WO2007043905A1

WO2007043905A1 - Aging procedure for fabrics using reducing or oxidizing discolorating agents spray applied.

Info

Publication number: WO2007043905A1
Application number: PCT/PT2006/000023
Authority: WO
Inventors: Manuel Carlos Saldanha Ribeiro Pizarro
Original assignee: Lavandaria Pizarro, Sa.
Priority date: 2005-10-07
Filing date: 2006-10-04
Publication date: 2007-04-19
Also published as: PT103364B; EP1957702A1; PT103364A

Abstract

The present invention is related to an uniform and non uniform fabrics aging procedure, with spray application of reducing or oxidizing agents over clothing pieces previously treated for watertightness and worn by the mechanical action of an abrasive.

Description

DESCRIPTION

AGING PROCEDURE FOR FABRICS USING REDUCING OR OXIDIZING DISCOLORATING AGENTS SPRAY APPLIED.

TECHNICAL FIELD

The present invention is related to new clothing and fabrics aging procedures, in general, and, particularly describes an advanced aging procedure which significantly reduces production costs and offers a wide range of applications, which results in a wide variety of effects.

TECHNICAL BACKGROUND

The following list is representative of the most relevant publications regarding the technique background until the present patent application.

PATENT iϊr

EP0238779 22.10.86 Ricci, Francesco

EP0298412 04.07.88 Ricci, Francesco

EP0303120 29.07.88 Ricci, Francesco

US4852990 01.08.89 Patterson, James R.

EP0554480 04.02.92 Ricci, Francesco

US5298027 29.03.94 Kuno, H. et al.

EP0704524 05.09.95 Caneva, Philippe

EP1433886 10.12.03 Iachini, Pino

Nowadays, it is of general knowledge that the use of aged clothing is largely widespread, according to Fashion trends. Because of this, clothing manufacturers such as Jeans Manufacturers, submit their products to treatments in order to obtain an old/used appearance, even being new. However, this trend demands the achievement of a more and more realistic «old/used» effect. This trend needs a more specialized approach for the processes by which these treatments are put into practise. Furthermore, the areas in which we intend to achieve the «used» effect suffer variations with time.

Nowadays, clothes are "aged" through wearing processes or through chemicals. Known aging processes imply the use of oxidizing or reducing agents in a carrier, rock-pomes, or other absorbing means that will then transfer the chemical to the fabric or jersey, aging, in this way, the contact areas and preserving the remaining, presenting a light/dark effect .

These processes present some drawbacks, among which the fact that one needs a large quantity of the chemical to impregnate the carrier (rock-pomes or another) ; on the other hand, it is difficult to control the uniformity of the chemical's quantity in the mean (pedra-pomes or another) at the moment of use (premature dehydration, gravity, oxidation or reduction) .

The European Patents EP0238779, EP0298412 and EP0303120 refer in general to a process to dye or to bring occasionally an old or used appearance to fabrics or to clothes. Therefore, the method described includes the following steps:

- Impregnate the porous/permeable aggregates of raw material that present high absortion with a discolorating or colorating compound;

- Place the impregnated aggregates in a rotating drum together with the fabric or the clothes;

- Colorating or discolorating step through the dry rotation of the drum containing the aggregates and the fabric or clothes; - Recovery or separation of the aggregates from the dyed or discolorated clothes or fabrics;

- Neutralizing the residues of colorating or discolorating agent from the cloth, through a normal washing cycle.

However, this method has several disavantages in the economical as well as in the production plans. The impregnation of the particles or aggregates of the porous material (rock-pomes, silica gel, polyestirene aggregates, sand, etc) implies the use of large quantities of chemical (colorating, whitener or discoloranting) , which turns the whole process significantly expensive. On the other hand, the method described in the mentioned patents is very restricted in its final result, because it does not allow the achievement of customized effects.

