FR2874030A1 - PROCESS FOR THE CONTINUOUS PRODUCTION OF A FLOCKE AND COLORED FLOOR HOLDER - Google Patents

Abstract

In this method of continuously manufacturing a flocked and colored sheet substrate (S), comprising steps of applying (3) a layer of polymerizable resin (RP) on at least one face of the sheet support, of spraying (4) white or unbleached flock fibers (FF) on said resin layer, polymerizing (5) the resin to fix the flock fibers to the web support, depositing (1) at least one sublimable dye ( E) for coloring the flock fibers, and sublimation (6) of the deposited dye, the step of depositing (1) at least one sublimable dye (E) is performed before the step of spraying (4) flock fibers and the sublimation step (6) is carried out after the polymerization step (5) of the resin by a simple application of heat without applying pressure to the web support (S).

Description

1 2874030

  The present invention relates to a method of continuously manufacturing a flocked and colored sheet support.

  Obtaining monochrome flocked surfaces having a given color is well known and controlled. Flock fibers are prepared by their manufacturer and dyed in the desired shade by conventional textile dyeing processes. These dyed fibers are then applied by the conventional method of "flocking" and fixed on a support by implantation in a layer of polymer resin. The final shade of the flocked product is then obtained by the combination of the initial color of the flock fibers, the density of these fibers applied to the support and the pigmentation of the resin in which the fibers are implanted. This method of obtaining monochrome flocked surfaces is widely used. It has, however, several drawbacks, both for the manufacturer of the flocks and for the industrial applicator: - for the manufacturer of the flocks, manufacturing in average quantities of a few thousand meters of products flocked in a given uniform color make use of some hundreds of kilograms of "flock" fibers, which are dyed in the given color desired (about 200Kg of "flock" fibers for 2000m2 of manufactured flocked product); the dyeing and finishing of such a large quantity of textile fibers leads to significant rejects of dyes and textile finishing agents, which themselves impose expensive wastewater treatment operations, as well as frequent operations of emptying and cleaning of manufacturing and dyeing equipment; - In the industrial applicator of "flock" fibers, these same fabrications in average quantities lead to significant downtime in the production as a result of machine cleaning operations which are essential between each change of color; 2 2874030 for example, a production of 2000m2 of flocked product, in a given color, can occupy a production time of 3 to 4 hours and a time of preparation and cleaning of the machine up to half the production time ; segmented fabrications also increase the systematic losses generated by the manufacturing process.

  On the other hand, it is known to use white or unbleached fibers to make flocked products. The use of white or unbleached fibers has many advantages both for the manufacturer of the "flock" fibers and for the industrial applicator: - for the manufacturer of flock fibers, elimination of textile dyeing operations and removal of the the use of dyestuffs, which leads to material and energy savings, reduced releases, the elimination of wastewater treatment operations and a strong improvement in industrial performance by significantly increasing the quantities produced by fiber reference: - for the industrial applicator of flock fibers, a strong improvement in productivity by reducing machine cleaning and downtime (time can represent 50% of production time); reduction of losses and rejections caused by these color changes and cleanings; and removal of dirty stains for the staff.

  Obtaining a flocked and colored product from white or unbleached fibers is obviously possible through an additional printing operation carried out on the white or ecru flocked product.

  Among the printing techniques, the sublimation printing which is applicable to certain synthetic fibers enables the continuous production (in rolls) of flocked and colored products, either united or reproducing a given single-color or multicolor design.

  This operation is usually done in recovery. More precisely, after the flocked product has been manufactured, a temporary paper preprinted with sublimable inks is brought into contact with the flocked product and the assembly is worn for several seconds at a temperature in the region of 200 ° C which can trigger the sublimation of the products. pigments contained in the ink used. The impression carried by the temporary paper is thus faithfully "transferred" hot on the flocked support, giving the latter a colorful, plain or multicolored, depending on the graphic characteristics of the preprinted temporary paper.

  This sublimation printing process, used by the holder of the present patent application to print his flocked articles continuously, is described in particular in documents EP-A-0 913 271 (or US-B-6 224 707), and EP -AO 993,963 (or US-B-6,249,297). These two documents provide for the use of "flock" fibers made of polyamide or polyester, whose "title" (diameter) is between 0.5 Dtex and 20 Dtex, and whose length is between 0.3mm and 3mm.

