CN1129394A - Cleaning brushes made of non-woven fabric - Google Patents

Abstract

A brush (30) made from a nonwoven, thermally bonded bicomponent fiber web is described. The nonwoven brush (30) of the invention includes a plurality of compressed annular sections (10) assembled about a central carrier (100) with each section made of a mat of bicomponent fibers which have been crimped and melt-bonded. In a preferred embodiment, the brush (30) will have a compacted density of between about 50 and about 250 kilograms per cubic meter. The fibers making up the compressed annular sections (10) are preferably a combination of polyolefins (e.g. polypropylene and polyethylene) but may also include polyesters and other materials.

Description

Cleaning brushes made of non-woven fabric

technical field

The present invention relates to a brush of non-woven hot-melt compacted fibers for use in corrosive environments such as strip mills. More particularly, the present invention relates to a brush for use in corrosive environments wherein the brush is compacted from a plurality of discs made of bicomponent nonwoven fibers. The brushes of the present invention are able to withstand extremely corrosive environments and do not require resin coatings, adhesives or the like.

technical background

Strip must be thoroughly cleaned before tinning. This is done in a strip mill by first sending the strip through a cleaning bath containing a hot corrosive solution and then through a rinsing bath containing hot water. During the cleaning process, the surface of the strip should be lightly wiped with a brush. Conventionally, brushes have been made of various materials. Until recently, stiff-bristle brushes were commonly used in the cleaning process and had bristles made of natural plant fibers. For example, brushes having Tambuco bristles (hereinafter referred to as "Tambuco brushes") made from a hard grass plant that grows in the area around Tambuco in Mexico have been widely used for steel strips. During cleaning. Scrub brushes may also include bristles of synthetic material such as polypropylene. However, bristle brushes have only a short service life in the corrosive environment of a strip mill.

About ten years ago, a cleaning brush consisting of compacted segments of nonwoven nylon fabric was developed and marketed by 3M Australia, a subsidiary of 3M in Australia. This brush has an effective service life two or three times longer than Tambuco brushes. This Australian brush is made from a 38 mm long fabric of 13-15 denier nylon fibers formed by air-laying. The nylon fabric is needled or false-stitched to increase its density and strength, and the fabric is thoroughly impregnated with a solution of phenolic resin that acts as a binder, which when cured gives the fabric strong corrosion resistance . This brush has been adopted in the last decade.

However, brushes made of phenolic resin bonded nylon fabric also have some disadvantages for use in corrosive environments. Although, it is favored for its longer service life than Tambuco brushes, nylon fabrics are not suitable for use due to the fact that the phenolic resin binder covering the nylon fibers gradually degrades under hot, corrosive conditions (typically pH 13 and 80°C). The resulting brush degrades to form waste or "fluff". This fuzzy phenomenon is caused by the loosening of nylon fibers. This loosening is problematic because it is difficult to remove from strip mill cleaning lines and it clogs filters.

In view of the above-described problems with cleaning brushes, there is a need for an improved cleaning brush for use in the corrosive environment of a strip mill or similar machine. Furthermore, there is a need for a cleaning brush having a higher resistance to corrosion by corrosive solutions to avoid degradation of the aforementioned phenolic resin material and fluff due to destruction of brush fibers in a corrosive environment.

disclosure of invention

The present invention overcomes the problems of the prior art by providing a rotating brush for cleaning strip mills and similar machines in a corrosive environment, such brush comprising:

A cylindrical body rotatable about its longitudinal axis, said cylinder comprising a compacted body of a plurality of equally oriented discs, each assembled around a central support, the discs each formed from a crimped bicomponent fiber Made of non-woven fabrics, the bicomponent fibers are composed of a first component polymer and a second component polymer having a lower melting point than the first component polymer, the first component The polymer and said second component polymer are welded or fused to bond the two components to each other in individual discs, said cylinders having a density between approximately 50 and 250 kg/m ³ .

The fibers from which the compacted discs are made are preferably polyolefinic compositions (eg, combinations of polypropylene and polyethylene), although polyester and other materials can also be used. It is best to needle or sew the discs before welding or fusing them. Spacers may be provided between the discs, and the finished brush will comprise discs and spacers in predetermined proportions.

