Carding machine, which is provided with alignment devices for the fibers of the edges of the fiber web, and corresponding method

Abstract

A combing machine (1) of a spin preparation plant according to the present invention comprises at least two combing heads (2) having a gripper and a rotating comb for combing a fiber web, as well as at least one pair of breaker cylinders (20') suitable for forming a fiber web with edges. In an innovative manner, the combing head (2) comprises aligning devices for the fibers of the edges of the web. Advantageously, the fiber aligning device pushes and realigns fibers that are not fully parallelized and that protrude from the fiber web inward and / or underneath the web. This solution results in a combed web of high quality, as it is free of misaligned fibers that can impair subsequent drawing steps by generating knots and crimps.

Description

[0001] The subject of the present invention relates to a combing machine of a spinning preparation plant.

[0002] In a spin preparation plant, after the initial steps of opening and cleaning the fiber, a carding process is performed by carding machines, resulting in the fiber taking the form of a combed sliver. The sliver emerging from the carding machine typically undergoes a first draft in a drawing machine, where several combed slivers are joined together.

[0003] The basic combing operations, which follow one another in conventional machines of newer design at a rate of 500 to 550 strokes per minute, are: - Discontinuous feeding of the fiber material; - combing, by means of a rotary comb, the head of the incoming tuft or beard, the gripper being closed; - superimposing and joining the head of the tuft with the web combed in the previous cycle, suitably set back, by means of breaker cylinders during their reverse rotation; - combing the rear part of the tuft by means of a straight comb of the gripper, the gripper being open; - Moving the combed tuft forward by means of the crusher cylinders during their forward rotation.

[0004] However, the crusher cylinders exhibit an alternating rotational movement. To eliminate the disadvantages caused by the alternating rotational movement of the crusher cylinders, several solutions have been developed in which the crusher cylinders exhibit a unidirectional rotational movement. An example of combing machines equipped with crusher cylinders with a continuous rotational movement (at a constant or variable speed, but unidirectional) is shown in the applicant's document WO 2020 / 208454 A1.

[0005] It has been observed that the fiber web emerging from the breaker cylinders with a continuous unidirectional rotating motion, in some cases, has fibers at the edges that are not completely parallelized and that tend to protrude towards the outside of the combed web, causing problems in subsequent spinning steps.

[0006] A combing machine is known in the art that includes a main cylinder with a perforated surface through which air is drawn to assist in the correct arrangement of the tufts one by one. This machine is described in document WO 2006 / 012759 A1. However, creating a suction flow through the surface of the main cylinder is an energy-consuming and technologically complex solution. Furthermore, this solution has no effect on the not fully parallelized fibers that tend to protrude from the edges of the combed web.

[0007] The object of the present invention is to construct a combing machine which can ensure a high level of quality of the combed web, especially at the edges.

[0008] This object is achieved by a combing machine constructed according to claim 1. The dependent claims describe further embodiments of the invention.

[0009] The features and advantages of the combing machine according to the present invention will become apparent from the following description, given by way of non-limiting example in accordance with the attached figures, in which: - Fig. Figure 1 is a plan view of a combing machine according to the present invention, comprising a plurality of combing heads; - Fig. 2 a schematic plan view of the combing machine in the Fig. 1, which shows the path of the strips N emerging from the respective combing head; - Fig. 3 is a schematic sectional view of a combing head according to an embodiment of the present invention; - Fig. Figure 4 is a schematic view of the combing head, showing fiber alignment devices according to an embodiment of the present invention; - Fig. Figure 5 is a schematic plan view of the combing head, showing fiber alignment devices according to an embodiment of the present invention; - Fig. 6 to 12 show example embodiments of fiber alignment devices according to the present invention; - Fig. Figure 13 is a schematic side view of a combing machine according to the present invention, comprising a plurality of combing heads, and wherein the gripper group is also visible; - Fig. 14 an axonometric sectional view of the gripper group in the Fig. 13 is; - Fig. 15 a top view of the gripper group in the Fig. 13, wherein fiber alignment devices according to an embodiment of the present invention are visible; - Fig. 16 is an axonometric view of the transmission device shown schematically in the Fig. 13, wherein fiber alignment devices according to an embodiment of the present invention are visible.

[0010] A combing machine 1 according to the present invention comprises a fixed frame and a plurality of combing heads 2 aligned along a transverse axis X.