  The polyamide fibers, for example "nylon 6" or "nylon 6-6" (registered trademarks) are quite resistant to the crushing imposed by the sublimation printing operation, during which the "flock" fibers are subjected to the combined effect of the heat approximately 200 C to 210 C and the pressure of support of the pre-printed paper on the flocked support. On the other hand, the resistance to washing and rubbing, dry and wet, of the colors thus obtained on the polyamide fibers, as well as the liveliness of these colors, are low.

  4 2874030 On the other hand, the polyester fibers lead to prints with very good fastness or resistance to washing, friction, light ... and they make it possible to obtain strong and lively colors. Under the conditions described in the aforementioned documents, polyester flock fibers, however, have the disadvantage of lying down under the combined action of temperature and pressure during the sublimation printing operation. As a result, the "flock" fibers on the surface of the flocked and colored support have a crush and general orientation unpleasant. The touch of the flocked surface is rough, at least in one direction, that is to say in the direction corresponding to the passage of a finger in the direction to "fur-back", and the printed surface is flat and crushed.

  This crushing phenomenon could be limited by decreasing the intensity of the pressure exerted during the printing-sublimation operation. However, a perfect and stable contact must be maintained between the flocked support and the preprinted temporary paper throughout the duration of the sublimation printing operation. If it were not so, any movement, even small, of one of the two elements relative to the other during this operation would give the impression obtained on the flocked medium a blurred or "drooled" appearance. However, the fact of having to maintain a close contact between the pre-printed paper and the flocked medium during the entire printing-sublimation operation obviously involves exerting a certain pressure on the assembly and to ensure that this pressure perfect consistency and a very good regularity. A compromise must therefore be found between, on the one hand, a sufficiently high pressure to maintain a close contact between the preprinted paper and the flocked medium and, on the other hand, a sufficiently low pressure to prevent crushing of the fibers. flocked media 2874030 during the sublimation printing operation. Such a compromise is difficult to find and, in any case, it does not allow to give complete satisfaction both in terms of the sharpness of the impression obtained and in terms of a soft touch of the flocked surface of the support .

  The negative effect of crushing caused by the imprinting operation could be limited by the use, as flocking adhesive, of a polymer resin with a high softening point and melting point, or by the choice of fibers. polyesters having improved temperature resistance, such as, for example, "PCT" type fibers. The improvement obtained with low temperature-sensitive polymer resins is significant, but it does not prevent the preferred orientation of the "flock" fibers. Fibers with improved thermal resistance exist, but they are only available in titers higher than 1.5 Dtex and the printed flocked product obtained with these fibers still retains a "rough" feel. The use of such fibers is therefore possible, but the result obtained is not satisfactory in terms of the "touch" of the flocked product.

  The present invention therefore aims to provide a method for obtaining a flocked and colored product, from white or unbleached fibers, requiring no printing operation in recovery, the flocked and colored product having an extremely soft feel, without orientation and insensitive to the action of the temperature (this method does not interfere with a possible orientation of the "flock" fibers conferred on the flocked layer before the sublimation operation).

  For this purpose, the subject of the invention is a process for the continuous production of a flocked and colored sheet support comprising steps for applying a polymerizable resin layer to at least one face of the sheet-like, spraying support. flock fibers, white or unbleached, on said resin layer, polymerizing the resin to fix the flock fibers to the web support, depositing at least one sublimable dye for coloring the flock fibers, and sublimating the deposited dye, characterized in that the step of depositing at least one sublimable dye is carried out before the step of spraying the flock fibers and the sublimation step is performed after the polymerization step of the resin by a simple applying heat without applying pressure to the web support.

  Since the sublimation step is performed without applying pressure to the flocked web support, there is no risk of crushing the flock fibers and, as a result, the surface of the flocked carrier retains a pleasant and soft feel. In addition, since the deposition of the dye (s) on the support is carried out before the step of projecting the flock fibers (flocking) there is no risk that the flock fibers are crushed in the case where the operation deposition of the dye (s) is carried out by contacting under pressure of any dye-bearing element with the web support to be colored and flocked. The invention does not exclude, however, the cases where the depositing of the dye (s) is carried out by a non-contact process, for example by spraying or by ink jet.

