GB1581947A

GB1581947A - Method of and apparatus for dyeing by mechanical impregnation

Info

Publication number: GB1581947A
Application number: GB1520277A
Authority: GB
Original assignee: TLD Group SAS
Current assignee: TLD Group SAS
Priority date: 1976-04-13
Filing date: 1977-04-12
Publication date: 1980-12-31
Also published as: IT1076719B; FR2348302B1; ES457758A1; DE2716310A1; FR2348302A1

Description

(54) IMPROVEMENTS IN OR RELATING TO A METHOD OF AND APPARATUS FOR DYEING BY MECHANICAL IMPREGNATION (71) We, TIssMETAL -- Departement de Tissmetal Lional Dupont, a company organised and existing under the laws of France of 138, Boulevard de la Croix Rousse, 69283 Lyon Cedex, France, do hereby declare the invention, for which we pray that a Patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- The invention relates to a method of dyeing by mechanical impregnation, an impregnating cylinder for carrying out the method and a dyeing installation comprising said impregnating cylinder.

The industrial dyeing of textiles by mechanical impregnation has been carried out for a long time as follows: a sheet of textile material is wound several times around an impregnating roller placed in a closed chamber, which is pressurised and kept at a temperature of the order of 1300C comprising a cylindrical face provided with uniformly distributed holes, closed at its first end and open at its second end. The required quantity of dye, but no excess dye, is injected under pressure inside the roller through its second end, passes radially in a centrifugal movement through the holes in the cylindrical face and travels through the successive layers of cloth.

This technique has a major drawback: the dye penetrates the cloth solely in the region of each hole in the roller and is distributed as it travels through the successive layers.

However, the first layers comprise excess dye at the location of the holes in the roller known as "impregnating points" and, on the contrary, a complete or partial absence of dye at the location of the intermediate solid areas. The initial end part of the sheet therefore cannot be used.

To prevent this drawback it has been proposed, c.f. "Manuel de la teinture et du finissage des fibres de polyester seules et en melange avec d'autres fibres" (Manual of dyeing and finishing of polyester fibres alone and mixed with other fibres) by BASF, to wind on the impregnation roller, several layers of a fabric having a loose texture and low power of retention of the dye, which ensures its uniform diffusion. This method which is derived from dyeing techniques is hardly satisfactory: the fabric having a loose texture does not form an integral part of the impregnating roller; it retains the dye to a certain extent; it therefore has to be changed periodically; it also uses an excessive amount of dye and it cannot be used in succession with various types of dye.The homogeneous distribution of the dye results from two simultaneous operations, namely a centrifugal radial diffusion of the dye through the successive layers and a transverse diffusion parallel to the generatrices of the impregnating roller.

On the other hand, French Patent No.

1,503,461 in the name of VEPA, proposes an installation for the treatment of textile material comprising a chamber, several perforated drums housed in the chamber and able to rotate, serving as support and transfer members for the textile material passing through the chamber, a screen permanently closing-off the perforations of each of the drums not covered by the textile material, means for passing a treatment fluid (for example hot air as mentioned) through the area of the textile material applied against the uncovered perforations of a drum in the centripetal direction, i.e. from the outside towards the inside of each drum.

An installation of this type intends to ensure the greatest delivery of treatment fluid and therefore the percentage of the total surface area constituted by perforations is as large as possible. To prevent the textile material from being drawn into the inside of the drum owing to the pressure of the treatment fluid, a wire-gauze screen is pro vided surrounding the drum. The latter is in no way comparable with an installation for dyeing by mechanical impregnation where only the required quantity of dye, without excess, is made to pass from the inside towards the outside of the roller which is completely covered with fabric.

Finally, the problem of the "impregnation points" does not occur in the case of the VEPA patent firstly owing to the centripetal circulation of treatment fluid and secondly to the presence of several drums over which the fabric travels in succession.

Since the VEPA and BASF documents contradict each other, they cannot be combined: BASF provides a centrifugal circulation of treatment fluid and VEPA a centripetal circulation. The wire gauze screen of the VEPA patent is suited solely to the case of centripetal circulation and is pointless in the other case.

