the opposite direction.

7. A process for manufacturing textile end products in a make-up machine comprising the steps of drawing slivers of discontinuous fibres into threads of the fineness of the end product, imparting a temporary twist to onehalf of said threads in one direction and to the other half of said threads in the other direction, joining oppositely twisted threads into pairs disposed in side by side relationship, imparting a temporary twist to each of said pairs of threads to form a temporary twisted assembly, feeding said temporary twisted assemblies of pairs of threads directly to the make-up machine, forming said temporary twisted threads into said end product in said make-up machine while permitting said temporary twisted threads to untwist, and recovering said end product from said make-up machine.

References Cited in the file of this patent UNITED STATES PATENTS 760,619 Fredenburgh May 24, 1904 819,298 Martin May 1, 1906 1,953,368 Spring Apr. 3, 1934 2,373,091 Astley Apr. '10, 1945 2,807,130 Trapido et al. Sept. 24, 1957 2,921,455 Furge Jan. 19, 1960 FOREIGN PATENTS 253,415 Great Britain June17, 1926

Claims (1)

1. A PROCESS FOR MANUFACTURING TEXTILE END PRODUCTS IN A MAKE-UP MACHINE COMPRISING THE STEPS OF DRAWING SLIVERS OF DISCONTINUOUS FIBRES INTO THREADS OF THE FINENESS OF SAID END PRODUCT, IMPARTING A TEMPORARY TWIST TO SAID THREADS, FEEDING SAID TEMPORARY TWISTED THREADS DIRECTLY TO THE MAKE-UP MACHINE, FORMING SAID THREADS INTO SAID END PRODUCT IN SAID MAKE-UP MACHINE WHILE PERMITTING SAID TEMPORARY TWISTED THREADS TO UNTWIST, AND RECOVERING SAID END PRODUCT FROM SAID MAKE-UP MACHINE.

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