  The method according to the invention may furthermore have one or more of the following characteristics: in a first embodiment of the process according to the invention, said at least one sublimable dye is deposited on the sheet support before the step of application of the polymerizable resin layer; in a second embodiment of the process of the invention, said at least one sublimable dye is deposited on the polymerizable resin layer before the flock fiberization and polymerization steps; in either of the first and second embodiments, said at least one sublimable dye is uniformly deposited on said at least one side of the web support or said polymerizable resin layer; alternatively, said at least one sublimable dye is deposited in the form of patterns on said at least one face of the sheet-like support or on said layer of polymerizable resin; in a third embodiment of the process according to the invention, said at least one sublimable dye is mixed with the polymerizable resin and a layer of the mixture obtained is applied to the sheet support; in any one of the three embodiments of the process of the invention, the polymerizable resin layer is uniformly applied to the at least one face of the web support; alternatively, the polymerizable resin layer is patterned on said at least one face of the web support; for the projection step of the "flock" fibers, "polyester" flock fibers having a fine titer, preferably less than 1.2 Dtex, are used; preferably, polyester fibers having a titer in the range of 0.3 to 1 Dtex, and having a length of between 0.2 and 0.5 mm; even more preferably, super micro-polyester fibers with a titre of about 0.3 Dtex are used; A resin having a high softening point, preferably having a softening point greater than 170 ° C., for example a polyurethane resin, is used as the polymerizable resin; a resin having a low adhesion power, for example an acrylic resin in modified aqueous dispersion, is used as the polymerizable resin.

  Other objects, features and advantages of the invention will become apparent from the following description of several embodiments of the invention given by way of example with reference to the accompanying drawings, in which: FIG. schematic a first embodiment of the method of the invention; FIG. 2 schematically illustrates a second embodiment of the method of the invention; and - Figure 3 schematically illustrates a third embodiment of the method of the invention.

  Referring firstly to Figure 1, it can be seen that the first embodiment of the method according to the invention comprises a first step 1 of depositing at least one ink E containing at least one sublimable dye on a support S continuously scrolling in the direction indicated by the arrow F, a second step 2 of drying the ink E deposited on the support S, a third step 3 of applying a layer of an adhesive A (polymerizable resin RP) on the ink layer E, a fourth step 4 or flocking step of projecting flock fibers FF onto the polymerizable resin layer RP, a fifth step or fixing step of polymerizing the resin of the adhesive A in order to fix the foot of the FF "flock" fibers in the resin, the free portion of said "flock" fibers FF 9 2874030 extending substantially perpendicularly to the surface of the resin layer, and a sixth step 6 or step Sublimation e sublimation sublimation dye (s) contained in the ink E to color the FF flock fibers.

  The support S can be chosen from a wide range of flockable media, such as paper, cardboard, plastic film, fabric or nonwoven. In the case where the support S is constituted by a plastic film, the support can, in certain cases, before treatment by the method of the invention, be advantageously stabilized by thermal bonding of the plastic film on a temporary support in a similar manner to that described in EP-A-0 993 963 already mentioned above. In any case, the support S may be in the form of a roll which is placed on a supply reel (not shown in FIG. 1) from which the roll is unrolled continuously to carry out the operations of the steps 1 to 6 of the process according to the invention.

  The first step 1, step of depositing the ink E, can be performed by any conventional continuous deposition means, such as by screen printing, heliography, flexography, offset, or by ink jet. The ink E may be deposited so as to cover the entire surface of the support S or only selected areas of the surface of the support S according to one or more predefined patterns. In both cases, it is possible to use a single ink or several inks so as to conventionally obtain a monochrome or polychrome printing according to the desires.

  The second step 2, drying step, can be carried out conventionally for example by passing on a heating drum or in a tunnel oven.

