JPS6348970B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for producing yarn from drawn rovings, in which the fiber ends protruding from the rovings are spirally wound around the rovings after the rovings have been twisted; and an apparatus for carrying out this method.

In order to produce yarn from the drawn roving, the drawn roving is drawn through a wedge-shaped area between two co-rotating suction drums, axially distant from the drawing end face of these suction drums. to 2
It is known to provide two mutually facing nap rings (Austrian Patent No. 367104). The roving is twisted and fluffed between two suction drums, and the fiber ends pulled out of the fiber bundle during fluffing of the roving are passed around the roving again between the suction drums, and the roving The twist angle is different from that of the twisting method. However, since the degree of winding is related to the slippage between the roving and the suction drum that twists it,
If the proportion of fibers wound around the roving is relatively small, the yarn strength that can be obtained is limited.

The problem on which the invention is based is to improve the method of the first type in such a way that it is possible to ensure the desired yarn strength in a small proportion of the fiber ends that are wound onto the roving. be. Furthermore, this method can be carried out using simple equipment.

In order to solve this problem, according to the present invention, the fiber ends protruding from the roving that rotates around the roving axis are bent at right angles to the roving axis by a sliding surface in contact with the roving, so that the roving Wrap it around the roving in the opposite direction to the twisting.

The present invention is based on the following fact. In other words, in the known winding method, the fiber ends of the roving that protrude from the fiber bundle are always wound in the twisting direction of the roving, so that when the roving tries to untwist again after being twisted in the false twisting direction, , a rotational moment in the untwisting direction inevitably acts on the ends of the fibers wound around the roving, reducing the bundling of the fiber bundles and thereby reducing the yarn strength. However, according to the present invention, when the twisted roving is wrapped around the protruding fiber ends in the opposite direction to the twisting, the rotational moment acting in the false twisting direction causes the fiber ends to wrap around the fiber bundle. As the fibers are twisted, the binding of the fibers is strengthened, and as a result, high yarn strength can be obtained even if the proportion of the fiber ends wrapped around the fiber bundle is relatively small.

Moreover, the fiber ends protruding from the rotating roving,
Since the sliding surface in contact with the roving is bent at right angles to the roving axis, the protruding fiber ends can be reliably wrapped around the roving in a direction opposite to the twisting of the roving. Due to the rotation of the roving caused by the twisting of the roving, the fiber ends of the roving protruding from the fiber bundle are successively brought closer to the sliding surface and pressed against the roving at right angles to the roving axis. The winding of the fibers onto the rovings then takes place necessarily in a direction opposite to the twisting of the rovings. Of course, the approach of the protruding fiber ends to the sliding surface causes the protruding fiber ends distributed over the circumference of the roving to lie along the sliding surface at right angles to its axis during the rotation of the roving. In order to be able to bend the roving, it is necessary to provide a sliding surface in the axial direction of the roving of a minimum length that is related to the rotation and withdrawal speed of the roving.

Sufficient contact of the roving with the sliding surface is important for tightly wrapping the protruding fiber ends onto the roving. This is because only with such sufficient contact can the protruding fiber ends be pressed against the rotating roving. In order to be able to guarantee sufficient contact of the roving to the sliding surface, it is advantageous to draw the roving onto the sliding surface.

The rotation of the roving with respect to the sliding surface has an effect on the winding of the fiber ends protruding from the fiber bundle onto the roving by the sliding surface in contact with the roving. In order to avoid disturbing this rotation, it is advantageous to guide the roving without tensile stress. In this case, introducing the roving without tensile stress means that the withdrawal speed of the roving is equal to or smaller than its feeding speed. This is because the necessary withdrawal of the roving inevitably causes tensile forces to be exerted on the roving.
However, by guiding the roving without tensile stress when winding the protruding fiber ends, the fiber ends that are spirally wound around the roving are not stretched, and the roving fibers are not stretched between the winding fiber ends. It can be prevented from being unfavorably extruded.

In order to easily carry out the above-described winding method, a drawing mechanism, a twisting device for the roving provided between the drawing mechanism and the draw-out roll, and a fiber end protruding from the roving provided before the draw-out roll are provided. It is possible to use a yarn manufacturing device which is equipped with a device for winding the yarn onto the roving. According to the invention, the device is characterized in that the device for winding the protruding fiber ends onto the roving consists of at least one sliding surface that contacts the rotating roving. At this sliding surface, the protruding fiber ends are bent at right angles to the roving axis;
Since it is pressed against the roving in the circumferential direction, the axial withdrawal of the roving results in a helical winding of the protruding fiber ends.