A preferred method of manufacturing the rotating brush of the present invention comprises:

preparing a fabric formed from crimped bicomponent fibers in an air-laid process, the fabric comprising a first component polymer and a second component polymer having a lower melting point than the first component polymer; heating the fabric to a temperature sufficient to soften the second component polymer to form a weld or fusion between the two component polymers so that the first and second component polymers in the fabric; A plurality of discs are made from said nonwoven fabric; said plurality of discs are aligned for rotation about a common axis; and a force of 250 kg/m ³ to compact the plurality of discs; the discs are constrained in the compacted structure.

Those skilled in the art can have a more complete understanding of the details of the present invention with reference to the following detailed description of the preferred embodiments and the appended claims.

Brief description of the drawings

Below in conjunction with accompanying drawing, preferred embodiment of the present invention is described, in the drawing number:

Fig. 1 (a) is used in the rotating brush body in the first embodiment of the present invention, is made of a plan view of non-woven fabric;

Fig. 1 (b) is a plan view of a spacer used in the rotating brush body in the first embodiment of the present invention;

Figure 1(c) is an exploded view of the rotating brush body according to the first embodiment of the present invention;

Fig. 1 (d) is according to the first embodiment of the present invention, the perspective view of the rotating brush body after making;

Fig. 2 (a) is used in the rotating brush body in the second embodiment of the present invention, is made of a plan view of non-woven fabric;

Fig. 2 (b) is the plan view that is used for the spacer of the rotating brush body of the second embodiment of the present invention;

Figure 2 (c) is an exploded view of the rotating brush body according to the second embodiment of the present invention;

Fig. 2(d) is a perspective view of a manufactured rotating brush body according to a second embodiment of the present invention.

detailed description

Details of preferred embodiments of the invention are now described in some detail. It will be understood by those skilled in the art that the present invention is not limited to the structural details of these embodiments, which are used only to illustrate the characteristics of the present invention. The description of the preferred embodiment is carried out in conjunction with the drawings, in which the structural features of the present invention are numbered, and the same numbers refer to the same structures.

Referring to the drawings, Figures 1 and 2 show first and second embodiments, respectively, of compacted cleaning brushes made of non-woven heat-fusible fiber fabrics. Figures 1(a)-(d) illustrate various features of a first embodiment of the present invention, showing a brush 30 and components of its tie-bolt structure. Figures 2(a)-(d) show another embodiment of the present invention, but instead of a bolt structure but a bonded structure, the material of the brush 40 is the same as in Figure 1 . According to one aspect of the invention, the fabric is free of phenolic resin binders. The brushes described herein can be made in sheet brush configurations and compact brush configurations, as will be apparent to those skilled in the art. Also, the spacers described herein may not be necessary in certain types of brushes, for example small brushes may be without a spacer.

In both of the examples described herein, nonwoven fabrics were used to make the discs 10 and 20 . In the fabric, no additional resin (eg, phenolic resin) or the like is used to protect or bond the fibers of the fabric. Preferred textile fibers include certain polymeric fibers such as polyolefinic fibers, polyester fibers and combinations thereof. Preferably polyolefin based bicomponent fibers are used and most preferably polypropylene and polyethylene crimped fibers. The diameter of the fibers is important in order to allow the construction of the brush to be used in a corrosive environment and to obtain satisfactory cleaning results. Polyolefin fibers having a denier of from about 3 to 40 are preferred. The range of fiber lengths may be continuous or of a certain length. The crimped polyolefin fibers preferably have a length of about 25 mm to 64 mm, more preferably about 38 mm to 50 mm, when fabrics are produced using conventional fabric equipment. The fibers may be slightly crimped and the fiber crimps may be conjugate or helical crimps. Typically the fibers are thermoplastic bicomponent fibres, ie, sheath-core or side-by-side, one component being preferably polyethylene and the other preferably polypropylene. Polyester bicomponent fibers may also be used.