  In step 3, the polymer resin RP used as adhesive A may be deposited in thickened and / or thixotropic aqueous emulsion (acrylic resins or polyurethanes), in the form of plastisols, or, in a preferred version of the invention, in the form of liquid resins 100% solid or "high solid", polymerizable thermally or by irradiation (ultraviolet or electron beam). The latter resins, 100% solids or "high solid" have the advantage of being able to present a very high softening point, which may be useful when the support S, once flocked, is subsequently subjected to heat treatments at high temperature. relatively high temperatures. An example of a "high solid" resin that can be used for step 3 is the "IMPRANIL-IMPRAFIX" system from Bayer, Germany.

  In the case where the flock fibers FF must be fixed temporarily to the support S, for example when the flock fibers FF of the flocked and colored support obtained by the process of the invention must be able to be transferred in whole or in part to another support, for example a textile support, after having been completely covered or selectively depending on the case, by a coating operation or by a screen printing operation, a heat-activatable adhesive layer (hot-melt-based system in the course of a subsequent treatment of the flocked and colored support, a resin having a low adhesive capacity is used as the polymerizable resin R. For this temporary fixation of the flocked fibers, it is possible to use, for example, an acrylic resin which is deposited in modified aqueous dispersion, in a limited amount, for example from 30 to 60 g / m 2 (weight of dry resin).

  According to the desires or requirements, the polymeric resin layer RP used as adhesive A may be uniformly coated or in a given pattern, for example by screen printing with the frame, rotary. The resin layer has a final thickness of between 15 and 100 μm, depending on the nature of the FF flock fibers used for the fourth stage 4. In general, the more flock fibers used have a fine title and a short length, the thickness of the polymerizable resin layer may be small.

  In the fourth step 4, the FF flock fibers are projected into the RP resin resin layer by any of the conventional flocking techniques, which are well known and need not be described in detail. detail.

  Although flock fibers, white or unbleached, of various kinds may be used for the flocking step 4, polyester fibers (standard polyester of the PET or PCT type modified polyester type) are preferably used because of their good resistance to washing and rubbing and because of their good resistance to light after they have been colored.

  Preferably, polyester fibers having a titer of less than 1.5 Dtex and, still more preferably, having a titer in the range of 0.3 to 1Dtex, and having a length of between 0.2 and 0, are used. , 5mm, so as to obtain a flocked medium having a soft or very soft feel.

  In a preferred version of the invention, "supermicro-fibers" of PET having a title close to 0, 3Dtex and cut to a length of between 0.2 and 0.5 mm are used. These fibers are sold by VELUTEX-FLOCK S.A. in GRANOLLERS, Spain. These "super microfibres" give the flocked surface an exceptionally soft feel and have the advantage of being virtually insensitive to crushing when subjected to the combined action of heat and pressure. This surprising and unexpected property (it is commonly and logically admitted that fibers of larger diameter have a higher resilience) allows the use of products flocked with these fibers in applications such as thermo-bonding, thermoforming or thermocompression (hot molding of parts covered with a flocked support) or mold decoration, better known to those skilled in the art under the designation "decoration in mold", without crushing of the fibers occurs "flocks" and without altering the visual appearance or the very soft touch of the flocked product. In the "decoration in mold" a plastic material is injected into a mold whose cavity has a surface which is at least partly covered with a flocked plastic film whose flock fibers are turned towards the inner surface of the cavity of the mold. mold.

  In step 5, the polymerizable resin RP is polymerized by irradiation (UV or electron beam) or by thermal means. The thermal polymerization can be carried out for example by passing the support S in a tunnel furnace or on the peripheral surface of a rotating heating drum at a temperature between 100 C and 180 C.

  In step 6, the sublimation of the sublimable dye (s) contained in the ink E is obtained by bringing said dyes to a temperature in the region of 200 ° C., for example 210 ° C., for a period of 30 to 30 ° C. 45 seconds. Again, this can be done by passing the support S in a tunnel oven or on the peripheral surface of a rotating heating drum (it can be the same tunnel oven or the same heating drum as that used for the step 5, said furnace or said drum then having sections at different temperatures).

  It should be noted that the time and temperature necessary to obtain sublimation can be reduced compared to the values indicated above, if one works in a low pressure (partial vacuum) atmosphere. In this case, the aforementioned tunnel furnace or heating drum may be placed in a partial vacuum chamber.

