DE9417186U1 - Tool for mechanical surface treatment - Google Patents

Description

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_ &igr; _ KEIL&SCHAAFHAUSEN

PATENT ATTORNEYS

Description:

Tool for mechanical surface treatment

The invention relates to a tool for mechanical surface treatment by rubbing, e.g. for brushing, polishing, shining, cleaning, wetting or drying, which consists of a cut and processed fleece made of fibers.

Mechanical surface treatment is used in particular for the processing of numerous products made of metal, wood, glass, leather, plastic and the like, such as kitchen appliances, cutlery, fittings, frames, profile bars, industrial parts, jewelry or musical instruments, as well as for the maintenance and care of floors, walls, glass panes, tiles and the like.

The surface treatment is carried out, for example, during polishing in several steps using different tools or tool configurations, which produce an increasingly finer surface through selected graduation. These tools consist, for example, of polishing rings or discs, which are made up of several layers of fabric and are generally arranged on a common axis of rotation or a clamping ring. For polishing rings, the fabric cut into bands is folded, placed in a ring shape around a core, which consists of cardboard rings or flanges or a metal clamping ring, and attached to it or with it. For polishing discs, cut layers of fabric are placed on top of one another and twisted, for example, by an angle of 30°.

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sewn and held together by stapled cardboard flanges. The fabric used for this purpose is generally a cotton fabric, especially for polishing. Fabric made of stiffer fibers, such as sisal, can also be used for the first polishing operations. Certain polishing rings or discs can also be made from a mixture of cotton and sisal fabric. The polishing rings or discs can optionally be impregnated with a resin that acts as a binding agent in order to increase their strength.

For years, fabric made of cotton or other unmixed or mixed fiber materials has had to be biased before it is cut and processed into pleated rings. Experts understand this to mean the slanting of warp and weft threads to a cut edge that runs diagonally to the original woven edge. This process requires a special turning machine that sews the edges of the fabric together to form a tube. The fabric tube is then cut into spiral strips (biaized) and rolled up into a bale. At the periphery of the pleated rings, the threads form an angle of 45°. The biasing counteracts the problem of fraying of the pleated rings (see magazine L'Usine Nouvelle, March 1961, "Techniques modernes de Bufflage et de Pollisage").

The folding of the fabric bands automatically ventilates the polishing ring during rotation; it acquires the necessary flexibility to better envelop the part to be polished and forms honeycombs on the periphery which absorb the polishing pastes. Polishing pastes are always required when polishing surfaces because of their grinding and lubricating properties.

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PATENT ATTORNEYS

However, conventional polishing tools have both economic and technical disadvantages. These are in particular the following:

- difficult procurement of goods on the world markets due to bureaucratic EU import quota regulations regarding cotton fabrics,

- strong fluctuations in the listed world market prices of the raw material cotton,

- lack of manufacturing capacity within the EU due to high wage costs,

- difficulty in producing blended fabrics due to the yarn manufacturing process,

- technical necessity for biasing as an additional non-automatable operation with disturbing side effects of hard and wide biasing seams, which affect both the manufacturing process and the quality of the surface treatment,

- considerable non-recyclable tissue waste, 25

- irregular wear of the grinding rings or discs due to fraying of the fabric,

- frequent tool changes due to limited service life of the slip rings or discs.

Polishing tools made of fleece are rarely used. FR-PS 1 426 721 describes, for example, a polishing or grinding material made of fleece, which consists of synthetic, permanently waved filaments. An adhesive with

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or without abrasive particles on the filaments under tension. If the tension is interrupted, the fibers intertwine and are then heat-set. The fleece obtained in this way is cut and processed into a ring-shaped polishing tool. FR-PS 2 310 838 also describes polishing rings which consist of several fleece layers. The disordered fibers of this fleece are connected at their intersection points using a resin.
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Despite some improvements over fabric rings and discs, such fleece polishing rings and discs still have the following disadvantages:

- high proportion of waste, which cannot be reused due to the binding agent,

- low fleece density, due to the limited penetration capacity of the binding agent (filter effect),

- resulting in insufficient mechanical strength with a correspondingly short service life,

- limited application possibilities because the distribution of the binding agents is irregular and this leads to different, erratic results,

- insufficient heat resistance, which leads to undesirable lubricating effects, and

- limited possibility of producing fibre mixtures due to different adhesion and binding properties of the binders to the different fibre materials.

