FR2881149A1 - Flocking patch material in automobile industries, comprises a support on which a flocking fibers are deposited by an adhesive, where the support is formed from a flexible thermoplastic elastomer and a flexible adhesive - Google Patents

Abstract

The thermoplastic elastomer is styrene ethylene butadiene styrene (SEBS), styrene ethylene butadiene styrene/polypropylene (SEBS/PP), styrene butadiene styrene/polypropylene (SBS/PP), ethylene propylene diene monomer/polypropylene (EPDM/PP), polyurethane (PU), thermoplastic elastomers (TPE), partially vulcanized thermoplastic rubbers (TPV), and/or plastic materials such as polystyrene (PS), acryl butadiene styrene (ABS), polycarbonates (PC), polypropylene (PP) and polyethylene (EP). The support (12) comprises a texture face on which flocking fibers (20) are applied, which is translucent/clear in color and a thermoplastic elastomer having adhesives in minimal quantity, where the support is obtained by injection/cutting. The flocking fibers (20) having a length of 0.1-1 mm, which resist repeated cycles of torsion of 180 degree. The adhesive is aqueous base made of flexible polymerizable resin, or an aqueous base with solvent, and an organic adhesive in aqueous phase containing synthetic rubber polymer optionally containing other additives/co-solvents such as glycols/vinylic/cellulosic additives. The adhesive is flexible, not to impair the flexibility of the support. An independent claim is also included for a manufacturing process using the above material.

Description

Piece of flocked material, particularly for motor vehicles, and

process for its manufacture

  The invention relates to a piece of flocked material of the type comprising a support on which are glued flocking fibers by means of an adhesive.

  Various types of flocked material parts are already known, which comprise a support on which flocking fibers, usually formed of natural, artificial or synthetic textile fibers of chosen length, are glued. These fibers are glued to the support by means of an adhesive while being oriented under the action of an electric field. This produces pieces that may have different aspects, for example velvet, carpet, plush, suede, etc. The flocking process itself can be performed on a variety of substrates, for example plastic, paper, metal, etc. The invention aims more particularly, but not exclusively, parts of flocked material for the field of the automotive industry.

  In this particular field, window wipers or storage pockets are particularly known, window wipers being parts used in the doors and against which the windows come to slide during their upward or downward movement. These parts are usually formed from a flexible material made either vulcanized rubber covered with a black flock or a thermoplastic rubber on which dark fibers are applied by bonding and surface treatment techniques. These parts can also be stiffened using a rigid core of metal or plastic.

  The pieces thus obtained are generally rigid and most often dark in color, which limits their possibilities of application.

  The object of the invention is in particular to overcome the aforementioned drawbacks.

  Its main purpose is to produce a piece of flocked material which is distinguished from known parts by its character of great flexibility.

  The invention also aims to provide such a piece of flocked material that can be obtained with shapes, designs, decorations, the most varied colors depending on the desired applications.

  It is also intended to provide such a piece of flocked material which can have a translucent character allowing the transmission of light or be carried out with light colors, for example pastel.

  It is another object of the invention to provide such a piece of flocked material which has a soft-touch appearance and offers retention and non-slip properties for objects that can be placed on the piece thus obtained. .

  Yet another object of the invention is to provide a part 25 of flocked material which can be obtained after injection molding or by cutting.

  The invention proposes for this purpose a piece of flocked material of the type defined above, wherein the support is formed from a flexible thermoplastic elastomer of selected composition, and wherein the adhesive is a flexible adhesive chosen to not alter the flexibility of the support.

  This flexible thermoplastic elastomer is therefore distinguished from rubber-like materials of the prior art, in particular by properties of great flexibility.

  The combination of such a flexible support with a flexible adhesive makes it possible to obtain a part which durably retains its properties of flexibility, without these being able to be altered by the adhesive.

