HK1002446B - Thermobonded lining material and method for its manufacture - Google Patents

Description

The invention relates to a thermo-adhesive liner and its manufacturing process.

It is known to make thermo-adhesive linings with a textile backing on which a layer of thermo-adhesive polymers is deposited by induction.

These linings are specifically designed to be glued to another textile, for example a drapery, so as to form a complex whose physical properties, hold, elasticity, flexibility, touch, volume, hand, etc. can be controlled.

These properties of the complex result from the nature of the drapery, the nature of the textile support, the liner, and also the nature of the composition and the method of application of the thermo-adhesive layer.

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The thermo-adhesive liner is then glued back onto the drapes to achieve the desired complex.

This is usually done by means of a press operating at temperatures between 90°C and 160°C, at pressures ranging from a few decibars to a few bars, for relatively short periods of time of 10 to 30 seconds.

During this phase, the thermo-adhesive polymers in the liner must at least partially regain their adhesive properties.

In addition, during this operation, it is necessary to prevent these thermo-adhesive or thermo-adhesive polymers from penetrating the drapery or producing returns, i.e. they penetrate the textile support of the liner.

Such piercings and backs would have an unsightly effect, rendering the support unfit for use or, at least, giving the complex unwanted properties.

The main consequences of these piercings are: to cause the migration of some of the thermo-adhesive polymers on the side opposite to the initially thermo-adhesive side of the liner. This has the negative effect of making the back of the thermo-adhesive liner adhere to the liner (liner, back, etc.) during the ironing and pressing of the garment. The use of the polymer in the textile material is to make it stiff by gluing the fibres and/or yarns together.

From the very beginning of the use of thermo-adhesive linings, the phenomena of crossing and returning have been observed and many attempts have been made since then to avoid these defects.

For example, document FR-A-2 177 038 proposed to make a coating by laying two layers of adhesive on a textile support in succession. e first layer is made by the induction of a viscous dispersion (paste) containing polymers with high viscosity and/or a high melting point higher than the temperature required for thermocollage, directly on the textile support by means of a screen printing frame.

The second layer is made by spraying a powder of thermo-adhesive polymers with a lower viscosity and/or melting point than the first layer.

The adhesive points of the first layer, due to the nature and composition of the compounds which make it up, have their adhesive surface until the next drying phase.

The materials used for the substrate have a higher melting point than the thermo-adhesive layer, thus forming a screen, the adhesive does not theoretically flow through the textile support when the liner is glued to a drapery.

However, as the points of the substrate are spherical or ellipsoidal, particles of thermo-adhesive material stick to the whole surface of the paste point, particularly at the point of contact between the paste point and the textile support; as a result, the thermo-adhesive material present at the point of contact flows through the textile support without the substrate being able to shield itself during the back-gluing, with the result that crossings appear.

On the other hand, the substrate penetrates more or less into the textile medium during direct induction due to its irregular surface, so that the adhesive surface of the substrate is variable and, consequently, the quantity of particles also, with adverse consequences for the adhesion forces between the liner and the drapery, and particularly for the heterogeneity of these adhesion forces.

A first object of the present invention is to propose thermo-adhesive linings and their manufacturing process which overcomes the limitations or drawbacks of those known to the state of the art.

In particular, one of the aims of the present invention is to provide a thermo-adhesive liner with which the thermo-adhesive material does not flow through the textile support when applied to a drapery.

Another object of the present invention is to propose a thermo-adhesive liner and its manufacturing process in which the adhesive is not in contact with the textile support, but only with the upper part of the substrate.

To this end, the invention relates first of all to a manufacturing process of a thermo-adhesive liner in which a textile support is induced by thermo-adhesive polymers distributed in points, characterized by the fact that successively: a substrate of polymers of crosslinking or dispersion pulp is deposited on a transfer medium with a smooth and regular surface by means of a screen printing frame in a solvent with a melting point above a predetermined thermocollage temperature; the resulting flat surface points are transferred to the textile medium; thermocollate polymer particles are applied to the substrate; the resulting thermocollate liner is radiated through a heating and/or irradiation chamber to ensure crosslinking and/or dispersion melting.

The transfer medium may be a cylinder or an endless carpet.

One method is to apply thermo-adhesive polymer particles by spraying and then to suck up polymer particles not in direct contact with the substrate points.

In another respect, the invention also proposes a thermo-adhesive liner characterized by the fact that it is obtained by the implementation of the process in accordance with the invention.

