WO2005014908A1

WO2005014908A1 - Machine for processing textile fabrics

Info

Publication number: WO2005014908A1
Application number: PCT/IT2004/000434
Authority: WO
Inventors: Alberto Ciabattini; Luigi Marcora
Original assignee: Coramtex S.R.L.
Priority date: 2003-08-06
Filing date: 2004-08-02
Publication date: 2005-02-17
Also published as: ITFI20030215A1

Abstract

The machine comprises: an advancement path of the web material (T); at least one essentially cylindrical rotating abrasive member (1), along the advancement path, on which the material is guided; a means (3) for feeding said web material to said cylindrical member; and a means for distancing (11) said web material from said cylindrical member. To the cylindrical member is associated a mobile guiding element (23, 25) on which the web material is guided, whose position varies with the variation of the contact arch between the web material and the cylindrical member. The speed of at least one of said feeding and distancing means is controlled according to the position of said mobile guide element. The essentially cylindrical abrasive member is constituted by a drum rotating about its axis, along the periphery of which abrasive rollers rotating about their respective axes are mounted.

Description

MACHINE FOR PROCESSING TEXTILE FABRICS DESCRIPTION Technical field The present invention relates to a machine for processing textile fabrics and more in general for processing web material. Specifically, the invention relates to a machine for processing web material comprising an advancement path of the web material and an essentially cylindrical rotating abrasive member which acts on the web material, which is entrained around the member itself. State of the art Machines in which continuously fed textile fabric is subjected to finishing and aging processes by means of abrasive material applied onto a rotating cylinder, around which the textile material is entrained, are employed in the fabric processing. The surface of the textile fabric is mechanically processed by exploiting the different speeds of the abrasive surface of the cylinder and of the textile fabric. US-A-3615990 describes a machine for processing textile fabric or non- wovens by means of rotating cylindrical brushes. The web material is tensioned and passed under the brushing member. US-A-5197305 describes a machine for processing textile fabrics by means of rotating brushes with the addition of abrasive powders. Also in this case, the textile fabric is tensioned and passed underneath the rotating members which act on the material. EP-A-0020109 describes a process and a method for artificially aging textile fabrics. The textile fabric is passed between an abrasive roller and a pressure roller. US-A-3872557 describes a machine for the superficial abrasion of previously dyed textile fabrics to alter the hues of color. The textile fabric is suitably tensioned and passed underneath a turning abrasive roller. EP-A-0532479 describes a method and a machine for the artificial aging surface treatment of continuous textile fabric. The textile fabric is tensioned and passed underneath an abrasive member in the form of a rotating cylinder or pivoting bar of abrasive material. Frequently, the abrasive effect is obtained by means of cylindrical rotating brushes formed by filaments of synthetic material, specifically nylon^®, charged with abrasive particles or granules, such as silica carbide or aluminum oxide. A machine for processing textile fabrics employing brushes of this type is described, for example, in patent EP-A-0417659. The bristles of these brushes are made, for example, of a synthetic product marketed by DUPONT^® under the brand name TYNEX^®. FR-A-2622217 describes a machine which employs cylindrical brushes made by these filaments for processing textile fabrics, specifically denim. US-A-3553801 describes a machine for the abrasive treatment of textile fabrics comprising a plurality of abrasive cylinders equipped with projecting helical ribbing which act on suitably tensioned spans of textile fabric guided on a complex trajectory which is tangent to a plurality of these cylinders. US-A-3204271 describes a brushing machine for textile fabrics in which the fabric to be processed is passed between a pair of counter-rotating brushes. FR-A-2525644 describes an abrasive member made of a body of abrasive pumice stone. EP-B-0757728 describes a machine for the continuous processing of textile fabric by means of a brush made of synthetic filaments charged with aluminum or carbon, of which an hypothetical abrasive capacity is claimed. In all known devices in which a continuous web of textile fabric is processed, the textile fabric is subjected to the abrasive action of the rotating member - which may be a brush, a cylinder covered with abrasive paper or abrasive cloth, a body integrally made of abrasive material or the like - by tensioning the fabric and putting it into contact with the rotating abrasive member. Tensioning the material causes a number of problems, particularly due to the formation of folds or creases in the longitudinal direction which leads to the fabric being processed in different ways along its transversal development. The tension induced in the fabric may also alter the structure of the warp and weft yarns with consequent processing irregularities. Some yarns are subjected to more abrasion than others causing the formation of irregularly distributed lines on the finished product, in correspondence to where the fabric was excessively consumed by the abrasive member and appears to have lost essentially all its color. The loose or taut selvages subjected to tension by traditional grinding machines cause problems related to variable degree of abrasion which affects processing quality. When the textile fabric, the non-woven or other web material is turned on a rotating abrasive cylinder without being adequately tensioned, the friction between the web material and the surface of the rotating cylindrical member tends to make the web material wind around the cylindrical member itself. The web material must be kept taut, which causes the aforesaid problems, to avoid jamming the machine. To overcome these problems a machine has been produced comprising in combination: an advancement path of the web material; along the advancement path, at least an essentially cylindrical rotating member, for example an abrasive member, about which the web material is guided; a means to feed the web material towards the cylindrical member; and a means to distance the web material from the cylindrical member. Associated with the cylindrical member is a mobile guiding element about which the web material is guided, the position of which varies with the arc of contact between the web material and the cylindrical member. Moreover, the speed of at least one of said feed and distancing means is controlled as a function of the position of said mobile guiding element. A machine of this type is described in WO-A- 03052193. .This machine allows considerable advantages to be obtained in terms of quality of the treatment of fabrics, to overcome or reduce the drawbacks of prior art. Object and summary of the invention Starting from a machine of the type described in WO-A-03052193, and utilizing the inventive principles described therein, the object of the present invention is to provide an abrasive cylindrical member which is more efficient and allows superior processing qualities to be obtained. These and other objects and advantages, which will be clear to experts of the field in the text that follows, are obtained in practice by a machine of the type described in WO-A-03052193, in which the essentially cylindrical member is constituted by a drum rotating about its axis, on which active or processing elements are mounted, distributed peripherally, and each rotating about a respective axis. Additional advantageous characteristics and embodiment of the invention are recited in the annexed dependent claims. -.. -

