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Title:
MACHINE AND METHOD FOR THE TREATMENT OF FABRICS TECHNICAL FIELD
Document Type and Number:
WIPO Patent Application WO/2018/086700
Kind Code:
A1
Abstract:
The present invention relates to a machine for the treatment of fabrics and a method for drying them wherein different types of drying are combined (mechanical, forced air convective and conductive drying) for drying the fabric continuously fed in the machine.

Inventors:
CORTIANA MARCO (IT)
GIORGETTI LUIGI (IT)
Application Number:
PCT/EP2016/077350
Publication Date:
May 17, 2018
Filing Date:
November 10, 2016
Export Citation:
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Assignee:
CIBITEX S R L (IT)
International Classes:
D06B21/00; D06P5/30; F26B13/10; F26B13/14
Domestic Patent References:
WO2016008575A12016-01-21
WO2012069242A12012-05-31
Foreign References:
GB1106507A1968-03-20
US20010007465A12001-07-12
US20050084614A12005-04-21
Other References:
None
Attorney, Agent or Firm:
MODIANO, Micaela, Nadia et al. (IT)
Download PDF:
Claims:
CLAIMS

1. Multifunctional machine (1) for the treatment of fabrics (T) wherein the fabric (T) in the unwound condition passes through a plurality of working stations, characterized in that it comprises in sequence one after the other, with reference to a feeding direction of the fabric (T) in the machine (1) :

- an impregnation and squeezing station (3) comprising an impregnation basin (31) and squeeze rollers (33, 34) placed downstream the basin with reference to a feeding direction of the fabric (T) , said squeeze rollers (33, 34) being intended to compress the fabric (T) and to squeeze it by means of a mechanical compression action;

- a pre-drying station (4) comprising at least one air- knife drying device (41) intended to convey a hot air stream on the fabric (T) and to remove at least a part of the moisture of the fabric by forced air convection;

- a drying station (5) comprising at least one heated drying roller (51, 52) the fabric (T) passing in contact therewith, intended to remove at least a part of the moisture of the fabric by conduction.

2. Machine (1) according to the preceding claim, wherein said squeeze rollers (33, 34) are parallel axis rollers made with a metal cylindrical core covered by a layer of rubber.

3. Machine (1) according to claim 1 or 2, wherein at least one of the two squeeze rollers (33, 34) is movable in the direction moving near/away from the other one.

4. Machine (1) according to one or more of the preceding claims, wherein the impregnation and squeezing station (3) further comprises a water supplying and purifying/softening system and holding reservoirs for pre- and post-treatment chemical products.

5. Machine (1) according to one or more of the preceding claims, wherein the pre-drying station (4) comprises :

- a plurality of air-knife devices (41)

- a heater for the air

- a fan (42) operatively connected to the air-knife devices (41) such to supply an air stream heated by the heater thereto.

6. Machine (1) according to one or more of the preceding claims, wherein the drying station (5) comprises at least a first and a second drying roller (51, 52) placed -with reference to the feeding direction of the fabric T- one downstream of the other and heated by means of heating means, preferably by internal flowing of hot diathermic oil.

7. Machine (1) according to one or more of the preceding claims, comprising at least at one of the drying rollers an ironing unit, comprising a felt assembly (54) comprising a felt strip movable near the fabric (T) wound on the drying roller (52), such to compress it between the latter and the felt by ironing the fabric (T) .

8. Machine (1) according to one or more of the preceding claims, comprising at least one among, preferably all:

- a winding station (6), downstream the drying station (5) , provided with at least one motorized winding roller (61) on which the roll of fabric (T) is wound and it further comprises an alignment assembly provided with at least one unit moving the winding roller (61) intended to translate it in two opposite directions along its axis of rotation and one or more photoelectric cells (63) intended to detect the free borders of the fabric substantially at the region of its entrance into the winding station (6);

a unwinding station (2) comprising a motorized roller, placed upstream the impregnation and squeezing station (3) in the feeding direction of the fabric (T) in the machine (1) .

9. Method for drying a fabric (T) in a machine (1) comprising the steps of:

- unwinding the fabric from a roll

- feeding the fabric (T) in a continuous manner

subjecting the feeding fabric (T) to a first mechanical squeezing

subjecting the feeding fabric (T) , downstream the squeezing, to a forced air convective pre-drying

subjecting the feeding fabric (T) , downstream the pre-drying, to a drying by conduction.