[0011] In each combing head 2, the processed web advances along a longitudinal direction Y. Downstream of each combing head 2, a hopper 4 is arranged, whereby the combed web is gathered into a single strip N. The individual gathered strips N from each combing head 2 are deflected by a special deflection device 6 and are arranged side by side on a support 61 so that they advance along a common direction of movement, typically parallel to the transverse direction X.

[0012] Each combing head 2 comprises a gripper 21 provided with a lower jaw 211, an upper jaw 212, and a straight comb, usually integrated with the lower jaw. The lower jaw 211 and the upper jaw 212 of the gripper 21 define a jaw closing area between them. Furthermore, the gripper comprises a feed cylinder that is intermittently rotatable according to an instruction and supported by the lower jaw.

[0013] The combing head comprises at least one pair of crushing cylinders 20' downstream of the grapple.

[0014] Preferably, immediately downstream of the gripper and facing the gripper, there is a pair 20' of superposed breaker cylinders 20a', 20b', preferably in pressure contact, which perform a continuous rotary movement (at a constant or variable speed, but not reversibly) so as to distort a segment of a web emerging from the jaws, detaching a tuft of the web and conveying it downstream.

[0015] Preferably, the lower crusher cylinder 20b' is motorized or is driven in rotation by means of a kinematic connection with another motorized cylinder, while the upper crusher cylinder 20a', which is preferably provided with a rubber coating, is in pressure contact with the lower crusher cylinder 20b' and is thereby driven in rotation.

[0016] According to one embodiment, downstream of the pair 20' of breaker cylinders 20a', 20b', a pair 20 of auxiliary cylinders is arranged, comprising an upper auxiliary cylinder 20a, which is preferably motorized or driven to rotate by means of a kinematic connection to another motorized cylinder, and a lower auxiliary cylinder 20b, usually in pressure contact with the upper auxiliary cylinder 20a and preferably driven to rotate thereby. The auxiliary cylinders 20a, 20b, which have a peripheral speed Vs, have a continuous rotational movement (at a constant or variable speed, but not reversible), so that a segment of a web output by the breaker cylinders 20a', 20b' is drawn, a tuft is detached from the web, and it is conveyed from upstream to downstream.

[0017] The combing head comprises a main device 26 arranged immediately downstream of the auxiliary cylinders 20a, 20b or immediately downstream of the crushing cylinders 20a', 20b', the main device being provided with a movable main surface 28, which, for example, rotates, against which, and in particular against an impact surface 29 of the main surface 28, a tuft emerging from the auxiliary cylinders 20a, 20b impacts. The main surface 28 has a main speed Va, in particular in the impact surface 29. For example, the main device 26 comprises a main cylinder 30 having a continuous rotary movement (at a constant or variable speed, but unidirectional) in a clockwise or counterclockwise direction and a side surface 30' forming the main surface 28 of the main device 26. The side surface 30', which is the main surface 28, is impermeable to air.In other words, no intake holes or openings are provided on the surface, or if they are provided, as in the case of a breathable fabric, they are not connected to an air intake device. The main cylinder 30 typically has a larger diameter than the diameter of the main crusher cylinders 20a, 20b and a peripheral speed Vm corresponding to an angular velocity Wm. The peripheral speed Vm of the main cylinder 30 is lower than the peripheral speed Vs of the auxiliary cylinders 20a, 20b.

[0018] The combing head further comprises a transfer device 40, on which a tuft of a web is conveyed, which leaves the main surface 28 of the main device 26, i.e., the side surface 30' of the main cylinder 30; the tuft is conveyed into a transfer area 42 of the transfer device 40. Preferably, the transfer device 40 is in engagement with the main surface 28 of the main device 26; for example, the transfer device 40 is tangential to the side surface 30' of the main cylinder 30 along an engagement line L. Preferably, the transfer device 40 can be moved, i.e., at a predetermined carrier speed Vs in the transfer area 42. For example, the combing head is provided with a movable mat 50 that moves along a closed path, preferably outside the main cylinder 30, and that forms the transfer device 40 for at least one segment.It should be noted that, as stated in the . Fig. 3, the transmission device 40 extends both upstream and downstream of the master cylinder 30.

