ITTO20070613A1 - PROCEDURE AND EQUIPMENT FOR THE TREATMENT OF TISSUES WITH THE SUPPORT OF CHEMICAL PRODUCTS FOR TANGENTIAL APPLICATION - Google Patents

Description

DESCRIPTION of the industrial invention entitled: "Process and equipment for the treatment of fabrics with the addition of chemical products for tangential application"

TEXT OF THE DESCRIPTION

Field of the invention

The present invention relates to a process and an apparatus for treating fabrics, and more particularly for giving a fabric a basically permanent finishing effect through the addition of chemical products on their surface, essentially by means of an initial phase of application of the chemical products, an intermediate phase of drying and solidification of the applied chemical products, and a final phase of surface action on the fabric.

In the variegated and potentially boundless sector of textile finishing, many physical (mechanical, thermal, ..) and chemical (sodaking, carbonizing, mercerizing ..) methods are used to give the fabrics an ideal appearance for their final use.

The present invention adds, to the methods known up to now, a new methodology that allows to modify the physical and / or visual and / or tactile characteristics of the processed fabric by applying, thanks to an innovative process, chemical products which, interacting with a succession of physical effects conferred by the equipment that carries out the procedure, modify the surface and / or the touch of the fabric itself in a more or less permanent way.

State of the prior art

The systems known today and most widespread for the application of chemical products on fabrics are summarized below.

Impregnation: it is a complete immersion of the fabric in a bath where the chemical agents are dispersed, which penetrate the entire thickness of the fabric, followed by cylinder squeezing and a subsequent reaction in drying systems such as air dryers or batteries of cylinders. Limits of the impregnation system are the excessive and useless consumption of the bath, the presence of product even where it would not be needed, the difficulty of double application carried out in succession (called "wet on wet") of different materials, where the second agent is sometimes "rejected" due to the invasive presence of the first agent, and for which the first and second agents sometimes have to be forcibly kept separate. Added to this is the high consumption of drying energy.

Coating: consists of a surface application of material (generally with a high viscosity) by means of a leveling blade and subsequent drying with known systems, typically applied only on one face (i.e. on one face of the fabric) especially in large runs for technical products. Limits of the system are the high set-up times and waste of material, together with problems also for regulating minimum product inputs.

Transfer: consists of a surface application with perforated "millepunti" cylinders (printing cylinders type) which deposit the product on the surface by pumping through the holes. The limitations of this methodology are the need to prepare various cylinders with different drilling, and long commissioning times. The treatment is applied to only one front of the fabric at a time.

Foaming: the chemical product is mixed in special machines that create foam with different granulometry, which is then distributed and leveled on the fabric with different mechanical methods. The limits are the limited types of products that can be used with this method, and the difficulty in controlling the contributions. Again, the treatment is applied only on one forehead at a time.

Transfer with "Kiss roll": these are rotating cylinders partially immersed in a liquid chemical product, which they are loaded by transferring it to the fabric that passes over the area above, creating effects similar to coating with a cylinder. The method is not very widespread and of precarious control.

For the intermediate phase of drying and solidification of the chemical products applied to the fabric, the following drying systems known and most widespread today can be included:

air dryers ("rameuse"): these are large chambers with forced air flow. The energy source can be various (diesel, gas, superheated water).

Hot cylinders: cylinders kept at a constant temperature by injection of steam, hot water or diathermic oil.

For the final phase of surface action on the fabric, the following systems are traditionally used:

cotton calendering: two or more high pressure and heated cylinders, between which the fabric is inserted, are made to slide one over the other in order to create a very strong and bright "iron" effect. However, this effect is not very permanent, with negative stretches of the fabric and an often excessive flattening of the thickness of the fabric itself, the consistency of which becomes similar to that of paper.

Wool chinning: following the application of chemical products (bisulfites) through deep "foulard" impregnation, the fabric is subjected to a subsequent reaction in the calender with silicone tape, to give it a shiny appearance. In this case, the effect is permanent, but involves a weakening of the fabric fibers and premature wear of the equipment components.