Description:
MACHINE AND METHOD FOR THE TREATMENT OF FABRICS

TECHNICAL FIELD

The present invention relates to the field of machines for the treatment of fabrics, for instance after a digital printing process (mainly carried out by ink-jet technologies) .

The term "treatment" herein means all the operations intended for fabric functionalization, particularly the set of "coating or pre-treatment", washing and drying operations and possibly other additional optional operations .

PRIOR ART

In the prior art it is known that the fabric pre- treatment (or "functionalization" necessary for the fabric to accept printing or coloring carried out with dyes, specifically those used in inkjet systems), and drying step is carried out in a machine called as "stenter" composed of a metal chamber thermally insulated and heated by suitable radiators; the fabric, in the unwound condition, is guided along a path on parallel planes, such to transfer moisture originally contained therein; the heat transmission mechanism in a stenter (from radiators to fabric) is by convection and/or radiation.

Although such machines have been known for a long time and serve their function in a satisfactory manner, they are mainly dedicated to process fabrics of large sizes. This derives essentially from the fact that the length of the fabric unwound into the stenter, from beginning to end of its path, is great as a whole, such that the treatment of small sizes is unprofitable as a whole, since it is necessary to connect the fabric with head and tail pieces to allow it to be properly processed in the stenter.

Such machine moreover is suitable for plants with considerable dimensions as a whole, resulting in that in small plants the relevant cost, encumbrance and complexity often are not justified.

This is even more true in case of plants performing a digital printing on the fabric (for instance by ink jets) : such technique is particularly employed in case of small or very small sizes of the fabric, in such case the presence of the stenter is even less justifiable, due to the above reasons.

It has to be noted that the dimensions of the conventional stenter lead to a considerable energy consumption (necessary to power the machine) , that is not justified in the case of small sizes of the fabric. Moreover if machines suitable for making different treatments are necessary, such as coating treatment, they have to be provided in addition to the stenter with the drawback of making the whole plant more expensive, but also more complicated and with a greater encumbrance .

OBJECTS AND SUMMARY OF THE INVENTION

It is the object of the present invention to overcome prior art drawbacks.

Particularly it is the object of the present invention to provide a multifunction machine for fabrics, able to carry out a plurality of treatments, among which the drying treatment, efficaciously even without requiring considerable spaces, able to operate on small sizes of the fabric.

Another object of the invention is to provide such a machine where energy consumptions are reduced compared to those of the known machines for similar operations.

Another object of the present invention is to provide such a machine able to be flexible in use.

Still another object of the invention is to provide a particularly efficacious system for drying fabrics, that can be used on small machines.

These and other objects of the present invention are achieved by a machine and a method according to the respective annexed independent claims.

The general idea at the base of the present invention is based on the fact of combining three different types of drying on a continuously fed fabric: a first mechanical squeezing followed by a forced air convective pre-drying, followed by a drying by conduction.

This makes it possible to reduce the dimensions of the machine, to operate on small sizes of the fabric, to reduce the plant complexity, in addition to reduce energy consumptions, especially those related to small sizes of the fabric.

A first object of the invention therefore is such a method and a second object is a machine carrying out such method.

Further advantageous characteristics are the subject matter of the annexed claims, which are an integral part of the present description.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described below with reference to some not limitative examples, provided by way of example and not as a limitation in the annexed drawings. These drawings show different aspects and embodiments of the invention and, where appropriate, reference numerals showing like structures, components, materials and/or elements in different figures are denoted by like reference numerals. In the annexed figures:

Figure 1 is a side sectional view of a machine according to the invention;

Figures 2-6 are the enlarged working stations of the machine of the previous figure.

DETAILED DESCRIPTION OF THE INVENTION

While the invention is susceptible of various modifications and alternative constructions, some preferred embodiments are shown in the drawings and will be described in details herein below.

It should be understood, however, that there is no intention to limit the invention to the specific disclosed embodiment but, on the contrary, the invention intends to cover all the modifications, alternative constructions and equivalents that fall within the scope of the invention as defined in the claims .

The use of "for example", "etc.", "or" denotes non ¬ exclusive alternatives without limitation, unless otherwise noted.

The use of "includes/comprises" means

"includes/comprises, but not limited to", unless otherwise noted.

Terms as "vertical" and "horizontal", "upper" and "lower" (with no other indications) have to be read with reference to the assembling (or operating) conditions and with reference to the standard terminology in use in common speech, where "vertical" means a direction substantially parallel to that of the vector of the force of gravity "g" and horizontal means a direction perpendicular thereto.