In substance, according to the invention, the effect of processing of the fabric along the peripheral extension of the cylindrical member is divided: the abrasive or other mechanical action on the fabric is performed by active elements in succession along the path of the fabric. This prevents any defects of the active elements from being reproduced on the fabric. Moreover, any defects in the fabric are concealed, eliminated or in any case not intensified, thanks to the fact that different elements in sequence act on it. Any creases in the fabric do not lead to processing defects thanks to the fact that the layout of the fabric may be varied while passing from one active element to the other. Moreover, by providing separate active elements, these may in turn be put into rotation about their axis with different speeds and directions from element to element. For example, it is possible to provide two motors make the active elements rotate in one direction or alternatively in the opposite direction. The active elements are preferably abrasive rollers, for example coated with diamond or glass sandpaper. They may be used in combination with abrasive brushes or be entirely replaced by abrasive brushes. Brief description of the drawings The invention will be better understood following the description and the accompanying drawing, which shows a practical non-limitative example of the invention. In the drawing: Fig. 1 schematically shows the structure of a machine according to the invention with a single rotating cylindrical member; Fig. 2 shows a perspective view of the drum in Fig. 1 ; Fig. 3 schematically shows a machine according to the invention with two rotating cylindrical members turning in opposite directions; Fig. 4 schematically shows a machine similar to that illustrated in Fig. 3, with two abrasive rotating cylindrical members, but in a configuration suitable for processing both sides of the material; and Fig. 5 shows a variant of embodiment with a detaching member, which modifies the path of the web material with respect to the periphery of the rotating cylindrical member. Detailed description of the invention Reference numeral 1 in Fig. 1 indicates a rotating cylindrical member, turning on an axis A. The rotating cylindrical member 1 is constituted by a drum equipped, along its periphery, with active or processing elements 2A and 2B. In the example shown, the active elements 2A, 2B are constituted by abrasive rollers, for example metal rollers coated with a helically wound strip of diamond sandpaper. Alternatively, other materials may be used, such as a coating of abrasive powders directly on a metal roller or the like. Alternatively, although less advantageously, the active elements 2A, 2B may be constituted by brushes with abrasive bristles, for example made of Tynex® filaments, rotating about their own axis. In this case, each active element may be constituted by a cylindrical brush. Alternatively, it may be constituted by two or more rectilinear slatted brushes, that is, produced on slats equipped with bristles, which extend parallel to their axis of rotation and which are distributed more or less uniformly about said axis. In a further embodiment, alternate arrangements of brushes and abrasive rollers may be used as active elements. As can be seen in particular in Fig. 2, the rollers 2A are carried in rotation through a belt 4A by a motor 6A. Vice versa, the rollers 2B are carried in rotation through a belt 4B by a motor 6B. The two motors 6A and 6B can consequently make the groups of rollers 2A and 2B rotate in the same or in opposite directions and at the same or at different speeds from each other according to processing needs. Fig. 2 shows opposite directions of rotation for the two groups of rollers. Again in Fig. 2, the numeral 8 indicates the main motor of the drum 1. The textile fabric T is fed along an advancement path by a feeding means, generically indicated by reference numeral 3 and consisting in this example of a driven cylinder 5 on which the fabric T is advanced by guiding it on two guiding rollers 7 and 9. A distancing means 11 consisting of a driven rotating cylinder 13 on which the fabric T is guided and a pair of guiding rollers 15 and 17 (similarly as the feeding means 3) is arranged downstream with respect to the rotating cylindrical member 1. Reference numerals 19 and 20 schematically indicate two independent motors for operating the driven cylinders 5 and 13 whose rotation speed may be reciprocally different. A baffle 21 presenting a rounded edge 21A whose curvature radius is relatively small to deviate the trajectory of the fabric to the cylindrical surface defined by the envelope of the active members 2A, 2B is arranged between the feeding means 3 and the rotating cylindrical drum member 1. A pair of arms 23, which carry a mobile guiding element (a roller 25 idly carried by the two pivoting arms 23 in the example shown) pivot on the axis A of rotation of the rotating cylindrical member 1. The fabric T is guided on the mobile roller 25 and forms therefore a curve in the section comprised between the point of detachment between the rotating cylindrical member 1 and the guiding roller 15 of the distancing means 11. The assembly consisting of the pivoting arms 23 and the guiding roller 25 is suitably balanced by a counterweight 27 fastened to the lower free end of a chain 29 whose second end is fastened to a chain wheel 31 integrally fastened to the arms 23 and consequently rotating on the axis A. In practice, two counterweights 27, two chains 29 and two chain wheels 31 fastened to the two counterpoised arms 23 can be provided. The pivoting movement of the arms 23 causes more or less winding of the chain 29 on the respective chain wheel 31. The counterweight 27 nearly entirely eliminates the tension due to the weight applied by the guiding roller 25 on the fabric T. The pivoting movement of the arms 23 and the guiding roller 25 modifies the path of the fabric T as shown in the two positions of the unit 23, 25 shown by the solid and dotted line in Fig. 1. When the fabric T tends to wind by a