This sliding surface is constructed to be air permeable and air is sucked in the area of the roving to ensure good contact of the roving to the sliding surface and good pressing of the protruding fiber ends against the roving surface. It would be advantageous to be able to do so.

As already mentioned, proper rotation of the rovings relative to the sliding surface must be ensured. The sliding surface must therefore not interfere with the rotation of the roving. For this reason, it is advantageous to design the sliding surfaces as smooth as possible. The reduction in friction between the sliding surface and the roving does not have a detrimental effect on the winding on the roving. This is because the protruding fiber ends are bent by being pressed against the sliding surface, and in this case forces act approximately perpendicularly to the protruding fiber ends and the sliding surface, and the longitudinal and rough edges of the protruding fiber ends are This is because no force is applied in the direction of rotation of the thread.

When the sliding surface is moved at right angles to the roving, the relative velocity between the roving and the sliding surface changes, which affects the sliding friction conditions between the sliding surface and the roving on the one hand and the sliding surface on the other hand. The winding motion of the protruding fiber ends that are brought closer to is affected. Particularly advantageous conditions for winding are obtained, especially if the direction of movement of the sliding surface is opposite to the direction of rotation of the roving. That is, an advantageous burnishing effect is obtained when the sliding surface moves in the direction of wrapping the protruding fiber ends around the roving.

If the sliding surface is moved along the length of the roving, the relative velocity between the sliding surface and the roving in the drawing direction is changed and can influence the helix angle during winding. Due to the motion of the sliding surface with motion components in the axial direction of the roving and in the direction perpendicular to this,
It becomes possible to adapt to various conditions. In order to move the sliding surface, it is preferable to form the sliding surface using a rotating body.

The device according to the invention will be further explained with reference to the drawings.

In order to be able to wrap the fiber ends 2 protruding from the roving 1 around the roving 1, the first
The roving 1 according to the figure is pulled alongside the sliding surface 3 while rotating. The fiber ends entrained by the roving 1 rotating in the direction of the arrow 4 are pressed against the sliding surface 3;
It is wound around the roving thread 1 at right angles to the roving axis, and a helical winding is carried out because the roving thread 1 moves simultaneously in the axial direction. What is important for this winding process is that the roving 1 has sufficient contact with the sliding surface 3 so that the fiber ends 2 are pressed onto the roving 1 and wound tightly around it. For this purpose, the sliding surface 3 is configured to pass air and is suctioned with air, so that the suction flow through the sliding surface 3 forces the roving 1 against the sliding surface 3 in the direction of the arrow 5.
However, this pressure against the sliding surface 3 necessary for winding the fiber ends 2 must not impede the rotation of the roving 1 too much. This is because the winding of the fiber ends 2 is related to the rotational movement of the roving 1 relative to the sliding surface 3. For this reason, the sliding surface 3 is designed to be as smooth as possible.

If the sliding surface 3 is moved additionally relative to the roving 1, a relative movement between the roving 1 and the sliding surface 3 takes place, so that the winding process is influenced via the sliding surface 3. According to FIG. 2, the sliding surface 3, shown as a belt 7 guided around the deflecting roll 6, is moved at right angles to the axis of the roving 1 and in the direction of its rotation in the area of the roving. On the other hand, since it is moved in the opposite direction of movement, winding of the fiber ends 2 around the roving 1 in a direction opposite to the twisting of the roving 1 is promoted.

According to FIG. 3, the belt 7 forming the sliding surface 3
is guided endlessly around a turning roll 6 whose axis extends at right angles to the roving axis, so that a movement of the sliding surface 3 parallel to the roving 1 occurs. This movement of the sliding surface controls the twist angle of the helical winding. The contact of the roving 1 to the belt 7 can be ensured by means of a suction channel 8 .

In order to bend the fiber ends along the sliding surface 3, it is important to ensure the rotation of the roving 1 in the area of the sliding surface, so the twisting of the roving is of practical importance. According to FIGS. 4 and 5, a device for carrying out the method according to the invention comprises a stretching mechanism 10.
It has a twisting device 9 consisting of two suction drums 11 which immediately follow and rotate in the same direction in close proximity. The suction drums 11 are equipped with inserted suction tube pieces 12 which form suction areas 13 in the wedge-shaped areas between the suction drums 11, the suction flow of which draws the roving 1 into the wedge-shaped areas. Therefore, the roving 1 sufficiently contacts both drum surfaces regardless of its thickness. This allows suitable twisting moments to be exerted on the rovings over both drum surfaces. In order to increase this twisting moment, the drum surface can be formed to have a rough surface. In order to prevent the individual fibers of the roving from becoming unwound from the fiber bundle, the topography of the drum surface must of course avoid engagement of the roving fibers with the drum surface.

