DE2812471C2 - - Google Patents

Description

The invention relates to a device for spinning a Thread made of single fibers with two rotating in the same direction, rollers forming a narrowest gap with one another, of which at least one has a porous jacket and an air suction device contains, whose mouth area in the area of narrowest gap is directed against the inner circumference and the a pressure drop from the outside of the roll through the porous jacket generated to the inside of the roll, and with a feed and Disintegration device for sliver, which with the area of narrowest gap is connected via a fiber feed channel that is designed as a flow channel for a compressed air flow, and the one opening roller provided with a set of teeth contains, in a dissolving chamber which can be placed under positive pressure is arranged, which is open to the fiber feed channel, wherein the opening roller feeder links with a previous one Inlet channel are arranged, in particular according to patent 27 32 678.

A belt inlet funnel is also known (DE-AS 11 37 982), its cross section up to a certain limit decreases continuously and then into a strong Extension passes from which a narrow bore continues. A suction line is attached to the extension connected.

The invention has for its object the subject of Main patent so that even thin slivers can be drawn in safely if there is overpressure in the pulping unit prevails.  

This object is achieved in that the inlet channel two has nozzles arranged one behind the other, between which one opening is provided in connection with the environment, and that the distance of the first nozzle in the sliver running direction from the Intake members (clamping point) smaller than the length of the individual fibers of the processed sliver.

This simple change makes it possible to use slivers or Insert roving of approx. 6000 dtex safely. The works Safe introduction, even if there is overpressure in the dissolving unit prevails.

This also ensures that an adaptation to the fiber lengths takes place. This makes it possible not only to use slivers of 6000 dtex, but can also be safely introduced with fiber lengths of approx. 40 mm.  

The invention is described below using an exemplary embodiment explained in more detail:

They represent:

Figure 1 is a section through an open-end spinning device along the yarn formation line.

Fig. 2 shows a cross section through the same apparatus;

Fig. 3, 4 a cross section through an opening unit.

The Spinnnvorrichtung according to Fig. 1, 2 consists of the rollers (1 and 2) whose shells are permeable to air (perforation 3). The rollers ( 1, 2 ) are overhung and driven on the one side by the shafts ( 4 ), pulley ( 6 ), drive belt ( 7 ) and motor ( 5 ) in the same direction.

The opening device ( 8 ) is surrounded by an overpressure housing ( 14 ) and has the inlet opening ( 9 ) for the fiber sliver ( 10 ). The fiber sliver ( 10 ) is drawn in by means of the conveyor roller ( 11 ) and broken up into individual fibers ( 15 ) by the opening roller ( 12 ). The opening roller ( 12 ) has a toothing ( 13 ) on its circumference, through which the individual fibers ( 15 ) are released from the sliver ( 10 ). The individual fibers ( 15 ) are detached from the opening roller ( 12 ) by centrifugal and air flow forces and conveyed into the flow channel ( 16 ). Due to the special design of the flow channel ( 16 ) and a corresponding air duct in the flow channel ( 16 ), the fibers ( 15 ) are rotated and stretched parallel to the mouth ( 17 ). The fibers ( 15 ) leave the mouth ( 17 ) of the flow channel ( 16 ) in this way at the smallest possible angle to the thread formation line and fly freely towards the thread formation line. There they are twisted into the thread ( 18 ) by contact with the rollers ( 1, 2 ) in the gusset formed between them under the action of the air currents penetrating the walls. The air flows in relation to both rollers ( 1, 2 ) are generated by air suction devices, consisting of air suction nozzle ( 22 ) and ( 23 ) with the negative pressure P₃ over the air suction nozzle ( 21 ) in the region of the mouth surfaces ( 24 and 25 ), respectively conform to the inner circumference of the rollers ( 1, 2 ). The mouth surfaces ( 24, 25 ) are - seen in the direction of rotation of the respective rollers ( 1, 2 ) - arranged essentially in front of the narrowest gap formed between the rollers ( 1 and 2 ). The mouth surfaces ( 24, 25 ) should overlap, a preferred overlap range being between 0 and 10 times the thread diameter. This is based on a theoretical thread diameter d, which is based on the formula

is calculated. In this formula:

γ = the specific weight in g / cm³
Nm = number metric in meters per gram.

The overlap area is preferably arranged 0 to 10 times the thread diameter in front of the narrowest gap - as seen from the mouth of the flow channel ( 16 ). The orifices extend over a certain length, which essentially corresponds to the length of the air-permeable part of the rollers ( 1, 2 ), parallel to the thread formation line.