Patent US-4,086,387 describes a method for treating fabrics with the addition of chemical products with tangential application, corresponding to the preamble of claim 1. This known process expressly provides for a deep impregnation of the fabric treated with conditioning chemicals, carried out by means of a roller revolving applicator, partially immersed in a tank containing the chemical products, and a revolving counter-roller that compresses the fabric against the applicator roller to thoroughly impregnate it throughout its thickness.

The impregnated fabric then proceeds, for the phase of solidification or drying at room temperature of the impregnating chemical products, on a series of rollers, resting against them with the face in correspondence with which it was impregnated by the roller.

Then, for the shaping phase, the fabric is compressed again between a single pair of further rollers, both heated to a very high temperature, equal to or higher than the melting point of the impregnating chemicals, and with a precise compression ratio ( 70% or less) of the fabric relative to its initial thickness. In practice, these rollers, and ultimately the entire known system, are entrusted with a simply mechanical "crash" function of the hardened textile structure to soften its hand.

Summary of the invention

The purpose of the present invention is to provide a method and equipment suitable for producing, in an industrially interesting form, a series of effects always using the same plant, without wasting treatment chemicals in order to produce both samples and quantities on large scale of fabric.

This object is achieved thanks to the method mainly defined in claim 1, and subordinately in claims 2-27, and to an apparatus principally set forth in claim 27.

The present invention involves the use of some of the known but improved methods, placed in line according to an unprecedented sequence, in order to obtain, in a single step, a variety of desired results on the same plant.

The final effects obtainable on the fabrics treated according to the invention are at least three, described below, but which do not limit other possible applications to come:

- "bubble" effect

- "glossy" effect

- "skin dye" effect

The "bubble" effect gives a "casual" look to fabrics with a classic structure to make them more "rubbery" and "bulky" to the touch. This effect is permanent on all fabrics.

The "glossy" effect gives a glossy and solid appearance to many fabrics, especially cellulose-based, which have never been achieved until now or have a different effect / appearance.

The "skin dye" effect involves the use of dyes (of various kinds) that can be applied as a uniform or "melange" over-dyeing for interesting iridescent color effects.

Brief description of the drawings

The invention will now be described by way of non-limiting example in the annexed drawings, in which:

figure 1 is a diagram which exemplifies a first embodiment of the apparatus for carrying out the process according to the invention, and

figure 2 shows a variant of figure 1.

Detailed description of the invention

The apparatus for carrying out the process according to the invention provides, in a nutshell, a series of stations which carry out the following operations in succession and continuously, on the moving fabric:

APPLICATION OF THE CHEMICAL PRODUCT,

SOLIDIFICATION,

MOLDING.

In the embodiment schematized in Figure I, the fabric T, after a series of possible accessories suitable for guiding and preparing the fabric for treatment, enters the application station generically indicated with 1.

The application of the product must take place only in superficial form, that is without impregnation of the fabric T in its thickness. Typically, the application is therefore carried out by means of an adjustable spraying system or more preferably by means of at least one "kiss roll" cylinder 2 which rotates at a speed synchronized with respect to the advancement speed of the fabric T.

The "kiss roll" cylinder 2 draws the product to be applied, in liquid or in any case fluid phase, from a tank 3 and transfers it to the fabric T by applying it tangentially on its surface resting on the cylinder 2.

Although in the case of Figure 1 a single applicator cylinder 2 of the chemical product is provided on a single face of the fabric T, the invention provides the same technical solution also in the case of multiple applicators on the same face of the fabric T, as well as single applicators on both faces and / or multiples on both faces of the fabric T.

The fabric, superficially soaked on at least one face with the chemical product, advances towards the solidification station, generically indicated with 4,

The chemical product, specifically developed in terms of viscosity, is therefore solidified and fixed on the fabric by partial evaporation of the water or in general of the liquid phase present as a dispersant of the chemical product. The solidification action must be controlled and fast enough to block the migration of the product towards the inside of the fabric T at the desired depth (which at the limit could even reach the opposite face).

In the example of Figure 1, the solidification station 4 includes a heated cylinder 5, rotatable in synchronism with the advancement of the fabric T.

The fabric T winds up and is returned by the cylinder 5 resting on it with its face opposite to that on which the chemical product has been applied.

The solidification phase can take place on several heated cylinders, or with the aid of an oven (air or infrared), without contact with the fabric.