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PATENT ATTORNEYS

The object of the present invention is to create a tool of the type mentioned at the outset which, while avoiding the disadvantages mentioned above, has reliable functionality while being easy to manufacture and has a long service life.

This object is achieved according to the invention in a tool of the type mentioned at the outset in that the fleece is produced as a random fiber fleece without binder by means of an exclusively mechanical process.

This represents a significant technical and economic advance in the field of surface treatment by friction. Tools according to the invention bring with them the following advantages:

- Independence from unstable raw material prices, because the nonwoven according to the invention can also be produced from artificial or synthetic fibres,

- reusable waste because there is neither a fabric structure nor binding agents,

- there are expanded fibre blending options because yarn production is no longer required,

- the work process of biasing is eliminated,

- accordingly, there is also better processability and application possibilities due to the elimination of bias seams,

- the manufacturing process is easy to automate,

- there is no fraying, which results in uniform radial wear,

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- consequently, the downtime and thus tool change times are also longer,

- it results in smoother running due to better concentricity, and

- there is less and more easily removable abrasion and therefore greater cleanliness and reduced risk of smoldering fires in the workplace.

In an advantageous embodiment of the invention, the mechanical fleece formation process is carried out either by the needling process known per se or by means of a liquid and/or gas jet, whereby a surprisingly durable random fiber fleece is created that is particularly suitable for the purpose of use according to the invention and that particularly well meets the requirements of a tool for mechanical surface treatment by rubbing with a long service life.

Water can preferably be used as the liquid and/or air as the gas. Both methods lead - as with the needle technique - to a binder-free fiber composite, whereby water as a liquid has the advantage that it completely evaporates during drying.

The fibers that make up the fleece can be natural, artificial or synthetic and can be present in the fleece unmixed or mixed. Natural plant fibers include cotton, linen, hemp or sisal, natural animal fibers include wool, mohair and silk, artificial fibers include viscose, mineral, ceramic, carbon and metal fibers, and synthetic fibers include polyester, polyamide, polypropylene, polyimide, acrylic and aramid.

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Preferably, cut fibers are used whose length is between about 10 and 100 mm and whose titre is between about 0.02 and 150 dtex.

It is further advantageous within the scope of the inventive concept if the density and thickness of the fleece in the fleece formation process by liquid jet are determined by a pressure of the liquid used that can be regulated between about 5 and 230 bar.
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The nozzles generating the liquid jets used for nonwoven production preferably have a diameter of between about 80 and 14Ox 10" ⁶ m.

The fleece further preferably has a basis weight between about 50 and 500 g/m ² and a thickness between about 0.3 and 5 mm.

The fleece can be designed, for example, as a pleated ring, flat disc, pad, roll, roller, belt or brush in order to meet specific application conditions.

As a folded ring, the fleece can have the shape of a ring consisting of at least one band cut from at least one fleece layer, which is folded, placed radially around a solid core and fastened there.

It is also possible for the fleece to be in the form of a ring consisting of at least one band cut from at least one fleece layer, which is folded in a wave shape, placed around a solid core and secured there.

Another alternative is that the fleece is in the form of a ring made of at least one fleece

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layer cut to size, which is folded and/or gathered and held together by a central tension ring.

Furthermore, it is also possible, for example, for the fleece to be in the form of a ring consisting of at least two discs cut from at least one fleece layer and placed on top of each other, which are held together by center pieces and/or quilting seams.

Where the use of disc- or ring-shaped tools is less suitable, it can be advantageous for the folded fleece, for example, to be attached to a belt-shaped endless carrier, which can be moved by one or more pulleys like a drive belt.

The fleece can be attached to a belt-shaped, endless carrier in the form of individual single- or multi-layered band sections formed into slats.

