GB2050292A

GB2050292A - Making core yarn

Info

Publication number: GB2050292A
Application number: GB8002755A
Authority: GB
Original assignee: EVOLUTION SA
Current assignee: EVOLUTION SA
Priority date: 1979-05-11
Filing date: 1980-01-28
Publication date: 1981-01-07
Also published as: GB2050292B; IT8019649A0; FR2456150A1; FR2456150B1; IT1129614B

Abstract

A method and apparatus for the production of yarn having a core covered by a wrapping thread applied at a controlled angle to the core yarn. The core yarn 24 is passed up a hollow spindle 32, the wrapping thread is fed from a bobbin 26, and the ballooning wrapping thread is guided by face 52 to be applied to the core yarn at a controlled angle to the core yarn. <IMAGE>

Description

SPECIFICATION Making core yarn The invention relates to a method for the manufacture of yarns by winding round of a core thread a covering thread (5) which is drawn off in the form of a thread balloon from a covering thread supply bobbin rotating around the core thread.

Such a method is known from public prior use in Germany.

Furthermore from German Patent Specification 2428483 a method for the manufacture of a yarn for wounding around a stretched high orientated spinning yarn is known which is guided through the hollow axle of a rotating filament yarn bobbin with at least one filament yarn which runs from the filament yarn bobbin and which likewise is guided through the hollow axle of the filament yarn bobbin so that the spinning fibres after stretching are wound round with atensioning of the filament of up to 5g preferably 1 9.

The winding round the core thread has among other things the object of influencing the optical properties of the core thread in the sense that to the yarn and to the product to be made from the yarn the optical and feed properties of another material are imparted,forexample, of a staple fibre yarn on a natural fibre base or on a cellulose acetate basis.

It has been proved thatthe thread material made according to the known material in particular with economical winding with covering thread in consequence of unequal placing of the covering thread on the core shown no complete covering of the core with the covering thread and the uncovered places of the core occur which as regards feed properties as well as in particular of regards the optical properties of the thread material which are undesired These faults may be attributed to the fact that too little attention has been given to the angle position of the covering thread in respect of the core on the run.

The invention is based on the problem of elaborating a method of the type designated above such that even with economic covering thread a winding the core is covered to the greatest extent on its whole surface and therefore so-called flasher effects of free lying surface areas of the core thread are avoided.

For the solution of this problem it is proposed according to the invention that the covering thread is applied substantially at right angles to the core thread.

It has surprisingly been proved that by this simple measure the distribution of the covering thread windings on the core thread receives such a uniformitythat a shining of the core thread through the covering thread to an extent hitherto not considered possible is obviated.

The feed angle of the covering thread to the core thread is not limited to precisely 90". It has been provided that even with feed angles deviating from the 90" angle very good results in the sense of the problem of the invention can be achieved in so far as only by means of the thread guide face as maintained at a constant feed angle during the maufacturing procedure of a yarn; of course a feed angle of about 700 to about 1100 can be used but it is still preferred to employ 90". The invention relates furthermore to an apparatus for the carrying out of the method comprising a hollow spindle connected to a rotary drive for the rotationally fixed receiving of a covering thread supply bobbin surrounding the hollow spindle, a delivery mechanism for the speed regulated supply of the core thread from a supply bobbin in one end of the hollow spindle, a draw off mechanism for the speed regulated joint drawing off of the core thread energising from the other end of the hollow spindle and of the covering thread looping around it running off from the covering thread supply bobbin in the form of a thread balloon.

In adaptation to the method according to the invention this apparatus is arranged such that the covering thread or threads is/are guided substantially at right angles to the core thread in its supply area to the core thread by means of a thread guide face rotating round with the hollow spindle.

In practice the invention can be realised in a comparatively simple manner in that the thread guide face is formed by the vinner face of the lid of a can lid which is located on a can surrounding two supply bobbins and rotating therewith.

