Method and equipment for evenly applying liquid to a textile moving web

Abstract

 The method is applicable to desizing, scouring, bleaching, dyeing and finishing processes and it consist in that the web (2) after passing through a bath module (9) is submitted to a lengthwise stress and even throughout its width, of an adjustable predetermined value, said stress being kept constant during the whole run of the web so as to cause a forced dripping of the soaked web. The equipment involves a web dripping device carried out from a single roll (1), free in rotation, exchangeable, of controlled alternative upright displacement, arranged horizontal and transversally supported by gravity on the textile web (2).

Description

[0001] The invention relates to a method for evenly applying liquid to a textile moving web, applicable to desizing (unglueing), scouring, bleaching, dyeing and finishing processes, as well as to an equipment for their implementation.

[0002] Known equipment of this kind comprise, thereafter a supplying station of the textile web to be soaked, following basic functional units:

• at least one elongated receptacle containing the soaking liquid, whose size is at least equal to the width of the textile web to be soaked, which crosses it;
• at least a device aimed to force out a part of the liquid which soaks the textile web, located following the soaking bath, the most common being of the roll-counter-roll type, known in the sector as foulard whose rolls exerts a pressure on both sides of the textile web, wringing it up and having the function to make even and adjust the remaining moisture content percentage of said textile web with respect to the dry weight thereof;
• a station for receiving the soaked web or a plant for a further treatment, single or repetitive (for example, a vaporization station, one or several washing modules, winding up on a collecting drum, etc.)

   In order to achieve an utmost effectiveness of this kind of equipments two requirements are to be met:

• that an even application of liquid, i.e a regular moisture content is obtained on the web after the treatment;
• that the amount of soaking product or bath to apply can be maximum, therefore intensifying the activity of the bath and/or its saturation capacity.

[0003] Anyway the ratio of moisture content on the textile web (percentage of liquid against dry weight of the textile web or fabric) must be compatible with the properties of the treating agents as well as to the operating conditions of the station or equipment further to the soaking treatment.

[0004] In well-known equipments of this kind, the squeezing devices used consist of highly sophisticated means and/or elements which have a high cost of production and maintenance.

[0005] As background of the invention, we can note patent EP-0274047-A which proposes a method which consists in subjecting the fabric web to through-flow measurements prior to application of the treatment agent whereby the resulting values are used for adjusting the pressure of a special foulard located downstream the bath module for squeezing off the treatment agent applied. Such an equipment is expensive as it includes special rolls, measuring probes, microprocessor, etc.

[0006] Patents EP-0310826-A and EP 0311796-A, likewise propose the use of some foulards having special squeezing rolls; the latter discloses a process of continuous treatment of a textile web, in two stages, each followed by a compressing action which is exerted on both sides of the web, allowing to achieve a highly even moisture content percentage of 100 - 200% . However, said patents means for their implementation, high costs as much of production as of maintenance.

[0007] The invention proposes a process to apply liquid on a textile web allowing to reach a maximum amount of liquid this latter is capable of sustaining or containing, in terms of the peculiarities of said web material (structure and/or constitution), and of the operating conditions of the rest of the plants to which the soaking equipment remains coupled, and all this with absolute evenness, and mainly, with much lower costs, as much of implementation as of maintenance, than those of the present state of the art.

[0008] The process, according to the invention, is on the ground of a working principle different from the ones in the mentioned state of the art, consisting in a forced dripping of the soaked textile web obtained by submitting it to an even stress after passing through the bath module.

[0009] More specifically, the process, according to the invention, is characterized in that the textile web, after passing through a bath module, is submitted to a lengthwise stress even through its width, of an adjustable predetermined value, which is kept constant during all its run from said bath module to its collection point, either for its winding, or for a further treatment. The degree of the liquid forced out from the soaked web i.e the forced dripping percentage will therefore directly depend on the value of said stress which will be adjusted to the characteristics of the fabric to be treated or of the soaking products (treating agents) allowing in every case to achieve the aim above stated of applying liquid on the textile web reaching any convenient percentage of the moisture content which can range from 100 to 200%.

[0010] The process can be carried out for example by an equipment characterized on that it includes a forced dripping device constituted from a stress automatic compensating device, already known in the art, but not used up to now as forced dripping element. Said forced dripping device can be constituted in one preferred embodiment of the invention by a single free in rotation roll, having a controlled alternative upright displacement, arranged horizontal and transversally supported by gravity on the textile web.

[0011] According to the process disclosed, the textile web can, in addition, remain subject to the action of one or several conventional foulards to provoke a pre-squeezing, which can likewise be obtained by its passage through a rotatable frame capable to exert a friction on the textile web, also by means of a well-known technique, but the textile web always keeping a predetermined constant lengthwise stress on all its width.