Other features and advantages of the present invention will be clearly seen by reading the following description made with reference to the attached drawings in which: Figure 1 is a schematic view of a device illustrating the manufacturing process of a notch according to the invention; Figure 2 is a schematic view of another manufacturing method of the device illustrating the manufacturing process of a notch according to the invention; Figure 3 is a schematic view, in cross-section, of a thermo-adhesive notch obtained by implementing a manufacturing process according to the invention; Figure 4 is a schematic view, in cross-section, of a thermo-adhesive notch of the state of the art.

According to the invention, a thermo-adhesive liner 1 is made which includes a textile backing 2 with 3 points of thermo-adhesive polymers on one of its outer surfaces.

The textile support 2 can be known in itself.

It can be a woven or knitted textile or a non-woven one.

Two layers of polymer induction, distributed in sections 5, 10 are successively applied to the textile backing 2.

To this end, sub-layer 5 of polymers in the form of paste or dispersion is first deposited in a solvent such as water in the form of points spread over a 6, 7, flat or convex transfer medium with a smooth, even surface.

The transfer support 6, 7 may be a cylinder 6 or a transfer mat 7, preferably in a closed loop, running on conveyor cylinders 8a, 8b.

This rotary frame, which is known by itself, cooperates with a screw 4a on the one hand and with a counter-cylinder which, as the case may be, is the transfer cylinder 6 or the transfer cylinder 8a of the transfer mat 7.

The axes of the screen frame 4 and the transfer cylinder 6 or the conveyor cylinder 8a shall be parallel to each other and perpendicular to the direction of rolling of the textile support 2.

The screen printing frame 4 allows the application of induction processes in the form of a paste or in dispersion in a solvent such as water.

In the case of wet-induction processes, very fine polymer powders, in aqueous dispersion, are applied to the support by a hollow screw installed inside the rotary cylinder which has a thin perforated wall.

The composition of sublayer 5 varies according to the application. In some cases, finely ground materials with a melting point higher than that of thermocolling particles 10 are used, e.g. polyethylene. In other cases, chemically reactive materials are used so that their reactivity leads to a fusible even higher than thermocolling particles 10, such as aminoplast resins, acrylic, and urethane-acrylate resins, polyurethane resins, epoxy resins.

To make an induction paste from these polymers, they are used finely ground in dispersion in water, and to obtain a pasty state of the mixture, thickeners may be added.

This paste is then deposited on the transfer cylinder 6 or transfer mat 7 and then undergoes processing to transform the solvent in whole or in part, and/or to melt the finely ground polymer or to activate polymers sensitive to radiation sources (such as UV, EB, etc.) by radiation.

The next step is to transfer the grid of points from sublayer 5 to the textile backing 2. To allow the transfer, textile backing 2 is pressed, as shown in Figure 1, between the transfer cylinder 6 and a backing cylinder 9; and as shown in Figure 2, the textile backing 2 is pressed between the transfer cylinder 8b of the transfer mat 7 and the backing cylinder 9.

The transfer support 6, 7 shall be tangent to the screen frame 4 in a zone 14 and the textile support 2 in a zone 15 respectively, the said zones 14, 15 being in the same plane or in parallel planes.

Textile support 2 is tangent to each of the two cylinders 6, 9 or 8b, 9 between which it passes, in zone 15.

Therefore, because the adhesion energy of sublayer 5/textile support 2 is higher than that of sublayer 5/transfer support 6, 7, the location of the transfer is at the point of contact between the transfer support 6, 7 and the textile support 2.

The points of sublayer 5 thus transferred have a flat surface and a low thickness and are arranged on the surface of the textile support 2.

A device is then used to disperse the thermo-adhesive polymer particles 10 onto the textile support 2 coated with sub-layer 5 in such a way that the particles 10 adhere to the surface of the points of the adhesive sub-layer 5.

These thermo-adhesive polymer particles 10 may be polyamide or polyester particles with a particle size of 60 μm to 200 μm. The latter adhere to the flat surface of the points of the transferred sub-layer 5 on the one hand, the other remaining in contact but not adhering to the surface of the textile support 2.

In order to remove excess particles 10 from the textile support 2 and to keep only particles 10 stuck to the flat surface of the points of the sub-layer 5, the assembly is depressed 11 and violently beat.

The textile support 2 is coated with thermo-adhesive polymers at points 3, then passes through a heating and/or radiation envelope 12 in order to evaporate the solvent in sub-layer 5 if necessary, to transform the sub-layer 5 to a melting point higher than the thermo-adhesive material 10 and to melt the thermo-adhesive particles 10.

The invention also relates to a thermo-adhesive liner 1 obtained by the application of the process just described.

