IT202100003779A1 - PROCESS AND APPARATUS FOR THE RECONDITIONING OF RELEASE PAPER - Google Patents

Description

PROCESS AND APPARATUS FOR RECONDITIONING

OF PAPER RELEASE

DESCRIPTION

The present invention relates to a process and to an apparatus for cleaning the so-called ?release paper? used in the ennoblement processes of leathers (natural or synthetic), fabrics (natural or synthetic) or in any case in all processes in which it? the use of release paper is foreseen.

background

In this description you will do? mainly reference, albeit purely by way of example, to the leather treatment sector (natural or synthetic).

The leather ennobling process? well known and therefore it will not be? described here in detail.

In general terms, this type of process involves the application of an ennobling layer on a typically laminar, natural, textile or synthetic support. Typically the ennobling layer ? made of a polymeric film, preferably the polymer ? a polyurethane.

For the application of the ennobling layer ? foreseen the use of the so-called release paper which, for example, can? present an embossed surface to make s? that the final product then reproduces the appearance of natural leather, or in any case presents the desired decoration. The ennobling layer is applied to the release paper, which is then placed next to the laminar support.

The whole is heat treated to allow the components to dry. The paper is separated from the support and the ennobling layer remains adhered to the laminar support, reproducing the external appearance of a natural product, or in any case exposing the desired decoration.

In order to be able to reuse more? Sometimes the release paper, it is necessary to clean it to eliminate the residues of the ennobling product and therefore make it ready for a new processing cycle.

At present, removing residue from newly used release paper ? carried out essentially mechanically.

In particular, the solution pi? common consists in adhering the adhesive tape on the face to be cleaned of the release paper and then removing the adhesive tape that carries with it? most of the residue present on the release paper.

However, this methodology has some important disadvantages.

First of all, the adhesive tape used must be replaced every time it runs out, with a consequent increase in process management costs.

The use of this method also involves considerable noise pollution in the industrial environment which requires workers to use specific safety devices.

Furthermore, used adhesive tape represents a huge environmental problem, as it is classified as special waste which must be disposed of properly so as not to cause damage to the environment due to the substances present on its surface.

Finally, the cleaning of the paper carried out with this methodology? sometimes not accurate, with a part of residues that remaining on the paper itself can affect the quality? of the operations connected to its subsequent use.

Technical problem solved by the invention

Purpose of the present invention? that of solving the problems left open by the prior art, providing a release paper reconditioning process as defined in the independent claim n.1.

Further object of the present invention ? a release paper reconditioning apparatus as defined in claim 12.

Further characteristics of the present invention are defined in the corresponding dependent claims.

The present invention has some important advantages.

First of all, the invention avoids the use of a roll of disposable adhesive tape, which can be used only once and which must subsequently be disposed of, with the relative huge costs both for supply and for disposal. In fact, adhesive tape contaminated by residues represents special waste, the disposal of which in any case has an environmental impact.

Furthermore, the present invention avoids the problem of noise caused by the detachment of the adhesive tape, which is causes discomfort for operators and requires the adoption of soundproofing systems to reduce noise pollution.

Furthermore, an apparatus according to the invention has decidedly reduced overall dimensions with respect to the prior art, and, above all, a high degree of simplicity. constructive, with consequent advantages in terms of maintenance.

Other advantages, together with the characteristics and modalities? of use of the present invention, will become evident from the following detailed description of preferred embodiments thereof, presented by way of non-limiting example.

Brief description of the figures

In the continuation of this description will come? with reference to the drawings shown in the attached figures, in which:

? figure 1 ? a reconditioning plant of known art;

? figure 2 ? a schematic representation of an apparatus according to a first embodiment of an apparatus according to the present invention;

? figure 3 ? a schematic representation of an apparatus according to a second embodiment of an apparatus according to the present invention;

? figure 4 ? a schematic representation of an apparatus according to a further possible embodiment of an apparatus according to the present invention, e

? figure 5 ? an overall view of an apparatus according to the embodiment schematized in figure 3.

Detailed description of preferred embodiments

The present invention will be described below with reference to the above figures.

In particular, figure 1 shows, by way of example, a system 1 of the prior art for cleaning release paper.

In particular, how can you see in figure 1, the release paper 5 is fed through a reel 4 and directed towards the treatment plant and coupling to the support, as already? described.

After being separated from the support, the release paper 5 enters the cleaning system 1, dragged by a carpet 7, moved by a roller 8.

At an adhesion area 12, the paper 5 comes into contact with an adhesive tape 6 which is fed through a coil 11.

A traction roller 9 facilitates the sliding of the release paper 5.