The twisting device 9 is followed by a pair of second suction drums 14 which rotate in the opposite direction to the direction of rotation of the suction drums 11 and have smooth surfaces. These suction drums 14 are also equipped with insertion suction tube pieces 15 whose suction areas 16 suck the roving 1 guided through the wedge-shaped area into this wedge-shaped area, so that the roving 1 is also It is made to come into sufficient contact with the surface of the suction drum 14. Therefore, the suction drum 1
4 is particularly suitable for forming a sliding surface 3 for bending the protruding fiber ends 2. The protruding fiber ends are bent approximately at the surface of the suction drum 14 leading out of the wedge-shaped region, while the suction drum 14 leading back into this wedge-shaped region facilitates the initiated winding and absorbs the resulting yarn. Gives shine. Since the drum surface is formed to be smooth and only slight sliding friction occurs between the roving yarn and the drum surface, the twisting of the roving generated by the twisting device 9 extends to the area of the suction drum 14, and the roving is twisted. By providing the second suction drum 14 that rotates in the opposite direction to the rotational direction of the yarn 1, the winding of the fiber ends protruding in the opposite direction to the twisting of the roving around the roving is possible. This is ensured by keeping the roving in sufficient contact with the sliding surface. After wrapping the fiber ends, the roving 1 can be drawn off via a pair of drawing rolls 17. The winding of the protruding fiber ends as the roving 1 rotates is achieved by selecting the drawing speed through the drawing roll 17 to be equal to or smaller than the feeding speed from the stretching mechanism 10, so that the roving is stretched during winding. This is further aided by stress-free guidance. Such tensile stress-free roving guidance, which of course does not remove all the tensile forces from the draw-off roll 17, improves the rotation of the yarn while ensuring that the fiber ends wound around the roving are wrapped tightly. The risk of stretching the spiral shape is eliminated.

The insertion suction of the suction drums 11 and 14, which are arranged coaxially with respect to each other, makes it possible to reduce the gap between the twisting device 9 and the suction drum 14 in order to ensure sufficient rotation of the roving in the area of the suction drum 14. The tube sections 12 and 15 are combined into a continuous insertion suction tube section 18, on which the suction drum is supported. These suction drums 11
and 14 are driven by belts 19 and 20.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of the sliding surface for explaining the action of bending the fiber end protruding from the roving along the sliding surface, and FIG. 2 is a side view of the sliding surface that can move at right angles to the roving. 3 is a side view of a sliding surface movable in the longitudinal direction of the roving, FIG. 4 is a side view of an apparatus for carrying out the method according to the invention, FIG. 5 is a plan view of this apparatus, and FIG. FIG. 4 is a sectional view taken along the - line, and FIG. 7 is a sectional view taken along the - line in FIG. 4. 1... roving, 2... fiber end, 3... sliding surface,
4...Roving direction, 9...Twisting device, 10...
...Stretching mechanism, 14...Suction drum, 17...Drawer roll.

Claims (1)

[Claims] 1. A method of spirally winding the fiber ends protruding from the roving after twisting the roving,
The fiber ends protruding from the roving that rotates around the roving axis are bent at right angles to the roving axis by the sliding surface in contact with the roving, and the roving is twisted in the opposite direction to the twisting of the roving. A method for producing yarn from drawn roving, characterized in that it is wound around. 2 Characterized by suctioning the roving to the sliding surface,
A method according to claim 1. 3. A method according to claim 1, characterized in that the roving is guided without tensile stress when winding the protruding fiber ends. 4. A drawing mechanism, a roving twisting device provided between the drawing mechanism and a pull-out roll, and a device provided in front of the draw-out roll for winding the fiber ends protruding from the roving around the roving, In a device that winds the protruding fiber ends around the roving in a direction opposite to the twisting of the roving, the device for winding the protruding fiber ends around the roving 1 is arranged around the roving axis. A device for producing yarn from drawn rovings, characterized in that it consists of at least one sliding surface 3 which contacts the rovings 1 under a pressing force perpendicular to the axis of the rovings 1 which rotates. 5. Device according to claim 4, characterized in that the sliding surface 3 is configured to allow air to pass through and that air is sucked in in the area of the rovings 1. 6. The device according to claim 4 or 5, characterized in that the sliding surface 3 is smooth. 7. Device according to any one of claims 4 to 6, characterized in that the sliding surface 3 is movable at right angles to the roving 1. 8. Device according to claim 7, characterized in that the direction of movement of the sliding surface 3 is opposite to the direction of rotation of the roving 1. 9. Device according to any one of claims 4 to 6, characterized in that the sliding surface 3 is movable in the longitudinal direction of the roving 1.