  It is appropriate for this purpose to choose the thermoplastic elastomer. This is advantageously chosen from elastomers of the Styrene Ethylene Butadiene Styrene (SEBS), Styrene Ethylene Butadiene Styrene / Polypropylene (SEBS / PP), Styrene Butadiene Styrene / Polypropylene (SBS / PP), and Ethylene Propylene Diene Monomer / Polypropylene (EPDM) families. / PP), more or less crosslinked, among the elastomers of the families Polyurethane (PU), Thermoplastic Elastomers (TPE) and partially vulcanized Thermoplastic Rubbers (TPV) and also among combinations of the above elastomers with traditional plastic materials. These include in particular Polystyrene (PS), ABS (Acryl Butadiene Styrene), Polycarbonates (PC), Polypropylene (PP) and Polyethylene (PE), this list not being limiting.

  These elastomers can be made by mixing different components comprising base polymers, as well as various additives such as oils or plasticizers, mineral or organic fillers, protective agents, crosslinking agents, processing agents, etc. In the invention, it will be necessary to ensure that these additives 30 do not exude so as not to leave a fatty layer on the surface of the workpiece after processing.

  The support itself may be opaque, but the invention particularly envisages translucent supports or light-colored supports for transmitting light through the part thus produced. To allow such a translucency, the thermoplastic elastomer should contain additives in a minimum amount, particularly with regard to the charges added to the base polymer.

  The support may be produced by various techniques known per se, for example by transformation into mono, bi or tri-material mode, in simple or expanded mode, by extrusion or calendering for cutting. The parts can also come from an overmolding operation on plastic, metal or any other compatible media.

  The thermoplastic elastomer is preferably obtained by injection of hot material into a cold mold.

  The choice of the adhesive is also decisive since it must not only be flexible and keep its flexibility, but not alter the flexibility of the support, that is to say, not be aggressive with respect to the support .

  In particular, adhesives having high elongations at break, such as those selected from water-based adhesives of flexible polymerizable resin, or aqueous base with co-solvent, and rubber-phase organic organic adhesives are contemplated. synthetic compound optionally containing other adjuvants or cosolvents (for example glycols or vinyl or cellulosic adjuvants). Polyurethane dispersions or catalyzed acrylic resins or mixtures of the two are particularly preferred. It should be noted that such adhesives may also contain isocyanates.

  The adhesive is generally applied by a technique known per se, for example by spraying with a spray, applying by roller, brush or brush, etc. Most often, a prior surface treatment of the support is necessary to allow good holding of the adhesive.

  This surface treatment, if necessary, must be chosen so as not to alter the flexibility of the support. Generally, it is preferred to apply a primer, that is to say a composition formed most often of one or more solvents. But plasma or corona type treatment techniques can also provide the expected results.

  By way of example, it is possible to use an adhesion primer chosen from solvents or solvent mixtures that may contain resins (natural or synthetic) or synthetic polymers of low molecular weight.

  Flocking fibers are those currently employed and commercially available. It may be so-called "long" or "very short" fibers. Although the invention is not limited to a particular length of fibers, fibers of 0.1 to 1 mm in length are preferred to provide the piece with a velvet appearance.

  It may be fibers commonly used in flocking techniques, such as polyamide, polyesters, viscose, cotton, etc. As already indicated, the fibers may be optionally stained or printed to give them a particular color.

  The flocking fibers are adhered to the support by means of the adhesive on one side of the support which may have a chosen texture. By the expression "chosen texture", it is meant that the face of the piece is either smooth or provided with particular reliefs. This may include a face having a grainy appearance.

  This texture is preferably imparted to the support before application of the adhesive and bonding of the fibers. It is conceivable, alternatively, to achieve the texture after flocking, or to achieve a combination of such operations.

  The support itself is advantageously obtained by injection or cutting.

  The piece of flocked material of the invention has excellent mechanical strength. In particular, the flocking fibers withstand repeated torsion cycles of at least 180 operated on the workpiece, without compromising the strength of the adhesive and fibers.

