CN210438869U

CN210438869U - Stretching device for textile fibre web and air flow spinning equipment

Info

Publication number: CN210438869U
Application number: CN201920749183.5U
Authority: CN
Inventors: 法比奥·达尼奥洛; 维托里奥·科拉维蒂; 索利塔里奥·内斯迪; 卢西亚诺·蒙奇尼; 帕特里齐奥·万尼尼
Original assignee: Savio Macchine Tessili SpA
Current assignee: Savio Macchine Tessili SpA
Priority date: 2018-05-24
Filing date: 2019-05-23
Publication date: 2020-05-01
Anticipated expiration: 2029-05-23
Also published as: EP3572565A1; IT201800005659A1; CN110528125A

Abstract

A drawing device for a textile web and an open-end spinning apparatus, the drawing device for a textile web comprising: a feeding device of the web to be stretched; a carding machine rotating according to a direction of rotation, the carding machine comprising on its outer side wall a plurality of teeth arranged with a constant tangential pitch arrangement suitable for stretching a web; an extraction cylinder located downstream of the carding machine and the web; wherein the feed device comprises a feed roller facing the card, which feed roller rotates to feed the web to the card at an input speed and according to an advancing direction coinciding with the direction of rotation of the card, wherein the card is driven in rotation such that the peripheral speed on the teeth is equal to ± 20% of the product of the input speed times the total draw of the web, such that the draw of the web is practically completely performed on the card, the total draw being the ratio between the yarn count of the yarn to be produced and the yarn count of the input fibrous web.

Description

Stretching device for textile fibre web and air flow spinning equipment

Technical Field

The utility model relates to a stretching device for net has the carding machine that is used for open-end spinning system, relates to an open-end spinning equipment, including the stretching device that is used for the net that has the carding machine.

Background

It is known that in air spinning systems, a fibrous web is required which has a fibre length of typically 38mm or more and above all a fibre distribution which is as uniform as possible. These properties of the upstream web allow good yarn-technical properties to be obtained, which are significantly deteriorated by the presence of staple fibers.

The drawing system used (drawing system) is generally formed by three or more pairs of drawing and pressure cylinders, each of which performs a partial and progressive drawing of the web. The last pair uses a belt system that ensures more fine fiber parallelization and drawing.

Output fiber stream continuity is a fundamental requirement.

The drawing systems used in open-end spinning devices are derived from those traditionally used for ring spinning and have the same drawbacks, namely poor parallelization efficiency at high processing speeds and limited maximum obtainable drawing.

Carding machine drawing systems, in contrast, are used in open spinning systems which use the mechanical action of teeth to convey the fibers from an inlet to a rotor to tear the fibers from the web, and the centrifugal action due to the high rotational speed to remove impurities and short fibers from the fiber stream entering the rotor. In these systems, a continuous fiber flow is not an essential requirement, nor is there a short or broken fiber. However, the systems with carding machines are more compact than those with rollers and it is of utmost importance to ensure, by the action of the teeth of the carding machine, that the parallelization function of the fibres is very efficient and not affected in any way by the working speed or by the amount of stretch applied.

SUMMERY OF THE UTILITY MODEL

Accordingly, there is a need to address the deficiencies and limitations noted above with reference to the prior art.

According to the utility model discloses a stretching device for textile fiber net, include: a feeding device of the web to be stretched; a carding machine rotating according to a direction of rotation, comprising on its outer lateral wall a plurality of teeth arranged with a constant tangential pitch suitable for stretching the web; an extraction cylinder located downstream of the carding machine and the web; wherein the feed device comprises a feed roller facing the card, rotating so as to deliver the web to the card at an input speed and according to an advancement direction coinciding with the rotation direction of the card, wherein the card is driven in rotation so that the peripheral speed on the teeth is equal to ± 20% of the product of the input speed and the total stretch of the web, which is the ratio between the yarn count of the yarn to be produced and the yarn count of the web input, so that substantially all the stretch of the web takes place between the card and the feed roller.

Further, the carding machine is driven in rotation so as to have a peripheral speed or extraction speed on the teeth equal to ± 10% of the product of the input speed and the total stretch of the web.

Further, the carding machine is driven in rotation so as to have a peripheral speed or extraction speed on the teeth equal to ± 5% of the product of the input speed and the total stretch of the web.

Further, said tangential pitch between said teeth of said carding machine is between 5 and 15 mm.

