FR2783441A1 - Pretreatment of flocked substrate for diverse printing processes lightly applies and dries polymer resin from suspension to prevent flock detachment, interference in printing machines and non-vibrant color printing - Google Patents

Abstract

Flocks, already attached to the substrate, are lightly impregnated with polymer resin in aqueous emulsion in a bath. The material, thus impregnated, is dried. The resin attaches any loose flock fibers to the substrate. It limits ink penetration into the flock, in any subsequent printing stage. An Independent claim is included for the product of such manufacture. Preferred features: The resin content in the aqueous bath is preferably 2-12 dry wt%, especially 6-7%. Impregnation density is 100-150 g/m<2>. The resin is deposited in a moist environment on the flocked side only. Processes typically involve moistening, coating or atomization. Following impregnation, excess resin solution is wrung out using pressure rollers, which also even-out the deposit.

Description

Process for treating the flocks of a flocked support and a product obtained by

This process The present invention relates to a process for treating the flocks of a flocked support, the support being able to be any one, for example of paper, cardboard, plastic, textile or nonwoven. The invention also relates to the product obtained by this process, whether or not it is

subsequently printed.

It is customary to decorate flocked supports, by printing multicolored patterns on the flocks or by marking the flocks by thermal application of a colored or metallized film, the latter process being generally known under the term "hot foil". Flocked substrates are thus decorated in many areas, for example packaging and packaging,

decoration, clothing, or wall covering.

The flocked supports can be decorated by screen printing, but such printing does not allow the precise reproduction of finely screened four-color patterns, because the screen printing frames used are

limited by the dimensions of the mesh.

The flocked supports can also be decorated by gravure printing, but this type of printing is also limited from the point of view of the quality and the fineness of the graphic representation, and also requires the prior production of specific printing tools. , such as

engraved cylinders, which are very expensive.

2 5 In addition, both screen printing and gravure printing require a large amount of ink to be deposited on the

flocks, and this whatever the nature of the support to be printed.

We also know the offset or flexographic printing processes, but these cannot be implemented in a simple way to decorate a flocked surface, for the following reasons: - unlike the serigraphic or heliographic printing process, the machines of offset or flexographic printing are sensitive to free flocks which are always more or less present on a

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sensitive to free flocks which are always more or less present on a flocked support; in fact, these free flocks leave the flocked support as it passes through the printing machine and get stuck in parts of the machine, such as the drive rolls and the lacquers, which deteriorates the quality of the printing machine. printing and requires frequent cleaning, and therefore significant downtime; - as offset, flexographic or inkjet printing deposits only small amounts of ink on the support to be decorated, a substantial amount of this ink deposit can be absorbed by the flocks of the flocked support which present, like any textile, a certain absorption power, which accordingly reduces the intensity of the printed colors and limits

the possibilities of achieving strong or bright colors.

The marking of a flocked support by thermal application of a colored or metallized film is also possible, under certain conditions. In such a process, a colored or metallized layer is applied to a temporary support, generally a transparent polyester film, then is partially transferred to the flocks of the flocked support using a heating tool, such as a punch, which briefly presses said layer strongly against the flocks of the flocked support, said layer then being transferred to the flocked parts of the support which have been crushed by the punch. However, the marking of a flocked support is more delicate than that of a paper or cardboard, due to the textile and irregular nature of the flocked support, which requires specific application conditions to be observed, to to know the selection of a hot stamping film adapted to the flocked support, and the absolute respect of the conditions of marking on a precise and very well regulated machine. Even if these conditions are perfectly respected, the marking of very fine drawings or texts of very small dimensions cannot be done in

good readability conditions or will not be very resistant to friction.

To make the flocked support easily printable by the aforementioned methods, it is also possible to modify the flocked surface by crushing the flocks by calendering or graining with a heating cylinder, smooth or with raised patterns, put under pressure, but in this case, the aspect and the

feel of the flocked support thus crushed are altered.

The object of the present invention is to provide a method for treating the flocks of a flocked support, which makes it possible to maintain a soft and pleasant feel of the flocked support thus treated, which makes it possible to print the latter by conventional offset printing methods. , flexographic, inkjet or thermal marking using a colored or metallized film, under the usual conditions of implementation of these processes, without particular adjustment or use of special raw materials, while allowing a precise reproduction of multicolored patterns, especially in four-color, with the quality of a

photography.

To this end, the subject of the invention is a process for treating the flocks of a flocked support, characterized in that it consists in impregnating the flocks of the flocked support with a small amount of polymer resin and in drying the flocked support. thus impregnated, said resin being intended to fix any flocks to the support in the free state and to limit penetration, when

of a possible subsequent printing step, inks in the flocks.

Preferably, the resin is in emulsion in an aqueous bath, and the resin content of the aqueous bath is advantageously between 2 and

12% by weight of dry matter, preferably between 6 and 7%.

In a particular embodiment, the method consists in impregnating the flocks of said emulsion with a density of between

Og / m2 and 150g / m2.

According to another characteristic of the invention, the process consists in depositing the resin in a humid environment on the flocks, on the only side of the flocked surface of the support, by any process such as wetting, impregnation, coating or coating. spray. Advantageously, the process consists, after impregnation of the flocks with the resin in aqueous dispersion, in wringing said flocked support thus impregnated between two pressing rolls.

to remove excess resin and even out the resin deposit.