Generally the method of the invention comprises the steps of

- unwinding the fabric from a roll

- feeding the fabric (T) in a continuous manner

subjecting the feeding fabric (T) to a first mechanical squeezing

subjecting the feeding fabric (T) , downstream the squeezing, to a forced air convective pre-drying

- subjecting the feeding fabric (T) , downstream the pre-drying, to a drying by conduction.

Feeding of the fabric is continuous, such that each portion of the fabric is involved in the different types of drying.

As it will be better explained below such arrangement allows dimensions of the machine to be reduced and allows it to process reduced sizes of the fabric and to use less energy.

Optionally, before or immediately before the mechanical squeezing there is provided the step of subjecting the fabric to impregnation by being immersed into a pre- treatment chemical substance.

Fig.l shows a machine as a whole according to the invention, denoted by reference 1; the stations of the machine are shown more in details in the annexed figures 2-6.

The machine 1 according to the invention comprises a first unwinding station 2 (see also fig.2), where the roll R of fabric T is unwound; such unwinding station 2 to this end comprises a motorized roller, but it is known per se and therefore no further reference is made thereto .

The fabric T exiting the unwinding station 2 is fed - in the unwound condition - to an impregnation and squeezing station 3 placed downstream the unwinding station (see also fig.3).

The impregnation and squeezing station 3 comprises at least two parallel axis squeeze rollers 33, 34 the fabric T being passed therebetween in its feeding movement .

The squeeze rollers 33, 34 are preferably made with a metallic cylindrical core covered by a layer of rubber or the like.

At least one of the two rollers is movable in a direction moving near/away from the other one: theoretically speaking both the rollers 33, 34 could be movable or, as in the shown example, one roller 33 is stationary and the other one 34 is movable near/away from it, such to adjust the pressure exerted on the interposed fabric T.

The two rollers 33, 34 cooperate by squeezing the fabric T that passes therebetween, such to squeeze it removing a part of the liquid (water and/or treatment liquids) with which it is impregnated, thus accomplishing a kind of preliminary drying, that however does not typically allow the liquid impregnated in the fabric T to be completely removed.

The squeezing station 3 further comprises a basin placed upstream the squeeze rollers 33, 34 and possibly one or more guide rollers 32.

The fabric T exiting the unwinding station 2, guided by the guide rollers 32, passes in the basin 31, that, depending on the use, can be empty or filled with products for coating the fabric. Such aspect will be disclosed in more details below, when describing the operation of the machine 1.

The impregnation and squeezing station 3 further comprises (not shown) a water supplying and purifying/softening system and holding reservoirs for pre- and post-treatment chemical products connected to the basin for filling it depending on needs.

Such chemical products are necessary for the fabric to accept a printing or coloring performed with dyes, specifically those used in inkjet systems.

Downstream the impregnation and squeezing station 3 there is provided a pre-drying station 4 (see also fig.4) .

Specifically the pre-drying station 4 is intended to pre-dry the fabric by means of one or more hot air- knifes directed on the fabric T passing therebetween.

To this end the pre-drying station 4 comprises at least one, preferably a plurality (in the example, four) of air-knife devices 41 and a fan 42 operatively connected to the air-knife devices 41 to feed them with an air stream, heated by a heater (not shown) - for example of the type comprising heating elements or the like.

The air external to the machine is sucked by the fan and is conveyed towards the heating elements and from there towards the air-knife devices 41 that direct it to the fabric T, causing the contents of water and/or liquids contained therein to evaporate, thus obtaining a forced convection drying.

It has to be noted that such type of drying is substantially different from the one accomplished in a stenter where air heated by heaters grazes the fabric not in a forced manner, but due to natural convective motions of hot air in the stenter, which, to this end, is suitably dimensioned and shaped.

Downstream the pre-drying station 4 there is provided a drying station 5 (see also fig.5) .

Such station 5 comprises - in the not limitative example shown - a first and a second drying roller 51, 52: the two drying rollers 51, 52 are (with reference to the passage of the fabric T) placed one downstream of the other; in other embodiments only one drying roller 51 or 52 may be provided.

The fabric T, when passing in the machine 1, contacts firstly the first drying roller 51 and then the second one 52.

The rollers 51, 52 are heated - preferably independently from each other - by heating means, for example by the internal flowing of a hot diathermic oil (heated for instance by heating elements -not shown) . The fabric T, while passing in contact with such rollers 51, 52 loses the remaining part of moisture, by being dried in a practically complete manner.

