GB2281920A

GB2281920A - Apparatus on a carding machine or a cleaning machine

Info

Publication number: GB2281920A
Application number: GB9417188A
Authority: GB
Inventors: Ferdinand Leifeld
Original assignee: Truetzschler GmbH and Co KG
Current assignee: Truetzschler GmbH and Co KG
Priority date: 1993-08-28
Filing date: 1994-08-25
Publication date: 1995-03-22
Also published as: ITMI941750A0; JPH07145518A; GB9417188D0; DE4328979A1; IT1274625B; ITMI941750A1

Description

Apparatus on a carding machine or a cleaning machine The invention relates to carding machines or cleaning machines for textile fibres, such as cotton or similar fibres, and, more particularly, to means for modifying the air flow in the vicinity of a roller of a said machine. In a known apparatus, a separator is provided, having an air gap leading to the circumference of the clothed roller of a carding machine and partly formed by the circumference of the clothed roller. The longitudinal side of the separator facing towards the clothed roller is formed by an air-deflecting baffle. Adjoining the air-deflecting baffle in the direction of rotation of the clothed roller there is an aperture (exit opening) leading into a collector. The longitudinal side of the aperture arranged at a distance from the air-deflecting baffle constitutes a front edge of the collector adjacent to the clothed roller. The air-deflecting baffle separates the air gap for the incoming air from the aperture for the exit of air. In operation, the rotating clothed roller causes air originating from the air in the machine room to be sucked into the space between the air-deflecting baffle and itself. At the downstream end (breakaway edge) of the air-deflecting baffle, this air current is stalled, resulting in the creation of turbulence, which presumably contributes to the loosening of dirt and also very short fibres from the fibre sliver held by the clothing; the centrifugal force can also contribute to this effect. In this apparatus, the incoming air is drawn in by force only through rotation of the clothed roller. In addition, the fibre is exposed to a certain degree of turbulence because of the breakaway edge. It is an object of the invention to provide an apparatus which avoids the disadvantages mentioned, in which in particular the separation of short fibres in addition to waste is improved, and which allows the short fibres to be separated in a careful manner from the fibre fleece. The invention provides a separating device in a textile machine, in which there is provided in a covering of a roller of the machine an air gap for admission of air and an exit opening for the exit of air and waste, the device comprising air current-generating means for generating an air current that flows inwardly through the air gap. Because the flow of incoming air is generated by means other than the roller of the machine with which the device is associated, it is possible for the fibre fleece to be influenced independently of the rotating air current of the roller. In this manner, the short fibres and the waste can be separated from the quality fibres (longer fibres) on the roller, for example on the clothing or needles of the roller, in a more controlled manner. A more controlled exit of the air current containing the short fibres that is substantially independent of the rotating air current of the roller may additionally be effected. The additional incoming air current has the effect of loosening and stripping out the short fibres. Using the apparatus according to the invention, short fibres can be separated out in such a quantity that, at least as far as qualities at the lower limit for combed qualities are concerned, it is possible to operate without a combing machine. As a result, for a given combing quality an increased proportion of fibre of carding quality is produced. An increased separation of short fibres right round the roller can be achieved. The roller may be a clothed roller. The roller may be a needle roller. The doffer in particular of the carding machine offers space for separating elements. This location is significant because it is here that the end result of the carding operation is obtained, the surface speed and air speed are moderate, yet there is also room next to a large fleece surface. In the region of the roller, for example, the saw-tooth roller, in particular the doffer, separating elements for dirt and short fibres are advantageously provided on the fleece-guiding side. Blades are here advantageously mounted after slit-shaped openings, the waste from which can also be disposed of by suction hoods. Several separating blades can also be provided. The exit opening or openings for the air current containing the short fibres and the waste can be simple slits that have suction applied to them, at least one air intake slit preceding the suction slit or slits. Between the or each intake slit and the respective succeeding slit there is provided a curved element, so that throttle cross-sections are created. That element may be a roller-shaped body which rotates, preferably in the same direction as the circumferential direction in which the fleece runs. The action of the apparatus can be matched to the task on hand through the diameter of the body (roll), the spacing of the roll from the fleece or the points of the clothing, and the speed of rotation. Air intake slits are provided in front of and/or after the roll. Through rotation of the roll, the roll surface draws air along with it, which is forced into the narrow gap between roll and clothing and is also discharged again. The resulting air current is able to loosen dirt and fibres that are not very tightly gripped from the fleece and carry them away with it. The shorter are the fibres, the poorer is their incorporation into the fleece. It is therefore easier and