Fabric treatment plant and related method

Abstract

A continuous fabric treatment plant includes a steaming section for carrying out a steaming treatment on a segment of fabric. Within the steaming tunnel there are the steaming tank into which the steam is introduced, generated by steam generation means, the steam suction means as well as at least one motorized conveyor belt of the fabric segment A in a forward direction X above this tank. Unlike similar known systems, the system of the present disclosure includes at least two distinct and separate conveyor belts configured to be moved at different speeds, as well as an equal number of motorized rollers each installed upstream of the respective conveyor belt and configured to place on a conveyor belt the fabric which advances in a flat or overlapping configuration different from that assumed by the fabric itself on the other conveyor belt. Also disclosed is a related fabric processing method implemented with the system of the present disclosure, in which the two conveyor belts travel at different speeds.

Description

[0001] FABRIC TREATMENT PLANT AND RELATED METHOD TECHNICAL FIELD

[0002] The present description relates to a fabric treatment plant and more particularly a plant having a tunnel steaming section as well as a related fabric treatment method.

[0003] BACKGROUND

[0004] Continuous fabric treatment processes are known which involve the following work sequence:

[0005] 1. impregnation and squeezing of the fabric with a solution of chemical products for scouring and / or bleaching;

[0006] 2. vaporization of the fabric placed on the conveyor belt;

[0007] 3. washing.

[0008] Of the three basic steps mentioned above, the first step will not be discussed below as it is relatively simple to implement.

[0009] Different types of fabric steaming processes are known which involve the use of systems with very different characteristics: post-printing fabric steaming systems to fix the dyes to the fibres, post-impregnation steaming systems of fabrics with chemical products to carry out reactions with various purposes (fixing, oxidation, etc.), steaming systems for the relaxation and consequent shrinkage of fabrics with the aim of giving dimensional stability to the fabrics.

[0010] Steaming systems for giving dimensional stability to fabrics include a steaming tunnel which is crossed by the fabric to be steamed via a conveyor belt having a vapor- permeable structure, on which the fabric is placed. The steaming tunnel includes a steaming tank at the bottom within which perforated tubes deliver steam which, after saturating this tank, rises upwards, crossing the conveyor belt and the fabric, and is sucked in by a suction hood, located above in the tunnel. The hood sucks in the steam once it has affected the fabric, to prevent it from escaping from the steaming tunnel and therefore invading the surrounding work environment. Since the fabric is simply placed on the conveyor belt, it can shrink freely under the action of the steam to reach its natural size.

[0011] The action of steam on the fabric generates relaxation of the fibers and a consequent shrinkage, thus improving the dimensional stability of the fabric thanks to the thermal action, due to the heat transmited by the steam, and to the chemical action, the hydrolysis generated by the water molecules in the gaseous state. This type of steaming process is suitable both for the treatment of fabrics made with natural fibers (cellulosic and animal) and with synthetic and artificial fibres.

[0012] Fabrics that are more critical to treat are cellulosic knitted fabrics, natural or artificial. Such fabrics in general should not be subject to tensile stresses during treatment because they are particularly sensitive to longitudinal elongation, which is caused by longitudinal tensions that are generated during the transport of fabrics along continuous treatment plants. Elongation of a fabric represents a negative element because it results in negative consequences such as the reduction in the density and weight per meter of the fabric, the formation of folds and the consequent risk of indelible markings caused by friction and rubbing of the folds themselves around the conveying means. The uniformity of the density of the fabric, i.e. the constancy of its weight per metre, is an extremely important factor on both a technical and commercial level, so it is important to avoid that even temporary or localized conditions of variation of longitudinal tension can be generated during processes, which would generate the aforementioned drawbacks.

[0013] W02022 / 096530 discloses a treatment machine for shrinking and dimensionally stabilizing fabric, provided with at least one module comprising a first fabric accumulation station and a second fabric accumulation station, an alternating movement path of the fabric between the two accumulation stations, an air distribution system on the fabric along the movement path at least between the accumulation stations and, in an intermediate zone of the movement path, a forming zone of a free loop of the fabric and a detection device of a loop of fabric in the forming zone, such that during the alternating movement of the fabric between the accumulation stations, the fabric is moved maintaining a free loop inside the forming zone.

