EP3631071B1

EP3631071B1 - Washing apparatus for washing fabric webs

Info

Publication number: EP3631071B1
Application number: EP18732160.9A
Authority: EP
Inventors: Alessandro ZUCCHI
Original assignee: Ferraro SpA
Current assignee: Ferraro SpA
Priority date: 2017-05-30
Filing date: 2018-05-29
Publication date: 2022-08-31
Anticipated expiration: 2038-05-29
Also published as: CN109312515A; EP3631071A1; IT201700058732A1; TW201907070A; WO2018220517A1

Description

Technical field of the invention

The present invention relates to the washing of fabrics subsequent to their industrial processes of weaving and printing, and more particularly to a washing apparatus for washing fabrics in the modes known in the art as "continuous" and "open", which respectively indicate the fact that fabric webs pass through a washing apparatus from the inlet to the outlet completely distended in the width direction.

Background

In industrial weaving processes, washing is necessary to remove impurities such as weaving residues from greige or semi-finished fabrics, as well as chemicals such as caustic soda and bleaching products. In the case of removal of weaving oils, the washing is more intense and requires specific solvents, for this reason this operation is generally referred to as "scouring".
Washing and scouring are generally performed before heat-setting treatments to avoid oxidation of fibers of a fabric and their consequent yellowing.
Known washing apparatuses for fabrics comprise one or more washing units inside which tanks are housed for containing washing and rinsing liquids. Inside the washing units, rollers or cylinders are rotatably mounted which define a washing path for a fabric web extending from an inlet to an outlet of the washing unit itself.
The washing is carried out with liquids such as mixtures of water with detergents, soaps and/or solvents, for example limonene, or only with water at temperatures between 20°C and 99°C. The washing of a fabric may be carried out by immersion in washing liquids, typically first in tanks containing mixtures of water with detergents, soaps and/or solvents and then in tanks containing only water for the rinsing operations, or by spraying by means of jets delivered from spraying bars provided with slits and/or nozzles which are arranged along the washing path. Washing apparatuses that employ combinations of immersion tanks and spraying bars are also known.
Italian patent 102013902142642 describes a machine for continuously scouring a web of fabric comprising a washing tank suitable for containing a washing liquid and means for heating the latter. The machine further comprises a plurality of rollers which define a washing path, along which a web of fabric is conveyed, and spraying means arranged along the washing path. The spraying means comprise first nozzles configured to emit respective fan jets against a first face of the fabric ribbon over its entire width without overlapping, as well as second nozzles arranged from the opposite side of the first nozzles with respect to the washing path in order to emit respective fan jets on a second face of the fabric web opposite the first face. Like the first nozzles, the second nozzles are also configured to emit fan jets against the second face of the fabric web along its entire width without overlapping.
The first and second nozzles are arranged so as to direct the respective fan jets onto the same area of the fabric web in transit, in order to cancel the resulting force of the forces directed perpendicularly thereto without resorting to supporting rollers.
The Italian patent 102013902188808 describes an apparatus for washing fabrics in continuous and open mode comprising at least one treatment unit in which a plurality of cylinders are arranged which define a washing path from an inlet to an outlet. The treatment unit comprises a first and a second perforated movement surface configured so as to receive a strip of fabric to be treated sandwiched between them. The movement surfaces are supported by a set of cylinders with which they form a closed loop path.
Similarly to the Italian patent 102013902142642 , the treatment unit further comprises a plurality of first and second nozzles arranged along the whole washing path and facing towards the perforated movement surfaces for delivering washing fluids against the opposite faces of the fabric transported sandwiched by them. The washing fluids are supplied at pressures ranging from 5 to 50 bar with flow rates between 20,000 and 40,000 liters / hour per linear meter of fabric in the direction of its width. Thanks to the arrangement of the nozzles and to the high pressures and flow rates of the washing fluids, it is possible to minimize the problems of elongation and formation of folds in the fabric along its washing path.
Notwithstanding the availability of machines and methods for washing and scouring fabrics in continuous and open mode, there is still the need to improve the washing processes and the relative apparatuses both from the point of view of effectiveness in removing impurities as well as regarding the speed of treatment. The need to minimize the risks of tissue damage caused by the forces exerted by the washing liquids is also strongly felt.
The document CN103088580 , upon the teaching of which the preamble of the independent claim is drafted, discloses a cloth washing device with a structure for continuous washing of cloths so as to improve production efficiency and washing quality of cloths.
The document WO2010/065270 discloses a web cleaning machine comprising spray nozzles attached to spray manifolds.