Preferably, the source of drying energy will be placed on the opposite side to the face of the fabric T treated with the chemical products, obviously in the case in which these products are - as in the case of the example of Figure 1 - applied to one face only.

After solidification, the T fabric and the chemical have achieved sufficient cohesion, which however still allows for structural changes.

In detail, these two layers, cohesive but still partly distinct and superimposed, can optionally remain as they are or be more interpenetrated thanks to mechanical and / or thermal energy, applied in an innovative and advantageous way, when the chemical product is still one semi-solid state and therefore modifiable and malleable, towards the underlying tissue T, whose fibers still contain moisture and are therefore more easily deformable.

The fabric T then arrives at the shaping station, generically indicated with 6, where it - with the chemical product applied on its surface - passes through a series of opposite cylinders 7 which give it the desired finishing with a more or less marked reduction in thickness. and / or polishing of the surface and / or modification of the surface roughness.

The fabric T advances through at least two pairs of heated and opposed rotating cylinders 7, 7 ', placed under adjustable pressure in such a way as to give the fabric and the chemical product applied thereon the desired final appearance.

The cylinders 7, 7 'may also have surfaces with different finishes: in a preferential form a cylinder 7, 7' of each pair will have a metal and very rigid surface, and the other opposite cylinder 7, 7 'will have its surface coated with elastically deformable material.

The fabric T, after a possible cooling, is finally collected in a lap or roll.

The use, in the phase of application of the chemical product on the fabric T, of the "kiss roll" cylinders, allows in an innovative and peculiar way to realize the controlled application of the chemical product in a superficial way, basic for applying the product only in the affected area. The subsequent and adjustable solidification of the chemical product applied, immediately followed by the definitive drying during its final shaping, define an unprecedented, innovative sequence with never before obtained results.

Surface application means reduced use of chemical products, application only in the required area, reduced preparation of the baths, possible instantaneous variation of the final effect thanks to the autonomous adjustment of the sliding speed between the material and the "kiss roll" cylinder (s).

There is preferably a temporal evaluation of the effects that contribute to obtaining the best results of the process, in these terms.

The distance between application and drying must necessarily be reduced to avoid migration of the product towards the inside of the fabric fiber.

In other words, it will be possible to lengthen the space if necessary in case you want to obtain greater penetrations (as well as of course acting on the viscosity of the chemical product).

The controlled and adjustable residual humidity (possibly with automated electronic systems) is a fundamental part of the process. In fact, in order to obtain the "shaping" of the fabric, it is advisable that the fabric, coming out of solidification, is immediately treated. Otherwise, in fact, if it were wound on a roll (or worse if it were folded in layers) before the shaping phase, a non-homogeneous, non-optimal result would be obtained which is difficult to industrial repeatability due to the natural effect of evaporation and / or cross-linking of chemical products applied to the fabric.

From an environmental / energetic point of view, the surface application is advantageous because it involves a lower supply of liquid and therefore a reduced energy consumption during solidification to evaporate excess water. The concatenated sequence of solidification-shaping application events allows to optimize the process with reduced use of personnel, excellent control of process parameters, very short preparation times and results modification. Further specific characteristics and variants of the apparatus for carrying out the method according to the invention will now be described hereinafter.

Application station 1:

1) the "kiss roll" cylinders (ie the spray applicators) can also be more than one, as indicated with 2 and 2 'in the case of the variant represented in the diagram of figure 2, placed on the same side or on opposite sides because:

or it is possible to apply chemical products on the same surface that cannot coexist in the same bathroom. For example, as in the case of Figure 2, a first product in a first tank 3 and a second product in a second tank 3 'which react with each other by contact on the fabric, but which remain separate in the respective application tanks 3, 3 ';

or it is possible to apply the same product on both surfaces of the fabric, or two distinct products to obtain a "doublé face" effect. For example a hydrophilic product on one face of the fabric T and a water repellent product on the opposite face;

2) The "kiss roll" cylinders 2, 2 'are conveniently equipped with a movable blade scraper, indicated by 8 in figure 2, capable of cleaning the surface of the cylinder 2, 2' and removing product residues to ensure a optimal draft with each new rotation.