According to the present invention there is provided a method of dyeing by mechanical impregnation a sheet of material, especially textile material, which is permeable to the dye, in which the sheet is wound, in at least one complete turn, around the perforated cylindrical surface of an impregnating cylinder and the dye is then injected under pressure into the impregnating cylinder, the method being characterised by using a first means surrounding and integral with the cylinder to distribute the dye leaving the perforations in the cylindrical face of the impregnating cylinder transversely uniformly along the cylindrical face and a second means surrounding the first means and ensuring a radial diffusion of the dye flowing along the cylindrical face.

Also according to the present invention there is provided an impregnating cylinder for carrying out the method defined in the preceding paragraph and comprising a cylindrical surface provided for at least part of its length with uniformly distributed perforations through which the dye can pass centrifugally, the cylinder being closed at one end, at least partly open at its other end in order to facilitate the entry of dye into the cylinder, there being provided a first means surrounding and integral with the cylinder to distribute the dye leaving the perforations in the cylindrical face of the impregnating cylinder transversely uniformly along the cylindrical face and a second means surrounding the first means and ensuring a radial diffusion of the dye flowing along the cylindrical face.

There is further provided an installation for dyeing by mechanical impregnation a sheet of material which is permeable to the dye, the installation comprising a closed chamber, means for heating this chamber, means for pressurising this chamber, and means for injecting dye into an impregnating cylinder incorporating integrally a first means for ensuring a homogeneous transverse distribution of the dye over the entire cylindrical face of the cylinder, and a second means surrounding the first means for ensuring a radial diffusion of the dye flowing along the cylindrical face.

The invention will be better understood by means of the ensuing description referring to the accompanying drawings in which: Figure 1 is a diagrammatic perspective view of an impregnation cylinder according to the invention.

Figure 2 is a diagrammatic sectional view through an axial plane of the impregnation cylinder illustrated in figure 1.

Figure 3 is a diagrammatic view, partly in section through an axial plane, to an enlarged scale, of an impregnation cylinder according to the invention, provided with several layers of material to be dyed.

Figure 4 is a diagrammatic view illustrating the initial free end part of the sheet of material treated by means of the impregnation cylinder according to the invention.

Figures 5 and 6 are diagrammatic views illustrating the state of the art.

Figure 7 is a diagrammatic view of an installation using the impregnation cylinder according to the invention.

Figures 1 and 2 show an impregnation cylinder 1 comprising a cylindrical face 2 having a circular base, for example on the axis 3, closed at one of its two ends by a solid base 4 of circular shape and provided at its other end with an opening 5 to facilitate introduction of the dye. By way of example, the opening 5 is provided in a second base 6, in the shape of a circular ring. Arms 7a, 7b or any other equivalent means, rigidly secured to the bases 4 and 6 respectively facilitate attachment of the impregnation cylinder which is normally stationary. The arm 7b is hollow in order to communicate with the opening 5. It is also possible for the impregnation cylinder 1 to have no arms 7a, 7b and to be secured by any other means.

The cylindrical face 2 is provided with a plurality of holes 8 of circular shape for example, uniformly distributed and facilitating the passage of a sufficient, but not excessive, quantity of dye, in the centrifugal direction.

In the case where the cylinder does not comprise any arms 7a, 7b, the holes 8 are provided on only part of the length of the cylinder. The two end parts devoid of holes facilitate retention and handling of the cylinder.

If necessary, depending on the width of the web of material to be dyed, part of the holes 8 are covered over a certain length of impregnating cylinder.

According to the invention, the impregnating cylinder comprises integral means ensuring a homogeneous and continuous distribution of the dye over the entire perforated cylindrical face 2 and thus of its points of entry into the sheet of material to be dyed.

In one possible embodiment, these means comprise, in combination, on the one hand, means ensuring a transverse flow of the dye along the outer cylindrical face 2 and on the other hand, means ensuring a radial centrifugal diffusion of the dye, flowing along the outer perforated cylindrical face 2.

The means ensuring a transverse flow of the dye are in the form of a first sheath 9, for example, placed directly on and embracing the outer cylindrical face 2, constituted by latticework offering a slight pressure drop to the dye. In particular, the latticework constituting the sheath 9 is formed by a wire-gauze of stainless steel.

In a first variation, the design of the gauze is plain or crossed and the wires constituting the latter are undulating in order to promote transverse flow of the dye. In a second variation, the wire-gauze is constituted by coils of wire screwed into each other, each coil being parallel to the generatrices of the impregnating cylinder.

