WO2004078540A1

WO2004078540A1 - Wiping/cleaning blade for a vehicle windscreen wiper

Info

Publication number: WO2004078540A1
Application number: PCT/FR2004/000329
Authority: WO
Inventors: Ralph Risse; Françoise Henrio
Original assignee: Rhodia Performances Fibres
Priority date: 2003-02-24
Filing date: 2004-02-13
Publication date: 2004-09-16
Also published as: FR2851534B1; FR2851534A1

Abstract

The invention relates to a wiping/cleaning blade for a vehicle windscreen wiper and more particularly a wiping/cleaning blade at least part of the surface of which is flocked. The invention further relates to a method for production of said blade and a windscreen wiper arm and windscreen wiper fitted with such a blade.

Description

WIPER BLADE / CLEANING OF A VEHICLE WIPER BLADE

The present invention relates to a wiper blade of a vehicle wiper blade. It relates more particularly to a wiping / cleaning and / or scraping blade of which at least part of the surface is flocked. The invention also provides a method of manufacturing this blade as well as a wiper blade and a wiper provided with this blade.

In the field of wipers for vehicles, it is sought to manufacture wipers having an optimal wiping or scraping capacity, or even cleaning when a detergent is used. We are also looking for wipers that cause the least noise possible during their operation for the comfort of the user. As much as possible, we finally try to make windshield wipers that do not cause scratches on the windows to be wiped and / or cleaned and / or scraped when the wipers pass over them.

These problems with wiping / cleaning capacity, noise and scratches can be linked in particular to the wiping blade of the wiper blade.

In order to improve the wiping capacity obtained by means of a wiping blade, made of natural (rubber) or synthetic elastomer, it is known to provide it with a coating comprising graphite, an ester of butyl titanate and of isopropyl alcohol. It is thus sought to reduce the coefficient of friction between the surface of the blade and the surface to be cleaned, in order to improve the wiping capacity and reduce the noise during the passage of the wiper.

It is also known to use as a coating a composition comprising a graphite powder, dispersed in suspension in a carrier liquid, and a gelling agent.

The disadvantage of these coatings is that they are fragile and in particular very little resistant to detergents and detergents which are used in particular for washing vehicles. There is thus a very short lifespan of the "lubricant" coating which quickly leads to its deterioration, or even to its complete disappearance, then significantly affecting the quality of the wiping.

The present invention provides a wiper blade for a vehicle wiper blade, which does not have these drawbacks. It proposes in particular a wiping blade of which at least part of the surface is flocked. The present invention also provides a method of manufacturing the blade by flocking the fibers on a base blade, comprising the following steps: a) optionally coating with adhesive all or part of the surface of a base blade b) spraying the fibers on the base blade The invention also relates to a method of manufacturing the blade by assembling a flocked surface and a base blade.

The invention also provides a wiper blade comprising the blade described above and a wiper comprising this blade.

By vehicle is meant any means of transport by land, air, sea. Examples of vehicles that may be mentioned include passenger vehicles, automobiles, trains, two-wheeled vehicles, heavy goods vehicles, transport vehicles. in common (bus, metro etc.), planes, boats etc.

By wiper means all the wipers likely to be on vehicles. Mention may be made, as examples of wipers, of the windshield wipers of vehicles, the windshield wipers of vehicle optics such as the headlight wipers, etc.

The material of the wiper blade of the invention can be a natural or synthetic elastomer. Examples of elastomers that may be mentioned include: natural rubber (NR), ethylene propylene diene terpolymer (EPDM), nitrile butadiene (NBR), polychloroprene (CR), isoprene (IR), styrene butadiene (SBR ), butadiene (BR).

The material of the wiping blade can also be a thermoplastic elastomer. As an example of a thermoplastic elastomer, mention may be made of: styrene ethylene butadiene styrene (SEBS), the acrylonitrile-butadiene-styrene terpolymer (ABS), the acrylic-styrene-acrylonitrile (ASA) terpolymer, styrene isoprene styrene (SIS) ).

The material of the wiping blade according to the invention can also be a combination, a mixture, of homopolymers, copolymers and / or terpolymers of the compounds mentioned above.

The material of the wiping blade may include fillers, lubricants, antioxidants, antiozonants, crosslinkers etc.