[0019] The combing head further comprises a stretching device 600 arranged downstream of the gripper, but upstream of the deflection device 6 of each combing head 2, and in particular upstream of its hopper 4. The stretching device 600 is located downstream of the main device 26, i.e., downstream of the main cylinder 30, and is fed by the transfer device 40. The stretching device 600 comprises a first pair 602 of stretching cylinders 602a, 602b, of which the first lower stretching cylinder 602b is preferably motorized, while the first upper stretching cylinder 602a is engaged under pressure with the first lower stretching cylinder 602b and is thereby driven to rotate. The stretching device 600 further comprises a second pair 620 of stretching cylinders 620a, 620b arranged downstream of the first pair 602.The second lower stretching cylinder 620b is preferably motorized, while the second upper stretching cylinder 620a is in pressure contact with the second lower stretching cylinder 620b and is thereby driven to rotate. The web leaving the first pair 602 of stretching cylinders 602a, 602b moves at a predetermined upstream speed V1. The stretching cylinders 620a, 620b of the second pair 620 have a peripheral speed V2, referred to as the "downstream speed," which is higher than the upstream speed V1, so that the web, which is simultaneously engaged between the stretching cylinders 602a, 602b of the first pair 602, in the contact segment 614 and between the stretching cylinders 620a, 620b of the second pair 620, is subjected to drafting.

[0020] The combing head and its operation are explained in detail in international applications PCT / IB2020 / 052861 and PCT / IB2019 / 051946, the teachings of which are expressly incorporated herein.

[0021] It has been found that in some cases, for example when exiting the breaker cylinders 20' and when exiting the main cylinder 30, the fiber web has fibers at the edges that are not completely parallelized, as a result of which they tend to protrude from the web, causing problems in the subsequent spinning steps.

[0022] The combing machine is therefore provided with fiber alignment devices 90, 91, 92, 96 at least at the edges of the web, said devices being suitable for aligning the fibers which are not completely parallel, that is to say those which project from the edges of the moving web, thereby causing them to be straightened and completely reintroduced into the web.

[0023] Preferably, the fiber alignment devices 90, 91, 92, 96 are in the form of blowing devices suitable for aligning the fibers by forcing them with an air stream. Preferably, the air stream pushes at least the fibers protruding from the edges of the fiber web downward and / or toward the center of the moving web. The purpose of the alignment devices is to push the fibers that are not fully parallelized under the edges of the moving web in order to realign them and recompact them with the other fibers that are already parallelized.

[0024] Preferably, the alignment devices 90, 91, 92, 96 are suitable for blowing an air stream at least on both sides, ie, both longitudinal edges of the moving fiber web.

[0025] The alignment devices are blowing devices 94, which provide an air stream F that can uniformly push the fibers in the desired direction and manner. Since the fibers of the moving web are very fine, they are not touched; pushing them by means of an air stream is highly preferred over mechanical solutions such as deflectors or partitions.

[0026] For example, the alignment devices are blowing devices 94 provided with at least one outlet hole 93 for compressed air. For example, the outlet hole 93 has a diameter between 1.5 mm and 3 mm, preferably 2 mm.

[0027] For example, the blowing device 94 provides an air flow with an inclination angle α between 0° and 90°, where 0° indicates an air flow parallel to the direction of movement D of the web (and which is concordant - as in the Fig. 6, Fig. 7 and Fig. 8 - or discordant - as in the Fig. 9, Fig. 10 and Fig. 11 - to the direction of movement), and 90° indicates an air flow that is orthogonal (with the direction to the track), ie, perpendicular, to the direction of movement D of the track, as shown in the Fig. 12. The direction of movement D of the fiber web coincides with the longitudinal direction Y.

[0028] The blowing device 94 may be arranged in line with the moving web or in a raised position relative thereto or in a lowered position relative thereto.

[0029] Fig. 6 to 12 show various example embodiments of the fiber alignment devices.

[0030] In the example in the Fig. 6, the alignment devices provide an air flow F concordant with the direction of movement D of the web at an angle α of 30° to the center of the fiber web.

[0031] In the example in the Fig. 7, the alignment devices provide an air flow F concordant with the direction of movement D of the web at an angle α of 45° to the center of the fiber web.

[0032] In the example in the Fig. 8, the alignment devices provide an air flow F concordant with and parallel to the direction of movement D of the web.

[0033] In the example in the Fig. 9, the alignment devices provide an air flow F discordant to the direction of movement D of the web with an angle α of 30° to the center of the fiber web.

[0034] In the example in the Fig. 10, the alignment devices provide an air flow F discordant to the direction of movement D of the web with an angle α of 45° to the center of the fiber web.

[0035] In the example in the Fig. 11, the alignment devices provide an air flow F discordant and parallel to the direction of movement D of the web.