3) The "kiss roll" cylinders 2, 2 'are preferably rotated with a variable speed regulator between a value lower than the synchronism speed (synchronism means peripheral speed of the cylinder = translation speed of the fabric T) and a higher value at the synchronism speed.

4) Fabric T can move towards and away from the "kiss roll" cylinders 2, 2 'during the stop phases of the process, for example by means of a movable inlet roller indicated by 9 in figure 1. This reduces fabric defects

5) With the multiple "kiss roll" configuration 2, 2 'the rotation speed of the cylinders can be differentiated.

6) The "kiss roll" cylinders, typically with a smooth metal surface, could also be made of different materials, smooth or sculpted, or be replaced at least in part by brushes or other flexible elements such as blades, spatulas, etc.

7) The chemical product applied may have any physical or chemical characteristics, which are not considered relevant or critical to the effects of the final results obtained with the invention. Experimental tests conducted by the Applicant have experimentally shown that the tangential application of the chemical products on the fabric is significantly more advantageous and effective than the usual methods with impregnation, because:

• uses less chemicals because it accumulates and concentrates them exactly and only where needed,

• the result is more stable,

• the tactile sensation of the fabric at the end of the process is completely different from that of a fabric to which the chemicals have been applied by impregnation.

Solidification station 4:

8) for applications on a single face of the fabric T, drying with a heated cylinder 5, with adjustable temperatures, will be preferred.

o The number of cylinders 5 and their diameter may vary and will substantially depend on the need for solidification of the product and on the production speeds, o The cylinders 5 may be arranged in various configurations to allow them to be wrapped by the fabric with more or less wide angles according to the need for drying and contact. For example, "C" or "S" shaped paths of the fabric can be envisaged (as in the case of the examples of Figures 1 and 2).

or II or the heated cylinders 5 may be equipped with means suitable for diverting the passage of the fabric so as to increase or decrease the angle of contact with the cylinders themselves, in order to increase or decrease the drying capacity.

9) For "double face" applications, where the contact of hot surfaces with the wet product is to be considered negative for its final result, compact systems of the infrared oven type are preferred, as schematically indicated with 10 in figure 2 (provided of any mobile anti-burn plates) or hot air chambers (with or without height control chain), in replacement or in combination with the heated cylinder (s) 5.

10) The solidification of the product could also take place, or rather it could be facilitated, by prolonged exposure of the T fabric in free air, before the shaping phase.

11) Solidification could also be facilitated by the application of chemicals at a temperature other than ambient (typically heated) to facilitate subsequent evaporation.

Shaping station 6:

o the shaping cylinders 7, 7 ', even with different characteristics, must be at least two pairs to obtain a sufficient permanent and appreciable effect, as well as for different internal characteristics and in terms of hardness of the relative coatings, of the material of the coatings and / or any surface carvings. For example, in the case of figure 2, two low hardness rubberized cylinders are used to enhance the "bubble" effect, superficial and opaque, a cylinder with a specular metal surface and a cylinder coated with material of various hardness to obtain crushing effects. and polishing.

12) The fabric T can pass through the two or more pairs of cylinders 7, 7 'with equal contact on all passages, or it can be rotated to obtain different right-reverse effects.

13) At least one cylinder 7, 7 'of each pair can be conveniently heated.

14) The fabric T will be able to pass through the cylinders 7, 7 'both perpendicularly to the axis of the cylinders 7, 7' as illustrated in the examples, for a minimum contact with the relative surfaces, in the form of partial, fixed or adjustable wrapping .

As already explained above, the final effects which can be effectively obtained on the fabrics treated according to the invention are at least three: "bubble" effect, "glossy" effect and "skin dye" effect. However, other different effects will also be foreseeable.

Naturally, the principle of the invention remaining the same, the details of construction and the embodiments of the apparatus may vary widely with respect to those described and illustrated purely by way of example, without thereby departing from the scope of the present invention.