Summary of the invention

The technical problem posed and solved by the present invention is therefore that of providing a system for washing fabrics in a continuous and open mode which allows to overcome the above mentioned drawbacks with reference to the prior art.
This problem is solved by an apparatus according to claim 1.
Preferred features of the present invention are defined in the dependent claims.
The apparatus according to the invention comprises, in a known manner, at least one washing unit which houses a washing tank and a rinsing tank arranged in series in a working direction, and also a plurality of rollers or cylinders which define in the washing unit a washing path that develops in the processing direction from an input to an output. Along the washing path spraying means are arranged, comprising spraying bars provided with nozzles or, alternatively, slits. These bars are arranged transversely to the washing path, for example substantially parallel to the rollers or cylinders. The spraying bars are restrained to the washing unit rotatably about the respective axes and are rotated during the passage of a fabric web, so that the washing and rinsing actions are distributed along sections of the washing path and not concentrated in specific areas as in the washing apparatuses according to the prior art.
The main advantage provided by the invention is that of expanding the radius of action of the spray bars, while allowing to reduce stresses on the treated fabric web.
The rotation of the spray bars is managed by an automatic control system. The direction and the rotation speed of spraying bars may be controlled according to washing requirements, as well as the type of treated fabric. The automatic control system ensures also a regulation of pressure and of flow rate of washing and rinsing liquids.
A further advantage provided by the invention is that the washing apparatus may be used both for the removal of processing residues from the fabric webs, as well as for scouring the fabric webs using suitable solvents.
Other advantages, features and methods of use of the present invention will be apparent from the following detailed description of several embodiments, presented by way of a non-limiting example.

Brief description of the figures

Reference will be made to the figures of the attached drawings, in which:

Figure 1 is a sectional side view showing schematically a washing unit according to the present invention;
Figures 2 and 3 show details of Figure 1;
Figure 4 is a cross sectional perspective view showing a spraying bar of the washing system of Figure 1 provided with a plurality of nozzles.