In order to adapt the tool to different purposes, the invention further proposes that the finished and possibly already assembled fleece be subsequently equipped with appropriately selected substances for the purpose of reducing wear or flammability or for the purpose of improving paste adhesion, abrasive behavior, surface attack, service life, liquid absorption, liquid repellency, antistatic effect or the like without significantly changing the mechanical bonding of the fibers in the fleece.

Further aims, features, advantages and possible applications of the invention emerge from the following description of embodiments based on the drawings. All described and/or illustrated features form the subject matter alone or in any combination.

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of the invention, regardless of its summary in the claims or their reference back.

Show it:

Fig. 1 shows schematically an embodiment of the manufacturing process for the nonwoven fabric according to the invention,

Fig. 2a to 2d oblique views of different embodiments of polishing rings and discs,

Fig. 2e Oblique view of a polishing ring with lamellae,

Fig. 2f and 2g Oblique view of belt-shaped tools,

Fig. 3a and 3b are views of two used polishing rings, one of a conventional type (Fig. 3a) and the other of a type according to the invention (Fig. 3b), and

Fig. 4a and 4b analogous to Fig. 3a and 3b views of other disc-shaped tools.

According to Fig. 1, a production line 10 for a nonwoven fabric 11 produced according to the invention without a binder by means of a liquid jet comprises, for example, the following essential devices: opener with mixing chamber 20 for fiber bales for producing a loose, homogeneous bulk, weighing and dosing device 30, carding machine 40, spreading machine 50, blasting system 60 for mechanically binding the fibers into a random fiber nonwoven fabric 11, drying oven 70 and winder 80. In a production line that works according to the needling process, a needling machine is used instead of the blasting system 60.

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The fiber bales are opened in the opener 20. These are preferably cut-to-length fibers of a natural, artificial or synthetic type with a length between about 10 and 100 mm and a titer between about 0.02 and 150 dtex. The opener 20 can process fibers of the same or different types with its connected mixing chamber. In the mixing chamber, similar fibers can be homogenized or mixtures of different fiber types can be produced. Accordingly, one or more similar bales or several dissimilar bales are used.

The weighing and dosing device 30 supplies the card 40, which converts the loose fibers into a fiber web in which the fibers have been aligned. The basis weight of the fiber web is predetermined and regulated by the amount of fibers supplied by the weighing and dosing device 30. This value can vary, for example, between approximately 5 and 10 g/m ² . The fiber web is then layered on a conveyor belt by means of the spreading machine 50 into layers which together form a fiber web 51. The basis weight of the fiber web 51 is between approximately 50 and 500 g/m ² . The fiber web 51 then runs through the blasting system 60 or, alternatively, the needling machine to produce a binder-free random fiber web 11. Up to a basis weight of approximately 150 g/m ² the liquid jet process is more cost-effective, above that the needling process. The web production process using a liquid jet is, for example, B. known per se from FR-PS 1 460 513. The blasting system 60 consists of two rows of injection nozzles 61, which apply high pressure to the front or the back of the fiber fleece 51 to produce the random fiber fleece. Depending on the desired bond strength, a single row of nozzles is sufficient. The openings of the injection nozzles 61 can have a diameter of about 80 to 140 x 10" ⁶ m and are filled with water, the pressure of which

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between about 5 and 230 bar. They are arranged perpendicular to the fiber fleece 51 lying on a metal sieve 62. In order to drain excess water from the fiber fleece 51, suction devices 63 are mounted underneath the metal sieve 62 opposite the injection nozzles 61. The water jets penetrate the fiber fleece 51 and intertwine the fibers with one another to form a solid sheet-like structure. In this process, the 2 cm thick fabric is compressed to form a 1 mm thick fleece 11. The thickness can be reduced in the random fiber fleece formation process in a ratio of about 10:1 to 50:1. The possible thicknesses of a fleece 11 that can be used in the context of the present invention are, for example, between about 0.3 and 5 mm. The strong reduction in thickness leads to a significant increase in the density of the fleece 11, which is then, for example, between approximately 0.1 and 0.5 g/cm ³ . Apart from the initial mass per unit area of the fiber material, the density is essentially determined by the jet pressure. The fleece 11 then passes through the dryer 70, in which residual moisture is removed.