Claims (54)

CLAIMS 1. Process for the treatment of fabrics (T) with the addition of chemical products, comprising a phase of application (1) of the chemical products in the liquid phase on the fabric (T), tangentially to this, a phase of solidification (4) of the products chemicals for their fixing on the fabric (T), and a shaping phase (6) of the fabric (T), characterized by the fact that: in the application phase (1) the chemicals are applied only superficially on the fabric (T), e - the solidification phase (4) occurs by only partial and controlled evaporation of the liquid phase of said applied chemical substances. 2. Process according to claim 1, characterized in that the application step (1) is carried out on the advancing fabric by means of at least one "kiss roll" cylinder (2, 2 '). 3. Process according to claim 2, characterized in that said at least one "kiss-roll" cylinder (2, 2 ') is rotated at a speed synchronized with the speed of advancement of the fabric (T). 4. Process according to claim 2, characterized in that said at least one "kiss-roll" cylinder (2, 2 ') is driven to rotate at a peripheral speed lower than that of advancement of the fabric (T). 5. Process according to claim 2, characterized in that said at least one "kiss-roll" cylinder (2, 2 ') is rotated at a peripheral speed greater than the translation speed of the fabric (T). 6. Process according to any one of claims 2 to 5, characterized in that it comprises the step of scraping the surface of said at least one "kiss-roll" cylinder (2, 2 ') prior to the application of the chemical products on the fabric (T ). 7. Process according to any one of claims 2 to 6, characterized in that the application step (1) is carried out by means of a single "kiss-roll" cylinder (3) on a single face of the fabric (T). 8. Process according to one or more of claims 2 to 6, characterized in that the application step (1) is carried out with a plurality of "kiss-roll" rollers (2, 2 ') on a single face of the fabric (T) . Method according to any one of claims 2 to 6, characterized in that the application step (1) is carried out with "kiss-roll" cylinders (2, 2 ') on both faces of the fabric (T). 10. Process according to claim 8 or 9, characterized in that the speed of rotation of said "kiss-roll" cylinders (2, 2 ') is differentiated. 11. Process according to any one of claims 4 to 10, characterized in that in the event of interruption of said application step (1) the fabric (T) is removed from said at least one "kiss-roll" cylinder (2, 2 ' ). 12. Process according to claim 1, characterized in that said application step is carried out by spraying. 13. Process according to any one of the preceding claims, characterized in that the solidification phase (4) immediately follows the application phase (1) and the shaping phase (6) immediately follows the solidification phase (4). 14. Process according to any one of the preceding claims, characterized in that if the application step (1) is carried out only on one face of the fabric (T), the solidification step (4) is carried out on the opposite face of the fabric (T). 15. Process according to one or more of claims 1 to 13, characterized in that the solidification step (4) is carried out on both faces of the fabric (T). Process according to any one of the preceding claims, characterized in that the solidification step (4) is carried out by winding the fabric (T) on at least one heated cylinder (5). 17. Process according to claim 16, characterized in that the temperature of said at least one heated cylinder (5) is adjustable. 18. Process according to claim 15 or claim 16, characterized in that the solidification step (4) is carried out by wrapping the fabric (T) on a plurality of heated cylinders. 19. Process according to any one of the preceding claims, characterized in that the solidification step (4) is carried out by heating without contact with the fabric (T). 20. Process according to claim 19, characterized in that the solidification step (4) is carried out by means of an infrared oven (10). 21. Process according to claim 19, characterized in that the solidification step (4) is carried out by exposing the fabric (T) in free air. Method according to any one of the preceding claims, characterized in that the shaping step (6) is carried out by multiple hot pressing of the fabric (T). 23. Process according to claim 22, characterized in that the shaping step (6) is carried out by means of at least two pairs of opposed rotating cylinders (7, 1 '). Method according to claim 23, characterized in that the phase at least one cylinder of each pair (7, 1 ') is heated. 25. Process according to claim 23 or 24, characterized in that the pressing surfaces of said cylinders (7, 1 ') have different characteristics. 26. Process according to any one of the preceding claims, characterized in that it is carried out continuously. 