DEVICE FOR FORMING BY CARDING ONE OR MORE FLEECES OF FIBRES, IN PARTICULAR NON-WOVEN

Abstract

Devices and methods for forming by carding one or more fleece(s) of fibres including a main carding drum supplied with raw fibres, one or more doffer cylinder(s) capable of removing the fibres worked on the carding drum and an associated stripper roller to strip the fleece(s) of fibres formed on the or each doffer and deposit them on one or more output belts. The device and methods also include at least one comb-cleaner flywheel capable of interacting with at least one doffer cylinder to remove dust and impurities therefrom, characterised in that it/they is/are fitted with prevention means which are configured so as to prevent the dust and impurities removed from the comb by the cleaner flywheel from escaping in the direction of the associated stripper roller.

Claims

1. A method for producing at least one fleece of fibers with few or no holes therein, comprising the steps of: supplying a carding drum with raw fibres so as to obtain carded fibers; collecting with at least one doffer roller said carded fibres from said carding drum to form at least one fleece of fibers; stripping said at least one fleece of fibres formed on said at least one doffer roller and depositing said at least one fleece of fibres on at least one output belt, the method also comprising: removing with at least one doffer cleaner flywheel dust and impurities from said at least one doffer roller at an interface between said at least one doffer cleaner flywheel and said at least one doffer roller; preventing said dust and impurities removed at the interface from escaping from said at least one doffer cleaner flywheel in a direction of the at least one stripper roller, so that said dust and impurities do not fall on said at least one fleece of fibers deposited on said at least one output belt; and obtaining said at least one fleece of fibers with few or no holes from said output belt.

2. The method of claim 1, wherein the removed impurities or dust are sent from said interface to the main carding drum along a path being the shortest path between the interface and the carding drum.

3. The method of claim 1, wherein the at least one doffer roller is rotated in a direction opposite to a direction in which said carding drum is rotated and the at least one doffer cleaner flywheel is rotated in said opposite direction.

4. The method of claim 1, wherein the preventing step comprises arranging a screen between the interface and the at least one stripper roller.

5. The method of claim 1, wherein at least one carding drum cleaner flywheel is arranged upstream of said at least one doffer roller.

6. The method of claim 5, further comprising arranging at least one downstream airtight roller downstream of the at least one carding drum cleaner flywheel, the at least one downstream airtight roller and the at least one carding drum cleaner flywheel being rotated in a same direction.

7. The method of claim 6, wherein the at least one downstream airtight roller is arranged to brush the at least one doffer cleaner flywheel.

8. The method of claim 5, further comprising the step of arranging an intermediate roller between the carding drum and the at least one doffer roller, so that said intermediate roller prevents a vacuum from forming in a space between the carding drum and the at least one doffer roller.

9. The method of claim 8, wherein the intermediate roller is located below the at least one downstream airtight roller.

10. The method of claim 1, comprising the step of providing two doffer rollers, upper and lower respectively, two respective upper and lower doffer cleaner flywheels, two respective upper and lower stripper rollers and an additional drum cleaner flywheel arranged upstream of the upper doffer roller and at least one downstream upper airtight roller downstream of the drum cleaner flywheel.

11. The method of claim 10, wherein the upper doffer flywheel cleaner is rotated in a direction opposite to a direction in which the upper doffer roller is rotated and the lower doffer cleaner flywheel is rotated in a direction opposite to a direction of in which the lower doffer roller is rotated.

12. The method of claim 6, wherein it comprises providing two airtight rollers, downstream and upstream, respectively of the carding drum cleaner flywheel.

13. The method of claim 12, wherein each of the two airtight rollers is rotated in a direction opposite to a direction in which the carding drum is rotated.

14. A method for forming at least one fleece of fibers, comprising the steps of: supplying a carding drum with raw fibres so as to obtain carded fibers; collecting with at least one doffer roller said carded fibres directly from said carding drum to form at least one fleece of fibers; stripping said at least one fleece of fibres formed on said at least one doffer roller and depositing said at least one fleece of fibres on at least one output belt, the method also comprising: removing with at least one doffer cleaner flywheel dust and impurities from said at least one doffer roller at an interface between said at least one doffer cleaner flywheel and said at least one doffer roller; and wherein said at least one doffer cleaner flywheel is rotated in a first direction, said at least one doffer roller is rotated in a second direction, said second direction being opposite to said first direction, and wherein a peripheral speed of said at least one doffer cleaner flywheel is selected to be less than a peripheral speed of said at least doffer roller.