Detailed description of preferred embodiments

With reference to the figures, an apparatus for washing fabrics in continuous and open mode is indicated as a whole with the reference number 100.
The washing apparatus 100 comprises, in a known manner, at least one washing unit 110 inside which are housed two tanks arranged in series in a working direction schematically indicated by an arrow L.
These tanks are respectively a washing tank 111 designed to contain a washing liquid, for example a solution of water and limonene, and a rinsing tank 112, designed to contain a rinsing liquid, for example water.
Figure 1 schematically indicates with dashed lines the levels of the liquids in each tank.
Inside the washing unit 110 there are also a plurality of cylinders rotating around their own axis 113a, 113b, etc., which together define a washing path for a fabric tape F, which is developed from an input 114 to an output 115 of the washing unit 110.
In the illustrated embodiment two sets of cylinders are shown, in particular three cylinders 113a, 113b, 113c arranged in correspondence of the washing tank 111 and three cylinders 113d, 113e, 113f arranged in correspondence of the rinsing tank 112.
In order to allow the passage of the fabric web F through the washing unit 110, at least some of the cylinders are motorized. Preferably all the cylinders are motorized so as to minimize friction problems with the passing fabric web, which may cause unwanted lengthening.
At the inlet 114 and at the outlet 115 of the washing unit 110, a guide cylinder combined with a dancer roller mounted on an oscillating arm are also shown.
As shown in Figure 1, with respect to a vertical direction V perpendicular to the longitudinal direction L, a cylinder of each assembly is arranged near the bottom of the respective tank, therefore in an operating condition the apparatus 100 works immersed in the washing or rinsing liquid, while the other cylinders are spaced therefrom and are located outside the washing liquid and of the rinsing liquid in an operating condition of the apparatus. It will be understood that this configuration of the washing unit 110 allows in a known manner to wash a fabric web by immersing it in the tanks 111, 112. In other words, the arrangement of cylinders is such that the washing path, schematically shown with a dashed line, is partially developed to the outside of the tanks 111, 112 and partially inside them.
Preferably, the cylinders designed to work in the tanks 111, 112 have a greater diameter than those arranged above them, thus allowing to lengthen the path along which the fabric tape is immersed without having to increase the number of cylinders. This configuration also reduces stresses on the fabric web.
The use in the tanks of cylinders having a larger diameter than those arranged above them actually reduces the volume available for the washing liquids, which provides the advantage of requiring a smaller amount of liquid both in the washing step as well as in the rinsing step.
The washing liquid and the rinsing liquid are supplied by respective tanks (not shown) of the apparatus 100 which are connected to the tanks 111 and 112 of the washing unit 110 through suitable pipes and flanged fittings 116, 117.
These tanks comprise in a known fashion heating means configured to pre-heat the washing and rinsing liquids at temperatures suitable for the treatment contemplated for a specific fabric web, as well as agitators devices, for example of the type with vanes, which favor the liquid heating and the possible mixing of their components.
The washing liquids fed into the tanks 111, 112 are maintained at the desired temperature, for example at a temperature of the order of 60°C, by means of suitable heating means, for example serpentine pipes 118, 119.
More generally, the temperature of the washing and rinsing liquids is determined by the type of used detergents, soaps and/or solvents and by the type of impurities that must be removed. Therefore, this is not a parameter that can be set as desired, but is determined by the operating condition envisaged for the apparatus 100.
The washing and rinsing liquids are recirculated in the tanks 111, 112 after purification.
The apparatus 100 also comprises a plurality of spraying means 120a, 120b, etc., arranged along the washing path in the portions that are above the tanks 111, 112, so that a strip of fabric F may be treated by spraying as well as by immersion.
The spraying means 120a, 120b, etc., comprise in a known manner a plurality of spraying bars 121a, 121b, etc., connected to the washing unit 110 transversely to the washing path, thus having respective axes substantially parallel to those of the cylinders, and including respective nozzles, or alternatively slits, 122a, 122b, etc., configured for the delivery of liquid jets towards the faces of a passing fabric web. The spraying bars 121a, 121b, etc., are hollow to allow the liquids to be fed to the nozzles or slits 122a, 122b, etc., by respective connections 123a, 123b, etc.
Figure 4 schematically shows a spraying bar with nozzles.
The spraying means are arranged so as to direct the jets of liquid against the opposite faces of the fabric web. For example, in the illustrated embodiment six spraying bars 121a, 121b, 121c, 121d, 121e, 121f arranged above the washing tank 111, and three spraying bars 121g, 121h, 121i arranged above the rinsing tank 112, are shown.
It will be understood that the number of cylinders and spraying bars is not a binding element for the invention.
According to the invention, the spraying bars 121a, 121b, etc., are constrained to the washing unit 110 rotatably around their respective axes and are operatively connected to rotating actuating means, for example pulleys keyed on their axes and toothed belts connected to one or more motors of the washing unit 110.