An up-twisting spindle with a supply bobbin located on the twisting spindle rotating therewith and a cylindrical can likewise rotating and a lid located on this can through the top of which the resulting yarn is drawn off from the supply bobbin coming upwards are known. The application is to a large extent within the scope of the so-called two stage twisting method in which on a ring twisting machine or the like two or more threads are first of all shedded with slight protective twist whereupon the bobbins with the shedded material thus obtained are inserted in the up-twister spindle with the protective can in order to obtain in the second twisting stage the final twist. It is however up till now not known to construct up-twister spindle with a rotating can and can lid as hollow spindles.Accordingly it was also not obvious with the new application of such a rotating can to use on a hollow spindle the lid as a thread guide face for the supply of the covering thread to the core thread at a predetermined, angle corresponding to the suggestion of the invention.

If, as preferably provided according to the invention one uses as a thread guide face the inner face of the lid of the can rotating therewith. It is thus naturally desirable that as a rule the cylindrical inner face of the can and as a rule the cupolar shaped inner face of the lid are as smooth as possible and connect with one another as smoothly as possible. The covering thread running off from the supply bobbin then finds an extremely protective guide whilst it runs as a thread balloon from the supply bobbin to the core thread. The thread balloon inside the can finds practically no air resistance as the air contained inside the can rotates therewith. It may therefore without regard to any air resistance of the thread balloon be operated with very high spindle speeds which leads to a considerable increase in production.The quality of the yarn is very good not only because of the careful covering of the core thread but also because of the protectivity guiding of the covering thread. The breakages are hardly to be expected. Also without considering the enlarging of the thread balloon necessitated thereby can also be operated with the diameter increased because of the practically excluded air resistance. A further essential feature is the carrying out of the core thread by the stationary tube inside the hollow spindle.

The covering thread may, as usual in the two for one stage twisting method, in the connected first twisting stage, for example, on a ring twisting machine may be composed of two or more single threads and thereby are provided with a pre-twist or protective twist. It is however also possible to use a single thread as a covering thread.

The core thread may be an elastic thread or consist of several elastic threads. The winding round of an elastic thread with a covering thread has the additional object of influencing the elastic behaviour in that the elastic core thread in consequence of the winding round can no longer be completely relieved up to its resting length, that is, that length which it would assume in the intensioned state with the non presence of the winding and/or in the sense that the elastic core thread, because of the existing lapping can no longer be expanded as that maximum length to which it could be expanded without exceeding the range of the elastic expansion with non presence of the lapping.

It is however also possible to use as a core thread any other desired threads in particular substantially non-elastic threads.

The invention will be described with reference to the accompanying drawing showing vertical section of the embodiment.

The drawing shows a spindle rail which is indicated quite generally by 10. On this spindle rail several twisting spindles are arranged, one being shown and quite generally designated by 11. The twisting spindle comprises a stationary shaft 32, a spindle tube 16 is rotatably mounted by means of spindle bearings 14,15. This spindle tube 16 stationary with a spindle whorl 18 around which a driving belt 20 is looped. On the spindle tube 16 is located a disc bobbin body 22 of a supply bobbin 26 carrying the covering thread 25. An axial bore 34 is formed in the stationary shaft 32 and terminates at 36.

A bearing flange 38 made in one piece with the spindle whore 18 is connected to the spindle tube 16.

A cylindrical can 40 is affixed on this bearing flange 38. The cylindrical can 40 has on its upper end an edge 42 of larger diameter to provide a should 44 is formed at the junction. On the enlarged edge 42 is inserted a cupola-like can lid 46 which is located on the shoulder 44. The can lid 16 is provided at the top with a draw off tube 50. The inner end of the tube 50 is substantially flush with a thread guide face 52 which is formed on the inside of the cupolo of the can lid 46. On the spindle rail a bearing arm 54 is fixed in which in a longitudinal direction of the machine continuous driving cylinders 56,58 of a delivery mechanism are mounted. The driving cylinders 56,58 are driven.A supply bobbin 60 for the core thread lies on the driving cylinders 56,58 with the thread lying on the driving cylinders 56,58 so that a peripheral speed is imparted to the thread which is dependent of the speed of the driving cylinders 56,58. From the supply bobbin 60 there is drawn off over the driving cylinder 56 the core thread 24 which runs into the axial bore 34 of the spindle shaft 32 over a guide roller 62 in the lower end of the spindle shaft. The core thread 24 after running through the axial bore 34 emerges through the drawn off mechanism not shown. It may be designed, for example, like the delivery mechanism formed by the driving cylinders 56, 58 that is, two draw off cylinders on which a winding bobbin lies.