Further, the teeth have a triangular shape protruding from the outer side wall of the card, the triangular shape having a first front portion directly facing the web and a second rear portion forming a vertex together with the first front portion.

Further, the apex has a radial height, measured in a radial direction through the axis of rotation of the card, relative to the outer sidewall, which is between 0.5 and 2 mm.

Further, the first front portion together with a radial direction through the rotational axis of the card defines a first angle, the first angle being between 5 degrees and 10 degrees.

Further, said second rear portion defines a second angle with a tangential direction perpendicular to a radial direction through said rotational axis of said card, said second angle being between 40 degrees and 70 degrees.

Further, the apex of the tooth and the side wall of the extraction cylinder are spaced by a pitch of between 0.1 and 2mm with respect to the direction connecting the rotation axis of the carding machine and the rotation axis of the extraction cylinder.

Further, the extraction cartridge defines an inner chamber in fluid communication with a vacuum source and having a perforated sidewall provided with a plurality of apertures in communication with the inner chamber adapted to separate fibers from the card.

Further, the holes are round holes with a diameter between 1 and 3 mm.

Further, the holes are arranged according to a matrix pattern along a pair of directions perpendicular to each other and spaced according to a first pitch and a second pitch.

Further, the first pitch and the second pitch are between 2 and 4 mm.

Further, the first pitch and the second pitch are the same as each other.

Further, the carding machine and the extraction cylinder rotate in opposite directions of rotation to each other.

Further, downstream of the extraction cylinder, a conveying device is provided, equipped with an outfeed roller, which is idle and facilitates the extraction of the yarn from the extraction cylinder.

Further, the extraction cylinder determines on its own outer side wall an extraction arc extending from an extraction starting point, in which the web is clamped between the extraction cylinder and the carding machine, to an extraction end point, in which the web is clamped between the extraction cylinder and the output roller.

Further, the extraction arc is fluidly connected to an inner cavity of the extraction cylinder, the inner cavity being fluidly connected to a vacuum source to facilitate fiber separation from the card.

Further, the extraction arcs have an extension of 0.7 to 1.5 times the average fiber length of the web extracted from the carding machine.

The utility model discloses still relate to an open-end spinning equipment, include stretching device and at least one open-end spinning device.

Drawings

Other features and advantages of the invention will be more readily understood from the following description of preferred embodiments, given by way of non-limiting example, in which:

fig. 1 shows a schematic view of a stretching apparatus with a carding machine according to an embodiment of the invention;

fig. 2a to 2b show enlarged views of detail II in fig. 1;

fig. 3 is an enlarged view of detail III of fig. 1.

Elements or components common to the embodiments described below will be denoted by the same reference numerals.

Detailed Description

With reference to the preceding figures, reference numeral 4 designates a drawing device for the entire textile web 8.

In particular, the stretching device 4 comprises a feeding device 12 of the web 8 to be stretched, comprising a feeding roller 16.

The feed roller 16 is driven to rotate about its rotational pivot.

According to a possible embodiment, the feeding device 12 further comprises a nozzle or mouth 20, which nozzle or mouth 20 feeds the web 8 to be stretched towards the continuous stretching process.

The nozzle or mouth 20 defines, with the feed roller 16, a passage 24 for the web 8.

The nozzle or mouth 20 is preferably pressed towards the feed roller 16 in order to apply a pressure as a function of the input web thread count.

The feed roller 16, by virtue of its motorized rotation, moves the web 8, which is fed at an input speed Vi.

Stretching device 4 further comprises a carding machine 28, which comprises, on its outer lateral wall 32, a plurality of teeth 36 arranged with a constant tangential pitch P. The teeth 36 are shaped to stretch the web 8.

Feed roller 16 rotates and directly faces carding machine 28 to feed the web to carding machine 28 at said input speed Vi.

Preferably, the tangential pitch P between the teeth 36 of the carding machine 28 is between 5 and 15 mm.

As described below, this pitch P is particularly wide compared to the pitch of the prior art solutions: this reduces the complexity and cost of carding machine 28.

Preferably, said teeth 36 have a substantially triangular shape projecting from the outer side wall 32 of the card 28, according to a first front portion 40 directly facing the web 8 and a second rear portion 44 forming an apex 48 with the first front portion 40.