The adhesion between adhesive tape 6 and release paper 5 in the adhesion area 12, makes s? that the residues present on the release paper are transferred to the adhesive tape 6.

At the same time, the adhesive tape 6 is drawn towards a recovery reel 13 on which it is wound.

The release paper 5, free of residues, is rewound on a secondary reel 10 to then be able to be reused in a new cycle, while the recovery reel 13 of the adhesive tape ? intended to be disposed of.

The cleaning process object of the present invention, differently from the prior art, does not require the use of disposable adhesive tape.

Otherwise, its operating principle is based on the use of a solution which is distributed on the release paper in order to soften and break up the paint and/or other residues present on it after use.

Therefore, according to the present invention, ? a release paper reconditioning process is provided, for the removal of residues from its surface, comprising at least one step of applying a solvent solution on the surface of the release paper to be cleaned.

For the purposes of the present invention, a solvent solution is to be understood as a solution which has properties solvents against the polymeric film used as ennobling film.

This solvent solution will be? therefore chosen, from time to time, by the expert in the field, and according to the known technique, according to the particular ennobling polymeric film used in the process.

Advantageously, this solvent solution can? be a polar solution. Preferably such a polar solution comprises an alcohol, a ketone, water or a combination thereof.

Preferably alcohol? ethyl alcohol, methyl alcohol, propyl alcohol, isopropyl alcohol, butyl alcohol, isobutyl alcohol, tert-butyl alcohol, pi? preferably ethyl alcohol.

Preferably the ketone ? acetone, butanone, methylisobutylketone.

Pi? preferably this solvent solution ? a hydroalcoholic solution or an aqueous solution comprising ethyl alcohol, preferably in a concentration from 30% to 95%, even more? preferably in a concentration of from 50% to 90%.

In a still further preferred form this solvent solution ? consisting exclusively of absolute ethyl alcohol.

Advantageously, can? a residence time of the solution on the surface to be cleaned must be foreseen.

This residence time can be, for example, obtained by regulating the speed? of transit of the card in the apparatus used for the reconditioning of the release card. Pi? low will be the speed? of transit, the more? long will be the residence time.

According to a preferred embodiment, the process can it also comprises a residue removal step, carried out through a mechanical cleaning action, after the application of the solvent solution. The mechanical action can be exercised in any way? selected among those already? known, for example by means of a spatula approached to the surface, or by means of a rotating brush, preferably counter-rotating with respect to the advancement direction of the release paper.

? it should be understood that other solutions of a mechanical nature may be adopted, also including solutions which provide for example for the use of jets of air, possibly compressed, directed towards the surface of the release paper to be cleaned.

As an alternative or in addition to those already? described, other solutions could also be envisaged, for example a mechanism which subjects the release paper to vibration.

Furthermore, ? to be understood that they can also be provided for more? mechanical cleaning phases, in which different techniques are used.

Furthermore, according to some embodiments of the present invention, ? possible to provide one or more? drying stages. A drying phase preceding the mechanical action of removing the residues would result in an advantage for this mechanical action. A drying phase following the mechanical action of removal would allow to rewind the well dried reconditioned release paper in a new reel, ready for subsequent reuses.

According to other embodiments of the present invention, it can be advantageously provided one or more? suction stages.

An aspiration phase pu? be foreseen for the suction of the vapors released by the solvent solution, in order not to pollute the surrounding air, above all for the well-being of the operators. For this purpose can therefore a phase of filtering of the aspirated must be foreseen.

An aspiration phase pu? be provided, in addition or as an alternative to the one already? described, for the suction of a light fraction of the residues separated from the release paper during the mechanical cleaning action. In this case a filtering phase would allow the collection and disposal of the light fraction of the residues.

A process like the one described pu? advantageously be implemented in an apparatus for reprocessing release paper. Such an apparatus will comprehend therefore at least one application station of a solvent solution on the surface of the release paper.

According to the present invention, possible embodiments of an apparatus of this type are schematically shown in figures 2 to 4.

In particular, figure 2 illustrates a first possible embodiment of an apparatus 20 for removing residues from a surface 5? of the release paper 5. The apparatus 20 comprises a station 21 for applying a solvent solution on the surface 5? of the paper release 5; a mechanical cleaning station 31 of the residues from said surface 5? of the paper release 5; and means for advancing the release paper 5 along an advance direction A.

According to some embodiments of the present invention, the application station 21 comprises a pair of rollers 22, 23, of which an engraved roller 22 and a contrast roller 23, arranged in such a way that the release paper 5 can pass between the two rollers along the feed direction A.

