MXPA97003141A - Cleaning element for rotating brush, made from a copolymer of ethylene vinyl acetate (a - Google Patents

Abstract

The present invention relates to a flexible cleaning element, suitable for joining a rotating support for rotating brushes, used for the automatic washing of vehicles, comprising a synthetic resin expanded in closed cell, wherein said synthetic resin expanded in closed cell includes an ethylene vinyl acetate copolymer containing about 80% by weight of said ethylene vinyl acetate copolymer, which contains 9 to 28 weight percent in vinyl acetate and further comprises: about 10 weight percent amorphous precipitated silica about 2 weight percent of bis (tert-butyl peroxy-isopropyl) benzene, about 2.5 weight percent of azodicarbonamide, about 0.5 weight percent of stearin, and about 5 weight percent of pigment

Description

Cleaning Element for Swivel Brush. Made of an Ethyl Vinyl Acetate Copolymer (AVE). This invention relates to cleaning elements for rotating brushes which are used, in particular, in automatic car wash systems. When in use, these elements, which are in the form of wires, strips, or sheets, undergo many stresses that, in addition to the traction caused by the centrifugal and bent force, include abrasion and the impacts that said elements suffer when they enter. in contact with the surfaces to be cleaned. Another aspect that is critical for a cleaning element, the fact is that it has to be joined at one end to a rotating support device; at the point of attachment, the cleaning element, by itself, necessarily undergoes an inevitable compression that is located near, among other things, the part of said element that is excessively subjected to the resulting overall tensile force, bending and effort cutting. These elements, above all, must be made of absolutely non-abrasive materials, and must be designed in such a way that they are not incorporated into the potentially abrasive particles that are removed during washing and do not absorb the washing water, which, in addition to making more heavy elements, they aggravate the tensions that act on them, they can freeze, irrigating the elements and completely compromising their function.

According to the specification of the art, in order to minimize the risks and drawbacks mentioned above, said cleaning elements are made of closed, macrocellular, expanded synthetic resins, ie, polymers, for example, such as phenylethylene, polypropylene, etc. It has been found that, when such materials are used, it is necessary to produce the cleaning element with a relatively large thickness (up to 4-5 millimeters), with macrocells of considerable diameter belonging to the type of process used to form the materials themselves ( extrusion), and this means that the flexibility of the elements is not always satisfactory and that the action of said elements in the body of the vehicle, when they come in contact with it, is relatively abrupt. Being aware of the characteristics of surface smoothness and abrasion resistance of ethylene vinyl acetate (AVE), whose characteristics are currently being exploited using such materials to coat relatively rigid internal parts such as high-tech toothbrush bristles and toothbrushes, the Inventor has conceived the idea of using vinyl acetate by adding ethylene to one of the synthetic resins that is currently used to produce cleaning elements for rotating brushes in order to obtain a copolymer, which, by itself, or mixed with other substances which then increase their physical-mechanical characteristics, and which will be described later, prove adequate to produce the cleaning elements described above, offering considerably higher levels of performance that can be obtained under the current state of the art. During the process of preparing the ethylene vinyl acetate copolymer, and during its cross-linking in a pressurization phase (which is achieved by mixing substances such as special peroxides) in order to produce a cleaning element, the vinyl acetate copolymer ethylenic which is formed by the addition operation described above, exhibits in cross-section, an agglomerate of closed microcells having a diameter which is considerably smaller than that of the materials currently used, with a substantially larger overall cross section of material which is resistant to traction and bending pension. This means that it is possible to reduce the cross section of the cleaning element, with greater flexibility and less stress arising from the bending stresses acting on its outer edges. All this, combined with the softness qualities ensured by the presence of vinyl acetate, makes the ethylene vinyl acetate copolymer the ideal material to produce flexible cleaning elements for rotating brushes. Above all, a copolymer as described above, that is, an AVE copolymer, exhibits excellent resistance characteristics to aggressive chemical agents and to atmospheric agents, especially exposure to radiation (including solar radiation). The object of this invention is, therefore, a flexible cleaning element for rotating brushes for automatic vehicle washing, whereby said element is suitable for joining a rotating support element and is formed of a synthetic resin expanded from cells closed and characterized by the characterization part of appended claim 1. Some preferred embodiments of the subject of the invention will now be described in greater detail. In order to ensure a better visualization of a flexible element and an example of the union thereof with a rotating brush, reference is also made to the attached figure, which shows the cross section of one of the different possible modes of the latter that are known. The flexible elements 3n of a known type in the form of a corrugated sheet are joined at one end to a support 2 with the system shown in the figure, ie, leaving at said end one or more holes 1 through which the material 4 (for example, polyurethane) which is injected into the support 2 by itself, thus connecting each element 3n with the latter. This kind of fixing can be achieved by folding along the midline a corrugated sheet at two ends in such a way that a single sheet forms a handle and forms two flexible elements which are attached to said support by the handle, which is Equi pada with holes whose function is exactly the same as that described in the previous case (this solution is not shown). According to some preferred embodiment, said elements are formed of said AVE copolymer, with which other chemical additives are mixed and, in some cases, natural or synthetic rubber. The latter substance then improves the physical-mechanical characteristics of the cleaning element, while other substances, which will be listed below, are used in order to ensure the cross-linking of the AVE copolymer or act as "faces" to improve the particular characteristics of mechanical resistance. Finally, other substances such as stearin or stearic acid are added in order to form a mixture more suitable for the washing cycle which is required to produce flexible cleaning elements as described above. In a preferred embodiment of the cleaning element according to the invention, the synthetic resin of which it is made contains: about 80% by weight of said copolymer (AVE), which in turn contains 9-28% of its weight in vinyl acetate; about 10% by weight of amorphous precipitated silica; about 2% by weight of bis (peroxios-propylterbutyl) benzene; about 2.5% by weight of azodicarbonamide; about 05% by weight of stearin; about 5% by weight of pigments. According to another preferred embodiment, the synthetic resin contains: about 60% by weight of said copolymer (AVE), which in turn contains 9-28% vinyl acetate; about 20% by weight of the natural or synthetic rubber; about 10% by weight amorphous precipitated silica; about 2% by weight of bis (perioxios-propylterbutyl) benzene; about 2.5% by weight of azodicarbonamide; about 0.5% by weight of stearin; about 5% by weight of pigments. In another embodiment, the synthetic resin contains: about 47% by weight of said copolymer (AVE), which in turn contains 9-28% vinyl acetate; about 5% by weight of low density polyethylene (PE); about 40% by weight amorphous precipitated silica; about 1.1% by weight of stearic acid; about 2% by weight of zinc oxide; about 3% by weight of azodicarbonamide; about 2% by weight of bis (peroxios-propyl tertbutyl) benzene.