The configuration and / or the shape of the blade are not decisive in the present invention. All blade shapes and / or configurations known to those skilled in the art and / or usually used in the field of wiper blades for wiper blades can be used in the context of the invention. The fibers of the flocked surface can be of a wide variety. Fibers are generally characterized by the material of which they are made, by their title, by their length, by their section, by their mattness. The material of which they are made is generally a polymeric material. The fibers may for example be chosen from polyamide fibers, in particular polyamide 6 or 66 fibers, their blends or copolymers, polyester (such as polyethylene terephthalate or polybutylene terephthalate), acrylic, polyolefin (such as polypropylene), viscose, rayon. A mixture of fibers of different natures can be used. Advantageously, the fibers are polyamide fibers, preferably chosen from polyamide 6, polyamide 66 fibers, their mixtures or copolymers. Indeed polyamide provides good properties in terms of abrasion, wear and resilience.

The fibers of the invention can be obtained from two or more materials, these fibers are called composite or two-component fibers of the "side by side" or "heart / skin" type.

The fibers of the invention can also be multicomponent, that is to say made up of several polymers.

The fibers can optionally comprise a wide variety of additives such as delustrants, matifiers, for example particles of titanium dioxide and / or zinc sulphide, pigments colored for example carbon black, stabilizers, property modifiers such as antistaticity, hydrophilia, anti-stain or anti-fouling effect, fireproofing, bioactivity, fillers (organic or mineral), alone or as a mixture. According to a particular embodiment of the blade of the invention, the fibers of the flocked surface are dyed and / or colored. The fibers, which can be dyed in various colors, allow obtaining a colored wiper blade, and great flexibility in the choice of the color of the blade. This is not the case with conventional wiper blades that do not include fibers, the elastomer material of which is difficult to color. The fibers or the precursors of these fibers - such as a cable or a wire - can be dyed in the mass or according to dyeing methods conventionally used by a person skilled in the art.

The fibers can have a titer between 0.1 and 100 dtex. The fibers advantageously have a titer between 0.5 and 80 dtex, preferably between 0.5 and 22 dtex. The fibers can have a length of between 0.1 and 6 mm. Fibers whose length is between 0.3 and 4 mm are preferred.

The fibers of the flocked surface of the invention can be flat or crimped. They can have a two-dimensional crimp and / or a three-dimensional crimp. The two-dimensional crimping of the fibers is generally obtained by mechanical crimping. The fibers can have various cross-sectional shapes such as round, multi-lobed. It can also be hollow fibers.

It is also possible to use a mixture of fibers, materials, titles, lengths; colors, different textures. The blade can for example comprise several flocked zones distributed over the surface of the blade. These zones can correspond to given fiber titles, to given fiber sections and / or to given fiber types, etc.

In fact, it is possible to use, for example, “large” titer fibers, having a titer advantageously between 6.7 and 100 dtex, preferably between 6.7 and 22 dtex, which will in particular have a cleaning / abrasive function. It is also possible to use fibers of "fine" titer, having a titer advantageously between 0.5 and 6.6 dtex, preferably between 0.5 and 3.3 dtex, which will play a role of wiping.

Thus, the blade may include one or more areas flocked with fibers of "large" title, and one or more areas with fibers flocked of "fine" title. In a given flocked area, for example a flocked area with fibers of

"Headline", a mixture of fibers of different "headline" may be present.

When the blade has for example two sides and a slice, each side being defined by a large and a small dimension, the different flocked zones can be distributed according to the large dimension of one or more sides, according to the small dimension of one or more sides, along the edge and / or on one side and the other of the blade. For example if the sides of the blade are in a rectangular shape, the different zones can be distributed along the length and / or the width of one or both sides.

One can for example have flocked zones distributed over the width of the blade: for example a flocked zone with fibers of “fine” titer near the edge of the blade, and a flocked zone with fibers of “coarse” titer , near the blade support.

We can also have one side of the blade with “big” fibers; the other side of the blade with fibers of "fine" title. The blade can be flocked over its entire surface. The density of the fibers on each flocked area is advantageously between 20 and 400 g / m ² , preferably between 50 and 250 g / m ² . The density of the fibers on the blade can be substantially the same over its entire surface.

According to a particular embodiment of the invention, the part of the blade intended to be in contact with the frame of the brush is not flocked.

According to a particular embodiment of the invention, the blade can comprise several superposed layers of fibers.

The invention also relates to a method for manufacturing the blade described above comprising the following steps: a) optionally coating with adhesive all or part of the surface of a base blade b) projecting the fibers onto the blade base By base blade is meant a wiper blade in its finished form or a precursor of this blade, for example a plate or joint or pre-cut shape obtained by extrusion, compression molding, or by injection.