The means ensuring a centrifugal radial diffusion of the dye are in the form of a second sheath 10 for example surrounding and pressed against the first sheath 9, advantageously constituted by a wire-gauze having a greater pressure drop than that of the first sheath 9. The gaps in the mesh of the gauze constituting the second sheath 10 are sufficiently large so as not to trap solid colorants in the dye. The pores of the second sheath 10 are very numerous and very close to each other.

According to a possible variation, the gauze constituting the first and second sheaths 9 and 10 are covered with an antiadhesion film of very slight thickness (of the order of several microns) made of plastics material such as polytetrafluoroethylene for example, which facilitates their cleaning.

Figure 3 shows diagrammatically the passage of the dye through the impregnating cylinder according to the invention, around which several layers 11 of a material to be treated are wound. The dye under pressure located in the impregnating cylinder 1 reaches the holes 8 in the direction of the arrows 12 and passes through the latter centrifugally. Since the first sheath 9 is placed on the outer cylindrical face 2, in particular opposite the holes 8, the dye is prevented from moving radially towards the outside of the impregnating cylinder 1 at the outlet of the holes 8 and thus follows the path represented diagrammatically by the arrows 13, which corresponds to a transverse flow along the outer cylindrical face 2.The dye is then diffused in a uniform manner owing to the second sheath 10 and passes through the successive layers 11 of the sheet of material to be treated in the direction of the arrows 14, in a homogeneous and continuous distribution.

Figure 4 shows the initial end part of the treated sheet of material, which is dyed uniformly from its free edge.

By way of comparison, Figure 5 shows the path followed by the dye in the case of conventional impregnating cylinder devoid of the means according to the invention.

The initial end part of the sheet of material treated with this roller comprises "impregnation points" 15 (Fig. 6).

Fig. 7 shows diagrammatically an installation comprising the impregnating cylinder 1 according to the invention, housed in a closed chamber 16 provided with heating means 17, pressurising means 18 and means 19 for supplying the dye to the inside of the impregnating cylinder.

The use of metal sheaths has the advantage of facilitating easy cleaning of these sheaths and thus their re-use. In fact, the metal sheaths are not marked by the dye.

WHAT WE CLAIM IS: 1. A method of dyeing by mechanical impregnation a sheet of material, especially textile material, which is permeable to the dye, in which the sheet is wound, in at least one complete turn, around the perforated cylindrical surface of an impregnating cylinder and the dye is then injected under pressure into the impregnating cylinder, the method being characterised by using a first means surrounding and integral with the cylinder to distribute the dye leaving the perforations in the cylindrical face of the impregnating cylinder transversely uniformly along the cylindrical face and a second means surrounding the first means and ensuring a radial diffusion of the dye flowing along the cylindrical face.

2. A method according to claim 1, in which the dye is circulated over the entire outer cylindrical face of the impregnating cylinder.

3. A method according to claim 1 or 2, in which homogeneous and continuous centrifugal radial diffusion of the dye is achieved.

4. An impregnating cylinder for carrying out the method according to claim 1, and comprising a cylindrical surface provided for at least part of its length with uniformly distributed perforations through which the dye can pass centrifugally, the cylinder being closed at one end, at least partly open at its other end in order to facilitate the entry of dye into the cylinder, there being provided a first means surrounding and in

