Method and apparatus for surface treatment of wet fabric webs in a finishing machine

Abstract: A method for surface treatment of wet fabric webs in a finishing machine containing an external housing, provided with an inlet zone and an outlet zone, through which a fabric web to be treated is run, and at least one grinder roller rotatably arranged inside it, against which said fabric web is caused to slide, in which method the surface treatment of the fabric is carried out by using abrasive diamond material as the grinding material for the grinder roller. Furthermore, a finishing machine for surface treatment of wet fabrics is discussed, which comprises an external housing (12), provided with an inlet zone and an outlet zone, through which a fabric web to be treated (11) is caused to run, and at least one grinder roller rotatably arranged inside it, against which the fabric web (11) is caused to run, in which, in order to carry out the treatment, the grinder roller (13, 15) is provided with an external surface equipped with abrasive diamond material (14, 17).

Description: The present invention relate to a method and an apparatus for surface treatment of wet fabric webs in a finishing machine. At present, methods and apparatuses are known and used which, in order to carry out the surface treatment of dry fabrics, use one or more revolutionary rollers coated with a conventional abrasive tape. Such a treatment method, usually referred to as "fluffing" , makes it possible a treated fabric to be manufactured, from the surface of which some fibrous material has been partially removed. Consequently, the fabric displays a more or less marked surface fluff. In that way, a modification is accomplished in the treated fabric from both the visual and tactile viewpoints, which unfortunately causes, as a negative characteristic, a certain loss of strength of said fabric. Furthermore, the use of the abrasive tape implies the drawback that it does not allow the surface treatment of wet fabrics to be carried out owing to the sudden degradation of said tape, which must be frequently replaced. However, the need exists always for obtaining new "hand" and visual surface effects. For example, hand effects are required which are such as to soften the fabric while simultaneously preventing surface grind to be formed. Furthermore, also visual effects are required which determine a fabric appearance which resembles a discoloration and/or ageing, as shown by an already used fabric. The purpose of the present invention is hence of providing a solution for the above requirements through methods and apparatuses which overcome the drawbacks and disadvantages of the methods and apparatuses already known and used in the prior art. This purpose according to the present invention is achieved by providing a method for surface treatment of wet fabric webs in a finishing machine containing an external housing, provided with an inlet zone and an outlet zone, through which a fabric web to be treated is run, and at least one grinder roller rotatably arranged inside it, against which said fabric web is caused to slide, characterized in that the surface treatment of the fabric is carried out by using abrasive diamond material as the grinding material for the grinder roller. Furthermore, according to the present invention, a finishing machine for surface treatment of wet fabrics is proposed, which comprises an external housing, provided with an inlet zone and an outlet zone, through which a fabric web to be treated is caused to run, and at least one grinder roller rotatably arranged inside it, against which the fabric web is caused to slide, characterized in that, in order to carry out said surface treatment, said grinder roller is provided with an external surface equipped with abrasive diamond material. The characteristics and advantages of the present invention will be clearer and more evident from the following exemplifying, non-limitative disclosure, made by also referring to the accompanying schematic drawing, which displays a possible embodiment of the apparatus according to the invention. In the figure, as said, a possible embodiment of apparatus is displayed which can be used in a finishing machine for the surface treatment of wet fabric webs according to the present invention. The apparatus is essentially constituted by an external housing 12 comprising a tank 22 for water impregnating a fabric web 11, in which water is also optionally admixed with suitable chemical products for favouring the treatment of said fabric. The continuous fabric web 11 is fed to the inlet of the housing 12 at an inlet zone and after being treated leaves the housing from an outlet zone. Inside the housing 12, according to the exemplifying embodiment displayed, a grinder roller 13 is provided, which can revolve both clockwise and counterclockwise, and on its side surface is provided with abrasive diamond material 14. Furthermore, for example, in a downstream position from the first roller 13, a second grinder roller 15 is provided, which also can revolve both clockwise and counterclockwise, and bears on its side surface a plurality of staves or stick elements 16 arranged according to generatrices of the roller 15. The staves or stick elements 16 bear, applied onto their external surface, abrasive diamond material 17. In both cases, said abrasive diamond layer can be constituted either by a water resistant support coated with abrasive diamond material, or by directly applying the abrasive diamond material onto the grinder roller 13 or 15. In such a way, said roller can be used, without any problem, with wet fabric webs. The fabric web 11 continuously fed to an inlet zone of the housing 12, is caused to run, by means of rollers 18, a long a trajectory partially immersed in a lowered zone or tank 22 of the housing 12, which contains an impregnation liquid or water, possibly with the aid of further rollers 19 which cause the fabric web to leave the tank after, being so dipped and possibly before another, further immersion. Furthermore mobile rollers 21 are provided, which, for example, can be moved upwards and downwards a long vertical planes and are installed downstream and upstream of the grinder rollers 13 and 15. By being moved up and down, these mobile rollers 21 cause the contact between the fabric web and the grinder rollers 13 and 15 to take place a long a larger or smaller contact angle, so as to vary and adjust the winding angle of the fabric web into contact with the same treatment grinder rollers. Over the grinder rollers 13 and 15, spraying elements 20 are furthermore provided and perform the task of "fabric washing showers", suitable for favouring the grinding action. At an outlet zone of the housing 12, further rollers are then provided, similar to rollers 19, which divert the trajectory of the surface-treated fabric web 11 towards a further lowered zone or tank 22 of the housing 12, containing a possible washing liquid means and subsequently towards one pair of squeezing rollers 23, which act on the fabric web while the latter is leaving the housing after the treatment. It should be observed that according to the present invention, the grinder rollers can be provided in an optimal number in order to perform the required surface treatment action, and may be all of the same type and/or of both types, as indicated hereinabove. In fact, the rollers 13 with side surface provided with abrasive diamond material 14, cause a surface shearing action to take place on the fibers of the fabric, with said fabric being consequently given a softer hand. On the contrary, the rollers 15 with side surface provided with localized portions 16 provided with said abrasive diamond material, such as the staves or stick elements, perform a mechanical action of flapping or shaking or the surface of the fabric web 11, with consequent visual effect of wear and ageing. Advantageously, according to the present invention it may be useful it to variously combine the arrangement, the succession and the type of grinder rollers 13, 15, as well as their revolution directions in order to obtain different effects of surface treatment. For example, an increase in the number of rollers may be useful in order to allow the fabric web 11 to run through the apparatus at a higher speed, with higher productivity and decreased costs. Therefore, according to the present invention also a novel and original method is provided in order to perform the surface treatment of wet fabrics in a finishing machine comprising an external housing, such as the one which is illustrated and disclosed hereinabove. In fact, such a method consists in causing the fabric to be submitted to surface treatment, continuously fed at a fabric web, to interact with at least one grinder roller rotatably installed inside the housing using, as the grinding material for said grinder rollers, abrasive diamond material. As previously mentioned, such a method makes it possible all the desired purposes of both hand and visual surface effects to be achieved as presently desired. Such a method is in fact capable, first of all, of softening the fabric, while simultaneously preventing a surface fluff to be formed. Secondly, by means of the method according to the present invention, an appearance of the fabric can be obtained which is similar to a typical discoloration and/or ageing of an already used fabric. The use of an abrasive diamond material supplies the possibility of submitting wet fabrics to surface treatment, to the contrary of as allowed by the prior art, i.e., by the abrasive tape. Furthermore, the abrasive diamond material supplies the grinder rollers provided with it with a high wear resistance, with an as long useful life and decrease of the operations of rollers or abrasive material replacement to a minimal number.