[0036] In the example in the Fig. 12, the alignment devices provide an air flow F perpendicular to the direction of movement D of the web.

[0037] The alignment devices may be blowing devices 94 projecting from the frame 95 of the machine (as in Fig. 6 to 11) or are integrated into the frame 95 of the machine (as in the Fig. 12).

[0038] Preferably, each combing head 2 is provided with at least one main alignment device 90 arranged between the gripper 21 and the breaker cylinders 20'. In particular, the main alignment devices 90 are arranged "on the gripper," ie, they move integrally with the gripper 21, and are arranged immediately downstream of the jaw closing area.

[0039] In a preferred exemplary embodiment, the main alignment means 90 are a pair of blowing means 94 provided for blowing an air stream F orthogonal to the direction of movement D, as shown in the Fig. 15 is the case. Preferably, the main alignment devices 90 are arranged in line with the moving fiber web. Preferably, the main alignment devices 90 are integrated with the lower jaw 211 of the gripper 21.

[0040] This solution allows the adjustment of the orientation of the fibers forming the edges of the web during the detachment process carried out by the breaker cylinders 20'.

[0041] Preferably, each combing head 2 is also provided with alignment devices 91 for the freshly separated fibers, i.e., those emerging from the breaker cylinders 20'. The alignment devices 91 for the freshly separated fibers process the edges of a single, freshly separated tuft of the fiber web.

[0042] In a preferred exemplary embodiment, the alignment devices 91 for the freshly detached fibers are a pair of blowing devices 94 suitable for blowing an air stream F orthogonal to the direction of movement D of the fiber web, as shown in the Fig. 12 is the case. Preferably, the alignment devices 91 for the freshly detached fibers are arranged in series with respect to the moving fiber web.

[0043] This solution allows the fibers to be uniformly pressed towards the center of the web and towards the center of the auxiliary cylinders 20 and the main cylinder 30, thus improving the subsequent stretching and compacting steps.

[0044] Preferably, each combing head 2 is provided with further alignment devices 92, 96 arranged between the main cylinder 30 and the transmission device 40.

[0045] In one example, the further alignment devices 92 are arranged downstream of the main cylinder 30.

[0046] Preferably, each combing head 2 is provided with alignment devices 92 for the stretched fibers exiting the main device 26. The alignment devices 92 for the stretched fibers process the edges of the fiber web.

[0047] In a preferred exemplary embodiment, the orienting means 92 for the stretched fibers are a pair of blowing means 94 suitable for blowing an air stream F parallel and opposite to the direction of movement D of the belt, as shown in the Fig. 11 is the case. Preferably, the alignment devices 92 for the stretched fibers are arranged in an elevated position relative to the moving web.

[0048] This solution allows the fibers to be pressed uniformly so that they are aligned with the rest of the fibers of the moving web in a suitable manner.

[0049] In a preferred exemplary embodiment, each combing head 2 is provided with both alignment devices 91 for the freshly detached fibers and alignment devices 92 for the stretched fibers.

[0050] In a further exemplary embodiment, each combing head 2 is also provided with alignment devices for the fibers emerging from the auxiliary cylinders 20.

[0051] In one example, the further alignment devices 96 are arranged upstream of the master cylinder 30.

[0052] In this example, the further alignment devices 96 are blowing devices 94, which are suitable for blowing an air stream F below the moving fiber web, as shown in the Fig. 16 is the case.

[0053] For example, the further alignment devices 96 are a pair of blowing devices 94.

[0054] In another example, the further alignment devices 96 are a blow cylinder 931, as shown in the Fig.16, which is provided with a plurality of outlet holes 93 for compressed air arranged in a line at least at the ends of the blowing cylinder 931. In a further exemplary embodiment, the further alignment devices 96 are a blowing cylinder 931 provided with a plurality of outlet holes 93 arranged in a line along the entire length of the blowing cylinder 931.

[0055] This solution allows maintaining edge alignment during the transfer of the web between the auxiliary cylinders 20 and the transfer device 40.

[0056] An example of a method for aligning the fibers at the edges of a fiber web is described below. The method provides at least one, preferably both, of the following steps: - treating the fibers emerging from the pair of breaker cylinders 20' with an air stream F suitable for pressing the fibers of the edges of the fiber web; - Treating the fibers emerging from the main cylinder 30 with an air flow F suitable for pressing the fibers of the edges of the fiber web.