In order to obtain a flexible cleaning element according to the invention which comprehensively offers better performance, on the basis of tests suggested by the inventor that a weight ratio of vinyl acetate of about 18% of the total weight of the vinyl acetate is used. AVE copolymer. Other substances such as pigments, etc. , can be selected from those known to one skilled in the art for this area of application. The inventor also suggests that the amorphous precipitated silica mentioned above be used as "charge" fibers. Clearly, it is possible to produce many other embodiments of a synthetic resin containing an AVE copolymer according to what is described in the appended claims and which It is suitable for making flexible cleaning elements for rotating brushes. If these modalities are based on the concepts set forth in the appended claims, said modalities are still within the scope of the protection conferred by the appended patent application.

Claims (8)

1. CLAIMS 1. The flexible cleaning element (3n) for rotating brushes for automatic vehicle washing, suitable for joining a rotating support (2) and made of a closed cell expanded synthetic resin, wherein said expanded synthetic resin includes a copolymer (AVE) which is obtained by adding vinyl acetate.
2. 2. The cleaning element according to the claim

   1, in which predetermined amounts of chemical additives are mixed with said copolymer.
3. 3. The cleaning element according to the claim
4. 2, in which a predetermined amount of natural or synthetic rubber is also mixed with said copolymer. The cleaning element according to claim 2, wherein said synthetic resin contains: about 80% by weight of said copolymer (AVE), which in turn contains 9-28% of its weight in vinyl acetate; about 10% by weight amorphous precipitated silica; about 2% by weight of bis (peroxios-propylterbutyl) benzene; about 2.5% by weight of azodicarbonamide; about 0.5% by weight of stearin; about 5% by weight of pigments. The cleaning element according to claim 3 wherein said synthetic resin contains: about 60% by weight of said copolymer (AVE), which in turn contains 9-28% vinyl acetate; about 20% by weight of the natural or synthetic rubber; about 10% by weight amorphous precipitated silica; about 2% by weight of bis (perioxios-propylterbutyl) benzene; about 2.5% by weight of azodicarbonamide; about 0.
5. 5% by weight of stearin; about 5% by weight of pigments.
6. 6. The cleaning element according to the claim

   4, wherein said AVE copolymer contains 18% by weight of vinyl acetate. The cleaning element according to claim 2, wherein said synthetic resin contains: about 47% by weight of said copolymer (AVE), which in turn contains 9-28% vinyl acetate; about 5% by weight of low density polyethylene

   (PE); about 40% by weight amorphous precipitated silica; about 1.1% by weight of stearic acid; about 2% by weight of zinc oxide; about 3% by weight of azodicarbonamide; about 2% by weight of bis (peroxios-propyl tertbutyl) benzene.

   8. The cleaning element according to claim 7, wherein said AVE copolymer contains 18% by weight of vinyl acetate.