more likely for short fibres to be removed than long fibres. In contrast with the known apparatus, air that is driven by an energy source is admitted to and/or removed from the space outside the clothed roller; that is, the admitted and/or removed air is not generated solely by the movement of the clothed roller. The energy source is additionally able to move a larger volume of air than the clothed roller alone. A more marked effect is therefore possible. In terms of the volume of separated short fibres, waste and so on, the effect of the known apparatus operating without external energy is insufficient to achieve the amount achieved with the apparatus according to the invention. The clothed roller is advantageously the doffer of a carding machine. The device may generate a suction air current. The device may generate a pressurised air current. The device is advantageously arranged between the air gap and the exit opening. The device expediently comprises a high-speed roll. The roll is preferably arranged axially parallel with respect to the clothed roller. The surface of the roll is preferably profiled, has raised areas, attachments or similar configurations. The saw-tooth roller and the high-speed roll advantageously rotate in opposite directions. The direction of movement of the part of the surface of the high-speed roll facing the fleece and the running direction of the fleece are expediently the same. A device for deflecting the air current containing the short fibres, waste or the like is preferably associated with the saw-tooth roller. The deflecting device is preferably the high-speed roll. The distance between the clothed roller and the high-speed roll is advantageously adjustable. The distance between the highspeed roll and the fleece is expediently adjustable. The circumferential speed of the high-speed roll is preferably equal to or greater than the circumferential speed of the clothed roller. The centrifugal force at the surface of the high-speed roll is preferably greater than the centrifugal force at the surface of the clothed roller. The high-speed roll is advantageously arranged between the air gap and the exit opening. By its rotation, the high-speed roll expediently draws in air from the surroundings through the air gap. By its rotation, the high-speed roll preferably discharges the air current containing the short fibres, waste and so on through the exit opening. The distance between the highspeed roll and the air intake and/or air exit opening in the circumferential direction of the clothed roller is preferably adjustable. An air-deflecting baffle for the incoming air is advantageously associated with the air gap. The air gap expediently leads to the circumference of the clothed roller. The air gap is preferably partly formed by the circumference of the clothed roller. The air gap preferably narrows approximately in the form of a funnel in the direction of rotation of the high-speed roll. The air gap advantageously runs so that the air current generated by rotation of the clothed roller and coinciding with the incoming air has a speed component directed in the direction of rotation. The air entrained by rotation of the highspeed roll is expediently forced into the narrow gap between the roll and clothing and is subsequently discharged again. The air current in the narrow gap is preferably accelerated relative to the air current generated by the clothed roller. A suction device is preferably attached to the air exit opening. A separating edge, a blade or similar means is advantageously associated with the air exit opening. The ratio of the diameter of the clothed roller to the diameter of the high-speed roll is expediently less than 2:1. The opening for the incoming air is preferably slot-shaped across its width. The opening for the exit of air is preferably slot-shaped across its width. Cleaning elements, for example scrapers, stripping elements, cleaner elements, cleaner rollers or similar means are advantageously associated with the roller. Two or more high-speed rolls are expediently provided one behind the other. A separating element is preferably arranged between the air exit opening and the air gap for the incoming air. The air exit opening and the air gap for the incoming air are preferably arranged separately from one another. The distance between the clothed roller and the fleece is expediently adjustable. The air gap is expediently connected to an external source of compressed air. The surface of the high-speed roll is preferably smooth. The surface of the high-speed roll has a clothing, for example a saw-tooth clothing, needles or similar means. The diameter of the high-speed roll is advantageously about 80 to 150 mm. The speed of rotation of the highspeed roll is expediently about 600 to 1200 rev/min. Certain embodiments of the invention will now be described, by way of example, hereinafter with reference to the drawings, of which Fig. 1 is a diagrammatic side view of a carding machine with a device according to the invention; Fig. 2 is a diagrammatic side view of the doffer of a carding machine with a high-speed roll with suction hood below the doffer; Figs 3a, 3b are, respectively, a schematic side view, and a plan view of the surface, of a high-speed roll, showing the surface shaping; Fig. 4 is a schematic view of a part of the device of Fig. 2 with the air currents marked; Fig. 4a shows diagrammatically the detachment of a short fibre; Fig. 5 is a schematic view of a part of a doffer having a high speed roll, the position of which is adjustable; Fig. 6 is a side view of a device having means for adjusting the variable speed of rotation of the high-speed roll; Fig. 7 is a side view of a device in which the air gap for the incoming air is connected to a source of compressed air; Fig. 8 is a side view of a doffer with