[0014] SUMMARY

[0015] The aim of the present disclosure is to provide a continuous fabric treatment plant which overcomes the limits of the known art. This aim is achieved with a fabric treatment plant whose main features are specified in the attached claims.

[0016] In particular, the Applicant has set up a treatment plant with a steaming section to carry out a steaming treatment on a segment of fabric. Within the steaming tunnel there are a steaming tank into which steam is introduced, generated by steam generation means, steam suction means as well as at least one motorized conveyor belt of the fabric segment A in a forward direction X above this tank.

[0017] Unlike similar known systems, the system of the present disclosure includes at least two distinct and separate motorized conveyor belts configured to be moved at different speeds, as well as an equal number of motorized rollers each installed upstream of the respective conveyor belt and configured to place the fabric on the conveyor belt which advances in a flat or overlapping configuration different from that assumed by the fabric itself on the other conveyor belt.

[0018] Also disclosed is a related method of fabric treatment implemented with the system of the present disclosure, in which the two conveyor belts travel at different speeds so that the fabric to be treated is transported flat through the steaming section on a first conveyor belt, forming first pleats or being completely stretched, and on the second conveyor belt, being completely stretched or forming second pleats of a different shape from the first pleats.

[0019] Further embodiments are defined in the attached claims.

[0020] BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1A shows a continuous fabric treatment plant according to a first embodiment of the present disclosure.

[0022] Figure IB is a detail view of the steaming section and the washing section of the system of Figure 1A.

[0023] Figure 2A shows a continuous fabric treatment plant according to a second embodiment of the present disclosure.

[0024] Figure 2B is a detail view of the steaming section and the washing section of the system of Figure 2A.

[0025] Figure 3A shows a continuous fabric treatment system according to a third embodiment of the present disclosure.

[0026] Figure 3B is a detail view of the steaming section and the washing section of the system of Figure 3A.

[0027] Figure 4A shows a continuous fabric treatment plant according to a fourth embodiment of the present disclosure.

[0028] Figure 4B is a detail view of the steaming section and the washing section of the system of Figure 4A.

[0029] DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[0030] The fabric treatment plant according to the present description will be described with reference to figures 1A to 4B, which show some exemplary embodiments. Corresponding elements in the various figures are designated with the same numerical references.

[0031] In general, a fabric processing plant comprises an inlet section 1 comprising a motorized inlet roller that feeds a fabric segment A into the plant. The fabric A passes through a tank 2 filled with fluid for scouring and / or bleaching and is impregnated with it. A section 3 arranged downstream of the tank 2 includes a pair of rollers which press the fabric to drain the excess liquid before transferring the fabric A to the steaming section V.

[0032] In all embodiments, at the inlet of the steaming section V there is a first motorized roller which advances the fabric A to be steamed at a nominal treatment speed and brings it over a respective steam-permeable conveyor belt 4, which defines a crossing direction X of the fabric A through the steaming section V. The conveyor belt 4 runs above a steaming tank 9 which has an opening oriented towards the conveyor belt 4 and as a consequence towards the tissue segment A. The conveyor belt 4 is positioned below an aspirator 10, which is configured to suck the steam that comes out of the steaming tank 9 and passes through the fabric segment A.

[0033] Several steam dispensing tubes open into the steaming tank 9, connected to a steam supply source, which for simplicity has not been represented in the drawings.

[0034] Differently from common fabric treatment systems, the steaming section V of the systems of the present disclosure includes at least two distinct and separate motorized conveyor belts 4 and 5 which transport the fabric segment to be treated A along the crossing direction. The two conveyor belts 4 and 5 are configured to move respectively at a first speed and a second speed, each different from the other. Furthermore, between the first conveyor belt 4 and the second conveyor belt 5 there is a second motorized transport roller, configured to rotate so that the advancement speed of the fabric A, which is above it, is equal to the nominal processing speed of the fabric A.

[0035] As shown in the figures, the steaming section V can include two distinct and separate steaming tunnels (figs. 1a-3b) containing the respective conveyor belts 4 and 5 and the related steaming tanks 9 and the related aspirators 10, or the two belts conveyors 4 and 5 can be located (figs. 4a-4b) on different planes as illustrated, or even on the same plane.