The dryer 70 can be, for example, a hot air blower, drum dryer, high frequency dryer or microwave dryer. After drying, the fleece 11 is rolled up using the winder 80.

As an example, process parameters for the production of a fleece 11 for tools according to the invention consisting of 100% viscose with a basis weight of 200 g/m ² and 1.7 dtex fibers are given in detail below:

- Carding:

Production of three fibre webs of 140 + 120 + 90 g/m ² and - beam binding:

- first page: pressure with 70 bar

- second side: pressure with 110 bar
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The fleece 11 produced in this way has very good mechanical properties and a high mechanical fiber cohesion due to the process, which is based on hydrogen bonds. The fleece 11 can be processed like a conventional fabric. 5

The tools that form the subject of this invention are manufactured using the new type of fleece material. The manufacturing process is simplified by the fact that biasing is no longer necessary. Tools of high quality are produced because the random fiber fleece manufactured and used according to the invention has good grinding paste absorption capacity and permanent grinding paste adhesion. The surface quality that can be achieved with them is improved because there are no hard biasing seams. The service life is increased due to even and low wear.

Figures 2a to g show various tools in the form of a folded ring (Fig. 2a to c), in the form of a flat disk (Fig. 2d), in the form of a lamella disk (Fig. 2e) and in the form of a band (Fig. 2f and 2g). A ring 101 (Fig. 2a) consists, for example, of a folded fleece band 102, which is laid flat in several layers around a core and fastened with two stapled cardboard flanges 103. This design is characterized by a high degree of adaptability to various processing contours, effective self-ventilation during rotation, good surface attack and optimal wrapping. The folded ring 110 shown in Fig. 2b is made from several superimposed, wave-shaped folded fleece bands 111, which are laid around a core and fastened between two stapled cardboard rings 112. This design has good dimensional stability and high strength. The pleated ring 120 shown in Fig. 2c consists of a nonwoven tape 121, which is wound up in several layers and gathered by constriction and fixed by a tension ring with metal hooks 123. This design has good properties

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ventilation, high dimensional stability and effective surface attack. The flat disk 130 shown in Fig. 2d consists of cut individual disks 131 which are placed on top of one another and connected to one another by means of concentric stitching 132. The middle is reinforced by sewn or stapled cardboard flanges 133.

The tool 140 shown in Fig. 2e consists of individual fleece lamellae 141, which are attached on one side to a round, cylindrical, conical or plate-shaped core 142, preferably by gluing but also by stitching or riveting, individually or in packages 143, which can also be folded in a U-shape 144 and arranged with or without a gap 145.

The tools 150 and 160 shown in Fig. 2f and 2g consist of a belt-shaped endless carrier 151 or 161, on which a fleece band 152 folded in several layers (Fig. 2f) or individual fleece lamellae 162 or lamellae packages 163, which can also be folded in a U-shape 164, are fastened by quilting 165 and/or gluing and/or riveting (Fig. 2g).

Fig. 3a and 3b show two polishing rings after use.

Both rings have the configuration of Fig. 2c, with the first (Fig. 3a) being made in the conventional way from a cotton fabric and the second (Fig. 3b) from a cotton fleece according to the invention. What is striking is the even radial wear of the second ring in comparison to the first.

In a nonwoven fabric made by needle punching or liquid jet, the radial wear is regular, unlike in a woven material. Thanks to this property, the second ring can be used for longer than the first, whose irregularly frayed contour impairs the polishing quality.

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PATENT ATTORNEYS

These different properties are also evident from the representations of Fig. 4a and 4b, which show two used layers of a multi-layer flat disk according to Fig. 2d. The first layer (Fig. 4a) is made in the conventional way from cotton fabric and the second layer (Fig. 4b) according to the invention from a cotton fleece. It can be seen that the first layer (Fig. 4a) shows clear signs of wear in the form of strong fraying, which leads to a complete change in the geometry, while the second layer (Fig. 4b) shows only slight regular fraying.

The invention is not limited to the embodiments described and shown as examples, but can be modified in various ways within the scope of the skill of the person skilled in the art without departing from the inventive concept.

