Reel manufacturing method and related roving frame

Abstract

The object of the present invention is a method for forming a reel on a roving frame (1) for processing a fiber web and forming a roving wound on a reel. The roving frame comprises a stretching device (10) for the fiber web for forming the roving and a flap spindle unit for winding the roving onto the reel. The method provides adding an initial twist (Ti) at the start of reel forming and a final twist (Tf) at the end of reel forming to the fibers emerging from the stretching device (10) and entering the flap spindle unit. The method is characterized by passing through with at least one step of increasing the twist from the initial twist (Ti) to the final twist (Tf). Advantageously, such a method makes it possible to reduce thread breakage during the winding of the reel without impairing the production speed of the roving frame.

Description

【Technical Field】 【0001】 The present invention relates to the field of fiber machines that convert ball fiber into yarn wound around a reel. 【Summary of the Invention】 【0002】 In a roving frame, a fiber web obtained from roving or combing and stored in a can is drawn by a drawing device, thereby obtaining roving. In a reel forming device downstream of the drawing device, the roving is wound around a bobbin, thereby obtaining a reel of roving to be sent to a spinning machine. 【0003】 Since the drawing generated in the roving frame is highly driven, the speed of the roving downstream of the drawing device becomes extremely high. Furthermore, since the roving is vibrated between the drawing device and the device for forming the reel, there is a risk of breakage. In particular, it has been pointed out that the breakage of the roving most frequently occurs in the final stage of forming the reel. It is obvious that if the roving breaks during the stage of winding the reel, the machine stops and as a result, production is delayed. Today, in order to reduce the number of breakages, measures are taken to lower the production speed of the roving frame, thereby accepting that production becomes somewhat slower. 【0004】 An object of the present invention is to provide a reel manufacturing method and a related roving frame that reduce the breakage of the roving during the stage of winding the reel without impairing the production speed of the roving frame. 【0005】 This object is achieved by the reel forming method according to claim 1 and the related roving frame I according to claim 11. Further advantageous embodiments are described in the dependent claims. 【0006】 The features and advantages of the method and the roving frame according to the present invention will become apparent from the following description given as a non-limiting example according to the figures of the accompanying drawings. 【Brief Description of the Drawings】 【0007】 【Figure 1】 Figure 1 shows a roving frame according to a preferred embodiment of the present invention. 【Figure 2】 Figure 2 is an enlarged view of the roving frame of Figure 1, highlighting a platform with holes through which the roving emerging from the drawing device passes from the upper region to the lower region of the roving frame. 【Figure 3】 Figure 3 is a schematic cross-sectional view of a part of the roving frame of Figure 1, highlighting a platform with holes through which the roving emerging from the drawing device passes from the upper region to the lower region of the roving frame. 【Figure 4】 Figure 4 shows a control scheme for roving twist parameters as a function of reel forming rate in various embodiments. 【Figure 5】 Figure 5 shows a control scheme for roving twist parameters as a function of reel forming rate in various embodiments. 【Figure 6】 Figure 6 shows a control scheme for roving twist parameters as a function of reel forming rate in various embodiments. 【Figure 7】 Figure 7 shows a control scheme for roving twist parameters as a function of reel forming rate in various embodiments. 【DETAILED DESCRIPTION OF THE INVENTION】 【0008】 With reference to the figures in the accompanying drawings, the numeral 1 is generally used to denote a roving frame of a spinning line. 【0009】 Generally, a drawing frame is arranged upstream of the roving frame 1, and the fiber web drawn by this drawing frame is supplied to the roving frame 1. The roving frame 1 processes the web and manufactures roving wound on appropriate tubes to form a reel. This reel is conveyed to a spinning machine downstream of the roving frame 1 and further processed. 【0010】 The roving frame 1 has a storage area 200 located behind the machine body 2. The web supplied by the stretching device and wound and stored in the can 4 is stored in the storage area 200. Also, in the storage area 200, there is arranged a creel 6 consisting of a frame provided with a roller 8 having a generally hexagonal cross-section, arranged above the can 4 and extending forward along the longitudinal direction X and generally being electrically driven. 【0011】 The web supplied from the can 4 is located above the roller 8 and is supplied to the roving frame 1. 