[0036] Given that the two permeable transport belts 4 and 5 travel at different speeds and are separated by a motorized intermediate roller 11, the fabric A is subject to the steaming treatment while it takes on different configurations on the two belts 4 and 5. For example, as illustrated in figures 1A-1B and 4A-4B in the case in which the first conveyor belt 4 advances at the nominal fabric treatment speed while the second conveyor belt 5 advances at a lower speed, the fabric A is transported lying flat on the first conveyor belt 4 and, through the motorized intermediate roller 11, it is deposited with pleats onto the second conveyor belt 5 which moves at a second speed lower than the nominal treatment speed of the fabric.

[0037] Conversely, as shown in figures 2A-3B, the first conveyor belt 4 moves at a first speed that is lower than the nominal treatment speed of the fabric, so that the fabric A is transported with pleats over the first conveyor belt 4. Instead, the second conveyor belt 5 moves at the nominal advancement speed so that, through the second intermediate motorized roller 11, the fabric coming from the first conveyor belt 4 is completely stretched over the second conveyor belt 5 and in this second configuration passes through the steaming tunnel of the section V.

[0038] According to another configuration not shown in the drawings, both conveyor belts 4 and 5 move at a speed lower than the nominal advancement speed of the fabric and the first advancement speed of the first conveyor belt 4 is different from the second advancement speed of the second conveyor belt 5. Clearly, both the first and second speeds must be no higher than the nominal fabric treatment speed. In this configuration not illustrated in the drawings, the fabric will be transported in layers on both conveyor belts 4 and 5, but it will take on different configurations on the two conveyor belts because the intermediate motorized roller 11 will unwind the pleats of fabric A coming from the first conveyor belt 4 nor will it create new ones when the fabric A is deposited onto the second conveyor belt 5. Consequently, also in this case the fabric will be subject to the steaming treatment in at least two different configurations.

[0039] Thanks to this method of carrying out the steaming treatment of the fabric in two different configurations, better results are obtained with regards to the uniformity of the steaming. Furthermore, the fabric is always placed on a transport belt during steaming so it does not undergo stretching or deformations due to its own weight, as instead happens when steaming is carried out with the fabric suspended between transport rollers.

[0040] According to an aspect illustrated in figures 1A-1B and 4A-4B, the fabric A is fed at the same speed as the first transport, belt 4, for example 30 m / min. The fabric A then rests on the transport belt 4 in a stretched and wrinkle-free configuration, allowing maximum heat exchange and therefore a very effective result on the fabric, because the mass to be heated by vaporization is minimal as there is only one layer of fabric. At the end of the first conveyor belt 4, the fabric is picked up by the motorized intermediate roller 11 and placed on the second conveyor belt 5 which advances at a lower speed, for example 5 m / min. The difference in speed causes the formation of partially overlapping pleats of fabric on the second conveyor belt 5 and therefore determines a vaporization time on the second conveyor belt 5 which is six times greater than the vaporization time on the first conveyor belt 4.

[0041] According to an aspect illustrated in Figures 2a-3b, the treatment mode is reversed by moving the first conveyor belt 4 at a low speed, for example 5 m / min, with a nominal treatment speed of 30 m / min, established by the input power supply. In this way, partially overlapping pleats of fabric A are generated on the first conveyor belt 4. The intermediate motorized roller 11 will rotate so as to advance the fabric A at the nominal treatment speed of 30 m / min and the second conveyor belt 5 will advance at same speed of 30 m / min, so fabric A will be transported completely flat, without any folds or overlaps.

[0042] According to an optional aspect shown in figures 3A-4B, between the first conveyor belt 4 and the second conveyor belt 5 there can be a second tank 2 containing a solution of water and products necessary for the scouring and bleaching process as weH as a related pair of squeezing cylinders 3. In this configuration, the fabric, following steaming on the first belt 4, is impregnated again and then subjected to steaming on the second conveyor belt 5.

[0043] Laboratory tests carried out by the Applicant have shown that carrying out a double impregnation before as many steaming treatments allows for even more effective results to be obtained.