The advantageous properties of thermo-adhesive liner 1 are due to the particular arrangement of the thermo-adhesive polymer 10 particles in relation to the sub-layer 5. The sub-layer completely shields thermo-adhesive 10 particles, i.e. these 10 particles are not in contact with the textile backing 2, but only with the upper part of the sub-layer 5 which is fine and perfectly flat (Figure 3). Therefore, when liner 1 is backed up on a cloth, thermo-adhesive 10 particles do not flow into the textile backing 2 under the influence of temperature and pressure, since the sub-layer coincides exactly with the thermo-adhesive 10 particles.

This was not the case with the liner from the earlier technique, as the dispersion of particles on substrate points directly coated by a screen frame on a textile support, left the possibility for some particles to stick to the periphery of the substrate points (Figure 4). As a result, the thermo-adhesive substance 10 could flow through the textile support 2 at the creep zones 17. Whereas this possibility does not exist for the thermo-adhesive liner 1 according to the invention, because the substrate is transferred.

The invention will now be described by two examples given for guidance but not as a limitation.

The Commission shall:

The screen printing frame: The surface of the meshwork is covered with a network of points: 75 holes per cm2 diameter of the holes in the frame: 300 μm Substrate material: Polyethylene Polyethylene powder with a particle size of less than 80 μm 25 %water 60 %adjuvants 10 %thickening 5 %Thermal adhesive material: Polyamide, in powder form, with a particle size of between 60 μm and 200 μmTextile backing: knitted textile, chain, single polyester with textured polyester frame. Weight 30 g/m2 Thermo-adhesive linings: total weight: 42 g/m2 of which 4 g is the weight of the substrate and 8 g of polyamide.

The Commission shall adopt the implementing acts referred to in Article 2 (2).

Cadre sérigraphique
	diamètre des trous : 320 µm
Matériau de sous-couche	Polymère acrylique et aminoplaste
Composition de la pâte	Polymère acrylique	50 %
	Aminoplaste	15 %
	Eau	25 %
	Divers	10 %
Matériau thermoadhésif	Polyamide en particules de 60 à 200 µm

The Commission shall adopt the implementing acts referred to in Article 4 (2).

The screen printing frame: 45 holes per cm2 diameter of the holes: 320 μm The following shall be indicated in the table: Polyamide in particles of 60 to 200 μm Textile support: Woven fabrics of cotton, containing predominantly, but < 85% cotton by weight, mixed principally or solely with man-made fibres and weighing > 200 g/m2, dyed

Claims (11)

1. A process for manufacturing a fusible interlining (1) wherein a base fabric (2) receives a coating of thermofusible polymers distributed in points (3), characterised in that the following steps are successively carried out :

   - depositing a sublayer (5) of polymers, in the form of a cross-linkable paste or a dispersion in a solvent, whose melting point is superior to a predetermined thermofusing temperature, on a transfer medium (6, 7) comprising a regular and smooth surface, by means of a silk screen printer (4) ;

   - transferring the flat surface, low thickness points thus obtained onto the base fabric (2) ;

   - applying particles of thermofusible polymers (10) on the sublayer (5) ;

   - running the fusible interlining (1) thus obtained through a heating and/or radiation chamber (12) so as to ensure the cross-linkage and/or melting of the paste or dispersion.
2. A process according to claim 1, characterised in that the particles of thermofusible polymers (10) are applied by powdering and in that the thermofusible polymer particles (10) which are not directly in contact with the points of the sublayer (5) are then drawn up.
3. A process according to claim 1 or 2, characterised in that the transfer medium is a roller (6).
4. A process according to claim 1 or 2, characterised in that the transfer medium is an endless conveyor (7).
5. A process according to anyone of claims 1 to 4, characterised in that the polymer of the sublayer (5) is selected among those having a melting point superior to that the thermofusible particles (10).
6. A process according to anyone of claims 1 to 5, characterised in that the polymer of the sublayer (5) is a polyethylene.
7. A process according to anyone of claims 1 to 5, characterised in that the polymer of the sublayer (5) is selected among the group made up of aminoplastic mixtures, acrylic resins, aminoplastic resins, polyurethanes.
8. A process according to anyone of claims 1 to 7, characterised in that the sublayer (5) is submitted, prior to its transfer, to a preliminary treatment so as to make it more homogeneous.
9. A process according to anyone of claims 1 to 8, characterised in that the transfer medium (6, 7) is tangent to the screen printer (4) in a region (14) and to the base fabric (2) in an region (15), respectively, said regions (14, 15) being located on the same plane or on parallel planes.
10. A process according to anyone of claims 1 to 9, characterised in that the thermofusible particles (10) have a size grading comprised between 60 and 200 µm.
11. A process according to anyone of claims 1 to 10, characterised in that the thermofusible particles (10) are polyamide, polyester, polyurethane or polyethylene particles.