According to the invention, the roller 22 allows to apply the solvent solution on the paper and, preferably, a motorized roller having a steel core and a rubberized outer surface. It ? contained in a tank 25 suitable for containing the solvent solution 26. Therefore the engraved roller 22, during use of the apparatus, is partially immersed in the solvent solution 26. It has surface incisions which retain a predetermined quantity? of solution which is then transferred by contact to the paper.

Such an application? facilitated by the idle contrast roller 23, in contact with the opposite surface of the paper 5.

According to a possible embodiment, the application station 21 further comprises a doctor blade 24 for regulating the quantity? of solvent solution applied to the surface 5? release 5 paper and remove the excess, to avoid wetting the paper excessively.

Furthermore, ? to be understood that they can also be provided for more? solvent solution application stations, each using a different solvent solution. The mechanical cleaning station 31, according to the preferred embodiment of the invention, comprises a rotating brush 32 rotatably mounted on a rotation axis R, arranged to be able to rotate in contact with the surface 5? of the release paper 5.

As also visible in figure 5, the rotating brush 32 can advantageously be enclosed in a casing, with the advantage of not excessively dispersing the residues separated from the release paper into the environment. The rotating brush can preferably provide nylon bristles so as not to be excessively aggressive on the paper and damage the surface.

Advantageously, the rotating brush 32 ? motorized, in such a way as to be able to control its rotation both in terms of speed? which direction of rotation. Preferably, the brush is made to counter-rotate as indicated by the arrow in Figure 2, therefore in the direction opposite to the direction A of the paper 5 in the apparatus. In this way ? improved the cleaning effect of the brush on the paper surface.

Advantageously, can? provision should be made for the mechanical cleaning station 31 to further comprise means for translating the axis of rotation R of the rotating brush 32 along an action direction M substantially orthogonal to the direction of advancement A.

In this way, ? allowed to move the rotating brush 32 towards or away from the surface 5? of the release paper 5, in order to increase or decrease the pressure of the bristles of the rotating brush 32 on the surface 5? of the release 5 paper, being able, in the limit, to avoid contact between the brush and the paper. Pi? is the brush approached to the surface 5? of the paper, the greater it will be? the pressure exerted, so the better sar? the cleaning action of the brush itself.

The translation means can advantageously be actuated by actuators of the pneumatic type. Alternatively, actuators of another nature, for example electric, hydraulic, etc., can be provided.

Advantageously, according to some embodiments, it can a contrast device 33 must be provided, placed precisely to contrast the action of the rotating brush 32, on the opposite side of the release paper 5.

For example, in the embodiment schematically shown in figure 2, the contrast device 31 comprises one or more? push rollers 34, preferably two push rollers 34. Preferably, the push rollers 34 are mounted idle.

? to be understood that can? even a single push roller may be provided, in contrast to the action of the brush.

Alternatively, or in addition, the contrast device 33 can comprising, as for example shown in the embodiment schematized in figure 3, a sheet metal 35, preferably adjustable in height.

Does this sheet metal work 35 ? however that of exerting a contrasting action to the rotating brush 32, in order to improve its mechanical cleaning action on the surface 5? of the release card.

Upon exiting the cleaning and reconditioning apparatus 20, the release paper continues its journey towards a winding station to be reused in subsequent processes.

? to understand that the station of mechanical cleaning will be able? It can also be based on different mechanisms, such as for example solutions involving the use of jets or blades of air, possibly compressed, directed towards the surface of the release paper to be cleaned.

As an alternative or in addition to those already? described, other solutions could also be envisaged, for example a mechanism which subjects the release paper to vibration.

Furthermore, ? to be understood that they can also be provided for more? mechanical cleaning stations, where different techniques are used.

For example, in figure 4 ? schematically illustrated a possible embodiment of the present invention, in which ? there is a further mechanical cleaning station 40, immediately downstream of the solvent solution application station 21. In particular, the station 40? such that the paper release ? made to pass at least for a stretch in the vertical direction (where it is assumed that the apparatus is placed on a horizontal plane and that the direction of advancement A of the paper is substantially horizontal).

During this vertical stretch, the release paper ? subjected to vibration, in such a way that, also exploiting the effect of the force of gravity, a part of the residues is separated even before the paper itself has reached the subsequent cleaning station 31.

Furthermore, according to some embodiments of the present invention, ? possible to provide one or more? drying stations. A drying station upstream of the mechanical cleaning station would result in an advantage for the subsequent mechanical action of removing the residues. A drying station following the mechanical cleaning station would allow rewinding the well dried and adequately conditioned reconditioned release paper into a new reel, ready for subsequent reuses.