The base blade is obtained by any method known to those skilled in the art for obtaining wiper blades for wiper blades. It can for example be obtained by extrusion / vulcanization of the material of the blade, or by injection of the material. All that has been described above in particular concerning the material, the shape and / or the configuration of the blade applies here for the base blade.

All that has been described above concerning the characteristics of the fibers applies here for the fibers of the process of the invention.

The method of the invention consists in adhering fibers, generally short fibers, to at least part of the surface of the base blade, the blade or part of blade preferably having been coated beforehand 'an adhesive. The adhesion of the fibers on the base plate is carried out by projection of the latter.

According to a particular embodiment of the method of the invention, the blade is obtained by flocking the fibers on the base blade, by coating an adhesive over all or part of the surface of the base blade, then projection of the fibers on the base blade. The methods of flocking fibers are known per se. Briefly, and without this constituting any limitation to the scope of the invention, they generally consist in coating a substrate with an adhesive and in projecting fibers which are generally very short. Thus, the fibers adhere to the substrate, preferably in a substantially perpendicular direction. The projection of the fibers can be carried out by beating the blade, by electrostatic means or by electrostatic and pneumatic way, or by conjunction of these three techniques. In the context of an electrostatic projection, the fiber is generally electrically activated in order to be oriented and projected into the electrostatic field. The fiber can be activated by an activation treatment. Two main families of activation treatments are cited as examples: treatments based on natural tannins, and those based on colloidal silica.

The adhesives which can be used to bond the flocked fibers, and their methods of application to the substrate, are known to those skilled in the art and do not constitute a limitation to the invention. They can be water-based or solvent-based. Mention is made, by way of examples, of adhesives based on plastisol vinyl acetate copolymers, acrylic latexes, polyurethane latexes, plastisol PVCs, solvent-based adhesives, for example chloroprene adhesives. According to a particular embodiment, adhesives forming foams are used, the surfaces obtained with such adhesives having greater flexibility.

According to a preferred embodiment of the method of the invention, the base blade is subjected to a treatment before step a) to facilitate the adhesion of the adhesive to the base blade during step a). As an example of treatment, mention may be made of plasma or corona treatment; sandblasting and / or grinding and / or brushing and / or degreasing. These methods are known to those skilled in the art.

Steps a) and b) of the process of the invention can be repeated several times, for example twice, in order to obtain several layers of fibers on the blade. After projecting the fibers onto the blade, these fibers can be coated with an adhesive and again projecting fibers onto the blade. According to another particular embodiment of the invention, the projection of the fibers is carried out without prior coating of adhesive. According to this embodiment, the fibers are projected onto a precursor of the blade, after extrusion of the material of the blade and before vulcanization of the latter.

The blade obtained according to the method of the invention can be subjected to functionalization operations. Such operations are known to those skilled in the art. It can for example be a question of applying a primer or a chemical agent (for example by spraying, coating, soaking) on the blade, so as to confer it anti-stain, anti-soiling properties, impermeability, antistaticity. , bio-activity, fireproofing, etc. The invention also relates to another method for preparing the blade of the invention comprising a step of assembling a flocked surface on a base blade as described above. Indeed, the flocked surface can be prepared by flocking on a substrate by a method known to those skilled in the art. The surface is then assembled on the base blade according to any known method of assembly, for example by gluing, welding, stapling; nailing, fixing with clips etc.

The invention also relates to a vehicle wiper blade comprising a frame and a wiping blade as described above or obtained by the method described above. It also relates to a vehicle windscreen wiper comprising an arm and a blade, the blade being as described above.

Other details or advantages of the invention will become more clearly apparent from the examples given below, which do not constitute a limitation to the invention.

EXAMPLES

Example 1

A blade is prepared from the following products:

- Substrate: base blade of wiper blade for motor vehicle made of synthetic elastomer

- Fibers: Fibers dyed in mass and in black, of polyamide 66 with titles of 3.3 dtex; between 0.4 and 0.6 mm in length

- Adhesive: Adhesive based on polyurethane, sold by the company Stockhausen under the reference Fisamin PUK The blade is prepared for flocking by emeryering using an emery cloth marketed by the company Norton under the reference P-280 E.

We go back and forth over the entire length of the blade. Then brush the blade and degrease it with acetone.