[0012] The advantages and characteristics of the invention will be more apparent from the detailed description which follows of an example of embodiment of the invention, given only for example purpose and represented in the attached drawings wherein:

• Fig. 1 is a schematized view showing an elemental equipment according to the invention with a kinematics with chains and sprockets;
• Fig. 2 is an equivalent view with a rotating arms kinematic;
• Fig. 3 is a view showing the principle of the invention with means which secure a pre-cleaning of the textile web detailed on Fig. 4.
• Fig. 5 is a detailed view of a kinematics with chains and sprockets associated to a squeezing roll according to Fig. 1.
• Fig. 6 is a variant of Fig. 3 showing an equipment specially conceived to perform a dyeing process with a forced dripping and a wringing out of the web the latter executed when rolling up the web on a drum..

[0013] The equipment shown on Fig. 1 includes:

• one roll -1-, free in rotation, having a controlled upright alternative displacement, horizontally arranged, supported on the textile web -2-, placed in a zone following a soaking receptacle -9- so as to simultaneously performing a function relative to making even and adjustable the moisture content percentage and the known function relative to an automatic adjustment of stress and/or speed variations of said textile web -2-, automatically exerting an even pressure on the surface of the web, whose intensity can be adjusted, acting transversally on one side of said web providing a forced dripping thereof and lengthwise to secure an automatic offset of the textile web stress/speed as well as its forced dripping.

[0014] The roll -1-, is linked, at each of its ends, with points directly facing each other, pertaining to a kinematics comprising two chains -3-, each associated to two sprockets -4- and to a device of the weight-counter-weight type -5-, and a detecting means -6- (including for example a potentiometer) to sense the roll position and to transmit, by means of a convenient electrical device, a signal which represents the position variations of said roll -1-, which acts on the textile web driving and/or guiding members to offset its speed-stress.

[0015] The forced dripping and compensating roll is located outside a soaking receptacle -9- and associated to an inclined wall -10- for recovering the liquid forced out from the web -2- in said receptacle which includes available conventional means to control the soaking liquid level and its concentration.

[0016] The equipment shown in Fig. 2, differs from the precedent in that the roll -1-, applied to the forced dripping function and to the offsetting of the textile web stress and/or speed variations is connected at each of its ends to two points, directly facing each other, pertaining to a kinematics which includes two rotating arms -7-, associated to weights having a positions adjustable along the lengthwise development of said arms, and a detecting means -8- to sense the roll positions and for transmitting, by means of an electrical device, a signal which will act on the textile web driving and/or guiding members to offset its speed/stress variation.

[0017] In the equipment of Fig. 3 the forced dripping and compensating roll -1- is located on the vertical of a soaking receptacle -11- and the textile web -2- enters several times in the soaking receptacle and crosses through several frames -13- which will be later on detailed.

[0018] Furthermore:

• the textile web moves, on the area of the receptacle around the forced dripping and compensating roll -1-, between several idle cylinders -12-, -17- which have the effect to secure to said textile web a high speed pre and post dripping, i.e. the forced dripping effect of the roll -1- is transmitted and enlarged to said fore -12- and rear -17- and -19- cylinders as shown in Figs. 3 and 6, the percentage of dripped liquid being therefore in the terms of the roll -1- weight and in the number of said idle cylinders -12-, -17- and -19- the equipment being thus able to adapt itself even to elastic items, using a light weight cylinder -1- and a suitable number of rolls -12- and -17- in the forced dripping area;
• the web enters to the receptacle -9- guided on idle cylinders -18-;
• the textile web passes through, at least, one adjustable rotatable frame -13- which exerts a slight friction on the textile web, to achieve a pre-cleaning thereof;
• Fig. 4 is a detailed view of one of the rotatable frames -13- acting with a certain friction on the textile web -2-.
• Fig. 5 is a detailed view of the roll -1- hauling kinematics according to Fig. 1, showing guiding strips -14-of the roll -1- ends -15- according to conventional art.
• Fig. 6 is a variant of Fig. 3, particularly suitable for a dyeing process wherein a long tray -16- has been associated to the soaking receptacle -9-, the textile web -2- extending over idle cylinders -12- and sinuously passing between idle cylinders -17 -, -19- preceding and subsequent to the roll -1- assuring a forced dripping of said textile web -2- and an automatic offset of the web stress which is then rolled up under constant stress on a drum -20- positioned on a support -21- above said tray -16-, so as to cause a wringing out of the web -2- the liquid forced out being recycled to the soaking receptacle avoiding oxidation of the dying treating agents.