The preferred construction of the fabric does not use additional resinous material to bond or protect the fibers of the fabric. An important aspect of the present invention resides in the manufacture of bicomponent fabrics in which the fibers are all fused or fused to each other at fiber contact points in the components. For example, in fabrics made of the preferred materials of the above-mentioned polyolefin compositions, the fabric is generally heated to the melting point temperature of the polypropylene component with a lower melting point, and in the heating step, the temperature of the polypropylene component with a higher melting point Dimensions remain the same. During this heating step, the molten polyethylene fibers fuse with the polypropylene at fiber contact points in the fabric, and the fabric experiences only minimal shrinkage during the welding process. Most suitable for use as brush structures are those having a basis weight of about 100 grams per square meter ("gsm") to about 500 gsm and those having a thickness of from about 5 mm to about 25 mm. The above-mentioned nonwoven fabrics can be produced in a known manner using RANDO WEBBER brand machines (Rando Machine Company, Mace-don, New York) or FIBER LOCKER brand machines (James Hunter, North Adams, Mass.).

In order to increase the strength (ie, tensile and tear strength) of the fabric, it has been found advantageous to perform a needling or stitching operation on the fabric prior to welding. Needling is a known technique which uses barbed or felting needles to further entangle the fibers of the nonwoven web by passing the needles into the fabric in a predetermined pattern. Satisfactory fabrics can be obtained by needle punching by using a needle sewing machine equipped with 15 x 18 x 30 x 3.5 CB Foster felting needles on a general needle plate. A preferred hub arrangement is five rows of needles spaced 8.5 mm, 8.5 mm, 10 mm, and 6.5 mm apart, with the needles in each row evenly spaced 12.5 mm apart.

After needling, the fabric is conveyed by a conveyor belt through a preheating oven. Satisfactory results have been obtained with a 25 m long, center-feed (i.e. reverse airflow towards the inlet end of the fabric, forward airflow towards the outlet end) gas furnace in which the gas at the inlet is about 8000 cubic feet per minute (227 cubic meters per minute), approximately 4000 cubic feet per minute (113 cubic meters per minute) at the outlet. The airflow is deflected by angled baffles above and below the frame belt to pass through the fabric, which is heated to the softening or melting temperature of one of the component fibers. With polyethylene/polypropylene fibers, the fabric is heated to about 142°C to about 148°C to melt the heat of the fibers. Those skilled in the art will recognize that the oven temperature can vary, depending on the weight of the fabric and the speed at which the fabric is fed into the oven. It has been found that satisfactory fabrics can be obtained by feeding unbonded fabric material weighing approximately 200 gsm at a rate of 4 meters per minute into a 25 meter long oven maintained at a temperature of approximately 142°C. As the weight of the fabric and/or its transport speed through the oven increases, the oven temperature must also increase. For example, a 250 gsm fabric is adequately welded at about 148°C when fed through the furnace at a speed of 5 meters per minute.

The fused web is cooled on exiting the oven with an air doctor knife and passed through a dancer nip roll from where the web enters a wire collector before being wound onto a main roll. Discs 10, 20 are then die cut from the resulting fabric. The discs 10, 20 are die cut from the fabric in various diameters varying between about 200 mm and about 600 mm, depending on the needs of the brush and the space available on the cleaning path where the finished brush will be installed size. It should be understood that the present invention does not impose any limitations on the diameter of the fabric or the length of the brush, which are purely a matter of engineering design.

Both discs 10, 20 are formed with central bores 70, 80 which may include opposed square keyways 90 (Fig. 1a) to fit over the keys of the support shaft. Additional slots 92 may also be provided to accommodate long tie bolts (or axial bolts) 100 which hold the brush elements together during assembly. When a glued brush is required, captive bolts 100 are not used and both disc 20 and spacer 50 are mounted to a steel mandrel 110 as shown in Figures 2(a)-(d).

Spacers 50, 60 are provided for positioning between the wafers. Both spacers 50,60 are typically made of a thermoplastic material such as polypropylene and have a central hole similar to (usually identical to) the holes 70,80 of the discs 10,20. As shown, the outer diameters of the spacers are smaller than those of the discs 10,20. Each brush is produced with a number of spacers located between the discs along a mounting shaft, such as the shaft bolt 100, with a certain number of discs between each spacer. For example, on the brush shown in Figures 1 and 2, the ratio of disks to spacers is 3:1 and the number of disks is 12.5 disks per 25 mm of brush length. Those skilled in the art will understand that the number of disks and the ratio of disks to spacers on the brush are not limited in any way. However, it is contemplated that a preferred brush will contain between about 5 and 20 discs per 25mm long disc, with a preferred ratio of discs to spacers between about 1:0 to 5:1. Preferably use spacer in the brush disclosed herein, because spacer can make disc 10,20 have some degrees of freedom of lateral movement in its peripheral portion to carry out cleaning operation better, can make disc 10,20 again simultaneously. Reinforced on its inner diameter. A polypropylene septum with an outer diameter of 200 mm, an inner diameter of 109 mm and a thickness of 1.9 mm is satisfactory.

