Title of Invention

A METHOD AND A DEVICE FOR SPINNING YARN WITH REDUCED HAIRINESS

Abstract

This invention relates to a method of spinning yarn with reduced hairiness. Yarn from the drafting zone is fed to the left or right bobbin adjacent to the bobbin directly below the drafting unit. This invention afeoincludes a device for spinning yarn with reduced hairiness wherein the spindle assemblytsdisposed with respect^to the drafting zone such that the roving is fed to the left or right bobn and not the bottorchdrectly below it.

Full Text

This invention relates to a method and a device for spinning yarn with reduced hairiness. Due to stringent quality requirements demanded by the global yarn market, efforts are being made for continual improvement of yarn quality, particularly through process optimization, proper raw material selection, machinery design modification and the like. Yarn hairiness is one of the properties which is considered important during yarn procurement by the importers. Indian cotton yarn is equivalent to the best quality yarn in the world in most of the parameters such as strength, evenness and lack of imperfections. But, generally these yarns are inferior in yarn hairiness as compared to the average yarn quality with respect to hairiness which is uster 50% level. A good number of studies have been undertaken oven the years and various measures have been implemented to reduce the yarn hairiness. It is observed that yarn hairiness increases with lower twist, higher spindle speed, roughness of the ring and traveller surfaces, mismatch of ring and traveller and eccentricity of the ring spindles. The spinning triangle and spinning angle affect fibre breakage considerably while the spinning triangle also influences yarn structure. Lately, various developments have taken place to modify the twist triangle zone which resulted in considerable reduction in yarn hairiness. However, many of these improvements are expensive and could not be retrofitted in the existing ring spinning frames. An attempt has therefore been made to reduce yarn hairiness using the existing ring frames. This objective is achieved by modifying the yarn path on the ring frames. The spinning triangle, though considered symmetrical is not so in reality. Reducing the height of the' spinning triangle is found to improve the yarn hairiness. One way of reducing the height is by increasing the twist level to form a smaller triangle during spinning. This is found to have limitations as hairiness increases after a certain level of twist and twist liveliness of the yarn. Yarn path modification also results in spinning triangle alteration. In the trials under this study, the spinning triangle was modified by using 'left-diagonal' and 'right-diagonal configuration'. In the 'left-diagonal' arrangement yarn, the yarn issuing from a drafting unit is taken up by a bobbin adjacent to the right of the drafting unit instead of the bobbin just directly below it. Similarly, for the 'right-diagonal' configuration, the yarn from a drafting unit is taken to the adjacent bobbin to the left of the drafting unit instead of the bobbin directly below it. Yarn properties and spinnability of the yarn produced by this method were studied. Knitted fabrics were produced using this yarn and the appearance of grey and dyed fabrics were assessed. Diametre of the yarn were measured using image analysis system and the compressibility of the knitted fabrics were measured. Yarn of nominal count 36s and 60s Ne were spin using left diagonal, right diagonal and conventional path by varying the angle of inclination a from 3° - 45° (0 to 70mm displacement) for left diagonal and 3° - 25° (0 to 35 mm displacement) for right diagonal. These yarns were spun using 'Z' twist. Results are reported in table 1 and 2. It can be seen from table 1 and 2 that there is a significant reduction in yarn hairiness as shown by Zweigle Hairiness Tester. The reduction in S3 value are in the extent of 10-30% (36s) & 10-55% (60s) for left diagonal feed yarn as compared to normal path yarn. The right diagonal path showed increased S3 value (15%) in case of 36s count. Other properties such as U%, Mass CV and Imperfections found marginal improvement for diagonal yarn path. The imperfections shows a decreasing trend with reduction 28-54% (60s). The yarn hairiness reduction for both the counts may be due to the increased pre-twisting effect at the right hand side of the spinning triangle when left diagonal path was used. With the left diagonal path, there is an increased concentration of fibre in the right hand side of the "Skew triangle", so an increased number of fibres will be pre-twisted. This pre-twisting improves the control of fibres and allows more fibres to be incorporated into the bulk of yarn structure, thus reducing hairiness. Changes in yarn structure As the drafted strand was fed by diagonal path to the twisting zone, it is expected that the farthest fibres will experience maximum pull and nearest fibres at the nip will have some contraction. This may result in change in yarn structure to some extent. It is seen that the diagonal path yarn have some fibres wrapped around the core. The conventional yarn does not show these wrappings. This may be due to the straightening of some fibres before twisting and contraction of some. As the long fibres wrap the yarn the short protruding fibres are suppressed which may be another reason for significant