[0044] Among the advantages of the presented solution, the following can be mentioned:

[0045] * possibility of combining two fabric geometries as desired (relaxed and partially overlapping pleats) to simultaneously obtain the beneficial effects of a maximum thermal transfer and a prolonged vaporization time;

[0046] * maximum uniformity of vaporization along the entire treated fabric;

[0047] * absolute absence of longitudinal tensions and therefore no risk of stretching;

[0048] * reduced space inside the tunnel with lowered and radiant heated upper cover which synergistically offers better heating of the fabric in a humid environment (oxidation and bleaching reaction).

[0049] According to an aspect not illustrated in the drawings, the steaming section V can also include a third conveyor belt distinct and separated from the first two belts 4 and 5 and downstream of them, preceded by a respective motorized roller, in which the third conveyor belt advances at a third speed different from the advancement speeds of the first two conveyor belts 4 and 5 so that the fabric A on the third conveyor belt assumes a further configuration different from the configurations assumed on the first two conveyor belts 4 and 5.

[0050] According to one aspect, downstream of the steaming section V, in the system illustrated in the figures there is also the washing section 6, in which the fabric A is washed.

[0051] According to one aspect, to also improve the washing process, the washing section 6 installed downstream of the steaming section V comprises a plurality of cylinders which define a washing path having at least one vertically oriented section, as well as permeable first transport belts and second supported by the cylinders with which they each form a closed ring. The permeable belts are configured to allow the passage of water through them and to transport the fabric segment A by sandwiching it on opposite faces and supporting it along the vertical section of the washing path. Thanks to this vertical washing configuration, the system has a small footprint, excellent washing results and no stretching of fabric A because the weight of fabric A is supported by the two permeable belts.

[0052] According to one aspect, there are also nozzle-holder bars in opposite positions, powered by a pump thanks to which the washing water is sprayed at a pressure, which for example can be between 5 and 12 bar, in a direction orthogonal to the two permeable belts cartying fabric A to be washed. The configuration represented in the figures involves the entry of fabric A from the lower part of the two permeable belts and the exit of the washed fabric from the opposite side, facing upwards. The speed of the water, deriving from the high supply pressure of the circuit, allows the atomized water drops to easily pass through the three-layer sandwich made up of the two permeable belts and the fabric.

[0053] According to one aspect, there is a first rinsing circuit, composed of a pump connected to the clean water supply line and to the last three nozzle-holder bars located in the upper part of the washing section 6, as well as a second washing circuit composed of a second recirculation pump, connected to the washing fluid collection tank located at the base of the washing section 6 and to three other nozzle-holder bars located below the first three rinse nozzle-holder bars.

[0054] Alternatively, a single washing and rinsing pump can be provided, connected to the collection tank located at the base of the washing section 6. In this case, the clean rinsing water is introduced directly into the washing tank via a pipe equipped with a supply valve, and the single washing circuit requires this pump to take the fluid from the tank and pump it to the six nozzle-holder bars at a pressure between 5 and 12 bar.

[0055] With these configurations it is possible to use high pressure washing and rinsing jets, which can reach pressures between 5 and 12 bar, as well as to obtain a reduction in clean water consumption of up to 4 kg of water for every kg of dry fabric washed, compared to the typical consumption of 10 kg of clean water consumed per kg of dry fabric washed of known systems.

[0056] According to one aspect, the system of this disclosure also includes a hydroextraction section 7 installed downstream of the washing section 6 and configured to eliminate the excess liquid with which the fabric segment A is impregnated when it exits the washing section 6, as well as a folding section 8 installed downstream of the hydroextraction section 7 and configured to fold the fabric segment A that comes out of the drying section 7 into overlapping layers.

[0057] Any variations or additions can be made by experts in the technical field to the embodiments described and illustrated here, while remaining within the scope of the following claims. In particular, further embodiments may include the technical characteristics of one of the following claims with the addition of one or more technical characteristics described in the text or illustrated in the figures, taken individually or in any reciprocal combination.