27. Equipment for the treatment of fabrics (T) with the addition of chemical products, comprising an application station (1) of the chemical products in the liquid phase of the fabric (T), essentially to this, a solidification station (4) of the products for their fixation on the fabric (T), and a fabric shaping station (6) (T), characterized by the fact that the application station (1) comprises means for the superficial application only (2, 2 ') of the products on the fabric (T), and by the fact that the solidification phase includes only partial and controlled evaporation means (5) of the liquid phase contained in said chemical substances applied to the fabric (T). 28. Apparatus according to claim 27, characterized in that the application step (1) is carried out on the advancing fabric by means of at least one "kiss roll" cylinder (2, 2 '). 29. Apparatus according to claim 28, characterized in that said at least one "kiss-roll" cylinder (2, 2 ') is rotated at a speed synchronized with the speed of advancement of the fabric (T). 30. Apparatus according to claim 28, characterized in that said at least one "kiss-roll" cylinder (2, 2 ') is driven to rotate at a peripheral speed lower than that of advancement of the fabric (T). 31. Apparatus according to claim 28, characterized in that said at least one "kiss-roll" cylinder (2, 2 ') is rotated at a peripheral speed greater than the translation speed of the fabric (T). 32. Apparatus according to any one of claims 28 to 31, characterized in that a movable blade scraper (8) is operatively associated with said at least one "kiss-roll" cylinder (2, 2 '). 33. Apparatus according to any one of claims 28 to 31, characterized in that it includes a single "kiss-roll" cylinder (3) for applying the chemicals on a single face of the fabric (T). 34. Apparatus according to one or more of claims 28 to 31, characterized in that it includes a plurality of "kiss-roll" rollers (2, 2 ') for the application of the chemical substances on a single face of the fabric (T) . 35. Apparatus according to any one of claims 28 to 31, characterized in that it includes a plurality of "kiss-roll" rollers (2, 2 ') for applying the chemicals on both faces of the fabric (T). 36. Apparatus according to claim 34 or 35, characterized in that the speed of rotation of said "kiss-roll" cylinders (2, 2 ') is differentiated. 37. Apparatus according to any one of claims 28 to 36, characterized in that it further comprises separator means (9) for removing the fabric (T) from said at least one "kiss-roll" cylinder (2, 2 '). 38. Apparatus according to claim 27, characterized in that said application step is carried out by means of spraying means. 39. Apparatus according to any one of claims 27 to 38, characterized in that the solidification station (4) immediately follows the application station (1) and the molding station (6) immediately follows the solidification station (4). 40. Apparatus according to any one of claims 33 or 34, characterized in that the solidification station (4) is arranged to operate only on the face of the fabric (T) opposite to that of application of said chemical substances by said at least one "kissroll" cylinder (3, 3 '). 41. Apparatus according to one or more of claims 27 to 39, characterized in that the solidification station (4) is arranged to operate on both faces of the fabric (T). 42. Apparatus according to any one of claims 27 to 41, characterized in that the solidification station (4) includes a heated cylinder (5) for winding the fabric (T). 43. Apparatus according to claim 42, characterized in that the temperature of said at least one heated cylinder (5) is adjustable. 44. Apparatus according to claim 42 or 43, characterized in that the solidification station (4) includes a plurality of heated rolls. 45. Apparatus according to any one of claims 27 to 44, characterized in that the solidification station (1) includes contactless heating means (10) for the fabric (T). 46. Apparatus according to claim 45, characterized in that the solidification station (4) includes an infrared oven (10). 47. Apparatus according to claim 45, characterized in that the solidification station (4) includes means for exposing the fabric (T) in free air. 48. Apparatus according to any one of claims 27 to 47, characterized in that the shaping station (6) includes multiple hot pressing means (7, 7 ') of the fabric (T). 49. Apparatus according to claim 48, characterized in that said means for multiple hot pressing of the fabric (T) include at least two pairs of opposed rotating cylinders (7, 7 '). 50. Apparatus according to claim 49, characterized in that at least one cylinder of each pair (7, 7 ') is heated. 51. Apparatus according to claim 49 or 50, characterized in that the pressing surfaces of said cylinders (7, 1 ') have different characteristics in terms of hardness and / or surface conformation. 52. Apparatus according to claim 51, characterized in that the pressing surfaces of at least part of said cylinders (7, 1 ') are elastically yielding. 53. Apparatus according to one or more of claims 27 to 52, characterized in that it comprises means for continuously advancing said fabric (T) through said application, solidification and shaping stations (1, 4, 6). 54. Process and apparatus substantially as described and illustrated.