  Sublimable dyes contained in the ink E are then activated. They pass into the vapor phase, pass through the polymer resin RP, which is in these conditions perfectly permeable to these gaseous dyes, and they are fixed permanently on the FF flock fibers. If, in step 1, the ink E had been uniformly deposited and monocolored, the product flocked with white or unbleached fibers then takes the uniform color corresponding to the chosen coloring formula. On the other hand, if in step 1, the ink E has been printed in a multicolored pattern, the surface of the flocked product will accurately and sharply reproduce the original pattern, the path of the gaseous dyes being unidirectional.

  During the process described above, it can be seen that, at no time, the flock fiber layer is subjected at the same time to a pressure and a high temperature. As a result, the flock fibers FF are not crushed and the flocked and colored surface of the support S keeps a very soft touch.

  After step 6, the assembly composed of the support S and the layer of colored "flock" fibers is cooled by natural cooling or, preferably by forced cooling, for example by passing on the peripheral surface of one or more rotary drums cooled by a circulation of water. In the case where the support S is a plastic film stabilized by a temporary support, the latter is separated from the plastic film 14 2874030 and wound on a winding reel for eventual re-use as a temporary support.

  On the other hand, whatever its nature, the support S, flocked and colored, can be wound on a reel for later use or for possible subsequent processing, for example "decoration in mold ", thermo-forming, thermo-compression, heat-sealing or other.

  In a second embodiment of the process of the invention, illustrated in FIG. 2, the sublimable dye (s) (ink E) are first mixed with the adhesive A (polymer resin), their formulation to obtain a given color. This formulation can be advantageously prepared by a computer-controlled mixing device. In this case, the coloring formula of the hue to be reproduced can be obtained by mixing four dyes composing a four-color process (trichromatic + black), the precise quantities of the four dyes being determined by a computer system according to the desired hue to reproduce .

  Then, the mixture A + E of the polymer resin and sublimable dyes is deposited on the support S (step 11 of Figure 2). The deposition of the mixture A + E may be carried out for example in a uniform layer by coating or according to a predefined pattern by rotating screen printing.

  After step 11, the method illustrated in FIG. 2 further comprises a flocking step 12 by which white or unbleached FF flock fibers are projected and implanted in the colored polymer resin, followed by a step of fixation 13 (polymerization), by which the flock fibers are fixed at their base by the colored polymer resin, and finally a sublimation step 14, by which the sublimable dyes 2874030 are sublimated and permanently affixed to the flock fibers. ". The three steps 12, 13 and 14 can be performed in a manner and under conditions similar to those described above with respect to steps 4, 5 and 6 of the first embodiment of the method of the invention illustrated in FIG. Figure 1.

  The second embodiment of the method of the invention illustrated in FIG. 2 only makes it possible to obtain a support having a flocked surface having a uniform hue. But this result is obtained from white or unbleached fibers, without prior dyeing or posterior printing of flock fibers, which leads to extremely important production savings. In addition, since no pressure is applied to the flock fibers EF during steps 13 and 14, the flock fibers are therefore not overwritten and retain the orientation that was given to them during the step. 12 flocking. As a result, the flocked and colored surface of the support S thus obtained retains a soft or very soft feel according to the fineness of the flock fibers used. Again, if we use the "super micro-fibers" mentioned above, the flocked and colored support will keep a very soft touch even if it is subsequently subjected to "in mold decoration", thermo-compression , thermoforming, thermo-bonding or other similar operations.

  In a third embodiment of the method of the invention illustrated in FIG. 3, the support S is first covered with a colorless or uniformly pigmented adhesive A in white (step 21).

  The adhesive A (polymer resin RP) can be applied in a uniform layer (single coating) or according to a predefined pattern by rotating screen printing. While the thus obtained polymeric resin layer RP is still liquid, this polymeric resin layer is then coated (step 22), uniformly or selectively, with an ink E containing at least one sublimable dye by non-contact coating or printing technique, for example by spraying, spraying or inkjet printing. While the polymer resin layers RP and ink E are still liquid, white or unbleached FF fibers are projected and implanted into the resin layer RP through the ink layer E (flocking step 23), then they are then fixed to their base by polymerization of the polymer resin (step 24) and finally stained by sublimation of the sublimable dye (s) contained in the ink E (step 25) . Steps 23, 24 and 25 may proceed in a manner and under conditions similar to those of corresponding steps 4, 5 and 6 of the first embodiment of the method of the invention illustrated by FIG. coating or printing the ink E (step 22), the flocked and colored surface of the support S will have a uniform color or a multicolored appearance reproducing a predefined pattern or a random appearance.