which there are associated two devices according to the invention; Fig. 9 is a side view of a device according to the invention on the cylinder of a carding machine; and Fig. 10 is a side view of a device having an air deflector. Fig. 1 shows a carding machine, for example a carding machine of the type known as the Trutzschler EXACTACARD DK 760, having a feed roller 1, feed table 2, licker-in 3, cylinder 4, doffer 5, stripper roller 6, squeezing rollers 7, 8, web-guide element 9, sliver funnel 10, delivery rollers 11, 12 and revolving card top 13. One form of device according to the invention, comprising a high-speed roll 14, is arranged beneath the doffer 5. The direction of rotation of each roller and cylinder is indicated by a curved arrow. In the embodiment of Fig. 2, beneath the doffer 5 there is a covering 15 which is interrupted by a slitshaped opening 16 extending across the width. A highspeed roll 14, which has a diameter of, for example, 120 mm, is arranged in the opening 16, axially parallel with the doffer 5. The doffer 5 has a diameter of 700 mm. The high-speed roll 14 rotates in a clockwise direction (arrow A) at a speed of 900 rev/ in. The doffer 5 rotates anticlockwise (arrow B) at a speed of 96 rev/min, i.e. the circumferential speed of the high-speed roll 14 is substantially higher than that of the doffer 5. By virtue of the positioning of the roll 14 in the opening 16, there is in the covering 15 an opening 17 for the exit of air containing short fibres, waste and so on, and an air gap 18 for the admission of air. A curved air-deflecting baffle 27 for the incoming air is associated with the air gap 18. A stripping edge 20 with a suction hood is associated with the air gap 17. A suction means (not shown) is associated with the suction hood. Figs 3a and 3b illustrate projections 14a on the roller 14 as the surface shaping. With reference to Figs. 4 and 4a, the air gap 18 for the admission of air is positioned upstream of the exit opening 17. Admission of air C is effected through the air gap 18 towards the clothing 5a of the doffer 5, and exit of air D is effected through the exit opening 17 away from the clothing 5a of the doffer 5. The air current C is generated by the roll 14 rotating and entraining air from the atmosphere, passes through the narrow gap a between doffer 5 and roll 14 and by rotation of the roll 14 is deflected outwards through the air exit opening 17 into the suction hood 19. The air current C meets the air current E which is created by rotation of the doffer 5. The two air currents C and E together pass through the narrow gap a, in substantially the same direction. They are then divided into the air currents D and F, air current D being separated with the assistance of the stripping edge 20 (not shown in Figs. 4 and 4a) from air current F which is entrained by the doffer 5. In operation, air current C strikes the fibre material containing long fibres 21a and short fibres 21b, as shown in Fig. 4a. It is believed that in operation one end of the long fibres 21a loops around the clothing points 5a which are aligned opposing the direction of rotation B; in the region of the high-speed roller, the other free end of the long fibres 21a points in the direction of rotation B. The short fibres 21b cling to the long fibres 21a. The short fibres 21b are detached and stripped from the long fibres 21a by air current C in particular, and pass outwards under the influence of air current D while the long fibres 21a remain on the clothing 5a. In the embodiment of Fig. 5, the distance a between the high-speed roll 14 and the doffer 5 is adjustable by means of a distance-adjusting device 22 for the high-speed roll. In the embodiment of Fig. 6, a drive means 23 for the high-speed roll 14, for example a variable-speed electric motor, is arranged to be varied by an electronic speed setting device 24 which can be connected to a microcomputer control system (not illustrated) . In the arrangement of Fig. 7, an air duct 25 is connected to the air gap 18 for the incoming air obliquely and approximately tangentially thereto; the air duct 25 is connected to an external source of compressed air 26. The reference number 17 denotes the air exit opening through which the air containing short fibres, waste and the like exits. Although not shown in Fig. 7, collection means for the short fibres and waste may be provided. In the arrangement of Fig. 8, two separation devices are arranged one behind the other, having respective air gaps 18a, 18b and respective downstream air exit openings 17a, 17b. A stripping edge 20 with suction hood 19 for short fibres, waste and the like is associated with each air exit opening 17a, 17b. In the arrangement of Fig. 9, a separation device comprising high-speed roll 14 is arranged beneath the cylinder 4, the high-speed roll 14 and the cylinder 4 rotating in the same direction. Arrow G designates the direction of rotation of cylinder 4. In the embodiment of Fig. 10 the circumferential surface of a high-speed roll 14 has associated with it an air switch 28, the upstream surface of which is positioned substantially tangentially with respect to the surface of the roll 14 and extending towards the roller in a direction opposed to the direction of rotation A of the roller. The air switch 28 acts as an air-separating element for the incoming air current C. Between the air intake duct 25 for the incoming air and the air outlet duct 27 for the outgoing air D, the circumferential surface of the high-speed roll 14 has associated with it an air current separating element 29, so that the outgoing air D containing short fibres is unable to get into the incoming air current C. As a result of the relative positioning of the air switch and the covering 15, the air inlet duct 25 and the air outlet duct 27 are in the form of throttles.