[0057] Preferably, the method provides at least one, preferably both, of the following steps: - treating the fibers emerging from the pair of breaker cylinders 20' with an air flow F orthogonal to the direction of movement Y of the fiber web and directed towards the fiber web; - Treating the fibers emerging from the main cylinder 30 with an air flow F parallel and discordant to the direction of movement Y of the fiber web.

[0058] In an innovative way, the combing head according to the present invention is provided with fiber alignment devices at the edges of the web, suitable for pressing and realigning fibers that are not fully parallelized and that protrude from the edges of the web inward and / or below the combed web. This solution results in a high-quality combed web, as it is free of misaligned fibers that can impair subsequent drawing steps by creating knots and crimps.

[0059] It should be noted that a person skilled in the art may make modifications to the combing head described above to meet unforeseen requirements, all of which are within the scope of protection defined by the following claims. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] WO 2020 / 208454 A1

[0004] WO 2006 / 012759 A1

[0006] WO 2020 / 052861

[0020] WO 2019 / 051946

[0020]

Claims

[1] Combing machine (1) of a spin preparation plant comprising at least two combing heads (2), wherein a fiber web provided with edges moves in a direction of movement (D), each combing head comprising: - a gripper (21) provided with a lower jaw (211), an upper jaw (212) and a straight comb; - at least one pair of crusher cylinders (20') arranged downstream of the grapple (21); - alignment devices (90, 91, 92, 96) for the fibers of the web in the form of blowing devices providing an air flow (F) directed at least towards the edges of the web; characterized by that the main alignment devices (90) are arranged between the gripper (21) and the crusher cylinders (20'). [2] Combing machine (1) according to claim 1, wherein the main alignment means (90) provide an air flow (F) orthogonal to the direction of movement (D). [3] Combing machine (1) according to one of the preceding claims, wherein the lower jaw (211) and the upper jaw (212) of the gripper (21) define a jaw closing area therebetween and the main alignment means (90) are arranged immediately downstream of the jaw closing area. [4] Combing machine (1) according to one of the preceding claims, wherein each combing head (2) comprises: - a main cylinder (30) arranged downstream of the crusher cylinders (20') and having a continuous rotary movement and provided with a side surface (30'); - a transmission device (40) extending both upstream and downstream of the master cylinder (30) and with which the side surface (30') of the master cylinder (30) is engaged; - further alignment devices (92, 96) arranged between the main cylinder (30) and the transmission device (40). [5] Combing machine (1) according to claim 4, wherein the further alignment devices (96) are arranged upstream of the main cylinder (30) and provide an air flow (F) below the fiber web. [6] Combing machine (1) according to claim 4, wherein the further alignment means are alignment means (92) for the stretched fibers arranged downstream of the main cylinder (30) which provide an air flow (F) parallel and discordant to the direction of movement (D). [7] Combing machine (1) according to claim 4, comprising both further alignment devices (96) arranged upstream of the main cylinder (30) and providing an air flow (F) below the fiber web, and alignment devices (92) for the stretched fibers arranged downstream of the main cylinder (30) and providing an air flow (F) parallel and discordant to the direction of movement (D). [8] Combing machine (1) according to claim 5 or 7, wherein the further alignment means (96) is a blowing cylinder (931) provided with a plurality of outlet holes (93) for compressed air arranged in a line at least at the ends of the blowing cylinder (931). [9] Combing machine (1) according to claim 8, wherein the outlet holes (93) are arranged in a line along the entire length of the blow cylinder (931). [10] Combing machine (1) according to one of the preceding claims, wherein each combing head (2) comprises: - a pair of auxiliary cylinders (20) arranged downstream of the crusher cylinders (20'); - Alignment devices (91) for the freshly detached fibers arranged between the crusher cylinders (20'). [11] Combing machine (1) according to claim 4, wherein the alignment means (91) provide an air flow (F) orthogonal to the direction of movement (D) for the freshly detached fibers. [12] Combing machine (1) according to one of the preceding claims, wherein the fiber alignment devices (91, 92) are blowing devices which are axially raised with respect to the fiber web or axially aligned with the fiber web or axially lowered with respect to the fiber web. [13] Combing machine (1) according to one of claims 9 to 11, wherein each combing head (2) comprises: - a deflection device (6) arranged downstream of the breaker cylinders (20') and suitable for deflecting the fiber web from the direction of movement (Y) to a common transverse direction of movement (X) along which the belts of the combing heads (2) adjoin one another; - upstream of the deflection device (6), a stretching device (600) which is located downstream of the main cylinder (30) and is fed by the transmission device (40).

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