  Again, with the third embodiment of the process of the invention illustrated in FIG. 3, since no pressure is applied to the flock fibers FF during the sublimation step 25, the fibers flocks "do not undergo any crushing and the flocked surface of the support S thus retains a soft or very soft touch depending on the fineness of the fibers used in the flocking step 23.

  It goes without saying that the three embodiments of the invention which have been described above have been given by way of purely indicative and non-limiting example, and that many modifications can be easily made by the man of the invention. art without departing from the scope of the invention. For example, although in all three described embodiments only one of the two faces of the web support S is coated with flock fibers and stained, the method described could be applied to both sides of the support S.

Claims (1)

18 2874030 Claims   A method for the continuous production of a flocked and colored sheet support (S), comprising application steps (3, 11, 21) of a polymerizable resin layer (RP) on at least one face of the support in ply, projection (4, 12, 23) of flock fibers (FF) white or unbleached on said resin layer, polymerization (5, 13, 24) of the resin for fixing the flock fibers to the sheet support, deposition (1, 11, 22) of at least one sublimable dye (E) for dyeing the flock fibers, and sublimation (6, 14, 25) of the deposited dye, characterized in that the deposition step (1, 11, 22) of at least one sublimable dye (E) is carried out before the step of projecting (4, 12, 23) flock fibers and the sublimation step (6, 14, 25) is carried out after the polymerization step (5, 13, 24) of the resin by a simple application of heat without applying pressure to the web support.   2. Method according to claim 1, characterized in that said at least one sublimable dye (E) is deposited on the web support (S) before the step of application (3) of the polymerizable resin layer (RP) .   3. Method according to claim 1, characterized in that said at least one sublimable dye (E) is deposited on the polymerizable resin layer (RP) before the steps (23 and 24) of flocking and polymerization fibers.   4. Method according to claim 2 or 3, characterized in that said at least one sublimable dye (E) is arranged uniformly on said at least one side of the sheet support (S) or on said polymerizable resin layer (RP). ).   5. Method according to claim 2 or 3, characterized in that said at least one sublimable dye (E) is deposited in the form of patterns 2874030 19 on said at least one side of the web support (S) or on said layer of polymerizable resin (RP).   6. Process according to claim 1, characterized in that said at least one sublimable dye (E) is mixed with said polymerizable resin (RP) and a layer of the obtained mixture is applied (step 11) to the web support (S). 7. Method according to any one of claims 1 to 6, characterized in that the polymerizable resin layer (RP) is applied uniformly on said at least one side of the web support (S).   8. Method according to any one of claims 1 to 6, characterized in that the polymerizable resin layer (RP) is applied in the form of patterns on said at least one side of the web support (S).   9. Method according to any one of claims 1 to 8, characterized in that for the step (4, 12, 23) of projection of flock fibers (FF) is used polyester fiber flocks having a fine title, preferably less than 1.5 Dtex.   10. A process according to claim 9, characterized in that polyester fibers having a titer in the range of 0.3 to 1 Dtex and having a length of between 0.2 and 0.5 mm are used.   11. The method of claim 9 or 10, characterized in that super polyester micro-fibers having a title of about 0, 3Dtex are used.   12. Process according to any one of Claims 1 to 11, characterized in that a 100% solid resin with a high softening point, preferably with a softening point greater than 170, is used as polymerizable resin (RP). vs.   13. Process according to claim 12, characterized in that a polyurethane resin is used as the polymerizable resin (RP).   14.Procédé according to any one of claims 1 to 11, characterized in that used as a polymerizable resin (RP) a low-tack resin.   15. The method of claim 14, characterized in that the polymerizable resin (RP) is an acrylic resin in aqueous dispersion modified.