FR2638468A1 - Method for fixing dye on cloth and apparatus for implementing the method - Google Patents

Abstract

The method for fixing dye on fabric, by keeping pieces of dyed cloth in an atmosphere of steam, inside a steamer fed by a source of steam consists in establishing a pressure difference between the source of steam and the steamer. Thus the steam is injected into the steamer under pressure. The appliance for implementing this method comprises, between the steamer 1 intended to enclose the cloth 7 to be treated and the source of steam 14, means, in the form of a nozzle 13, for injecting the steam.

Description

 The present invention relates to a dye fixing method for decorating fabrics or fabrics; it also relates to the apparatus for implementing the method.

 To carry out the fixing of the dyes on fabrics such as silk, cotton or wool, necessary for good color fastness over time, it is known to subject the colored material to an atmosphere of unsaturated water vapor, in an oven.

 The material used to carry out this heat treatment consists of a mandrel around which the colored fabric is wound; this mandrel is arranged in an enclosure constituting the fixing column, at the foot of which a vapor atmosphere is created by evaporation of water.

 The steam source is placed under the fixing column and is in direct communication with the latter; the vapor released by the heating of the water (electric or gas), has the possibility of rising and filling the column to carry out the fixing of the dye on its support.

The upper part of the column is provided with an evacuation orifice to limit the pressure inside the enclosure.

 This fixing technique, known for a long time, however has the disadvantage of being relatively long; it is indeed necessary to subject the tissue to treatment for a period of three or even four hours to obtain the desired result. In addition, the quality of the fixing is not maximum, this being linked to the poor rise and poor distribution of the vapor in the column, during the treatment, and therefore to the heterogeneity of the temperatures applied to the colored support.

 The invention aims to overcome these drawbacks by providing a fixing method and apparatus ensuring very quickly a good distribution of the vapor in the fixing column. The object of the invention makes it possible to very significantly reduce the durations of application of the treatment while obtaining an improved fixing quality compared to the prior techniques. Given the acceleration of the treatment and the efficiency of steam production, the invention also allows energy savings.

 The subject of the invention is a process for fixing dye to fabric consisting in maintaining pieces of colored fabric in an atmosphere of water vapor, inside an oven fed by a source of steam.

According to the invention, this method consists in establishing a pressure difference between the source of water vapor and the oven. The pressure is therefore greater, on the one hand, at the source of water vapor than in the oven and on the other hand, in the oven than outside.

 The invention also relates to the apparatus intended for fixing dyes to fabrics, for implementing the method described above. This device comprises, between the oven intended to contain the tissues to be treated and the source of steam, means for injecting water vapor into the oven, under pressure.

 Still according to the invention, these injection means consist of a nozzle installed in the lower part of the oven; this nozzle can be associated with a screen device to avoid water splashes on the fabric being treated.

 According to a particular arrangement, the fixing device comprises a tank, arranged in the lower part and intended for the recovery of the condensation water; this tank is also used to ensure, by a water seal, sealing against the circulation of steam.

 Still according to the invention, the source of steam consists of a device of the pressure cooker type provided with a flexible connection to the means for injecting steam into the oven.

 According to another arrangement of the invention, the oven is provided with a conical device, of conical shape, placed above the material to be treated, which paragout device is intended to receive and direct the condensation water formed. in the upper part of the oven, towards the peripheral wall.

 Still according to the invention, the upper part of the oven has a valve cover, fitted with a thermometer.

 Still according to the invention, the oven consists of a column in the form of a cylindrical pipe provided with stabilizing feet extending radially, in its lower part, which feet come to rest on the tank for collecting the condensation water.

 But the invention will be further illustrated without being in any way limited, by the following description of a particular embodiment, given only for information and shown in the accompanying drawing showing a side view of the fixing device according to the invention, with the sectional oven.

 This device for fixing dyes on fabric consists of an oven 1 associated with a source of steam.

The oven 1 consists of a cylindrical pipe forming column lb which may for example have a height of 1.50 m and a diameter of 0.15 m. The lower part of the column 1b is provided with stabilizing feet 2 extending radially; these feet 2 are intended to rest on the edge of a tray 3 serving as a base and are positioned so that the bottom of the column 1b almost reaches the bottom of the tray 3, slightly above. Two grips 4 facilitate the installation or removal of the column lb on the lower tray 3.

 The lower part of the cylindrical pipe 1b is also provided with a member 5 in the form of a tab intended to support a removable mandrel 6 around which the fabric 7 to be treated is wound. This colored fabric is wound in a conventional manner around the mandrel 6 forming an axis, for example sandwiched in fixing paper. A metal key 8 is threaded into an orifice provided in the lower part of the mandrel 6. This key, of length slightly less than the diameter of the column lb, is intended on the one hand for positioning and holding the mandrel in the central part of the column and, on the other hand, to support the material 7 to be treated to prevent it from descending into the bottom of the oven 1.

 The mandrel 6 has a height less than that of the column 1b so as to allow its complete integration into the cylinder; its upper end part is provided with a "parachute" system 9 in the form of a conical umbrella.

This paragout 9 of diameter substantially smaller than that of the pipe 1b, can be welded to the end of the mandrel 6 or screwed onto a threaded end rod. It ensures, like the key 8, the positioning and the maintenance of the mandrel 6 and therefore of the tissue to be treated, in the central part of the oven.