15. The method of claim 14, wherein said carding drum is rotated in a third direction, said third direction being identical to said first direction.

16. The method of claim 15, wherein the removed impurities or dust are sent from said interface to the carding drum along a path being the shortest path between the interface and the carding drum.

Description

[0022] FIG. 1 is a diagrammatic side view of a fleece forming device according to a first method of implementation of the invention;

[0023] FIG. 2 is a diagrammatic side view of a fleece forming device comprising an upper doffer and a lower doffer to form two fleeces of fibres, upper and lower respectively;

[0024] FIG. 3 is a diagrammatic side view of another method of implementation of a device according to the invention; and

[0025] FIG. 4 is a diagrammatic side view of another method of implementation of a device according to the invention.

[0026] FIG. 1 shows a first method of implementation of the invention. A carding roller 1 is supplied with raw fibres by a feed cylinder (not shown in the diagram). Traditionally, the carding drum comprises a covering equipped with spikes to perform the actual carding. A doffer 3 is placed at the top of the carding drum to collect the fibres worked by the carding drum. The doffer thereby forms a fleece of fibres, for example non-woven, the fleece being collected by a stripper roller 7 placed on the opposite side of the carding drum with respect to the doffer, the stripper roller 7 detaching the fleece of fibres from the doffer and depositing it on an output belt of the device (belt not shown in the diagrams).

[0027] The device according to the invention in FIG. 1 also comprises a cleaner flywheel or roller 4 placed on the top of the doffer and arranged so as to bear against the doffer spikes to remove impurities and other dust from it. Traditionally, the doffer flywheel cleaner 4 has flexible spikes forming a brush, while the doffer has rigid spikes.

[0028] FIG. 1, the carding drum 1 rotates in a clockwise direction (this is when it is fitted on the left in relation to the output belt). The doffer cylinder rotates anticlockwise, that is in the opposite direction to the carding drum. The doffer cleaner flywheel rotates in the same direction as the carding drum and in the opposite direction to the doffer, so that at the interface between the doffer 3 and the doffer cleaner flywheel 4, the peripheral speeds of the flywheel and the doffer are in the same direction, that is in the direction of the carding drum opposite to it.

[0029] The device in FIG. 1 also comprises a smooth roller 5 placed between the carding drum 1 and the doffer cylinder 3 and below the doffer cleaner flywheel 4. The purpose of the smooth roller is to prevent a vacuum causing turbulence that can cause faults in the fleece formed.

[0030] The device also comprises a drum cleaner flywheel 9 rotating in the opposite direction to the drum, and two airtight rollers 10 with rigid seals upstream and downstream respectively of the drum cleaner flywheel 9, located on each side of the cleaner flywheel 9. An enclosure 20 blocks emissions from the cleaner flywheel 9. However, it is not necessary to provide enclosures for the airtight rollers.

[0031] The downstream airtight roller 10 is located firstly above the smooth roller 5 and secondly so that its seal bears on, in particular brushes, the circumference of the doffer cleaner flywheel 4. The two airtight rollers 10 and the cleaner drum flywheel 9 rotate in the same direction as the doffer cylinder 3 and in the opposite direction to the drum and the doffer cleaner flywheel 4.

[0032] Traditionally, when a drum cleaner flywheel 9 is used, the speed of rotation of the main drum may be between 750 and 1,100 m/min and the speed of rotation (tangential or peripheral speed) of the doffer between 0 and 250 m/min, while the speed of rotation (tangential or peripheral speed) of the doffer cylinder cleaner may be between 0 and 230 m/min and the speed of rotation of the stripper roller may be between 0 and 400 m/min. Regarding the ratio of the peripheral speed of the doffer cleaner flywheel and the peripheral speed of the doffer, this can be such that the speed of the cylinder cleaner is 5 to 30 times less than the speed of the doffer in the case where the two cylinders rotate in opposite directions. Traditionally, the peripheral speed of the doffer is lower than the peripheral speed of the carding drum, in particular the ratio of the two speeds is between 5 and 100.