The opening device ( 8 ) is surrounded by an airtight pressure housing ( 14 ). The walls of this housing ( 14 ) are only penetrated by the flow channel ( 16 ), the shafts of the opening and conveying rollers ( 12 and 11 ) as well as the fiber inlet opening ( 9 ) and the air supply nozzle.

A preferably constant pressure P _{u is} maintained in the housing ( 14 ), for which purpose the air pressure P _u can be regulated via a measuring device ( 26 ) and compressed air generator ( 14.1 ). Between the overpressure housing ( 14 ) and the chamber of the opening roller ( 12 ) there is a connecting channel ( 14.2 ) and further channels (eg 14.3 ) which are attached as appropriate. The channel ( 14.3 ) is used in particular to generate an air flow in the housing of the opening roller ( 12 ) against the running direction of the opening roller ( 12 ). As a result, the fibers ( 15 ) are detached from the opening roller ( 12 ) and the air flow in the flow channel ( 16 ) is evened out.

The housing ( 14 ) is sealed in the area of the sliver inlet opening ( 9 ) by the funnel ( 20 ). According to the invention, the funnel ( 20 ) has the nozzles ( 20.1 and 20.2 ). The distance between the nozzle ( 20.1 ) and the clamping point ( 20.3 ) between the conveyor roller ( 11 ) and the counter-pressure plate ( 20.4 ) is smaller than the stack length of the individual fibers ( 15 ). The air duct ( 20.5 ) opens between the two nozzles ( 20.1 and 20.2 ) and connects the funnel duct and in particular an annular groove ( 20.6 ) let into the funnel duct between the nozzles ( 20.1 and 20.2 ) with the atmosphere ( Fig. 3).

This design of the funnel ( 20 ) allows the air escaping as a leak through the funnel channel to expand without destroying the sliver ( 10 ) drawn in by the conveyor roller ( 11 ).

Furthermore, it should also be mentioned that the flow channel ( 16 ) is inclined at an angle α relative to the thread ( 18 ) or the mouth ( 17 ) in such a way that the fibers ( 15 ) flying onto the thread formation line have a movement component which is counter to the thread withdrawal direction ( 19 ) is directed. This arrangement of the channel ( 16 ) allows the thread ( 18 ) to be substantially uniform. The angle α should be as small as possible and is preferably less than 45 °.

The device described now allows the following mode of operation.

By means of compressed air generators ( 14.1 ) a constant air pressure P _{ü is} generated in the housing ( 14 ), which is also established in the chamber of the opening roller ( 12 ) via the fiber inlet opening ( 9 ) and the connecting channel ( 14.2 ) as well as any further channels ( 14.3 ) .

As a result of the pressure drop occurring in the flow channel ( 16 ) from P _ü via P₁ to P₂, there is a defined air flow. This air flow means that the sliver ( 10 ) behind the conveyor roller ( 11 ) is broken up by the opening roller ( 12 ) with the teeth ( 13 ) into individual barrels ( 15 ) so that the individual fibers ( 15 ) are released by the opening roller ( 12 ). thrown and blown as a free-flying fiber cloud, then parallelized, aligned and stretched and conveyed to the thread formation line at high speed. In the area of the thread formation line, the atmospheric pressure P₂ prevails. In the area of the narrowest gap between the rollers ( 1 and 2 ), the individual fibers ( 15 ) are now collected in front of the mouth surfaces ( 24 and 25 ) of the suction device ( 22, 23 ) and twisted into a thread ( 18 ). In the air extraction devices ( 22, 23 ) there is a negative pressure P₃, which is less than the atmospheric pressure P₂.

The air pressures P _ü , P₁, P₂ and P₃ are so cascaded and adapted to the individual process steps of the spinning process. The pressure P₁ in the flow channel decreases from the beginning to the mouth of the flow channel from P _ü to P₂ and is thus higher than the atmospheric air pressure P₂, while the air pressure P₃ arising in the suction devices is always lower than the atmospheric air pressure P₂. Suitable values for the pressure P _u are from 200 to 1000 mm Ws pressure with the lowest values in the lower range. Favorable values for the pressure P₃ are 1000 to 2500 mm Ws vacuum.

In FIG. 4, an alternative embodiment of the hopper according to the invention (20) of Fig. 3 is shown for closing the fiber inlet opening (9). The funnel ( 20 ) also makes it possible to process a sliver ( 10 ) of low titer on the otherwise unchanged machine.