【0012】 The roving frame 1 includes a machine body 2 that supports a stretching device 10. The stretching device 10 is formed from a pair of superimposed stretching rollers 11, engages under pressure, and has an increasing circumferential rotational speed from upstream to downstream, and gradually stretches the web passing between the connected stretching rollers 11. In particular, the stretching device 10 includes, for example, a number of three or four electric lower rollers 111, each of which extends along the longitudinal direction X along the frame 1. Each lower roller cooperates with a plurality of spaced upper idling rollers 112 that are paired and generally supported by a pressure arm 113. Preferably, the pressure arm 113 is pneumatically pressed to ensure a pressure connection between the lower roller 111 and the upper roller 112. In one embodiment, the stretching device 10 includes a support band that contacts at least one stretching roller 11 to guide its rotation. The stretching device 10 needs to process the fiber web to produce roving and then wind it onto a suitable tube for reel forming. 【0013】 Downstream of the stretching device 10, the machine body 2 includes a platform 20 having an extension extending along the longitudinal direction X over the entire length of the frame 1. The platform 20 defines an upper region above the upper region of the frame 1 and a lower region below the lower region of the frame 1. 【0014】 The platform 20 comprises a perforated flat platform 21 through which the roving emerging from the drawing device 10 moves from the upper region of the frame 1 to the lower region of the frame 1. The platform 20 actually houses a plurality of necks 22 that define passage openings for the roving flowing towards the respective flaps 30. The necks 22 protruding from the platform 21 are arranged in two rows at a longitudinal distance from each other therebetween. 【0015】 The frame 1 is provided, below the platform 20, with a plurality of winding devices for winding the individual rovings around the respective thin tubes, thereby forming reels. The winding devices are flaps 30 arranged in the lower region of the frame 1, in particular below each neck 22. The flaps 30 are supported by the platform 20. 【0016】 Each flap 30 is adapted to rotate about a relative flap axis Z. The flap 30 is arranged to be rotated by an electric flap motor. 【0017】 The machine body 2 further comprises a carriage 40 arranged in the region below the frame 1 and carrying a plurality of spindles 42 into which the thin tubes for reel forming are inserted. The spindles 42 are coaxially arranged below the respective flaps 30. 【0018】 The carriage 40 is movable vertically in an alternating motion for reel forming by a first electric carriage motor. 【0019】 Furthermore, the carriage 40 is movable horizontally and / or rotatable by a second electric carriage motor for the operation of lifting the completed reels and loading the empty thin tubes. 【0020】 Also, the spindles 42 aligned along the longitudinal direction X are rotationally movable coaxially with the vane 30 by an electric spindle motor. 【0021】 The flap 30 comprises shaping means 31 adapted to maintain roving inserted into the associated spindle 42 during shaping or attached to a capillary tube attached to a reel. 【0022】 In use, the web N passes through the stretching device 10, leaves it in the form of roving S, then enters each neck 22, thereby passing from the upper region of the frame 1 to the lower region of the frame 1. Here, the roving enters each flap 30 again through the neck 22 and exits therefrom from the lower end by the shaping means 31. The carriage 40 moves up and down alternately so that the roving is wound around a capillary tube inserted into the spindle 42 to form the reel B. When the reel forming is completed, the reel is taken out and transported to a spinning machine automatically or manually for subsequent processing. 【0023】 The frame 1 comprises an electronic control unit that manages the speed of the electric motor and thus the speeds of the flap 31, the spindle 42, the stretching device 10 and the roving torsion. 【0024】 The production speed of the roving frame is defined by the speed of the stretching device 10. 【0025】 Roving torsion is a basic element in that it enables the web bundle to have the required binding force to obtain the value of strength required in subsequent spinning machine processing. Torsion is obtained by rotating the web bundle parallel to its axis. In this way, the more outer fibers take a helical arrangement. The inner fibers also take a helical arrangement, but the inclination decreases gradually towards the center of the bundle. This arrangement gives the fibers a radial pressure, avoiding uncontrollable and undesirable stretching before entering the spinning machine stretching unit, but not impairing the stretching step of the spinning machine stretching unit. Therefore, the greater the torsion, the higher the strength of the roving, but the greater the torsion, the more difficult it is to draw the roving. Furthermore, as the torsion increases, the production speed decreases, and as a result, the productivity of the machine decreases. 【0026】 Twisting is applied to the roving in the frame 1 emerging from the drafting device 10, especially at the entrance of the neck 22, during the step in which the flap spindle unit enters. 