Claims: Method for surface treatment of wet fabric webs in a finishing machine containing an external housing, provided with an inlet zone and an outlet zone, through which a fabric web to be treated is run, and at least one grinder roller rotatably arranged inside it, against which said fabric web is caused to slide, characterized in that the surface treatment of the fabric is carried out by using abrasive diamond material as the grinding material for the grinder roller. Method according to claim 1, characterized in that said fabric web is caused to run through a water impregnation tank before being submitted to said surface treatment by means of said grinder roller (13, 15) with abrasive diamond material. Method according to claim 1, characterized in that the winding angle of said fabric web around said grinder roller (13, 15) with abrasive diamond material, is varied. Method according to claim 1 or 2, characterized in that the fabric is submitted to said complete surface treatment by means of said grinder roller (13) provided on its whole side surface with abrasive diamond material, and by means of at least one grinder roller (15) with side surface provided with localized portions coated with abrasive diamond material. Finishing machine for surface treatment of wet fabrics, which comprises an external housing (12), provided with an inlet zone and an outlet zone, through which a fabric web (11) to be treated is caused to run, and at least one grinder roller rotatably arranged inside it, against which the fabric web (11) is caused to slide, characterized in that, in order to carry out said fabric surface treatment, the grinder roller (13, 15) is provided with an external surface equipped with abrasive diamond material (14, 17). Machine according to claim 5, characterized in that in said at least one roller (13), the whole external surface is provided with abrasive diamond material (14). Machine according to claim 5, characterized in that said at least one roller (15) has its side surface provided with localized portions (16) coated with abrasive diamond material (17). Machine according to claim 5, characterized in that said external housing is provided with an impregnation tank (22) for impregnating a fabric with water. Machine according to claim 5, characterized in that it is provided with at least one roller (13), the whole external surface of which is provided with abrasive diamond material (14), and with at least one roller (15), the side surface of which is provided with localized portions (16) coated with abrasive diamond material (17), with said rollers being installed in a mutually alternating arrangement. Machine according to claim 9, characterized in that between said rollers (13, 15) a mobile roller (21) is provided which can be moved upwards and downwards along at least one vertical plane and is provided upstream and downstream from said grinder roller (13, 15), which mobile roller, by getting moved, causes said fabric web (11) to wind around said grinder rollers (13, 15) by a larger or smaller winding and contact angle. Machine according to claim 5, characterized in that above said at least one grinder roller (13, 15), a spraying element (20) is installed. Machine according to claim 5, characterized in that it is provided with at least one pair of squeezing rollers (23) installed downstream from said external housing (12), at an outlet zone. Machine according to claim 5 or 8, characterized in that at an inlet zone to said housing, a lowered zone or tank (22) is provided, which contains impregnation liquid.

Inventors: BERTOLDO FRANCO, BERTOLDO, FRANCO
Applicants: SPEROTTO RIMAR SPA, SPEROTTO RIMAR S.P.A.
Application year: 1993
Main classification: D06C23
IPC codes: D06C23, D06C19, D06B11, D06C11