  In another aspect, the invention relates to a method of manufacturing a piece of flocked material, as defined above, which comprises the following operations: a) forming a support of a flexible thermoplastic elastomer 15 of selected composition, by molding or cutting; b) apply on one side of the support a flexible adhesive selected to not alter the flexibility of the support; c) applying flocking fibers to the face of the adhesive-coated backing, the fibers being oriented by an electric field; and d) attach the adhesive and clean the fibers. Operation b) advantageously comprises: bl) the application of a layer of a primer on the face of the support; and b2) applying a layer of the flexible adhesive to the layer of the primer.

  The operation c) is carried out by flocking techniques, known in themselves, using known apparatus which allow the implantation of the fibers in the adhesive with a chosen orientation, generally perpendicular to the surface of the support .

  Fixing the adhesive of the operation d) consists in making the setting of the adhesive, for example by polymerization or crosslinking, to maintain the flocking fibers on the support.

  In the following description, given by way of example only, reference is made to the accompanying drawings, in which: FIG. 1 is a perspective view of a piece of flocked material according to the invention; - Figure 2 shows the detail II of Figure 1; and FIG. 3 is a sectional view on an enlarged scale of a portion of the part showing schematically the various components that constitute it.

  FIG. 1 shows a piece of flocked material intended in the example for the automobile industry and which may constitute in particular a part of a dashboard or a console, a door panel, etc. It is therefore a part of appearance Figure 1 shows the part 10 in its entirety, while Figure 2 shows a detail of this piece and Figure 3 shows a sectional part, on an enlarged scale, of the room 10.

  As can be seen in FIG. 3, the part 10 comprises a support 12 made of a flexible thermoplastic elastomer of chosen composition which has an apparent or upper face 14. In the example, the support is translucent and has a thickness E between 0.05 and 50 mm. The face 14 has a chosen structure. It can be smooth or grained or have another form of reliefs. Here, the face 14 has raised portions 16 in the form of elongate rods directed in two perpendicular directions (see also FIG. 2).

  The support 12 is made by injection or cutting according to techniques known per se.

  On the face 14 is applied a layer of an adhesive 18, namely a flexible adhesive chosen to not alter the flexibility of the support. This adhesive is applied by techniques known per se, for example by spraying, roller, brush or brush application, etc. Preferably, the application of the adhesive is carried out after surface treatment, typically after application of a primer which facilitates the holding of the adhesive, without affecting the flexibility of the support. However, other treatment techniques, for example plasma or corona type are possible.

  On the adhesive are applied flock fibers 20 which are oriented by means of an electric field to form a selected angle with the surface, generally an angle of 90.

  The application of the fibers is carried out by techniques known per se by means of a known installation.

  Generally, the length of the flocking fibers is between 0.1 and 1 mm. These fibers may be selected from natural, artificial or synthetic fibers.

  The process therefore mainly comprises the following operations: application of the adhesive, implantation of the fibers under the action of a field, electrical, fixing of the adhesive (by polymerization or crosslinking), removal of unbonded fibers (generally by suction ) and possibly finishing. This latter operation may comprise, for example, a surface treatment, a color printing, etc. After manufacture of the piece of flocked material, it is desirable to control its properties, in particular its hardness (for example Shore hardness) and the resistance of the flock (flocked fibers) by using known tests or tests specially designed for this effect.

  It has been found that the floc resists repeated cycles of torsion operated on a piece of flocked material according to the invention. Indeed, when such a piece is subjected to repeated twists at an angle of at least 180 °, the flock remains integral with the support without the adhesive, and therefore the flocked fibers, separating from the support. This excellent mechanical strength comes from both the choice of support and the choice of adhesive, both of which retain their flexibility, while remaining mutually connected.

  It should be noted that the application of the flocking fibers may be pneumatic or electro-pneumatic.

  An example embodiment of the invention will now be described.

EXAMPLE

  A piece of flocked material is produced in the form of a dashboard or dashboard of a motor vehicle by injecting a material of the Styrene Ethylene Butadiene Styrene (SEBS) type having a hardness of 70 Shore A and exhibiting a grained honeycomb surface. On this surface is deposited a layer of a primer, then a layer of a flexible adhesive formed here of a mixture of polyurethane dispersion (PU) and acrylic resin in the presence of an isocyanate. Pink fibers are then applied by a flocking process. The adhesive is fixed by crosslinking and the workpiece is then cleaned.