[0033] FIG. 2 shows a method of implementation of a device for forming two fleeces of fibres, upper and lower respectively, comprising a carding drum 1 and two doffers, 3 upper and 3 lower.

[0034] The arrangement of the upper doffer 3 is the same as that shown in FIG. 1, the device comprising at the top the same components as the device shown in FIG. 1, in particular the drum cleaner flywheel 9, the two upstream and downstream airtight rollers, the doffer cleaner flywheel and the smooth roller.

[0035] At the bottom, there is a cleaner flywheel 4 and a stripper roller 7 in an identical arrangement to that shown in FIG. 1 for the upper doffer. On the other hand, at the bottom there is no drum cleaner flywheel nor the associated airtight cylinders, nor the lower smooth roller between the drum 1 and the doffer 3. The carding drum 1 rotates clockwise (when it is on the left in relation to the output belt). The rollers 3 and doffer 3 rotate anticlockwise, that is, in the opposite direction to the carding drum. The doffer cleaner flywheels 4 and 4 rotate in the same direction as the carding drum and in the opposite direction to the doffers, so that at the interfaces between the doffer 3 and the doffer cleaner flywheel 4, the peripheral speeds of the flywheel and the doffers are in the same direction, that is in the direction of the carding drum opposite to it. An airtight roller 10 is arranged between the carding drum 1 and the lower doffer 3 arranged so that the seal bears against, in effect brushes the periphery of the lower doffer cleaner flywheel 4. The lower airtight roller 10 rotating in the same direction as the lower doffer 3 and in the opposite direction to that of the drum 1 and the lower doffer cleaner flywheel 4.

[0036] FIG. 3 shows another method of implementation of a device according to the invention. The device comprises a carding drum 1 supplied by a feed roller 2, a doffer 3, a stripper roller 7 and a doffer cleaner flywheel 4 coupled to an airtight flywheel 10, arranged between the carding drum 1 and the comb 3, so that its seal bears against, in effect brushes the periphery of the doffer cleaner flywheel 4.

[0037] The doffer cleaner roller 4 and the doffer 3 rotate in the same direction. In particular, the direction of rotation of the cleaner flywheel 4 is such that dust and impurities from the doffer roller at the interface between the doffer roller and the cleaner flywheel 4 are sent in the opposite direction to that of the carding drum, the absolute value of the peripheral speed of the flywheel 4 being greater that of the doffer roller 3. According to the invention, a screen is provided, in particular in the form of an enclosure 11 arranged so as to prevent impurities and dust removed from the doffer roller 3 by the cleaner flywheel 4 from falling on the stripper roller 7, thus preventing these impurities and dust from contaminating the fleece of fibres formed by the device.

[0038] FIG. 4 shows yet another method of implementation of a device according to the invention in which a drum cleaner flywheel is not provided. The device comprises a carding drum 1, upper and lower doffer rollers 3, 3, two associated stripper rollers 7, 7 and two doffer cleaner flywheels 4, 4. An airtight roller 10 with rigid seal is also fitted between the carding drum and the upper doffer roller, below the doffer cleaner flywheel 4 to clean the flywheel 4 and recycle the dust and fibres from the carding drum and also preventing turbulence forming in the region between the drum and the upper doffer. In addition, an airtight roller 10 with rigid seal is placed between the carding drum and the lower doffer roller. The device is completed by a traditional carding unit formed from a worker 21 and a sweeper 22.

[0039] In all methods of implementation, the airtight rollers 10, 10, 10 and the flywheel 9 rotate anticlockwise, in the opposite direction to the carding drum. However, these rollers can rotate in the same direction as the drum, in particular in the case of very dusty fibres to the point that they may not be captured by the airtight roller seals.

[0040] In the methods of implementation shown in FIGS. 1 and 2, the smooth roller 5 rotates clockwise, in the same direction as the carding drum. However, this roller can rotate in the opposite direction to that of the drum as a function of the aerodynamic phenomena observed.

[0041] In the present invention, the, or each doffer roller immediately follows the carding drum (except for the fibres and/or the collected fleece which lies between them). In the same way, the stripper roller immediately follows the doffer roller (except for the fleece it is stripper from the doffer). On the other hand, the, or each output belt follows the doffer roller, but may be fitted between one or more rollers, in particular transfer rollers.