larger arch around the rotating cylindrical member 1, the pair of pivoting arms 23 and the guiding roller 25 pivot downwards counterclockwise. In order to prevent the textile fabric T from wrapping around the rotating cylindrical member 1 forming an excessive arch which tends to integrally encompass the rotating cylindrical member 1, that is, coming into contact with all the active elements 2A, 2B carried by the drum 1 , a position sensor, e.g. an encoder or potentiometer, schematically indicated by reference numeral 33 in Fig. 1, is associated to the assembly formed by the pivoting arms 23 and the guiding roller 25. The encoder 33 interfaces with a control unit 35, which in turn interfaces at least with the motor 20 and possibly with the motor 19. In this way, by suitably programming the control unit 35, the angular position of the pivoting arms 23 and the guiding roller 25 (and consequently the contact arch between the fabric T and the rotating cylindrical member 1) can be corrected by varying the speed with which the driven cylinder 13 pulls the fabric from the cylindrical member 1. Essentially, when the pivoting arms 23 and the guiding roller 25 tend to be excessively low, the speed of the driven cylinder 13 is temporarily increased to pull the fabric T and consequently reduce the loop formed between the rotating cylindrical member 1 and the guiding roller 15. An opposite correction can be applied when the contact angle between the fabric T and the surface of the rotating cylindrical member 1 is excessively small, i.e. when the position of the pivoting arms 23 is excessively high. In both cases, a variation of the angular position of the arms 23 essentially causes a variation in the number of active members 2A, 2B with which the fabric T is in contact. In practice, two limit angular positions can be defined in correspondence with which the correction by temporary acceleration of the motor 20 is either started or stopped. The encoder 33 may be replaced by two limit micro switches which start and stop an acceleration control. Alternatively, a plurality of micro switches or position sensors arranged along the trajectory of the pivoting arms 23, e.g. a plurality of capacitance, magnetic or linear sensors, to detect the passage of one of the two pivoting arms 23 and consequently control the acceleration or deceleration of the motor 20 associated to the driven cylinder 13. Fig. 3 shows an embodiment of the machine according to the invention with two rotating cylindrical drum members produced with active elements as in Figs. 1 and 2. The machine comprises two consecutive sections, indicated by references 51 A and 51 B. Section 51 A is essentially equal to the machine in Fig.1 and equal numbers indicate parts equivalent or corresponding to those in the previous embodiment. Section 51 B has members equivalent to those in section 51 A, indicated with the same reference numbers increased by 100. It has in common with section 51 A the arrangement of the means 11 forming the feeding means of the fabric T to a second rotating cylindrical member, indicated by reference numeral 101 equivalent to the drum 1. The arrangement of the section 51 B differs with respect to the arrangement of the section 51 A, in that the drum 101 turns in the direction opposite to that of the drum 1. The motors 19, 20, 120 and the encoders 33, 133 interface with a programmable central control unit 35 which is similar to the unit 35 in the previous example of embodiment. The operation is illustrated below. When the machine is started, the arms 123, 23 are in an intermediate position, in an acceptable angular range. If the fabric T tends to wrap excessively around the drum 101, (i.e. towards the feeding means 11 to section 51 B) by effect of the dragging exerted by the members 102A, 102B of the drum 101 , the distancing means 111 are consequently accelerated to pull the fabric. Section 51 A works in the way already described with reference to the machine in Fig. 1, with the difference that it is subordinated to the control of section 51 B. In other words, the speed of the distancing means 11 from section 51 A is corrected after correcting the speed of the means 111, to return the arm 123 to the correct position. Fig. 4 shows a form of embodiment which is similar to that shown in Fig. 3, but in a configuration in which the first abrasive rotating cylindrical member works on one side of the web material while the other abrasive rotating cylindrical member works on the second side of the material. This machine is consequently capable of processing the front and the back of the fabric at the same time. Equal numbers indicate parts which are the same as or equivalent to the embodiment in Fig. 3. In this case, the mobile guiding elements are always downstream to the corresponding rotating cylindrical member because the web material embraces in the first case the upper arch and in the second case the lower arch of the respective rotating cylindrical member. Fig. 5 shows, limited to a single rotating drum, a configuration in which the path of the fabric around the rotating drum is modified by a detaching member 71. If the machine comprises more than one cylindrical member or rotating drum, this arrangement may be repeated on each of them. The detaching member may, for example, be constituted by an idle roller, by a fixed bar or the like. In substance, the fabric T is in contact with some active elements 2A, 2B upstream of the detaching member 71 and with further active elements 2A, 2B downstream of the detaching member. This detaching member may be employed in cases in which the abrasion force is excessive and could thus cause an excess of tension on the fabric being processed to interrupt continuity of processing and may, for example, have advantageous effects in terms of eliminating defects of the fabric caused by the presence of creases or the like. It is understood that the drawing only shows a possible embodiment of the invention, which may be Varied in its forms and dispositions without however departing from the scope of the underlying concept of the invention.

