CA2227123A1 - False-twisting warping - Google Patents

Abstract

THE WARP ENDS ARE GATHERED TO FORM THE SHAPE OF ROPE,AND ARE
APPLIED FALSE TWIST AND STORED IN A STATIONARY CONTAINER. AFTER
THE FULL CONTAINER IS MOUNTED IN A LOOM, THE FALSELY-TWISTED WARP
IS UNWOUND FROM THE STATIONARY CONTAINER,AND THE FALSE TWIST IN
THE WARP DISAPPEARS AND THEREFORE THE WARP IS RESTORED TO
TRADITIONAL FORM OF WARP. AS THE CONTAINERS ARE ALWAYS KEPT
STATIONARY,IT IS MADE POSSIBLE TO CHANGE AND TIE WARP WHEN THE
LOOM IS RUNNING.IT IS ALSO POSSIBLE TO POSITIVELY KEEP THE
FEEDING SPEED OF WARP CONSTANT, NO MATTER WHETHER THE WARP
CONTAINER IS FULL OR CLOSE TO EMPTY,AND THE FALSE TWIST IN WARP
TENDS TO PREVENT WARP FROM GETTING MESSED UP IN CASE OF BROKEN
END IN WARP CONTAINER.

Description

FALSE-TWISTING WARPING
The present invention relates to a method for preparing warp in fabric and warp knitting producton.
Traditional method for preparing warp is that,before the yarns or filaments, no matter whether they experience sizing process,are used as warp,they are first wound into a warp beam in such a way that the yarns or filaments are arranged to be parallel to each other and form a sheet before being wound into warp beam, then the beam is mounted on the beam support in the loom(the case is same for warp knitting machine),after that the yarns or filaments are, as a parallel sheet, fed to the loom, by either being negatively pulled, in which case the brake is usually used to apply pressure to the beam, or the beam's being positively driven through a set of mechanism,or combination of both.In all the situations, the warp beam should turn in order to feed the warp.
This traditional method has several disadvantages. First, when the warp beam runs out,the loom should stop and wait for people to replace with a full warp beam and tie the warp before continues running. This sort of waiting constitutes a loss of production efficiency. Second, warp tension controll requires sophisticated mechanism and electrical devi.ce.Because,in order to achieve even feeding of warp,the speed of the warp beam should be controlled to increase accordingly when t:he warp beam goes from full to empty. This kind of controll ha;s been proven difficult in many situations and causes not only the quality problem, but further loss of production efficiency.Third,when a yarn or filament is broken inside the warp beam, it is often hard to find the broken end.And this frequently results in a messed warp beam and is another source of quality problem and efficiency loss.
Another method of warp preparation, which is known as LOCKER
BAND system and can only find its use in safebelt production, uses the narrow needle loom to produce a kind of semiproduct which serves as warp and is known as locker band. The locker band is, in fact,a kind of narrow fabric with a very loose weft density of 2-5 picks/inch.The warp which is required to form the locker band is fed directly from the cone creel. Because one edge of locker band is knitting edge, the weft can be drawn from the locker band. After the weft has been drawn from the locker band through a device in the loom,there is only warp left,which is fed to narrow loom as traditional warp.Although this method can eliminate the need of stopping loom while tying locker band and make possible a very constant warp tension,it has two big drawbacks.One is that the output of locker band is very low, it is very hard for the output to exceed 15 meters/minute.Second one is that, when the locker band is woven,the warp experiences severe vibration and friction,therefore the mechanical property of the warp will be damaged to a greater or less extent.For the materials which are fine or filamenting-sensitive, the warp breakage in weaving process will increase considerably. As a matter of fact, the warp experiences weaving process twice when they are woven into final product, therefore this method is limited to production of narrow fabric with strong yarn and high weft density.
It is desirable to have a method of warp preparation, which can eliminate the need of stopping loom while warp tying and more conveniently keep the warp tension constant,make the broken end finding easier, and in the mean time, doesn't sacrifice the warping efficiency and the range of its application.
The present invention consists of a method for preparing warp in fabric production, which would increase the weaving efficiency and improve product quality, and comprises three steps.
In the first step,the yarns or filaments are gathered into a guide hole to form the shape of the rope, and are held through pairs of rollers which apply pressure on the rope warp(i.e. the gathered yarns or filaments) and can control movement of the rope warp.The yarns or filaments before being gathered may come the cone creel, or the sizing machine.
In the second step of the invention, the rope warp is applied false twist and stored into a stationary container. The container ~ may be the usual empty beam,or the beam without the flange on one side, or simply a cone object.
In one embodiment of this invention, through a rope warp guide which rotates around the stationary container, the rope warp obtains the false twist and is wound into the stationary container.The movement of the rope warp guide is arranged to be that of combination of both rotation and parallel movement to the axis of the container.
In the third step of thi;a invention, the falsely-twisted rope warp container is mounted in the loom and the falsely-twisted rope warp is unwound axially from the stationary container through another pairs of pressure rollers in the loom and is fed to loom. As the direction of warp movement in this step is exactly opposite to that in step one and step two of this invention, the false twist formed in step two will disappear and the falsely-twisted rope warp can. be restored to its traditional shape:a parallel sheet, and serve as usual warp.
When the falsely-twisted rope warp is stored in the step two, we can leave outside the container a length of rope warp which can be tied to another full container even when the loom is running, because the containers are always stationary.
In the third step,the feeding speed of the rope warp is totally controlled through the pressure rollers which hold and move the rope warp,therefore we simply need to set the speed of the rollers as required, the feeding speed of the rope warp would not change,no matter whether the container is full or close to empty. Thus, the warp tension is kept constant.