The European Patent EP0554480 describes a non uniform aging procedure for dyed textile products, comprising the following steps:

- coating of the textile product surface to treat with a material resistant to whitener and/or discolorating agents;

- breaking the referred coating in a random manner and in several locations, by the action of a mixer;

- next, treat the textile product with a water based solution of a whitener and/or discolorating agent, for an adequate period of time in order to obtain de desired degree of effect;

- removal or neutralization of any whitener or discolorating chemical residues that may have remained in the tissues;

- removal of the textile products from the chemical resistant coating material. However, this method presents some limitations. Due to the way the resistant coating is applied (in one or both sides of the piece to treat) and afterwards broken (by the action of the mixer), one can only obtain two effects: one side with the desired used or aged effect and the other side uniformly discolorated or whitened, or, both sides with the use or aged appearance. On the other hand, the procedure referred becomes a little bit expensive due to the number of mixing and warming steps, as well as to the time that the operation lasts and also due to the quantitites of whitener and/or discolorating agent required, because the pieces are «washed» with a water based solution of the used chemical, which will reflect on the cost/price of the final product.

The American Patent US4852990 presents as its object a procedure for the uniform whitening of both sides of the piece to treat and in a single step. To achieve that, the whitening cycle is consisting of a water based bath containing a mixture of the whitener and polyacrilamide. However, this method is restricted to instances when is wanted total whitening or discoloration of the clothing or fabric piece.

Despite describing several alternatives of abrasive particles and of its manufacturing way, the discolorating method referred to in the American patent US5298027 suffers from the same vices of the procedures just described.

The object of the European Patent EP0704524 is a total or partial discolorating procedure of jeans denims, both in raw fabric and in finished products, allowing the achievement of a range of variable appearances, which works in a water based media at room temperature, in presence of a permanganate acid hydrosoluble salt. The various effects are achieved by the use of different combinations of the bath conditions, in terms of pH, anionic, cationic, amphoteric caracterization and of the tensioactive agents used, as well as of the reducing agent nature and of the permanganese acid quantity. This procedure limitations are linked to the facts that the final result is uniform, fails to achieve the «used» appearance, and that the execution is difficult due to the number of solutions required and of the parameters requiring a close control during the whole procedure.

The European Patent EP1433886 describes an aging procedure exclusively applied in trousers, for which a inflating device was developed; the procedure consists in the manual application of the discolorating solution in the desired places. This procedure presents several limitations, namely, the low productivity associated with the fact that the treatment has to be made unit by unit, and, on the other hand, because its application range is reduced to a single type of clothing.

Object of the Invention

The object of the present invention is to develop an aging method for fabrics or clothing pieces that succeeds in avoiding all the drawbacks described above, namely, to reduce the quantity of chemical used, to be applicable to a wider range of articles, to allow to obtain several patterns, without requiring excessive labor or very difficult stages and not being of difficult execution. Furthermore, it is also an object of the present invention to provide an alternative to the random creation of a pattern, allowing the prodution, even manually of this kind of effect in any desired place, which makes this a versatile method. It is also an object of the present invention the achievement of a method that promotes enough wearing of the clothing in order to obtain the most natural effect possible.

Thus, the present invention allows the achievement of aging effects more or less deep and more or less regular/uniform, thus avoiding some of the drawbacks associated to the conventional aging processes.

Brief Description of the Drawings

Before proceeding to the detailed description of the present invention, a brief description of the drawings will be presented.

Figure 1 is a block diagram that shows the whole dimension of the aging procedure, including not only the stages related to the presented method, but also the preceding ones .

Figure 2 depicts the equipment used and two ways of treatment of the clothes.

Figure 3 depicts the placing of the whitener/discolorating agent into the reservoir.

Figure 4 depicts the spray application stage of the discolorating/whitener agent.

Figure 5 depicts the terminus of the stage depicted in Figure 4, with the removal of the clothes just treated for the following neutralization. Detailed Description

This procedure uses "spray aging" and aims at the achieving an uniform aged appearance through a bigger or smaller contrast between the superficial areas (more lighter) and the inner areas (more darker) , through the combination of mechanical and chemical agents. Before being exposed to the aging procedure itself, clothes, both fabrics and finished clothing must undergo the conventional treament stages, as depicted in Figure 1. Therefore, the clothes are pressed in A, smoothed in B by its placement in a hot water bath and dried in C; these three stages can be done in standard equipments.

In stage D, the watertightness of the dyed clothes is achieved using by hidrophobic chemicals, fat acids, polyethylene waxes, fluorocarbons or any other chemical that promotes hydrophobicity, by breakdown or by spray.

In case a particular effect is desired, there is an intermediate stage - E2 - where the clothes are tied (6) in one or several places, which allows the pieces to keep their original color on the inside when exposed to the next step, that is, in the protected areas. If not, stage El follows, where the clothes enter the machine (1) stretched (5) .