The operation of the spray bars 121a, 121b, etc., is managed by an automatic control system for controlling the washing system 100.
The nozzles or slits of the spray bars are distributed over the entire lateral surface, both in the direction of the perimeter as well as axially.
In the embodiment shown in Figure 4, the spraying bars, for example the bar 121a, has a tubular body with a square cross section with nozzles 122a arranged on the four faces of the tubular body.
In the case of a spraying bar with a tubular body having a circular cross-section, the nozzles or, alternatively the slits, could be spaced circumferentially by 90° and could be spaced axially in the direction of length of the tubular body.
Thanks to this combination of characteristics, the fabric web F is treated, in particular washed or rinsed, not in a concentrated manner at a single zone substantially corresponding to the position of the spraying bar and/or of the respective nozzles or slits, but in a distributed way along the entire section from time to time affected by the jets of the nozzles or of the slits that are facing the same fabric web F during the rotation of each spraying bar.
The washing and rinsing liquids thus act on a more extended portion than the portion that would be possible to treat with fixed spraying bars of the prior washing apparatuses. As a consequence, the cleaning action is more effective.
Moreover, thanks to the rotation of the spraying bars, the tangential component of the forces exerted on the fabric web F by the washing and rinsing liquids is comparable to that of a brush, which further increases the effectiveness of the cleaning action.
The spraying bars 121a, 121b, etc., may advantageously be enclosed in respective casings 124a, 124b, etc., fixed to the inside of the washing unit 110 and having a longitudinal opening 125a, 125b, etc., that is, parallel to the direction of development of the single spraying bar, having an amplitude determined to allow the delivery of the liquid jets towards the fabric web F only in a given angular range of rotation of the spraying bars.
The angular range of the jets dispensed by each spraying bar is schematically shown in figures 1, 2 and 3 by means of fillings with parallel lines.
Thanks to this configuration it is possible to optimize the spraying effect by precisely defining the affected sections of the washing path.
As shown in Figures 1 and 2, the arrangement of the openings of the individual casings 123a, 123b, etc., of the spraying bars 121a, 121b, etc., is such that the jets of liquid dispensed therefrom are directed in correspondence of the sections of the washing path passing between consecutive cylinders. Moreover, the arrangement of the spraying bars is determined so as not to create overlaps between the jets in the entire angular range between consecutive bars facing towards the same face of the fabric web F, as well as between consecutive bars facing towards the opposite sides of the fabric web F.
This arrangement offers the advantage of allowing the washing liquids to pass through the fabric web F in the thickness direction by effectively removing impurities, which are collected in the tanks under the cylinders.
In the embodiment shown in Figures 1, 2 and 3, two spraying bars, in particular the bars 121c, 121d, are arranged in a central position between the portions of the path of the fabric web F which respectively descend and rise from the washing tank 111. The casings 124c, 124d of these spraying bars are configured so as to direct the jets in opposite directions towards the portion of the washing path which goes down towards the bottom of the washing tank 111, as well as towards the section which, from it, goes back to reach the tank 112.
The spraying bars arranged above the rinsing tank 112 have a similar configuration, though between the descending and ascending portions of the path of the fabric web F there is only one spraying bar whose casing is configured to direct the jets in opposite directions.
In light of the foregoing, it will be understood that, due to the rotation of the spraying bars 121a, 121b, etc., the delivery of the washing and rinsing liquids is intermittent and can take place both in the direction of feed of the fabric web F as well as in the opposite direction, depending on the direction of rotation of the bars themselves. The rotation of the spraying bars, suitably managed by the automatic control system of the apparatus 100, may also be in opposite directions in an alternating manner, for example using a cam mechanism or equivalent driving means.
This feature of the invention, in synergy with the washing or rinsing action distributed on portions of the fabric web, provides excellent washing results while minimizing stresses on the fabric itself.
According to a further aspect of the invention, the automatic control system of the apparatus 100 is configured in such a way that the rotation speed of the spraying bars 121a, 121b, etc., is regulated according to the transit speed of the fabric web. More specifically, depending on the type of treated fabric and the required cleaning action, it is possible to adjust the rotation speed of the spray bars so that the same portion of the web in transit is affected one or more times by a single spraying bar.
The automatic control system shall also regulate pressure and flow rate of the washing and rinsing liquids.
As a whole, the washing action is thus finely adjustable, thus allowing the quality of the treated fabric webs to be preserved in the best possible way.
The present invention has been described up to now with reference to preferred embodiments. It is to be understood that other embodiments may exist which belong to the same inventive core, as defined by the scope of the protection of the claims set forth below.