【0027】 Roving twist is defined as the ratio between the rotational speed of the flap spindle unit and the speed of the drafting device 10, and is customarily expressed as torsion / meter or torsion / inch. 【0028】 The object of the present invention is a method of forming a reel on a roving frame 1 for processing a fibrous web and forming the roving wound on the reel. The roving frame 1 comprises a drafting device 10 for the fibrous web for forming the roving and a flap spindle unit for winding the roving around the reel. The method provides for applying an initial twist (Ti) at the start of reel forming to the fiber bundle emerging from the drafting device 10 and entering the flap spindle unit. The method is characterized in that it provides at least one step of increasing the roving twist while passing from the initial twist Ti to the final twist Tf. For example, the method provides for reaching the end of forming with a final twist Tf greater than the initial twist Ti. 【0029】 Thus, the reel forming method according to the present invention provides for varying the twist of the roving in the reel forming step. In particular, the reel forming method according to the present invention provides for increasing the roving twist in the reel forming step. Advantageously, this solution makes it possible to reduce the breaks that are common in the final reel forming process while increasing the strength of the roving without impairing the productivity of the machine. 【0030】 In the graph of FIG. 4, the variation in twist is indicated by ΔT, i.e., the variation between the initial twist Ti, i.e., the twist at the start of reel forming, and the final twist value Tf, i.e., the twist at the end of reel forming, is shown. 【0031】 This forming method increases the twist of the roving by 10%, preferably 5%, more preferably 3%. This range of twist increase increases the strength of the yarn without making the yarn too stiff and unsuitable for subsequent processing. 【0032】 Preferably, this forming method provides for increasing the roving tension by increasing the speed of the flap spindle unit in relation to the speed of the drawing device 10 during the reel forming step. 【0033】 Preferably, this forming method provides for increasing the roving tension by increasing the speed of the flap spindle unit while maintaining the speed of the drawing device 10 unchanged during the reel forming step. 【0034】 In the flap spindle unit, the flap 31 rotates at a flap speed different from the rotational speed of the spindle 42. In particular, the speed of the spindle is faster than the speed of the flap. Therefore, increasing the flap spindle unit speed without changing the ratio of the spindle speed to the flap speed results in a significant increase in the flap speed. In other words, this means increasing the speed of the spindle in proportion to the speed of the flap. 【0035】 The forming of the reel is measured using a diameter from an initial diameter equal to the diameter of the tube to a final diameter equal to the final diameter of the formed reel. 【0036】 Figures 4 to 7 show some control schemes of the roving twist parameters as a function of the reel forming rate. 【0037】 In the example of Figure 4, the twist increases linearly from an initial value Ti to a final value Tf. 【0038】 In the example of Figure 5, the twist shows a stepwise progression, i.e., the initial value Ti is maintained up to the twist increase point P, where it rises directly to the final value Tf. 【0039】 In the example of FIG. 6, the twist shows a two-stage increase, i.e., the initial value Ti is maintained up to the first twist rise point P, where it increases to an intermediate twist value and the intermediate value is maintained up to the second twist rise point P where it increases to the final value Tf. 【0040】 Preferably, the increase in the twist value is carried out in the final reel forming step, i.e., after 50% of the reel forming. Preferably, the increase in the twist value is assumed to be from 60% to 70% of the reel forming. 【0041】 In an exemplary embodiment shown in FIG. 7, the increase in the twist value is assumed up to the final reel forming step and the decrease in the twist value is assumed to a final value Tf equal to or less than the initial value Ti. 【0042】 Furthermore, an object of the present invention is a roving frame 1 for processing a fiber web and forming a roving wound on a reel, a stretching device 10 for the fiber web for forming the roving, a flap spindle unit for winding the roving on the reel, management means according to the above-described forming method adapted to control the twist of the roving exiting the stretching device 10 and entering the flap spindle unit, and comprising. 【0043】 Innovatively, the reel forming method according to the present invention makes it possible to reduce roving breakage during the step of winding the reel without impairing the production speed of the roving frame. 【0044】 It will be apparent to those skilled in the art that modifications can be made to the above-described roving frame and method to meet current needs, and all such modifications are included within the scope of protection defined by the following claims.