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Claims (1)

FL 10 G 188 i _ ₁₅ _ Keil&Schaafhausen PATENT ATTORNEYS Protection claims: 1. Tool for mechanical surface treatment by rubbing, e.g. for brushing, polishing, shining, cleaning, wetting or drying, which consists of a cut and processed fleece made of fibers, characterized in that the fleece (11) has been produced by means of an exclusively mechanical process as a random fiber fleece without binder. 2. Tool according to claim 1, characterized in that the mechanical fleece formation process was carried out by means of needling or a liquid and/or gas jet. 15 3. Tool according to claim 2, characterized in that water was used as the liquid and/or air as the gas. 4. Tool according to one of the preceding claims, characterized in that the fibers forming the fleece (11) are of a natural, artificial or synthetic nature and are present in the fleece (11) unmixed or mixed. 5. Tool according to one of the preceding claims, characterized in that the fibers forming the fleece (11) are cut fibers whose length is between about 10 and 100 mm and whose titre is between 0.02 and 150 dtex. 6. Tool according to one of claims 2 to 5, characterized in that the density and thickness of the fleece (11) are determined by a pressure of the liquid used in the fleece formation process by liquid jet, which pressure can be regulated between approximately 5 and 230 bar. FL 10 G 188 i .... _ ie - Keil&Schaafhausen PATENT ATTORNEYS 7. Tool according to one of claims 2 to 7, characterized in that nozzles with a diameter between about 80 and 140x 10" ⁵ m were used to produce the fleece (11) used by means of liquid jets. 8. Tool according to one of the preceding claims, characterized in that the fleece (11) has a surface mass of between about 50 and 500 g/cm ² . 9. Tool according to one of the preceding claims, characterized in that the density of the fleece (11) is between about 0.1 and 0.5 g/cm ³ . 10. Tool according to one of the preceding claims, characterized in that the thickness of the fleece (11) is between approximately 0.3 to 5.0 mm. 11. Tool according to one of the preceding claims, characterized in that the fleece (11) is designed as a pleated ring, flat disc, pad, roll, roller, belt or brush. 12. Tool according to claim 11, characterized in that the fleece (11) has the shape of a ring (101) made of at least one band (102) cut from at least one fleece layer, which is folded, placed radially around a fixed core and fastened there (Figure 2a). 13. Tool according to claim 11, characterized in that the fleece (11) in the form of a ring (110) consists of at least one band (111) cut from at least one fleece layer, which is folded in a wave shape, placed around a fixed core and fastened there (Figure 2b). 25.10.94 FL 10 G 188 i - 17 - KEIL&SCHAAFHAUSEN PATENT ATTORNEYS 14. Tool according to claim 11, characterized in that the fleece (11) in the form of a ring (120) consists of at least one band (121) cut from at least one fleece layer, which is folded and/or gathered and held together by a tension ring (Figure 2c). 15. Tool according to claim 11, characterized in that the fleece (11) in the form of a ring (130) consists of at least two disks cut from at least one fleece layer and placed on top of each other, which are held together by middle pieces (133) and/or quilting seams (132) (Figure 2d). 16. Tool according to claim 11, characterized in that the fleece (11) in the form of individual single- or multi-layered band sections formed into lamellae (141) is attached to a round, cylindrical, conical or plate-shaped core (142) (Fig. 2e). 17. Tool according to claim 11, characterized in that the folded fleece (11) is attached to a belt-shaped endless carrier (151, 161) which can be driven by pulleys like a drive belt (Fig. 2f and 2g). 18. Tool according to claim 11 or 17, characterized in that the fleece (11) in the form of a band (152) folded into several layers or individual single- or multi-layer band sections formed into slats (162) is fastened to a belt-shaped endless carrier (161) (Fig. 2f and 2g). 19. Tool according to one of claims 1 to 18, characterized in that the finished and possibly already assembled fleece (11) is subsequently FL 10 G 188 i _ ₁₈ _ Keil&Schaafhausen PATENT ATTORNEYS wear or flammability or for the purpose of improving paste adhesion, abrasive behavior, surface attack, service life, liquid absorption, liquid repellency, antistatic effect or the like without any significant change in the mechanical bonding of the fibers in the fleece (11). 25.10.94