Claims

A washing apparatus (100) for washing fabric webs in a continuous and open mode, said apparatus (100) comprising:
i) at least one washing unit (110) inside which a washing tank (111) adapted to receive a washing liquid and a rinsing tank (112) adapted to receive a rinsing liquid are arranged,

ii) a plurality of rollers or cylinders (113a, 113b, 113c, 113d, 113e, 113f) arranged within said washing unit rotatably about their axes, wherein said rollers or cylinders define a washing path extending from an inlet (114) to an outlet od the washing unit (110), and wherein at least some of said rollers or cylinders are motorized,

iii) a plurality of spraying bars (121a, 121b, 121c, 121d, 121e, 121f, 121g, 121h, 121i) restrained to the washing unit (110) transversely to said washing path, said spraying bars (121a, 121b, 121c, 121d, 121e, 121f, 121g, 121h, 121i) comprising nozzles (122a, 122b, 122c, 122d, 122e, 122f, 122g, 122h, 122i), or alternatively slits, suitable for dispensing jets of washing or rinsing liquids against opposite faces of a fabric web (F) carried along the washing path,
characterized in that the spraying bars (121a, 121b, 121c, 121d, 121e, 121f, 121g, 121h, 121i) are restrained to the washing unit (110) rotatably about their respective axes and are operably connected to driving means configured to cause them to rotate, said nozzles (122a, 122b, 122c, 122d, 122e, 122f, 122g, 122h, 122i) or slits being distributed over the whole lateral surface of each spraying bar and being spaced both in the peripheral direction and in the axial direction.
A washing apparatus according to claim 1, wherein the spraying bars (121a, 121b, 121c, 121d, 121e, 121f, 121g, 121h, 121i) are enclosed in respective casings (124a, 124b, 124c, 124d, 124e, 124f, 124f, 124h, 124i) fixed to the washing unit (110), each casing having a longitudinal opening (125a, 125b, 125c, 125d, 125e, 125f, 125g, 125h, 125i) of a predefined size that allows dispensing of liquid jets only in a given angular range of rotation of the spraying bars (121a, 121b, 121c, 121d, 121e, 121f, 121g, 121h, 121i).
A washing apparatus according to claim 1 or 2, wherein the spraying bars (121a, 121b, 121c, 121d, 121e, 121f, 121g, 121h, 121i) are arranged so as to direct the liquid jets against the fabric web (F) where it passes between subsequent cylinders of the washing path.
A washing apparatus according to claim 3, wherein the spraying bars (121a, 121b, 121c, 121d, 121e, 121f, 121g, 121h, 121i) are arranged such that the jets dispensed by consecutive spraying bars facing the same face of the fabric web (F) do not overlap each other, and such that the jets dispensed by consecutive bars facing opposite faces of the fabric web (F) do not overlap each other as well.
A washing apparatus (100) according to any one of claims 1 to 4, further comprising an automatic control system.
A washing apparatus (100) according to claim 5, wherein said automatic control system is configured to adjust the rotation speed of the spraying bars (121a, 121b, 121c, 121d, 121e, 121f, 121g, 121h, 121i) depending on the speed of the fabric web (F).
A washing apparatus (100) according to claim 5 or 6, wherein said automatic control system is configured to adjust the rotation direction of the spraying bars (121a, 121b, 121c, 121d, 121e, 121f, 121g, 121h, 121i) in the same or in the opposite direction relative the movement direction of the fabric web (F), or in a reciprocating manner.
A washing apparatus (100) according to any one of the claims 5 to 7, wherein the automatic control system is also configured to adjust the pressure and the flow rate of the washing and rinsing liquids.