In the embodiment shown in FIGS. 1c and 1d , both the disc 10 and the spacer 50 are mounted between the end flanges 120 of the axle bolt 100 . In the embodiment shown in FIGS. 2c and 2d , both the disc 20 and the spacer 150 are located on the mandrel 60 . After installing a certain number of spacers and discs as described above, the spacers and discs are compacted at room temperature with a sufficient force to make a non-woven brush of a certain length of dense structure, which can then be Attached to the working shaft (not shown) of the strip mill for cleaning operations. The brushes of the invention generally have a compacted density of about at least 5 kg/m ³ , preferably between about 50 and 250 kg/m ³ , most preferably 125 kg/m ³ . The compaction force may be provided by any suitable means known to those skilled in the art. Once the desired compaction density is obtained, the disks and spacers are held in their proper position by any suitable means, such as end flanges 120 or locking collars that slide over the axle bolt 100 and mechanically cooperate therewith. compacted shape. Similarly, the disc 20 and spacer 150 in FIG. 2 may be held on the mandrel 60 by gluing. The typical hardness of the resulting brushes is between about 5 and 25 Shore A2 hardness.

In a preferred configuration of the invention, the fabric is a side-by-side bicomponent polyethylene/polypropylene known as Chisso Type Es supplied by Chisso Corporation (Polypropylene Fiber Division, 6-32 Naanoshima 3, Kita-Ku, Osaka 530, Japan) Made of fiber. A preferred fiber is 18 denier and 64mm long. A preferred weight is 250gsm. The fabric can be punched by needle punching, the needle punching density is about 8 punches/cm ² , the speed of needle sewing or false sewing is 760 cycles/min, the depth of penetration into the fabric is 21 mm, and the line speed is 4 per minute. rice. For example, when the line speed increases to five meters per minute, the needle sewing or dummy sewing speed should increase to about 950 cycles/minute. Other line speeds may be required, the adjustment of which is well known to those skilled in the art. A preferred brush 30, 40 comprises about 600 discs and about 200 polypropylene spacers 50, 60, each about 1.9 mm thick, to form a compacted brush 1.2 meters long x 406 mm in diameter.

It has been found that when the brushes of the present invention are operated in the same hot, corrosive environment as conventional nylon/phenolic bonded brushes, they outlast nylon/phenolic brushes by approximately 70%. It has been noted that brushes of the present invention produce substantially less "lint" or waste under typical use in corrosive environments. When compared to the Tambuco brushes discussed above, the brushes of the present invention have an approximately 350% increase in service life while requiring significantly less mill maintenance.

The following examples illustrate the manufacture, construction and durability of a preferred embodiment of the nonwoven brush of the present invention.

Example

An 18 denier, 38 mm long "CHISSO" polyethylene/polypropylene sheath core fiber (Chisso Co., Osaka, Japan, or Chisso America Inc., New York, NY) to prepare 250 g/m ² , 50 mm thick nonwovens, consolidated with a conventional needle sewing machine supplied by Foster Needle Company (Manitowoc, WI.), There are 10 needles per inch (3.9 per centimeter) on the needle board of the needle sewing machine, and the name of the needle is 15×18×30×3.5 CB. The needle seam was adjusted to create a penetration depth of 85 mm and a penetration depth of 49 penetrations/in ² (7.6 penetrations/cm ² ). The consolidated nonwoven fabric was passed through a 25 m long forced air sintering furnace heated to 148°C at a speed of 5 m/min. The resulting non-woven fabric is about 10 mm thick, well fused and hard, and has no fuzz.