Preferably, said vertex 48 has a radial height 52, measured with respect to the outer side wall 32 along a radial direction R passing through the rotation axis C of the card 28, comprised between 0.5 and 2 mm.

According to one embodiment, the first front portion 40 defines a first angle β with a radial direction R passing through the axis of rotation C of the card 28, the first angle being between 5 and 10 degrees.

According to one embodiment, second rear portion 44 defines a second angle α with a tangential direction T perpendicular to a radial direction R passing through an axis of rotation C of carding machine 28, the second angle being between 40 degrees and 70 degrees.

Web 8 is fed by feed device 12 at an input speed Vi according to a direction of advance F coinciding with the direction of rotation S of carding machine 28.

In this way, the teeth of carding machine 28 during rotation stick to web 8 and stretch it according to its direction of advance F.

This operating condition is contrary to known solutions in which the teeth are opposite to the direction of advance of the wire.

Advantageously, carding machine 28 is driven in rotation so that the peripheral speed or withdrawal speed Ve on teeth 36 is equal to the product of the input speed Vi times the total stretch St of web 8, so that the stretching of web 8 is completely carried out on carding machine 28.

In other words: ve is Vi × St ± 20%.

Therefore, the Ve value must be maintained at about 20% of the product of the input speed Vi times the total stretch St.

Preferably, the Ve value must be maintained at about 10% of the product of the input speed Vi times the total stretch St.

Even more preferably, the Ve value must be maintained at about 5% of the product of the input speed Vi times the total stretch St.

The total stretch St represents the ratio between the yarn count of the yarn to be produced (thread count) and the yarn count of the incoming web.

Stretching device 4 further comprises an extraction cylinder 56 arranged downstream of carding machine 28 and web 8.

In other words, carding machine 28 receives web 8 from feeding device 12 and, by rotating in the same direction as the direction of advancement F of web 8, pulls and stretches web 8 towards extraction cylinder 56, extraction cylinder 56 being arranged downstream of carding machine 28 and web 8 with respect to said direction of advancement F of web 8.

It is worth noting that carding machine 28 and extraction drum 56 rotate in opposite rotational directions S, G. In particular, extraction cylinder 56 rotates in a counter-rotation direction G with respect to rotation direction S of carding machine 28.

By virtue of the balanced rotation of carding machine 28 and extraction cylinder 56, continuous removal of the fibers of web 8 is facilitated and improved.

For this purpose, the extraction cartridge 56 has a particular shape.

In particular, extraction cylinder 56 defines an internal cavity 60 and has a perforated side wall 64 provided with a plurality of holes 68 communicating with internal cavity 60 and adapted to generate a suction flow to facilitate the separation of the fibers from carding machine 28. In particular, the inner chamber 60 is connected to a vacuum source in order to generate a suction flow through said holes 68, which facilitates the removal of the fibres from the card 28.

Obviously, the counter-rotation between carding machine 28 and take-up roller 56 further facilitates this separation of the fibers of web 8 from carding machine 28.

For this purpose, the holes 68 are circular holes with a diameter of between 1 and 3 mm.

According to one embodiment, the holes 68 are arranged according to a matrix diagram along a pair of directions perpendicular to each other and spaced according to a first pitch L1 and a second pitch L2.

Preferably, the first and second pitches L1 and L2 are between 2 and 4 mm.

Preferably, the first pitch L1 and the second pitch L2 are equal to each other.

According to a possible embodiment, one of the directions of the matrix diagram is parallel to the rotation axis W of the extraction drum 56.

Obviously, the axes of rotation W, C of extraction cylinder 56 and carding machine 28, respectively, are parallel to each other.

Typically, the perforated side wall 64 of the extraction drum 56 has holes 68 arranged along an extraction strip 72, the extraction strip 72 having an axial thickness H parallel to the axis of rotation W of the extraction drum 56 of between 4mm and 11 mm.

With respect to the relative arrangement of carding machine 28 and extraction drum 56, it is preferred that the apexes 48 of teeth 36 and side walls 64 of extraction drum 56 are spaced apart by a pitch 76 of between 0.1 and 2mm, with respect to direction Q of rotation axis C, W connecting carding machine 28 and extraction drum 56.

Downstream of the extraction cylinder 56, a delivery device 80 is arranged, which is equipped with an output roller 84, the output roller 84 rotating in an idle manner and facilitating the extraction of the yarn from the extraction cylinder 56.