reduction in yarn hairiness. As also mentioned earlier due to pretwisting of fibres at right hand side of the 'skew triangle', more fibres are incorporated into the yarn structure. Structural studies show that the yarn spun using the diagonal path feed are compact and are less hairy. Results also show that the diameters of diagonal feed yarn are less as compared to the conventional feed yarn. This invention relates to a method of spinning yarn with reduced hairiness which comprises the step of feeding in yarn issuing from the drafting unit to either the left or right bobbin adjacent to the bobbin directly below said drafting unit and thereafter continuing the spinning operation in a known manner. This invention also includes a device for spinning yarn with reduced hairiness which comprises roving bobbins guide rails, for leading said roving to a drafting zone and spindle assembly wherein said spindle assembly is disposed with respect to said drafting zone such that the roving from the drafting zone is fed to either the left or right bobbin of the spindle assembly. This invention also includes yarn with reduced hairiness produced by a method as herein before described. This invention will now be described with respect to the figures shown in the accompanying drawings. Fig. I shows the normal yarn path where the roving from the front roller of the unit is fed to the bobbin directly below it. Fig. II shows right diagonal path as envisaged by this invention, while Fig. Ill shows the left diagonal yarn path. Fig. IV shows the operating diagram with inclined drafting zone. This invention will now be described with respect to Fig. II showing right diagonal displacement of the yarn. Reference letters F.D.R stands for the front drafting roller from which yarn is fed through a lappet hook LH to the bobbin B mounted on the spindle S. SD is the spindle drive while RR is the ring rail. R and T are the ring and traveller respectively through which the yarn pass with angle of displacement (a). In Fig. IV the roving bobbins are shown by numeral (1) which are reeled in appropriate holders (3). Roving is indicated by numeral (2) which pass through guide rails (4) to the drafting zone (5) inclined at an angle of about 45° - 60°. Fine fibre strand emerging from the drafting zone is indicated by numeral (6) which receives the required twist generated by the spindle rotating at high speed. Each revolution of the spindle (8) imparts one twin of twist to the strand. Traveller is indicated by reference numeral (9) and the ring is shown by numeral (10). Advantages of the yam produced by this method are listed below: 1. Improved yam quality by reducing surface hair 2. Reducing end breakage 3. Increase in productivity by reduction of the twist multiplier 4. Compact structure improves packing 5. Reduction in compressibility and size pick up, size cost as well as reduction in pollution particularly due to reduced fly liberation in knitting and weaving operation 6. This mechanism can be employed in the existing machinery with either maintenance or alteration and investment. Though this invention has been described herein above with respect to a specific embodiment, alterations and modifications known to persons skilled in the art are not excluded from the scope and ambit of the appended claims. WE CLAIM: A method of spinning yarn with reduced hairiness comprising the step of feeding the yarn issuing from the drafting unit either to the left or right bobbin adjacent to the bobbin directly below said drafting unit and thereafter continuing the spinning operation in a known manner. The method as claimed in claim 1 wherein the yarn is fed to the left or right bobbin at an angle of inclination of 45° (70 mm displacement) from the normal yarn route. The method as claimed in claim 1 or 2 wherein the yarn is fed to the bobbin through a lappet hook and ring rail assembly. A device for spinning yarn with reduced hairiness comprising roving bobbins, guide rails for leading said roving to a drafting zone, and spindle assembly wherein said spindle assembly is disposed with respect to the drafting zone such that the roving from the drafting zone is fed either to the left or right bobbin of the spindle assembly. The device as claimed in claim 4 wherein said spindle assembly is disposed at an angle of 3° - 45° (0 to 70 mm displacement) to the left and 3° - 25° (0 to 35 mm displacement) to the right. The device as claimed in claims 4 and 5 wherein guide rails, lappet hook, ring and traveller assembly and bobbins mounted on spindles provided with spindle drive means. Spun yarn with reduced hairiness made by a method as claimed in claims 1 to 3. A method of spinning yarn with reduced hairiness substantially as herein described with reference to the accompanying drawings. A device for spinning yarn with reduced hairiness substantially as herein described with particular reference to the accompanying drawings. 9 Spun yarn with reduced hairiness substantially as herein described with reference to the accompanying drawings.

Documents:

016-che-2004-abstract.pdf

016-che-2004-claims duplicate.pdf

016-che-2004-claims original.pdf

016-che-2004-correspondnece-others.pdf

016-che-2004-correspondnece-po.pdf

016-che-2004-description(complete) duplicate.pdf

016-che-2004-description(complete) original.pdf

016-che-2004-drawings.pdf

016-che-2004-form 1.pdf

016-che-2004-form 19.pdf

016-che-2004-form 26.pdf

016-che-2004-form 3.pdf