Thereby the draw off cylinders are likewise driven and impart to the winding bobbin a peripheral speed which is given by the speed of the draw off cylinders.

As the peripheral speed of the supply bobbin 60 and the peripheral speed of the winding bobbin not shown are fixed the thread take-up by the draw off mechanism and the thread delivery by the delivery mechanism are in affixed ratio. With the use of elastic core threads as a rule it, will be such that the peripheral speed of the winding bobbin is adjusted substantially greater than the peripheral speed of the thread supply bobbin 60 so that a predetermined expansion ratio of the elastic core thread is wound on the winding bobbin in a stretched state determined by this expansion ratio. The constant adjustment of this expansion ratio is essential for the achieving of an optimum end product.

With the use of a non-elastic core thread the peripheral speed of the winding bobbin is the same or adjusted to be a little greater than the peripheral speed of the thread supply bobbin 60 so that a desired thread tension is maintained.

The covering thread 25 is drawn off from the supply bobbin 26 forming a thread balloon. This shape of the thread balloon 25 is determined by the thread guide face 52. The thread guide face 52 is so formed that the covering thread 25 runs at an angle of approximately 90 to the core thread 24. The covering thread 25 is in consequence of the rotation of the supply bobbin 26 with the spindle tube, wound around the core thread 24.

The thread guide face 52 and if necessary the lower end of the draw off tube 50 ensures that the supply angle at which the covering thread 25 is applied to the core thread 24 remains substantially constant. It is not necessary for the thread guide face to guide the running covering thread 25 over the whole length of the thread balloon. A comparably good result is, for example, also obtained when the thread balloon protrudes from the area A to the run in into the draw off tube 50 axially downwards, below the thread guide face 52.

The rotating can 40 is enclosed by a housing 64 which is stationary and suppresses production of wind due to the rotating can 40., noticeable by the operating staff.

The apparatus may also be varied in that it is possible to supply a liquid treatment medium to the covering thread 25; for example, a liquid treatment medium can be dropped in through one or more lid openings of the can lid 46 which as a consequence of the centrifugal force is distributed over the thread guide face 52, and the inner face of the can forming a liquid film on these surfaces and moistens the covering thread 25 contacting these faces in the form of a thread balloon.

For the quality of the resulting thread material it is of substantial importance for the core thread to run through the axial bore 34 of the stationary shaft 32 so that no false twist phenomena can occur. As the thread balloon inside the can 40 encounters substantially no air resistance winding can be done at very high spindle speed without consideration of air resistance which means a considerable increase in production.

The covering thread 25 may be composed of two or more single yarns produced in a connected first twisting state, for example, on a ring twisting machine and thus be provided with a pretwist or protective twist. It is however also possible to use a single yarn as a covering thread 25.

In-stead of a single core thread 24 several yarns may also run simultaneously through the axial bore 34 and be wound together by the covering thread 25.

The covering thread 25 may, for example, be a staple fibre yarn on a natural fibre base 1 cotton yarn or on a cellulose acetate base so that the optical properties and the feel of the core thread 24 consisting as a rule of synthetic material are varied as desired.

According to a first example a polyamide thread with a dtex 44/31 was used and as a covering thread a cotton thread No. 155/1. The spindle speed amounted to n 1000 revs per min, and the winding corresponded to 400T/m.

According to a second example a smooth polyamide thread with dtex 22/7 was used as a core thread and a cotton thread Nm 85/1 as a covering thread. The spindle speed amounted to n 10000 revs per min and the winding to 500 T/min.

With the invention the hitherto extremely difficult and in many cases almost impossible problem is solved of imparting to a core yarn, for example, a polyamide thread the optical properties and feel of a cotton thread which was not possible in many cases with the hitherto usual methods of twisting.