If a yarn or filament is broken, the twist in the rope warp tends to keep the broken end in fixed position,and the broken end will follow adjacent ends and automatically appear after it has left the pressure rollers, therefore the warp wouldn't tend to get.
messed up.
In the second step of this invention,when the container i~;
full, if the rope warp isn't cut and is carefully handled so that the rope warp is positioned in another errpty container and then the false-twisting processing is resumed. So, we can put together two or more containers wii:h uncut rope warp between each other, therefore the volume of continuous warp can be several fold;
increased without the need of increasing the size of the container.This arrangement will reduce the need of warp tying and further increases weaving efficiency.
In drawings which illustrate embodiments of the invention.
Figurel shows how the false twist is formed.
Figure2 shows how the falsely-twisted rope warp is restored to traditional warp.
Referring to drawings,the present invention consists of a method for preparing warp. The method comprises three steps.
First, the yarns or filamentsl which may come from the cone creel or from the sizing mach:ine,are passed through the reed2,then gathered into guide3 and are held through the pressure rollersn which are also arranged to control the movement of the gathered yarns or filaments(rope warp). The speed of rope warp is controlled through rollers9.The guide3 p_s preferable to be open so that the rope warp can be easily put through and taken out, and the thread which is placed in rope warp to separate one end from each other when necessary can easily pass through rollers9.The number of warp ends is preferable to be less than 1000,depending on the count of the warp end. For this reason, this method is preferable to be used in narrow fabric and narrow warp knitting production, or broad fabric where section warping is used.
Second,when the rope warp is delivered from rollers4,it i~;
wound into a stationary containers through the rope warp guideEs which is constructed to be able to rotate around and traverse' along the axis of the stationary container5.The rotation movement.
of the guide6 may be achieved through a belt which is arranged to be able to slide on pulley which drives the guide6,when the feeding speed of rope warp from roller4 limits the speed of the guide6.That is, the driving force of the guide 6 is preferably friction force.The transversal movement of the guide6 may be achieved through a cam so that: the rope warp can be wound into the containers in the desired shape. The container may be the usual.
beam,or modified beam with only one flange on one side,or simply a cone objector something else which can be fixed in position and accommodate the rope warp and cann't cause rope warp messed up.When the rope warp is wound into the container5,a length of rope warp which contains the separation thread is left outside the containers.
Third,the full container7a is mounted in a loom.When the falsely-twisted rope warp is axially unwound from the stationary container7a,through another pressure rollers8 which hold and control movement of rope warp, the false twist in rope warp will disappear,and the rope warp passes through the rollers8 and is separated through another reed9 in the loom. In this way, the rope warp is restored to traditional warp.
As the containers are always kept stationary,the length of rope warp left outside container7b can be tied to another containerl0,even when loom is running. During the process, special care should be taken to ensure that real twist shall not be added to the rope warp.
When the containers in step2 becomes full,we can leave the rope warp uncut,and position it in another empty container and then resume the false-twisting processing.In this way,we can put together 2 or more containers. with uncut rope warp between each other(for example:7a and 7b),therefore the volume of continuous warp can be many folds increased.
Because the feeding speed of rope warp is totally controlled through rollers8 in the loom,we simply need to set the speed of rollers8 as required,the feeding speed of rope warp would not .7 change, no matter whether the container7a is full or not, Thus, the warp tension is kept constant.
If one end is broken inside the container7a,the twist tends to keep the broken end in fixed position and the broken end will follow adjacent ends and automatically appear after it leaves the rollers8,the warp wouldn't tend to get messed up.
Although only a single embodiment of the present invention has been described and illustrated,the present invention is not limited to the features of this embodiment,but includes all variations and modifications within the scope of the claims.

Claims (3)

1. A method for preparing warp, which comprises applying false twist to rope warp, and then restoring the falsely-twisted rope warp to the traditional form of warp:a parallel sheet.

2. A method as defined in claim 1,in which the falsely-twisted rope warp is stored in the stationary container and then is fed to loom from the stationary container.

3. A method as defined in claim 1,in which the false twist is applied to rope warp by winding the rope warp into the stationary container.