A spinning apparatus for carrying out a continuous operation on the yarn may advantageously be arranged downstream of the drawing device 4.

The operation of the stretching apparatus according to the present invention will now be described.

In particular, as described above, the feeding device sends the web 8 through the nozzle or mouth 20 at an advancing speed Vin. The advancing speed Vin of the web 8 also corresponds to the tangential rotation speed of the feed roller 16 at the point where it comes into contact with the web itself.

Thus, carding machine 28 is driven in rotation according to direction of rotation S, in a direction coinciding with the direction of advance F of web 8.

The difference in speed between the tangential or extraction speed Ve of the teeth 36 of the carding machine 28 and the advancing speed Vi of the web 8 determines the total stretch St of the web 8.

Further, web 8 is then transferred from carding machine 28 to extraction cylinder 56, as shown, extraction cylinder 56 rotates in a direction of rotation G opposite to direction of rotation S of carding machine 28.

The perforated extraction cartridge 56 defining the internal cavity 60 has a perforated sidewall 64 provided with a plurality of apertures 68 in communication with the internal cavity 60 and with a vacuum source.

The removal of the fibers of web 8 from carding machine 28 is facilitated by means of the vacuum and the opposite rotation of extraction cylinder 56 according to a direction of rotation W opposite to the direction of rotation S of carding machine 28.

The rotational speed of extraction drum 56 is such that the tangential velocity on sidewall 64 is approximately equal to the tangential velocity of teeth 36 of carding machine 28.

The fibers of web 8 are then transported from lumen 60 out of take-up drum 56 toward conveyor 80 and out-feed roller 84.

As can be understood from the above description, the present invention allows overcoming the drawbacks existing in the prior art.

The use of a carding machine in the conditions and manner described in this patent ensures a "soft" handling of the fibres, minimizing the possibility of breakage thereof and ensuring the continuity of the fibres at the input of the subsequent spinning unit.

By virtue of the present invention operating conditions according to which the carding machine operates at a linear speed equal to the product of the web input speed times the total web stretch ± 20%, it is possible to obtain such continuity and reduce the presence of short fibres.

As long as the value of the linear velocity is within 20% of such a value, yarn continuity can be obtained with fibers having a longer length and with a minimal risk of thread breakage.

Advantageously, the present invention allows to obtain a high quality yarn according to the required yarn count, since the continuity of the fibers is always ensured. In other words, although the drawing is done in one step on the carding machine, the fibers are drawn rapidly but gradually, most importantly continuously. The result is a homogeneous and uniform yarn with no broken fibers and/or short lengths.

Advantageously, the solution of the present invention envisages that the carding machine rotates according to a direction of rotation coinciding with the direction of rotation of the web: in this way the working speed and the amount of stretching can be significantly increased compared to prior art solutions without the risk of damaging the fibres.

Advantageously, the fibers of the web are practically completely stretched on the carding machine, which for this purpose is provided with teeth that are not very dense compared to prior art solutions.

This reduces the production costs of the card itself. Furthermore, the stress of the fibers is less and the stretching can be done in a more gradual manner than in prior art solutions.

This therefore strongly limits the risk of obtaining broken threads and therefore "short" fibres due to the excessively sudden mechanical action of the teeth of the carding machine.

Furthermore, by virtue of the fact that the entire stretching action is performed by the carding machine, the overall size and cost of the stretching device can be reduced.

The drawing apparatus and the drawing method according to the present invention may be subject to numerous changes and variants, all of which are included within the scope of protection defined by the appended claims, in order to satisfy specific needs that may occur.

Claims

1. Stretching device for a textile web, comprising:

a feeding device (12) of the web (8) to be stretched,

a carding machine (28) rotating according to a direction of rotation (S), comprising on its outer lateral wall (32) a plurality of teeth (36) arranged with a constant tangential pitch (P) suitable for stretching the web (8),

an extraction cylinder (56) located downstream of the carding machine (28) and the web (8),

it is characterized in that the preparation method is characterized in that,

said feeding device (12) comprising a feeding roller (16) facing said carding machine (28), rotating so as to feed said web to said carding machine (28) at an input speed and according to an advancement direction (F) coinciding with said rotation direction (S) of said carding machine (28),

wherein the carding machine (28) is driven in rotation so that the peripheral speed on the teeth is equal to ± 20% of the product of the input speed and the total stretching of the web, so that all stretching of the web takes place between the carding machine (28) and the feed roller (16),

the total draw is the ratio between the yarn count of the yarn to be produced and the yarn count of the web fed in.