Claims

1. A separating device in a textile machine, in which there is provided in a covering of a roller of the machine an air gap for admission of air and an exit opening for the exit of air and waste, the device comprising air current-generating means for generating an air current that flows inwardly through the air gap.

2. A device according to claim 1 , in which the air current-generating means generates a suction air current.

3. A device according to one of claim 1 or claim 2, in which the air current-generating means generates a pressurised air current.

4. A device according to any one of claims 1 to 3 , in which at least a part of the air current-generating means is arranged between the air gap and the exit opening.

5. A device according to any one of claims 1 to 4, in which a device for deflecting the air containing the short fibres, waste or the like is associated with the roller.

6. A device according to any one of claims 1 to 5 , in which the air current-generating means is a roll.

7. A device according to claim 6, in which the roll is arranged axially parallel with respect to the roller.

8. A device according to claim 6 or claim 7, in which the surface of the roll has protruding portions.

9. A device according to anyone of claims 6 to 8, in which the roller and the roll rotate in opposite directions.

10. A device according to any one of claims 6 to 9, in which the direction of movement of the part of the surface of the roll facing the fleece and the running direction of the fleece are the same.

11. A device according to any one of claims 6 to 10, in which the roll is so arranged that it is able to deflect the air containing the short fibres, waste or the like.

12. A device according to any one of claims 6 to 11, in which the distance between the roller and the roll is adjustable.

13. A device according to any one of claims 6 to 12, in which the distance between the roll and the fibres on the roller is adjustable.

14. A device according to any one of claims 6 to 13, in which the circumferential speed of the roll is equal to or greater than the circumferential speed of the roller.

15. A device according to any one of claims l to 14, in which the centrifugal force at the periphery of the roll is greater than the centrifugal force at the periphery of the roller.

16. A device according to any one of claims 6 to 15, in which the roll is arranged between the air gap and the exit opening.

17. A device according to any one of claims 6 to 16, in which, by means of its rotation, the roll draws in air from the surroundings through the air gap.

18. A device according to any one of claims 6 to 17, in which, by means of its rotation, the roll causes discharge of air containing short fibres and waste through the exit opening.

19. A device according to any one of claims 6 to 18, in which the distance between the roll and the air intake in the circumferential direction of the roller is adjustable.

20. A device according to any one of claims 6 to 19, in which the distance between the roll and the air exit opening in the circumferential direction of the roller is adjustable.

21. A device according to any one of claims 1 to 23, in which the means defining the air gap are so arranged that the gap decreases in width in the direction of rotation of the roll.

22. A device according to any one of claims 6 to 21, in which air entrained by rotation of the roll is forced into the gap between the roll and the roller and is subsequently discharged again.

23. A device according to claim 22, in which the air current in the gap is accelerated relative to the air current generated by the clothed roller.

24. A device according to any one of claims 6 to 23, in which the ratio of the diameter of the roller to the diameter of the roll is greater than 2:1.