Next, in stage F, the stretched or tied (just as described) clothing pieces are placed together with the abrasive agent (that might be rock-pomes, silica, sand, etc.) into the rotating drum of machine (1) . The machine is tumbled on dry, in order to remove part of the hydrophobic chemical, thus obtaining hydrophilic superficial areas and inner hydrophobic areas. After this stage, the abrasive agent particles are collected and the discolorating or whitening agent is placed into the reservoir (7), which will feed the nebulizing gun (4) through tube (3).

Next is step G, depicted in Figure 4 in which the atomized discolorating agent is applied, being absorbed by the hydrophilic superficial areas only, with the achievement of an uniform aging pattern with light/dark contrast between the outer and inner areas.

The clothing pieces must be in constant rotation and since the quantity of liquid is very small, they keep themselves practically dry, which facilitates their movement.

After the application of the discolorating agent, the clothing pieces must rest for a period of time (step H) (to define according to the type and quantity of discolorating agent used and to the desired discolorating effect) , and step I follows, which consists of the neutralization of the discolorating agent in a conventional washing machine.

With this "spray aging" procedure there is the possibility of obtaining other effects:

• direct application of the discolorating agent over the dyed and dried clothing pieces, with the achievement of discoloration in the outer area only, which can be more or less uniform, depending on the spraying device, pressure and the quantity of discolorating agent used;

• application of the discolorating agent over tied clothing pieces; • application of the discolorating agent over clothing pieces partially impervious to water (localized waterproofness) .

The present procedure is more ecological than the conventional ones, because the quantity of chemical (oxidizing or reducing agent) used is much lower, which facilitates the control of the application.

The oxidizing or reducing chemical is used in variable quantities depending on the desired degree of aging and on the sensitivity of the coloring products involved in the dying.

The spraying is made with a nebulizing gun (4) which is located on the door (2) of the rotating drum (1) machine (1), over the dry clothing pieces.

In case a very uniform aging is desired, an air atomizing spray nozzle should be used, in order to obtain very small droplets .

If the size of the droplets raises (changing the spray nozzle or lowering pressure), an irregularity becomes apparent, which is translated into a particular effect.

The clothing pieces destined to this effect must be dyed with dyes that are sensitive to the chemical to be sprayed.

If, in three colors, all the dyes present similar sensitivity, we will have an effect light/dark shade over shade. If they don't show the same sensitivity, we will have bicolor effects.

The same happens in the conventional aging procedures. The difference in the procedures compared to the traditional aging starts after the dying. In the traditional procedure, discoloration is achieved by the exposure of the superior areas to the discolorating agent, the inferior areas being protected from discoloration.

In the present invention, discoloration is achieved through the absortion of discolorating agent by the hydrophilic areas, hydrophobic areas remaining protected.

Claims

1. Aging procedure of finished clothing pieces characterized by the fact that it comprises the following steps:

• Promote waterthightness of the dyed pieces with hydrophobic agents;

• Placement of said pieces together with the aggregates of an abrading agent inside a rotating drum, which will work in dry condition during enough time to randomly expose the areas of the pieces that will be discolorated in the next step;

• Spraying of the discolorating agent while the pieces are in their continuous rotational movement;

• Resting period;

• Neutralizing the remainder of the whitener in the fabric by means of a regular washing cycle;

2. Aging procedure of finished clothing pieces, according to Claim 1, characterized by the fact that, watertightness of the dyed clothes is achieved using hydrophobic chemicals, fat acids, polyethylene waxes, fluorocarbons or any other chemical that promotes hydrophobicity.

3. Aging procedure of finished clothing pieces, according to Claim 1 and 2, characterized by the fact that, watertightness may be achieved by breakdown or spray, according to the desired effect.

4. Aging procedure of finished clothing pieces, according to Claim 1, characterized by the fact that the dry washing is made with aggregates from rock- pomes or any other abrasive.

5. Aging procedure of finished fabrics, according to Claim 1 and 4, characterized by the fact that the dry washing with the abrasive removes part of the hydrophobic chemical, obtaining random surface hydrophilic areas (permeable to discolorating agent) and hydrophobic areas (impervious to the discolorating agent) .

6. Aging procedure of finished fabrics, according to Claim 1, characterized by the fact that when the discolorating agent is sprayed, it is absorbed only by the surface hydrophilic areas randomly created by the abrasive action of the aggregates.