Claims

CLAIMS1. A fabric treatment plant, having a steaming section (V) configured to perform a steaming of a fabric segment (A) and comprising: at least one steaming tunnel, defined between an inlet and an outlet along a advancement direction (X) of the fabri c (A) through the steaming section (V), conveyor means (4, 5, 11) suitable for transporting said fabric segment (A) between said inlet and said outlet of the steaming section (V), at least one steam aspirator (10) placed above said conveyor means (4, 5, 11), at least one steaming tank (9) located below said conveyor means (4, 5, 11), said at least one steaming tank (9) comprising an opening configured to let steam out of the steaming tank (9) towards said conveyor means (4, 5, 11) and consequently towards said fabric segment (A), steam delivery pipes which flow into said steaming tank (9), wherein said conveyor means (4, 5, 11) comprises: a first motorized roller for transporting said fabric segment (A), said first motorized roller being configured to rotate so as to establish a nominal speed of treatment of the fabric (A) through the steaming section (V); a first conveyor belt (4) placed within said at least one steaming tunnel downstream of the first motorized roller along said advancement direction (X), configured to receive the fabric segment (A) from said first motorized roller and to transport the fabric segment (A), wherein said first conveyor belt (4) is motorized to advance at a first speed not greater than said nominal treatment speed; characterized in that it comprises a second motorized roller (11) for transporting said fabric segment (A) downstream of the first conveyor belt (4) along said advancement direction (X), said second motorized roller (11) being configured to rotate to establish said nominal speed of treatment of the fabric (A); a second conveyor belt (5) downstream of the second motorized roller (11) along said advancement direction (X), configured to receive the fabric segment (A) from said second motorized roller (11) and to transport the fabric segment (A), wherein said second conveyor belt (5) is motorized to advance at a second speed which is notgreater than said nominal speed of treatment and is different from said first speed.

2. The plant according to claim 1, further comprising: an intermediate tank arranged between said first conveyor belt (4) and said second motorized roller (11), configured to contain a solution for scouring and bleaching the fabric segment (A) and configured to impregnate said fabric segment (A) when it passes from said first conveyor belt (4) to said second motorized roller (11); a pair of squeezing cylinders arranged between said intermediate tank and said second motorized roller (11), configured to squeeze said impregnated fabric segment (A) coming from said intermediate tank before being placed on said second motorized roller (11).

3. The plant according to one of the preceding claims, comprising a first vaporization tunnel and a second vaporization tunnel distinct and separate from the first vaporization tunnel, wherein: said first motorized roller and said first conveyor belt (4) are installed in the first steaming tunnel, said second motorized roller (11) and said second conveyor belt (5) are installed in the second steaming tunnel.

4. The plant according to one of the preceding claims, comprising a washing section (6) of said fabric segment (A) installed downstream of the steaming section (V), wherein said washing section (6) comprises: a plurality of cylinders which define a washing path having at least one portion oriented vertically; first and second permeable tapes supported by said cylinders with which they form each a respective closed ring, said permeable tapes being configured to allow the passage of water through them and to transport said fabric segment (A) by sandwiching it from opposite faces along said vertically oriented portion of the washing path, a plurality of first nozzles and of second nozzles arranged along said vertically oriented portion of the washing path and facing perpendicularly from opposite sides respectively towards the first permeable belt and towards the second permeable belt, said nozzles being connected to sources of supply of washing fluids and being configured to deliver said washing fluids under pressure.

5. The plant according to claim 4, further comprising: a hydroextraction section (7) installed downstream of the washing section (6) and configured to eliminate excess liquid with which the fabric segment (A) leaving the washing section is impregnated (6); a folding section (8) installed downstream of the hydroextraction section (7) and configured to fold the fabric segment (A) that exits the hydroextraction section (7) into overlapping layers.

6. A method of treating a segment of tissue (A), comprising the following operations: procuring and installing a plant according to one of the preceding claims; rotating said first and second motorized rollers (11) of the plant so as to establish a same nominal speed of treatment of the fabric (A) through the steaming section (V) of the plant; making the first conveyor belt (4) of the plant advance at a first speed not higher than said nominal speed of treatment; making the second conveyor belt (5) of the plant advance at a second speed which is not greater than said nominal speed of treatment and is different from said first speed.

7. The treatment method according to the preceding claim, wherein either said first speed or said second speed is equal to said nominal speed of treatment.

8. The treatment method according to one of claims 6 or 7, wherein said first speed is equal to 30 m / min and said second speed is equal to 5 m / min or vice versa, and wherein said nominal speed of treatment is equal to 30 m / min.

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