Claims

[Claim 1] A method for processing a fiber web and forming a reel into a roving frame (1) for shaping roving wound on a reel, The aforementioned roving frame is A stretching device (10) for forming the roving, A flap spindle unit for winding the aforementioned roving onto a reel, Equipped with, The method provides that the fibers coming out of the stretching device (10) and entering the flap spindle unit are subjected to an initial torsion (Ti) at the start of reel forming and a final torsion (Tf) at the end of reel forming. The present invention provides at least one step of increasing the torsion from the initial torsion (Ti) to the final torsion (Tf). How to shape a reel. [Claim 2] The initial torsion (Ti) in the reel forming step is increased until it reaches a final torsion (Tf) at the end of reel forming, which is greater than the initial torsion (Ti). A method for forming the reel described in claim 1. [Claim 3] The flap spindle unit has a unit rotation speed, The stretching device (10) has a stretching speed, The aforementioned increase in the initial torsion (Ti) is obtained by increasing the rotational speed of the flap spindle unit relative to the stretching speed. A method for forming a reel according to claim 1 or 2. [Claim 4] The aforementioned increase in the initial torsion (Ti) is obtained by increasing the rotational speed of the flap spindle unit without changing the stretching speed. A method for forming the reel according to claim 3. [Claim 5] The aforementioned flap spindle unit is A flap (30) having a flat rotation speed, A spindle (40) having a spindle rotation speed, Equipped with, The aforementioned increase in the initial torsion (Ti) is obtained by increasing the flap rotation speed without changing the ratio of the flap rotation speed to the spindle rotation speed. A method for forming the reel described in claim 1. [Claim 6] The initial torsion (Ti) increases by 10%, preferably 5%, and more preferably 3%. A method for forming the reel described in claim 1. [Claim 7] The initial torsion (Ti) increases linearly. A method for forming the reel described in claim 1. [Claim 8] The initial torsion (Ti) remains constant until the torsion rise point (P), and is directly increased until the final torsion (Tf) is reached. A method for forming the reel described in claim 1. [Claim 9] The aforementioned torsional rise point (P) is provided within the final reel forming step, A method for forming the reel according to claim 8. [Claim 10] The aforementioned torsional rise point (P) is located between 60% and 70% of the reel forming step. A method for forming the reel according to claim 9. [Claim 11] The initial torsion (Ti) has at least one torsion rise point (P) such that the torsion increases. A method for forming the reel described in claim 1. [Claim 12] A roving frame (1) for processing a fiber web and forming roving wound on a reel, A stretching device (10) for forming the roving, A flap spindle unit for winding the roving onto a reel, Control means adapted to control the twisting of the fibers as they exit the stretching device (10) and enter the flap spindle unit, according to the method for forming a reel according to claim 1, Equipped with, Roving frame (10).

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