Ne is the English designation for yarn fineness, Nm is the metric designation for the yarn fineness.

Both designations are used internationally.

Claims

1. A method for the manufacture of yarns by winding round of a core thread at least one covering layer of thread which is drawn off in the form of a thread balloon from a covering thread supply bobbin rotating around the core thread, characterised in that the covering thread is supplied substantially at right angle to the core thread.

2. A method according to claim 1, characterised in that an elastic thread is used as a core thread.

3. A method according to claim 1, characterised in that a substantially non-elastic thread is used as a core thread.

4. An apparatusforthe manufacture of yarns according to the method of any one of the claims 1 to 3, comprisng a hollow spindle connected to a rotary device for the rotationally fixed receiving of a covering thread supply bobbin surrounding the hollow spindle, a delivery mechanism for the speed regulated supply of the core thread from a supply bobbin on one end of the hollow spindle and a draw off mechanism for the speed regulated common drawing off of the core thread energising from the other end of the hollow spindle and of the covering thread wound around the core thread, the covering thread running from the covering thread cupply bobbin in the form of a thread balloon, characterised in that the covering thread orthreads are guided by a thread guide face rotating with the hollow spindle to feed the covering thread substantially at right angles to the core thread.

5. An apparatus according to claim 4, characterised in that the supply angle (d) of the covering thread or threads to the core thread amounts to 700 to 1100, preferably about 90".

6. An apparatus according to one of the claims 5, and 5, characterised in that the thread guide surface from the can and the curved inner surface of the lid of a can lid is formed which is located on a core enclosing the supply bobbin.

7. An apparatus according to any one of the claims 4, to 6, characterised in that the core thread runs through an axial channel of thee stationary spindle shaft for substantially the whole height of the covering thread supply bobbin.

8. A method for the manufacture of threads by winding a covering thread round a core thread substantially as herinbefore described.

9. Apparatus for the manufacture of yarn by winding a covering yarn round a core yarn substantially as described with reference to the accompanying drawing.

9. Apparatus for the manufacture of threads by winding a covering thread round a core thread substantially as described with reference to the accompanying drawings.

New claims or amendments to claims filed on 25 June1980 Superseded claims 1 to 9 New or amended claims:

1. A method for the manufacture of composite yarns by winding round a core yarn at least one covering layer of yarn which is drawn off in the form of a thread balloon from a covering yarn supply bobbin rotating around the core yarn, characterised in that the covering yarn is supplied substantially at right angle to the core yarn.

2. A method according to claim 1, characterised in that an elastic yarn is used as a core thread.

3. A method according to claim 1, characterised in that a substantially non-elastic yarn is used as a core thread.

4. An apparatus for the manufacture of yarns according to the method of any one of the claims 1 to 3, comprising a hollow spindle integral with and driven by a whorl carrying a covering yarn supply bobbin surrounding the hollow spindle, a delivery mechanism for the speed regulated supply of the core yarn from a supply bobbin at one end of the hollow spindle and a draw off mechanism for the speed regulated common drawing off of the composite yarn from the other end of the hollow spindle and of the covering yarn wound around the core yarn, the covering yarn running from the covering yarn supply bobbin in the form of a thread balloon, characterised in that the covering yarn or yarns are guided by the internal face of a dome shaped thread guide rotating with the hollow spindle to feed the covering yarn to the core yarn substantially at right angles thereto.

5. An apparatus according to claim 4, characterised in that the supply angle a of the covering yarn or yarns to the core yarn amounts to 700 to 1100 preferably about 90".

6. An apparatus according to any one of claims 4, and 5, characterised in that the thread guide surface for the yarn gearing is formed on the inner surface of the can lid.

7. An apparatus according to any one of the claims 4, to 6, characterised in that the core yarn runs through an axial bore in a stationary spindle shaft for substantially the whole height of the covering yarn supply bobbin.

8. A method for the manufacture of yarns by winding a covering yarn round a core yarn substan tially as hereinbefore described.