  The resulting piece has and maintains a great flexibility and a soft touch, which makes it particularly suitable for constituting an appearance part for a motor vehicle.

  The invention finds particular application in the field of the automotive industry, for example to form a component of a dashboard, a console, a door panel or any other room in the passenger compartment.

  It makes it possible to produce flexible parts, which may be translucent or have a light shade, and thus allow the light to pass through, which may be advantageous for night driving to visualize certain parts of the vehicle.

  Depending on the nature and length of the flocking fibers, the piece can be given a soft touch like velvet, suede, plush, fur, etc. This touch can be combined with a particular texture of the piece such as, for example, a grainy appearance.

  The parts of the invention also have the advantage of having interesting properties of thermal and acoustic insulation.

  As already indicated, the fibers may optionally be made with different colors or even be printed to make special decorations, pictograms, etc. The invention also has applications in other fields than the automotive industry, such as furniture, home appliances, decoration.

Claims (12)

claims   A flocked material part, comprising a support (12) on which flocking fibers (20) are bonded by means of an adhesive (18), characterized in that the support (12) is formed from a flexible thermoplastic elastomer of selected composition, and in that the adhesive (18) is a flexible adhesive chosen to not alter the flexibility of the support.   2. Piece of flocked material according to claim 1, characterized in that the thermoplastic elastomer is selected from the elastomers Styrene Ethylene Butadiene Styrene (SEBS), Styrene Ethylene Butadiene Styrene / Polypropylene (SEBS / PP), Styrene Butadiene Sty-rene / Polypropylene (SBS / PP), Ethylene Propylene Diene Monomer / Polypropylene (EPDM / PP), more or less crosslinked, among the elastomers Polyurethane families (PU), Thermoplastic Elastomers (TPE) and partially vulcanized Thermoplastic Rubbers (TPV) and also among combinations of the above elastomers with traditional plastic materials, such as, in particular, Polystyrene (PS), ABS (Acryl Butadiene Styrene), Polycarbonates (PC), Polypropylene (PP) and Polyethylene ( PE).   3. Part flocked material according to one of claims 1 and 2, characterized in that the carrier (12) is translucent or light in color.   4. Piece of flocked material according to one of claims 1 to 3, characterized in that the thermoplastic elastomer contains adhesives in minimum quantity.   5. Piece of flocked material according to one of claims 1 to 4, characterized in that the adhesive is selected from water-based adhesives flexible polymerizable resin, or aqueous base with solvent, and organic adhesives in aqueous phase based on synthetic rubber polymer optionally containing other adjuvants or co-solvents (for example glycols or vinyl or cellulosic adjuvants).   6. Part flocked material according to one of revendica-5 tions 1 to 5, characterized in that the flocking fibers (20) have a length between 0.1 and 1 mm.   7. Part flocked material according to one of claims 1 to 6, characterized in that the carrier (12) has a face (14) of selected texture on which the flocking fibers (20) are applied.   8. Piece of flocked material according to claim 7, characterized in that the face (14) of the support (12) has a grainy appearance.   9. Flocked material part according to one of claims 1 to 8, characterized in that the support (12) is obtained by injection or cutting.   10. Piece flocked material according to one of claims 1 to 9, characterized in that the flocking fibers resist repeated cycles of torsion of at least 180 'operated on the workpiece.   11. A method of manufacturing a piece of flocked material according to one of claims 1 to 10, characterized in that it comprises the following operations: a) forming a support (12) of a flexible thermoplastic elastomer of selected composition; b) applying on a face (14) of the support (12) a flexible adhesive (18) chosen not to alter the flexibility of the support; c) applying flocking fibers (20) to the face (14) of the adhesive-coated support, the fibers being oriented in an electrostatic field; d) fix the adhesive and clean the flocking fibers.   12. The method of claim 11, characterized in that the operation b) comprises: bi) the application of a layer of a primer on the face of the support; and b2) applying a layer of the flexible adhesive to the layer of the primer.