Collect in the opening device (8) in order to thin slivers (10) is inserted in the feed direction upstream of the feed roller (11) of the funnel shown in Fig. 4 (20) into the sliver inlet opening (9) of the opening device (8).

The funnel ( 20 ) consists of two nested nozzle housings ( 41 and 42 ). The outer nozzle housing ( 41 ) can also be integrated directly into the housing ( 14 ). The nozzle housing ( 41 ) forms with its front end in the sliver transport direction a nozzle ( 43 ) which is arranged above the conveyor roller ( 11 ).

A first nozzle housing ( 42 ) is introduced into the second nozzle housing ( 41 ) in the sliver running direction. However, it should be noted here that a largely circumferential gap ( 44 ) remains free between the second and the first nozzle housings 41 and 42 , which is in communication with the surroundings of the opening device ( 8 ). The first nozzle housing ( 42 ) forms at its front end a nozzle ( 45 ) which ends at a short distance from the inlet into the second nozzle ( 43 ). According to the invention, the distance from the inlet into the nozzle ( 45 ) to the clamping point ( 20.3 ) on the conveyor roller ( 11 ) is less than the length of the individual fibers ( 15 ) in the sliver ( 10 ). The passage opening in the nozzles ( 43 and 45 ) are different in such a way that the nozzle opening of the nozzle ( 45 ) is larger than that of the nozzle ( 43 ). Since there is usually an overpressure in the opening device ( 8 ), a sealing effect is achieved with this arrangement. However, the sealing effect is not such that air can no longer penetrate into the surroundings against the direction of the sliver feed.

However, the arrangement of the funnel ( 20 ) according to the invention prevents the air flowing out at a conventional sliver inlet opening ( 9 ) from tearing the sliver ( 10 ) as a result of sudden expansion. This is achieved in that the distance of the nozzles ( 20.1, 45 ) from the clamping point ( 20.3 ) on the conveyor roller ( 11 ) is smaller than the length of the individual fibers ( 15 ) and that between the nozzles ( 20.1, 20.2 and 43, 45 can escape) the _above under pressure P stagnant air to the environment. As a result, the entire length of the individual fibers ( 15 ) is no longer exposed to the outflowing air, since the cross sections of the nozzles ( 20.1, 20.2 or 43.45 ) simultaneously exert a frictional effect on the inserted fiber sliver ( 10 ), so that a small amount Clamping effect occurs. In addition, this device ensures that there is no turbulent flow in the first nozzles ( 20.1, 45 ), so that the intake in this area can take place without problems.

Claims (4)

1.Device for spinning a thread of individual fibers with two co-rotating rollers, forming a narrowest gap with one another, of which some have a porous jacket and contain an air suction device, the mouth surface of which is directed in the area of the narrowest gap against the inner circumference and through which porous jacket creates a pressure gradient from the outside of the roll to the inside of the roll, and with a feed and dissolving device for sliver, which is connected to the area of the narrowest gap via a fiber feed channel, which is designed as a flow channel for a compressed air stream, and one with a set of teeth Contains opening roller which is arranged in an opening chamber which can be set under positive pressure and which is open towards the fiber feed channel, the opening roller being arranged upstream of intake members with a preceding inlet channel, according to patent 27 32 678, characterized in that the inlet channel al two nozzles ( 20.1, 20.2; 43, 45 ), between which an opening ( 20.5; 44 ) communicating with the surroundings is provided, and that the distance of the first nozzle ( 20.1; 45 ) in the fiber sliver running direction from the feed elements (clamping point 20.3 ) is smaller than the length of the Individual fibers of the processed fiber material is. 2. Device according to claim 1, characterized in that the passage opening of the first nozzle in the sliver running direction ( 20.1; 45 ) is larger than that of the second nozzle ( 20.2; 43 ). 3. Device according to one of claims 1 to 2, characterized in that the nozzles ( 20.1, 20.2; 43, 45 ) are arranged interchangeably. 4. Device according to one of claims 1 to 3, characterized in that the nozzles ( 20.1, 20.2; 43, 45 ) are formed by the outlets of two nested funnels ( 41, 42 ), between the outer wall of the first funnel in the sliver running direction ( 42 ) and the inner wall of the second funnel ( 41 ) in the sliver running direction there is a circumferential annular gap ( 44 ).