Optionally at the second roller 52 there is provided an ironing unit, comprising in this example a felt assembly 54; the felt assembly 54 comprises a V arranged felt strip movable near and away from the roller 52, such that when necessary the felt can be brought in contact with the roller 52 on which the feeding fabric T is arranged, thus it being ironed. The drying station 5 is further provided with idle rollers, in such a number and arrangement to facilitate the passage of the fabric T in contact with the drying rollers 51, 52: the number and arrangement of such idle rollers are variable depending on needs and can be provided by the person skilled in the art, in the light of information provided up to now.

Downstream the drying station 5 finally there is provided a winding station 6 (see also fig.6), provided with a motorized winding roller 61 on which the roll of fabric T is wound.

The winding station comprises an alignment assembly intended to translate in the two opposite directions the winding roller 61 along its axis of rotation, such to align the external borders of the fabric T and to obtain a properly wound roll.

To this end the alignment assembly comprises one or more photoelectric cells 63 that detect the free borders of the fabric substantially at the region of its entrance in the winding station 6; the alignment assembly further comprises a unit moving the winding roller 61 along its axis of rotation (for instance an electric motor suitably connected to the roller 61), intended to move it depending on detections by the photoelectric cells 63, such to align the borders of the wound roll of fabric T.

The machine 1 just described exhibits a multifunction characteristic that allows it to accomplish several functions depending on when it is used within the cycle processing the fabric T.

A first functionality of the machine is the application of the coating: in this step the basin 31 is filled with a coating liquid suitable for the functionalization desired for the fabric T.

The latter, by passing into the basin 31, gets impregnated with the liquid, while getting wet with it. The excess liquid is removed firstly by squeezing the rollers 33, 34 then by the air-knife pre-drying in the station 4 and finally by the drying rollers 51,52.

A typical example of a coating is a fixative compound for ink, allowing an ink, for instance intended for inkjet printing, to be fixed optimally on the fabric.

Generally, however, it is possible to say that such functionalization liquid baths are known per se and therefore no further reference is made thereto, it being possible make changes depending on the fabric and/or use and/or functionality desired to be given thereto .

It has to be noted that the presence of squeezing rollers 33, 34 upstream the pre-drying station 4 and the air-knife devices 41 (of the pre-drying station 4) advantageously allow the diameters of the drying rollers 51, 52 to be reduced: the amount of liquid that they dry is a function of the time of contact with the fabric; with the same feeding speed of the fabric in the machine 1 it results that in order to remove (dry) a higher amount of liquid, it would be necessary rollers with greater diameters, with the consequence of having a machine 1 that is bulky as a whole, quite expensive and with a high energy consumption (a higher amount of diathermic oil is necessary) .

By means of the impregnation and squeezing station 3 and pre-drying station 4 on the contrary the fabric T arriving to the rollers 51, 52 is already partially dried, which allows rollers 51,52 with reduced diameters to be made with advantages for encumbrances, cost and amount of used energy.

The method for drying the fabric T used according to the invention therefore comprises three distinct consecutive steps: a first mechanical squeezing or wringing of the fabric, followed by a forced air convective pre-drying, followed in turn by a drying by conduction, with the advantages just described.

Preferably and advantageously temperature and flow rate (or speed) of the hot air stream emitted by the air- knife devices 41 is selected such to reduce the moisture contents in the fabric T (downstream the squeeze rollers 33, 34) by about 15-20%.

Still more preferably the air temperature is about 50°C.

A further functionality of the machine 1 just described is about its possible use in a post-washing drying step for a fabric (for example a fabric already subjected to printing operations, vaporization and therefore washing operations) . In this case the basin 31 is left empty and the fabric in the roll in the station 2 is wet. The advantageous effects of the three-step drying have been just described and no further reference is made thereto, except noting that in this case the squeeze rollers 33, 34 can be not in operation (that is kept at a distance greater than the thickness of the fabric, such not to squeeze it) if the water amount in the fabric T is considered low and removable only by the following stations 4 and 5.

A further functionality of the machine 1 is in the use of a phase reactivating and fixing the color (post- printing) ; such operations need heat to fix dyes on the fabric .

In such use the impregnation and squeezing station 3 and pre-drying station 4 can advantageously remain not in operation.

Thus the objects listed above are achieved.

Obviously several variants to what described up to now are possible, all to be considered as a part of the present invention.