[0019] This invention is not limited to the examples of embodiments disclosed and shown for which other variants can be foreseen without being out of the scope of the invention disclosed in following claims. In particular, the proposed equipment can be arranged operatively coupled, thereafter any other soaking equipment, built according to conventional techniques and use preceding the roll -1-conventional means like a foulard to successfully introduce the treating agents into the web structure. The equipment can also be suitably matched with other equipment for treating the textile web. Likewise, any device capable to impose a constant lengthwise stress to the textile web, throughout its width, of an adjustable amount, would be effective to achieve an implementation of the process according to the invention.

Claims

1. Method for evenly applying liquid to a textile moving web,
characterized in that said web (2) after passing through a bath module (9) is submitted to a lengthwise stress and even throughout its width, of an adjustable predetermined value, said stress being kept constant during the whole run of the textile web, from said bath module to a collection point, either for its winding up or for a subsequent treatment, in such a way that the liquid amount forced out from the web throughout its width and the remaining moisture content percentage directly depends on the value of said stress.

2. Method according to above claim, characterized in that the soaked textile web is submitted in addition, to the action of one or several groups of roll and counter-roll which exert a pressure on both sides of the web, or to the action of other means providing a forced penetration of the treating agents into the web, located preceding the zone where an even stress is applied to said web.

3. Method according to claim 1, characterized in that the soaked textile web extends on a series of cylinders, having parallel shafts, crosswise the textile web, of free rotation, which have the function to secure a pre and post forced dripping when transmitting the lengthwise stress, evenly applied throughout the width of the textile web.

4. Method according to claim 1, characterized in that the soaked textile web (2) extends on and sinuously moves around a series of parallel idle cylinders (12), (17), (19) extending across said web, and then is rolled up on a drum (20) under an even stress so as to cause a wringing out of the web (2) when revolving and superimposing around said drum (20) the liquid forced out being recycled towards the bath module (9).

5. Equipment for evenly applying a liquid to a textile moving web, successively comprising:

- a supply station of the textile web (2) to soak; -

- at least one bath module receptacle-like (9), containing the liquid to be applied, with a width at least equal to the width of the textile web to soak, associated to some input and output (18), (12) guiding means, of said textile web and provided with means which allow to control the soaking liquid level and concentration;

- a squeezing device, located following the soaking bath, of the roll-counter-roll type which exerts a pressure on both faces of the web providing a penetration of the treating agents into the web and securing a soaking percentage even and regular;

- a receiving station for the soaked web or a plant for a subsequent treatment

characterized in that it includes a web forced dripping device carried out from a single roll (1), free in rotation, exchangeable, of controlled alternative upright displacement, arranged horizontal and transversally supported by gravity on the textile web (2) placed following the soaking receptacle (9) and the conventional means to squeeze the web (2).

6. Equipment, according to the claim 5, characterized in that the roll (1), is engaged at each of their ends, to points directly facing each other which pertain to a kinematics which includes two chains (3) associated each to two pulling wheels (4) and means, of the weight-counter-weight type (5), and means (6) for detecting the position of the roll and transmitting an electrical signal which act on the hauling and/or guiding members of the web to offset its speed and/or stress.

7. Equipment, according to claim 5, characterized in that the roll (1) is engaged, at each of its ends, to points directly facing each other which pertain to a kinematics bearing two rotating arms (7) associated to weights of adjustable positioning along said arms, and detecting means (8) for sensing the roll position and transmitting an electrical signal which will act on the hauling and/or guiding means of the web to adjust its speed and/or stress.

8. Equipment, according to claim 5, characterized in that the forced dripping and compensating roll is located outside to the soaking receptacle (9) and associated to an inclined wall (10), which has the function to recover the dripped liquid toward said receptacle.

9. Equipment, according to claim 5, characterized in that located before and after the forced dripping and compensating roll (1), several parallel idle cylinders (12), (17) are provided on them the web (2) is moved, so as to secure a pre and post dripping, when transmitting and extending on them the drip function of said roll (1) the liquid forced out from the web (2) being recycled by a tray (16) towards the soaking receptacle (9).

10. Equipment, according to claim 1 characterized in that it includes a drum (20) on which the textile web (2) after extending on several idle cylinders (12), (17) and sinuously moved around idle cylinders (19) is rolled up under a constant stress causing a wringing out of the web over an inclined long tray (16) to recycle the liquid forced out from the web (2).

11. Equipment, according to claim 5, characterized in that the textile web (2) passes, before reaching the roll (1), through at least a rotatable adjustable frame (13), in such a way it exerts a slight friction on said web (2) to carry out a pre-cleaning thereof.

Drawing