2. Stretching device for textile webs according to claim 1, characterized in that the carding machine (28) is driven in rotation so as to have a peripheral speed or extraction speed on the teeth equal to ± 10% of the product of the input speed and the total stretching of the web.

3. Stretching device for textile webs according to claim 1 or 2, characterized in that the carding machine (28) is driven in rotation so as to have a peripheral speed or extraction speed on the teeth equal to ± 5% of the product of the input speed and the total stretching of the web.

4. Stretching device for textile fibre webs according to claim 1, characterised in that the tangential pitch (P) between the teeth (36) of the carding machine (28) is between 5 and 15 mm.

5. Stretching device for a textile web according to claim 1, wherein said teeth (36) have a triangular shape protruding from said outer side wall (32) of said comb (28), said triangular shape having a first front portion (40) directly facing said web (8) and a second rear portion (44) forming an apex (48) together with said first front portion (40).

6. Stretching device for a textile web according to claim 5, wherein said apex (48) has a radial height (52) measured with respect to said outer side wall (32) along a radial direction (R) passing through a rotation axis (C) of said carding machine (28), said radial height being comprised between 0.5 and 2 mm.

7. Stretching device for a textile web according to claim 5 or 6, wherein said first front portion (40) determines a first angle (β) with a radial direction (R) passing through a rotation axis (C) of said card (28), said first angle being between 5 and 10 degrees.

8. Stretching device for a textile web according to claim 5 or 6, wherein said second rear portion (44) defines a second angle (α) with a tangential direction (T) perpendicular to a radial direction (R) passing through a rotation axis (C) of said carding machine (28), said second angle being between 40 and 70 degrees.

9. Stretching device for textile webs according to claim 5 or 6, characterized in that the vertices (48) of the teeth (36) and the side walls (64) of the extraction cylinder (56) are distanced by a pitch (76) of between 0.1 and 2mm with respect to a direction (Q) connecting the rotation axis (C) of the carding machine (28) and the rotation axis (W) of the extraction cylinder (56).

10. Stretching device for textile fibre webs according to claim 1, characterized in that said extraction cylinder (56) defines an inner chamber (60) in fluid connection with a vacuum source and having a perforated side wall (64) provided with a plurality of holes (68) in communication with said inner chamber (60) suitable for separating fibres from said carding machine.

11. Stretching device for textile fibre webs according to claim 10, characterised in that the holes (68) are circular holes with a diameter between 1 and 3 mm.

12. Stretching device for textile fibre webs according to claim 10 or 11, characterised in that said holes (68) are arranged according to a matrix diagram along a pair of directions perpendicular to each other and are spaced according to a first and a second pitch (L1, L2).

13. Stretching device for textile fibre web according to claim 12, wherein said first and second pitch (L1, L2) are between 2 and 4 mm.

14. Stretching device for textile fibre web according to claim 13, wherein said first and second pitch (L1, L2) are identical to each other.

15. Stretching device for textile webs according to claim 1, characterized in that said carding machine (28) and said extraction cylinder (56) rotate in opposite directions of rotation (S, W) to each other.

16. Stretching device for textile webs according to claim 1, characterized in that downstream of the extraction cylinder (56) a conveying device (80) is provided, equipped with an output roller (84) which is idle and facilitates the extraction of the yarn from the extraction cylinder (56).

17. Stretching device for textile fibre web according to claim 16, wherein said extraction cylinder determines on its own outer side wall an extraction arc extending from an extraction starting point, in which said web is clamped between said extraction cylinder and said carding machine, to an extraction end point, in which said web is clamped between said extraction cylinder and said output roller.

18. Drawing device for a textile web according to claim 17, characterized in that said extraction arcs are fluidly connected to an inner chamber (60) of said extraction cylinder, said inner chamber being fluidly connected to a vacuum source for facilitating the separation of fibers from said carding machine.

19. Stretching device for a textile web according to claim 17 or 18, wherein said extraction arcs have an extension of 0.7 to 1.5 times the average fiber length of the web extracted from the carding machine.

20. An open-end spinning apparatus, characterized in that it comprises at least one open-end spinning device and at least one drawing device (4) for a textile web according to any one of claims 1 to 19.