25. A device according to any one of claims 6 to 24, in which one or more cleaning elements, for example scrapers, stripping elements, cleaner elements, or cleaner rollers is associated with the roll.

26. A device according to any one of claims 6 to 25 , in which two or more rolls are provided one behind the other.

27. A device according to any one of claims 6 to 26, in which the surface of the roll is substantially smooth.

28. A device according to any one of claims 6 to 26, in which the surface of the roll has a clothing, for example a saw-tooth clothing, needles or similar means.

29. A device according to any one of claims 6 to 28, in which the diameter of the roll is from 80 to 150 mm.

30. A device according to any one of claims 6 to 29, in which the speed of rotation of the roll is about 600 to 1200 rev/min.

31. A device according to any one of claims 6 to 30, in which an air-separating element for the incoming air, for example, an air switch, is associated with the roll opposing its direction of rotation.

32. A device according to any one of claims 6 to 31, in which an air current separating element is associated with the roll between an air intake duct and an air exit duct.

33. A device according to any one of claims l to 32, in which an air-deflecting baffle for the incoming air is associated with the air gap.

34. A device according to any one of claims 1 to 33, in which the air gap leads to the circumference of the roller.

35. A device according to any one of claims 1 to 34, in which the air gap is in part defined by the circumference of the roller.

36. A device according to any one of claims 1 to 35, in which the air gap is so arranged that the air current generated by rotation of the clothed roller and coinciding with the incoming air has a speed component directed in the direction of rotation.

37. A device according to any one of claims 1 to 36, in which a suction device is attached to the air exit opening.

38. A device according to any one of claims 1 to 37, in which a separating edge, a blade or similar means is associated with the air exit opening.

39. A device according to any one of claims 1 to 38, in which the opening for the incoming air is slot-shaped across its width.

40. A device according to any one of claims 1 to 39, in which the opening for the exit of air is slot-shaped across its width.

41. A device according to any one of claims l to 40, in which a separating element is arranged between the air exit opening and the air gap for incoming air.

42. A device according to any one of claims 1 to 41, in which separate openings in the covering are provided for the air exit opening and the air gap for incoming air.

43. A device according to any one of claims 1 to 42, in which the air gap is connected to an external source of compressed air.

44. A device according to any one of claims l to 43, in which the roller is a clothed roller.

45. A device according to any one of claims l to 44, in which the roller is a doffer of a carding machine.

46. A device according to any one of claims 1 to 43, in which the roller is a needle roller.

47. A device according to any one of claims 1 to 46, in which the air gap is upstream of the exit opening in the direction of travel of the fibre on the roller.

48. A device on a carding machine or a cleaning machine for textile fibres, such as cotton or similar fibres, in which in the covering of a clothed roller, needle roller or the like there is an opening for the exit of air containing short fibres, waste or the like, and an air gap for the admission of air is located in front of the exit opening in the opposite direction to the direction of rotation of the clothed roller, the admission of air being effected in the direction onto the clothed roller and the exit of air being effected away from the clothed roller, characterized in that an external means for generating the incoming air current that flows through the air gap is associated with the clothed roller.

49. A separating device substantially as described herein with reference to and as illustrated by Fig. 1, Fig. 2, Figs. 3a and 3b, Figs. 4 and 4a, Fig. 5, Fig. 6, Fig. 7, Fig. 8, Fig. 9 or Fig. 10.

50. A textile machine including a device according to any one of claims 1 to 49.

51. An apparatus on a carding machine for textile fibres, such as cotton or similar fibres, in which in the covering of a clothed roller there is an opening for the exit of air containing short fibres, waste or the like, and an air gap for the admission of air is located in front of the exit opening in the opposite direction to the direction of rotation of the clothed roller, a separating element being provided between the air exit opening and the air gap for the incoming air, characterized in that beneath the doffer of the carding machine there are covering elements which define a plurality of exit openings for discharge of waste, short fibres and the like, there being arranged at the downstream end of each said exit opening a blade edge, for example a stripping blade, and a suction chamber being associated with the blade edge and the respective exit opening, the apparatus further comprising, upstream of each separating opening, a respective opening for incoming air.

52. A method for separating waste and/or short fibres from fibre material in which there is used a device according to any one of claims 1 to 49.