The blade is coated with adhesive and the fibers are flocked according to a usual method. The density of the fibers on the blade is approximately 60 g / m ²

Examples 2 to 5

Four variants of blade preparation are produced here using the following products:

- Substrate: base blade of wiper blade for motor vehicle in synthetic rubber - Fibers:

Fibers A: Fibers dyed in mass and in black, of polyamide 66 with titles of 0.9 dtex; between 0.4 and 0.6 mm in length

Fibers B: Fibers dyed in mass and in black, of polyamide 66 of titles of 17 dtex; between 0.4 and 0.6 mm in length

- Adhesive: Polyurethane-based adhesive, sold by the company Stockhausen under the reference Fixamin PUK

The blade is prepared for flocking by emery-making using an emery cloth sold by the company Norton under the reference P-280 E. Several back and forth movements are carried out over the entire length of the blade. Then brush the blade and degrease it with acetone.

The four variants of the invention corresponding to Examples 2 to 5 are blades having several flocked zones corresponding to fibers of different titles.

For these variants, one proceeds, after preparation of the blade for flocking (as indicated above), the successive flocking of the different zones. Indeed, an area of the blade intended to be flocked with an adhesive is coated and the fibers corresponding to this area are flocked. Then we proceed in the same way on another area with other fibers: we coat the area with adhesive then we flock the fibers etc.

For the four variants, the fiber density of each flocked area can vary between 60 and 250 g / m ²

Figures 1 to 4 are a schematic representation of the distribution of flocked areas of different fiber titles on the sides of the blade, corresponding to the four variants of Examples 2 to 5. Figure 1 shows the distribution of flocked areas of different titles on a blade side, according to the variant of Example 2

Figure 2 shows the distribution of flocked areas of different titer on one side of the blade, according to the variant of Example 3

Figure 3 shows the distribution of flocked areas of different titer on one side of the blade, according to the variant of Example 4: the fibers of "big" titer are located near the frame of the wiper blade

Figure 4 shows the distribution of flocked areas of different title on one side of the blade, according to the variant of Example 5, and on the other side of the blade.

Claims

gREVENDICATIONS

1. Wiping blade of a vehicle wiper blade, characterized in that at least part of the surface of the blade is flocked.

2. Blade according to claim 1, characterized in that the length of the fibers of the flocked surface is between 0.1 and 6 mm, preferably between 0.3 and 4 mm.

3. Blade according to claim 1 or 2, characterized in that the titer of the fibers of the flocked surface is between 0.1 and 100 dtex, preferably between 0.5 and 80 dtex

4. Blade according to one of the preceding claims, characterized in that the fibers of the flocked surface are chosen from polyamide, polyester, acrylic, polyolefin, viscose, rayon fibers, their mixtures or copolymers

5. Blade according to claim 4, characterized in that the fibers are chosen from polyamide 6, polyamide 66 fibers, their mixtures or copolymers.

6. Blade according to one of the preceding claims, characterized in that the fibers of the flocked surface are dyed and / or colored

7. Blade according to one of the preceding claims, characterized in that it comprises several flocked zones distributed over the surface of the blade, each zone corresponding to a fiber count, to a fiber section and / or to a type of given fiber.

8. Blade according to claim 8, characterized in that it comprises one or more flocked areas with fibers of titer between 6.7 and 100 dtex, and one or more flocked areas with fibers of titer between 0.5 and 6.6 dtex.

9. Blade according to claim 7 or 8, characterized in that it has two sides and a slice, each side being defined by a large and a small dimension, and in that the different zones are distributed along the large dimension of one of) side (s), according to the small dimension of one (s) side (s), along the edge, and / or on one side and the other of the blade.

10. Blade according to one of the preceding claims, characterized in that the density of the fibers on each flocked area is advantageously between 20 and 400 g / m ² , preferably between 50 and 250 g / m ²

11. A method of manufacturing the blade according to one of claims 1 to 10, comprising the following steps: a) optionally coating with adhesive all or part of the surface of a base blade b) spraying the fibers onto the base blade

12. Method according to claim 11, characterized in that the blade, prior to step a), is treated to facilitate the adhesion of the adhesive to the blade, by plasma or corona, sandblasting and / or emery-making and / or brushing and / or degreasing

13. Method according to claim 11, characterized in that the base blade is obtained by extrusion of the material of the blade followed by vulcanization, and in that step b) of projection of the fibers is carried out after extrusion of the material and before its vulcanization, without step a) prior to coating a substrate.

14. A method of manufacturing the blade according to one of claims 1 to 10, comprising a step of assembling a flocked surface with a base blade

15. Vehicle wiper blade comprising a frame and a wiper blade, characterized in that the wiper blade is a blade according to one of claims 1 to 10 or a blade obtained by the method according to l one of claims 11 to 14

16. Vehicle windscreen wiper comprising an arm and a blade, characterized in that the blade is a blade according to claim 15