According to other embodiments of the present invention, it can also be advantageously provided for one or more? suction stations.

A suction station can for example be provided for the suction of the vapors released by the solvent solution, in order not to pollute the surrounding air, above all for the well-being of the operators. For this purpose can therefore it must be foreseen that the suction station also provides for a filtering of the aspirated.

A suction station can be provided, in addition or as an alternative to the one already? described, for the suction of a light fraction of the residues separated from the release paper during the mechanical cleaning action. In this case the filtering would allow the collection and disposal of the light fraction of the residues.

The present invention ? heretofore described with reference to preferred embodiments thereof. ? to be understood that each of the technical solutions implemented in the preferred embodiments, described here by way of example, can advantageously be combined, in a different way from what has been described, with the others, to give shape to further embodiments, which pertain to the same inventive core and all in any case falling within the scope of protection of the claims set out below.

Claims (22)

1. Release paper reconditioning process (5), for the removal of residues from a surface (5?) of said release paper (5), comprising at least one step in which said surface (5?) of the release paper (5) is placed in contact with a solvent solution. 2. Process according to claim 1 wherein said solvent solution is a polar solution. The process according to claim 1 or 2, wherein said solvent solution comprises an alcohol, a ketone, water or a combination thereof. 4. Process according to claim 3, wherein said solvent solution comprises an alcohol selected from the group consisting of ethyl alcohol, methyl alcohol, propyl alcohol, isopropyl alcohol, butyl alcohol, isobutyl alcohol, tert-butyl alcohol, preferably ethyl alcohol. 5. Process according to claim 2, wherein said solvent solution is a hydroalcoholic solution or an aqueous solution comprising ethyl alcohol, preferably in a concentration from 30% to 95%, even more? preferably in a concentration of from 50% to 90%. 6. Process according to claim 2, wherein said solvent solution is consisting exclusively of absolute ethyl alcohol. 7. Process according to one of the preceding claims, further comprising at least one step for exercising a mechanical cleaning action for the removal of said residues. 8. Process according to one of the preceding claims, wherein said mechanical action ? exercised by means of a rotating brush (32). Process according to one of the preceding claims, further comprising at least one step of suction and filtering of vapors and/or of a light fraction of the residues removed from the surface of the release paper (5). 10. Process according to one of the preceding claims, further comprising at least one step of drying the release paper subsequent to said step of applying a solvent solution. 11. Process according to claim 10, wherein said at least one drying step precedes or follows said step of exerting a mechanical cleaning action. 12. Apparatus (20) for reconditioning release paper (5), for removing residues from a surface (5?) of said release paper (5), comprising at least one application station (21) of a solvent solution ( 26) on said surface (5?) of the release paper (5). The apparatus (20) according to claim 12, further comprising: - at least one mechanical cleaning station (31) of said residues from said surface (5?) of the release paper (5); And - means for advancing said release paper (5) along an advance direction (A). 14. Apparatus (20) according to claim 12 or 13, wherein said application station (21) comprises an applicator roller, preferably engraved (22) and a contrast roller (23) arranged so as to drag the release paper (5 ) along said feed direction (A). The apparatus (20) according to claim 14, wherein said applicator roller (22) is contained in a tank (25) suitable for containing said solvent solution (26). 16. Apparatus (20) according to one of the claims 12 to 15, wherein said application station (21) further comprises a doctor blade (24) for regulating the quantity? of solvent solution applied to the surface (5?) of the release paper (5). 17. Apparatus (20) according to one of claims 12 to 16, wherein said mechanical cleaning station (31) comprises a rotating brush (32) rotatably mounted on a rotation axis (R), arranged to be able to rotate in contact with said surface (5?) of the release paper (5). 18. Apparatus (20) according to claim 17, wherein said mechanical cleaning station (31) comprises means for translating said axis of rotation (R) along an action direction (M) substantially orthogonal to the feed direction (A), so as to approach/remove said rotating brush (32) from/from said surface (5?) of the release paper (5), to increase/decrease the pressure of said rotating brush (32) on said surface (5?) of the paper releases (5). The apparatus (20) according to claim 18, wherein said means for translating said axis of rotation (R) comprises pneumatic actuators. 20. Apparatus (20) according to one of claims 12 to 19, further comprising at least one suction station, for the suction of vapors released by the solvent solution (26) and/or of a light fraction of the residues separated from the release paper during the ?mechanical cleaning action. Apparatus (20) according to one of claims 12 to 20, further comprising at least one release paper drying station downstream of said solvent solution application station. The apparatus (20) according to claim 21, wherein said at least one drying station precedes or follows said mechanical cleaning station (31).