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. According to the invention, the impregnating cylinder comprises integral means ensuring a homogeneous and continuous distribution of the dye over the entire perforated cylindrical face 2 and thus of its points of entry into the sheet of material to be dyed. In one possible embodiment, these means comprise, in combination, on the one hand, means ensuring a transverse flow of the dye along the outer cylindrical face 2 and on the other hand, means ensuring a radial centrifugal diffusion of the dye, flowing along the outer perforated cylindrical face 2. The means ensuring a transverse flow of the dye are in the form of a first sheath 9, for example, placed directly on and embracing the outer cylindrical face 2, constituted by latticework offering a slight pressure drop to the dye. In particular, the latticework constituting the sheath 9 is formed by a wire-gauze of stainless steel. In a first variation, the design of the gauze is plain or crossed and the wires constituting the latter are undulating in order to promote transverse flow of the dye. In a second variation, the wire-gauze is constituted by coils of wire screwed into each other, each coil being parallel to the generatrices of the impregnating cylinder. The means ensuring a centrifugal radial diffusion of the dye are in the form of a second sheath 10 for example surrounding and pressed against the first sheath 9, advantageously constituted by a wire-gauze having a greater pressure drop than that of the first sheath 9. The gaps in the mesh of the gauze constituting the second sheath 10 are sufficiently large so as not to trap solid colorants in the dye. The pores of the second sheath 10 are very numerous and very close to each other. According to a possible variation, the gauze constituting the first and second sheaths 9 and 10 are covered with an antiadhesion film of very slight thickness (of the order of several microns) made of plastics material such as polytetrafluoroethylene for example, which facilitates their cleaning. Figure 3 shows diagrammatically the passage of the dye through the impregnating cylinder according to the invention, around which several layers 11 of a material to be treated are wound. The dye under pressure located in the impregnating cylinder 1 reaches the holes 8 in the direction of the arrows 12 and passes through the latter centrifugally. Since the first sheath 9 is placed on the outer cylindrical face 2, in particular opposite the holes 8, the dye is prevented from moving radially towards the outside of the impregnating cylinder 1 at the outlet of the holes 8 and thus follows the path represented diagrammatically by the arrows 13, which corresponds to a transverse flow along the outer cylindrical face 2.The dye is then diffused in a uniform manner owing to the second sheath 10 and passes through the successive layers 11 of the sheet of material to be treated in the direction of the arrows 14, in a homogeneous and continuous distribution. Figure 4 shows the initial end part of the treated sheet of material, which is dyed uniformly from its free edge. By way of comparison, Figure 5 shows the path followed by the dye in the case of conventional impregnating cylinder devoid of the means according to the invention. The initial end part of the sheet of material treated with this roller comprises "impregnation points" 15 (Fig. 6). Fig. 7 shows diagrammatically an installation comprising the impregnating cylinder 1 according to the invention, housed in a closed chamber 16 provided with heating means 17, pressurising means 18 and means 19 for supplying the dye to the inside of the impregnating cylinder. The use of metal sheaths has the advantage of facilitating easy cleaning of these sheaths and thus their re-use. In fact, the metal sheaths are not marked by the dye. WHAT WE CLAIM IS:

1. A method of dyeing by mechanical impregnation a sheet of material, especially textile material, which is permeable to the dye, in which the sheet is wound, in at least one complete turn, around the perforated cylindrical surface of an impregnating cylinder and the dye is then injected under pressure into the impregnating cylinder, the method being characterised by using a first means surrounding and integral with the cylinder to distribute the dye leaving the perforations in the cylindrical face of the impregnating cylinder transversely uniformly along the cylindrical face and a second means surrounding the first means and ensuring a radial diffusion of the dye flowing along the cylindrical face.

tegral with the cylinder to distribute the dye leaving the perforations in the cylindrical face of the impregnating cylinder transversely uniformly along the cylindrical face and a second means surrounding the first means and ensuring a radial diffusion of the dye flowing along the cylindrical face.

5. A cylinder according to claim 4, in which the means ensuring a transverse flow of the dye is in the form of a sheath of wire-gauze presenting a resistance to the radial flow of the dye and allowing the circulation of dye in its own plane, the sheath embracing the outer cylindrical face of the cylinder.

6. A cylinder according to claim 5, in which the wire gauze is formed by a single layer of undulating wires in order to promote the transverse flow of the dye.

7. A cylinder according to claims 5 or 6 in which the means ensuring radial diffusion of the dye is in the form of another sheath embracing the first-mentioned sheath and constituted by a single layer of wire gauze having a greater pressure drop than that of the first-mentioned sheath.

8. A cylinder according to claim 7, in which the wire gauzes constituting the sheaths are made from stainless steel or other steel or alloy compatible with the conditions of use.

9. An installation for dyeing by mechanical impregnation a sheet of material which is permeable to the dye, the installation comprising a closed chamber, means for heating this chamber, means for pressurising this chamber, and means for injecting dye into an impregnating cylinder incorporating integrally a first means for ensuring a homogeneous transverse distribution of the dye over the entire cylindrical face of the cylinder and a second means surrounding the first means for ensuring a radial diffusion of the dye flowing along the cylindrical face.

10. A method of dyeing by mechanical impregnation, substantially as hereinbefore described with reference to the accompanying drawings.

11. An impregnating cylinder, substantially as hereinbefore described with reference to the accompanying drawings.

12. An installation for dyeing by mechanical impregnation, substantially as hereinbefore described with reference to the accompanying drawings.