Discs of three different diameters were then cut from the consolidated and fused nonwovens. Most of the discs cut are 406mm outside diameter (“o.d.”) and 109mm inside diameter (“i.d.”), the i.d. is further provided with 4 equiangularly spaced slots to receive 4 axle bolts, and two symmetrical Keyway for installation on the shaft. A small number of 300mm and 255mm outer diameter discs were also cut, which also had an inner diameter of 109mm and had the same notches as the 406mm outer diameter discs. The two smaller diameter discs are used to provide sloped or stepped ends to the final brush. A polypropylene spacer with an outer diameter of 200 mm, an inner diameter of 109 mm, and a thickness of 1.9 mm was cut from the polypropylene sheet and was also notched to accommodate the shaft bolt and shaft key. After these different discs and spacers have been arranged, the cleaning brush of the present invention can now be assembled.

All 4 axle bolts are secured to an end flange which has the same bolt holes as the axle bolt notches in the disc and spacer. The end flange also has two oppositely arranged keyways, which are also matched with the keyways provided on the disc and the spacer. 4 255mm discs are placed over the axle bolts so that the axle bolts engage the axle bolt notches. A spacer was then similarly placed on the axle bolt, followed by two 300 mm OD discs, followed by a spacer, followed by two 406 mm OD discs and the same spacer. This assembly continues to be arranged alternately by 3 406mm discs and a spacer until 250 discs are loaded onto the axle bolts. The disk and spacer assembly is then compacted under a force of approximately 850 psi (5.9 MPa) and held by a clamping device. Then this whole assembly procedure is repeated by three 406mm outer diameter discs followed by a spacer until 600 discs are loaded. This assembly is accomplished by attaching a spacer, two 300 mm OD discs, a spacer, four 255 mm OD discs, and another end flange. The entire assembly is then compacted and the end flanges secured under a force of approximately 850 psi (5.9 MPa). The resulting cleaning brush was 1.2 meters long.

The cleaning brush is mounted on a keyed shaft and can be identified as a cleaning brush for use in electroplating operations where it will be subjected to a highly corrosive, The effect of a cleaning solution with a pH value of approximately 13. The brushes will perform satisfactorily for cleaning operations without fuzzing and will have twice the life of conventional nylon/resin brushes.

Although preferred embodiments of the present invention have been discussed and described in considerable detail above, those skilled in the art will recognize Various changes and modifications can also be made to the above-described embodiments.

Claims (31)