Claims

CLAIMS 1. A machine for processing a web material, in particular a textile fabric or other textile material, comprising: an essentially cylindrical rotating member, around which the web material is entrained; a means for feeding the web material to said essentially cylindrical member; a means for distancing the web material from said essentially cylindrical member; a mobile guiding element on which the web material is guided, whose position varies with the contact arch between the web material and the essentially cylindrical member; and control means of the speed of at least one of said feeding and distancing means programmed to control said speed according to the position of said mobile guiding element; characterized in that said essentially cylindrical rotating member comprises a drum disposed around the periphery of which are active elements rotating about respective axes of rotation. 2. Machine according to claim 1, characterized in that said active elements comprise abrasive rollers. 3. Machine according to claim 2, characterized in that said abrasive rollers have a surface equipped with abrasive powders. 4. Machine according to one or more of the preceding claims, characterized in that said active elements comprise rotating abrasive brushes. 5. Machine according to one or more of the preceding claims, characterized in that said active elements are associated with two separate motors, each active element being operated by a different motor with respect to the adjacent active elements. 6. Machine according to one or more of the preceding claims, characterized in that a detaching member is associated with said drum, about which said web material is guided, said detaching member defining, with the drum, a path of the web material which is in contact with said drum in two areas upstream and downstream of said detaching member with respect to the direction of advancement of the web material.