 The upper part of the pipe 1b is closed by a cover 10 in the form of an inverted cylindrical tank, with a diameter slightly greater than that of the column 1b and simply placed on the latter. This cover 9 is provided with a grip handle 11 and a thermometer 12 provided with a sensor, screwed in its central part and intended to control the temperature in the upper part of the oven.

 In the lower part, between the level of the radial feet 2 and the position of the retaining key 8, the column 1b is provided with a calibrated orifice 13 in the form of a nozzle.

 The fixing oven 1 is associated with a source of steam consisting, in the illustrated embodiment, of a device of the pressure cooker type 14 whose valve 15 is hermetically connected to the nozzle 13 by means of a flexible of connection 16. This pressure cooker 14, containing water heated by the heat source 17, is intended to produce pressurized steam, injected into the oven by the nozzle 13.

 In order to fix the colored fabrics, the material 7 to be treated, sandwiched in fixing paper, is firstly wound around the mandrel 6, between the retaining key 8 and the paraglider system 9. The mandrel 6 is introduced into the column 1b and comes to rest on its support tab 5; the key 8 and the paragoutte 9 ensure the central positioning of the material to be fixed. The cover 10 forming a valve is placed on the upper edge of the pipe 1b to close off the upper part of the oven and, optionally, a small amount of water 18, forming a seal, is placed in the tank 3, forming a base, so to avoid the exit of water vapor from the bottom of the column lb during treatment.

 After switching on the heat source 17 under the pressure cooker 14, the water vapor created in the latter is injected under overpressure into the oven 1, by means of the nozzle 13. A protective screen 19 can be arranged opposite the nozzle to avoid any water splashes on the material 7 to be treated.

 The creation of a pressure difference between the source of water vapor and the oven allows the injection of water vapor into the lower part of the column, under overpressure. This ensures rapid diffusion of the vapor in the fixing column and, this vapor being well distributed, allows rapid obtaining of a homogeneous ambient temperature over the entire surface of the colored fabric to be treated.

 The cover 10, simply placed on the column 1b, acts as a safety valve and allows the evacuation of excess steam and thus the circulation of a stream of unsaturated steam inside the oven.

The pressure inside the oven is significantly higher than the ambient pressure.

 The temperature inside the enclosure, during treatment, fluctuates around 92 to 98 C; it is checked, for safety reasons and to guarantee proper functioning, by the upper thermometer 12.

 Given the temperatures obtained, the heat exchanges with the outside, via the wall of the column 1b, condense the vapor over the entire inner periphery and the upper internal part of the said column. The dropout 9 prevents the droplets of water created at the level of the cover 10 from falling onto the fabric to be treated. This metal cone receives the drops of water and directs them towards the internal wall of the column 1b, which wall takes charge of them via the slight peripheral clearance and then directs them towards the receiving tank 3.

 The fixing method according to the invention allows excellent fixing of the colors on fabrics in a relatively rapid time which can vary from 1 hour 15 to 1 hour 30 minutes, while effectively preserving the material from any contact with the water of condensation.

 Of course, the invention is not limited to the details of the embodiment which has only been described by way of example and for which adaptations can be made.

 For example, it is possible to provide extensions, changes in shape, dimensions or proportions for column 1b, in order to adapt the dimensions of the oven to those of the material to be treated.

 Other types of steam sources can be used and several nozzles can provide the injection of steam under pressure, for example at different levels.

 The reference signs inserted after the technical characteristics mentioned in the claims are intended only to facilitate the understanding of the latter and in no way limit their scope.

Claims (8)

- CLAIMS  1.- Method for fixing dye to fabric by holding pieces of colored fabric in an atmosphere of water vapor, inside an oven (1) supplied by a source of steam (14), characterized in that that it consists in establishing a pressure difference between said source of water vapor (14) and said oven (1).  2. Apparatus for fixing dye to fabric, for implementing the method according to claim 1, comprising an oven (1) containing the fabrics (7) to be treated and a source of steam (14), characterized in that 'It comprises, interposed between the oven (1) and the steam source (14), means for injecting steam into the oven (1) under pressure.  3. A fixing device according to claim 2, characterized in that the steam injection means consist of a nozzle (13) installed in the lower part of the oven (1).  4. A fixing device according to any one of claims 2 or 3, characterized in that it comprises a tank (3) disposed in the lower part of the oven (1) and intended on the one hand for the recovery of the water of condensation and on the other hand, to ensure by a water seal, the tightness with the circulation of vapor.  5. A fixing device according to any one of claims 2 to 4, characterized in that the steam source consists of a device (14) of the pressure cooker type provided with a connection hose (15) by means of injection. (13) steam in the oven (1).  6.- Fixing device according to any one of claims 2 to 5, characterized in that the oven (1) is provided with a device "paragoutte" (9), conical in shape, disposed above the material (7) to be treated, receiving the condensation water formed in the upper part of the oven and directing it towards the peripheral wall of the oven.  7. A fixing device according to any one of claims 2 to 6, characterized in that it comprises a cover (10) forming a valve provided with a thermometer (12).  8. A fixing device according to any one of claims 3 to 7, characterized in that the oven (1) consists of a column (lb) in the form of a cylindrical pipe, provided with stabilizing feet (2) s' extending radially in its lower part, which feet (2) come to rest on the tank (3) for collecting the condensation water.