1. A rotating brush comprising: A cylinder rotatable about its longitudinal axis, said cylinder comprising a compacted body formed of a plurality of co-oriented discs, each disc mounted around a central support, each disc consisting of a first set of A nonwoven fabric made of corrugated bicomponent fibers of a polymer and a second polymer having a melting point lower than that of the first polymer, the first polymer and the second The two-component polymers are bonded together by fusion to each other in the individual discs, the cylinders having a density between about 50 and about 250 kg/ ^m3 . 2. The rotating brush of claim 1, wherein at least one of said discs is needle stitched or dummy stitched. 3. The rotating brush of claim 1 wherein said first component polymer is polypropylene and said second component polymer is polyethylene. 4. The rotating brush of claim 1 wherein said fibers are side-by-side crimped bicomponent fibers having a fiber count in the range of about 3 to about 40 denier. 5. The rotating brush of claim 1 wherein each of said discs has a basis weight in the range of about 100 to about 500 gsm. 6. The rotating brush of claim 1, further comprising at least one spacer disposed between adjacent discs. 7. The rotating brush of claim 6, wherein said spacers are located between adjacent discs, the ratio of said discs to said spacers in said brush being from about 1:0 to About 5:1. 8. A rotating brush for use in cleaning operations, comprising: a plurality of compacted sheets of nonwoven fabric rotatable about a common axis, each of said sheets being made of fibers of at least two different materials selected from the group consisting of polyolefin, polyester and combinations thereof, one of said materials is at least partially weldable to the other material in the sheet; In the brush, spacers are interposed between at least two of said sheets, and said sheets and said spacers are compacted along the length of said axis to a density of from about 50 to about 250 kilograms per cubic meter between. 9. A rotating brush as claimed in claim 8, wherein at least one of said sheets is needle stitched or dummy stitched. 10. A rotating brush as claimed in claim 8, characterized in that said different materials are crimped fibers of polypropylene and polyethylene. 11. The rotating brush of claim 8 wherein said fibers are side-by-side crimped bicomponent fibers of between about 3 and about 40 denier. 12. The rotating brush of claim 8, wherein each of said sheets has a basis weight in the range of about 100 to about 500 gsm. 13. The rotating brush of claim 8, wherein said spacers are located between adjacent pieces, the ratio of said pieces to said spacers within said brush being from about 1:0 to about 5:1. 14. The rotating brush of claim 8, wherein each of said sheets has a basis weight of about 100 to about 500 gsm. 15. A rotating brush for use in cleaning operations, comprising: A cylinder, which is a compact body composed of a plurality of discs rotatable in the same direction and about the same axis, each of which is composed of a non-woven fabric made of crimped bicomponent fibers comprising a first a component polymer and a second component polymer having a lower melting point than said first component polymer, both the first and second component polymers being selected from polyolefins, polyesters and combinations thereof, said bicomponent at least one component of the subpolymer is partially fused to another said polymer component; Spacers are located between adjacent sheets of said cylinder, said sheets and said spacers being compacted along the length of said same axis to a density of approximately 125 kg/m ³ . 16. The rotating brush of claim 15, wherein the disc is stitched or dummy stitched. 17. The rotating brush of claim 15 wherein said first component polymer consists of crimped polypropylene fibers and said second component polymer consists of polyethylene. 18. The rotating brush of claim 15, wherein said fibers are side-by-side crimped bicomponent fibers of between about 3 and about 40 denier. 19. The rotating brush of claim 15, wherein each said sheet has a basis weight in the range of about 100 to 500 gsm. 20. The rotating brush of claim 15, wherein the ratio of said tabs to said spacers on said brush is about 1:0 to 5:1. 21. A method of preparing a rotating brush for use in cleaning operations, comprising: making a nonwoven fabric formed by airlaying crimped bicomponent fibers comprising a first component polymer and a second component polymer having a lower melting point than the first component polymer; heating the fabric to a temperature sufficient to soften the second component polymers to cause welding or fusing between the polymers so that the first and second component polymers in the fabric stick to each other; forming a plurality of discs from said nonwoven fabric; aligning the plurality of discs for rotation about a common axis; compacting said plurality of sheets along said axis with a compacting force sufficient to compact said sheets to a density of about 50 to about 250 kg/m ³ ; and The disc is confined within the compacted body. 22. The method of claim 21, wherein preparing the airlaid fabric is accomplished using fibers selected from polyolefins, polyesters, and combinations thereof. 23. The method of claim 21, wherein the fabric formed by air-laying is prepared using polypropylene as said first component polymer and polyethylene as said second component polymer And done. 24. The method of claim 23, wherein said fusing or fusing step is accomplished by heating said fabric to a temperature in the range of about 142°C to greater than 148°C. 25. The method of claim 24, wherein said fusing or fusing step is performed by passing said fabric at a speed of about 5 m/min through a forced-air fusing furnace heated to about 148°C And done. 26. The method of claim 21, wherein forming a plurality of discs is accomplished by die-cutting circular discs of various sizes from said fabric, said respective discs being made Consists of a central hole that accommodates an axle. 27. The method of claim 21, wherein said step of compacting said plurality of sheets comprises applying a compaction force of about 850 MPa to said sheets. 28. The method of claim 27, wherein said sheet has a compacted density of about 125 kg/ ^m3 . 29. The method of claim 21, wherein orienting the sheets comprises aligning a number of the discs along a coaxial axis and a number of the circular spacers along the same axis, the spacers The plates are aligned between adjacent discs along said axis such that the ratio of discs to spacers in the rotating brush is about 1:0 to 5:1. 30. The method of claim 21, further comprising reinforcing said fabric prior to said step of fusing or fusing said fabric, said needling or dummy stitching at a density of 3.9 per centimeter Needle board with one needle. 31. The method as claimed in claim 30, characterized in that, during the needle sewing or dummy sewing, the puncture rate of puncturing the fabric is about 7.6 punctures/cm ² , and the needles on the needle board penetrate The fabric depth is approximately 85mm.

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