Advantageously, the resin is a synthetic polymer resin

chosen from acrylic esters, synthetic latexes and polyesters

polyurethanes, so that the flocked support thus impregnated retains a

soft, dry and non-sticky touch.

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Preferably, the support is chosen from paper supports, in

cardboard, plastic, textile or non-woven.

The invention also relates to the product obtained by the process as described above, characterized in that it comprises a flocked support, the flocks of which are impregnated with dry resin, the density of which is included.

between 2 and 12g / m2, preferably between 6 and 7g / m2.

Advantageously, the resin-impregnated flocks of the aforementioned product are printed with multicolored patterns, for example in four-color, by an offset printing process, flexographic, by inkjet or by

thermal application of a colored or metallized film.

We will now briefly describe the implementation of the method

according to the invention.

The flocked backing is manufactured by a method known per se, using conventional textile fibers and an adhesive polymer resin to bond the flocks to the chosen backing. Preferably, according to the invention, small-sized flocks are used, for example between 0.3 and 2 mm, and the fibers are chosen from natural fibers, rayon fibers based on viscose, or cotton fibers, so that the support thus flocked has a

soft and pleasant touch.

The flocked support is then impregnated with another polymer resin in emulsion in an aqueous bath, rather than in organic solution, in order to

protect the environment.

The aqueous bath containing the resin in dispersion is deposited uniformly on the flocks of the flocked support, by any process, for example by wetting, impregnation, coating or spraying. Advantageously, the flocked support passes between two cylinders, the applicator cylinder of which comprises a layer of foam impregnated with said emulsion in order to deposit it on the flocks of the flocked support. Then, the flocked support thus impregnated passes between two pressing rolls, for example one made of steel and the other of rubber, to remove the excess resin and make the resin deposit uniform. In a way, this is a step of dewatering the impregnated flocked support. The concentration of the impregnation bath is adjusted so as to deposit a very small amount of resin on the flocked supports, so as to maintain a soft and pleasant touch, but the amount of resin must be sufficient to allow subsequent printing, such as

explained below.

After the impregnation step, the impregnated flocked support is dried by passing it through a heat treatment oven, in order to evaporate the water contained in the treatment bath. Then, the product thus treated is rolled up and packaged under conditions suitable to the nature of the support. In the case of paper or cardboard supports, the moisture content of the packaging must be close to the recovery rate of the supports. Finally, the product thus treated is cut into formats adapted to the types of printing required, or else in the form of small rolls of

dimensions adapted to different printing machines.

Alternatively, the treatment bath can be applied by coating by passing the flocked support between a cylinder and a doctor blade.

applicator.

It is important to note that thanks to the presence of the resin in the flocks, the surface of the flocks is more regular, substantially like paper or cardboard, which allows printing under the usual conditions of implementation, without particular adjustment. In particular, offset or flexographic or inkjet printing can be used, since the presence of the resin in the flocks limits the absorption of ink by the flocks. In addition, there is no longer any risk of the free flocks getting stuck in the parts of the printing machine, as they

are retained on the support by the resin.

It will also be noted that it is preferable not to proceed to brushing or cleaning the flocked support after its treatment with the

method of the invention.

Although the invention has been described in connection with examples of particular embodiments, it is obvious that it is in no way limited and that it includes all the technical equivalents of the means described thus.

that their combinations which come within the scope of the invention.

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Claims (10)

1. A method of treating the flocks of a flocked support, characterized in that it consists in impregnating the flocks of the flocked support with a small amount of polymer resin and in drying the flocked support thus impregnated, said resin being intended to fix to the support any flocks in the free state and to limit penetration, during a possible subsequent printing step, inks in the flocks. 2. Method according to claim 1, characterized in that the resin is as an emulsion in an aqueous bath. 3. Method according to claim 2, characterized in that the resin content of the aqueous bath is advantageously between 2 and 12% in weight of dry matter, preferably between 6 and 7%. 4. Method according to claim 3, characterized in that it consists in impregnating the flocks of said emulsion with a density of between g / m2 and 150g / m2. 5. Method according to one of claims 2 to 4, characterized in that that it consists in depositing the resin in a humid environment on the flocks, on the only side of the flocked surface of the support, by any process such as wetting, impregnation, coating or spraying. 6. Method according to claim 5, characterized in that it consists, after impregnation of flocks with the resin in aqueous dispersion, in wringing said flocked support thus impregnated between two pressing rolls. to remove excess resin and even out the resin deposit. 7. Method according to one of claims 1 to 6, characterized in that the resin is a synthetic polymer resin chosen from esters- acrylics, synthetic latexes and polyester-polyurethanes, so that the flocked support thus impregnated retains a soft, dry and non- tights. 8. - Method according to one of claims 1 to 7, characterized in that that the support is chosen from among the supports in paper, cardboard, plastic, textile or non-woven. 7 2783441 9. - Product obtained by the process according to one of claims 1 to 8, characterized in that it comprises a flocked support whose flocks are impregnated with dry resin whose density is between 2 and 12 g / m2, preferably between 6 and 7g / m2. 10. - Product according to claim 9, characterized in that the resin-impregnated flocks of the aforementioned product are printed with multicolored patterns, for example in four-color process, by an offset printing process, flexographic, by inkjet or by application. thermal film colored or metallic.