THEREOF

FIELD OF THE INVENTION

The present invention relates to a method of manufacturing brush cleaning elements. More particularly, the invention relates to brush cleaning elements for vacuum cleaner brush bars using the hot-melt adhesive technique.

BACKGROUND

Vacuum cleaners have been in use for many years to clean residential or office spaces. Depending on multiple distinct criteria, vacuum cleaners are developed for specific markets. Nozzles of vacuum cleaners are equipped with brush materials attached to brush bars which enables removal of dust and dirt from the floor. Brush materials are also utilized by other cleaning equipment’s for cleaning electronic or mechanical machines.

It is desirable to combine two or more different brush material to form the cleaning element of the brush. The unique properties of each material such as the filament stiffness, trim length, material abrasiveness and moisture absorption can be optimised to improve the cleaning performance.

However, joining two or more different brush cleaning material has challenges. One barrier to achieving good cleaning performance is due to the bonding technology that is employed. In the state-of-the-art process, the brush materials are sewn together using lockstitching to make the desired brush material.

The sewing process has numerous quality and reliability problems. To join the two surfaces, an uneven amount of tension is placed between the two material. This creates a bumpy, uneven and wave-like surface commonly known as the roping effect. The roping effect impacts the subsequent process of fixing the brush material to the brush bar uniformly. Once the substrate is fixed to the vacuum clean brush bar and used in the field, the brush strips will have to withstand the multiple operating conditions such as the brush bars encounter high centrifugal forces measured in thousands of rpm. Also, the vacuum cleaners will be used in dirty environments where there are various types of dust particles and debris. Further, the brush elements/strips will be exposed to wet surfaces and household chemicals. All these factors acting individually or in combination will impair the quality and reliability of the brush elements/strips.

Lock- stitching of the brush elements also causes high stress points where the needle punctures through the grain of the brush material. In combination with the roping effect, this structural damage will worsen over time due to the high centrifugal forces, accumulation of debris or dirt, or exposure to moisture and chemicals. Over time, these tears will weaken the joints and eventually dislodge the brush cleaning elements.

In view of the above problems, there is a continuing need for improved brushes to overcome the performance problems associated with the current technology.

SUMMARY OF THE INVENTION

Accordingly, the present invention provides a method of manufacturing a brush. The method includes the steps of applying at least one adhesive tape each on a plurality of brush materials, removing the adhesive tape from each of the plurality of brush materials to be bonded, assembling the brush materials in multiple profiles, heat pressing the brush materials for bonding into a single piece with secured joints and fixing of the bonded materials to a brush bar.

In an advantageous aspect, the present invention addresses the quality and reliability issues by providing brush with high bonding strength obtained using a hot melt pressure-sensitive adhesive. The joints that are formed have stronger shear and T-peel bonds and are creep resistant.

In another advantageous aspect, the brush provides better moisture and debris resistance because there are no gaps at the joints.

Also, the use of hot melt adhesives is aesthetically appealing because there are no visible marks on the substrate. With the current stitching process, there are visible stitch marks and pieces of thread on the substrate surface. Further, the present method enables a more robust manufacturing process as there are shorter production cycle times, less material wastage and simpler quality check criterion.

DESCRIPTION OF THE DRAWINGS

Fig. 1 shows a process flow diagram depicting a brush manufacturing process is shown in accordance with an embodiment of the present invention. Fig. 1A shows a flowchart depicting a method of manufacturing a brush in accordance with an embodiment of the present invention.

Fig. 2 shows a hot melt adhesive strip to be applied on brush material in accordance with an embodiment of the present invention. Fig. 3 shows a brush material preparation for manufacturing a brush in accordance with an embodiment of the present invention.

Fig. 3a shows a brush material spool in accordance with an embodiment of the present invention.

Fig. 3b shows a plurality of brush materials stacked together in accordance with an embodiment of the present invention.

Fig. 4 shows a hot-melt pressure sensitive adhesive production machine assembly in accordance with an embodiment of the present invention.

Fig. 5 shows a front view of hot-melt pressure sensitive adhesive production machine assembly in accordance with an embodiment of the present invention. Fig.6 and 6a provide pre-bonding brush material in accordance with an embodiment of the present invention.

Fig. 7 shows a de-taping of the brush material in accordance with an embodiment of the present invention.

Fig. 8 shows front view of bonding elements like rollers for bonding brush materials in accordance with an embodiment of the present invention.

Fig. 8a shows a perspective view of bonding elements like rollers for bonding brush materials in accordance with an embodiment of the present invention.

Fig. 8b shows a perspective side view of bonded brush materials in accordance with an embodiment of the present invention Fig. 9 shows bonded brush materials assembled in a first profile of multiple profiles/ configurations in accordance with an embodiment of the present invention. Fig. 10 shows bonded brush materials assembled in a second profile of multiple profiles/ configurations in accordance with an embodiment of the present invention.

Fig. 11 shows bonded brush materials assembled in a third profile of multiple profiles/ configurations in accordance with an embodiment of the present invention.

Fig. 12 shows bonded brush materials assembled in a fourth profile of multiple profiles/ configurations in accordance with an embodiment of the present invention.

Fig. 13 shows a post bonding trimmer and shear test in accordance with an embodiment of the present invention.

Fig. 14 shows brush material placed on brush bar to manufacture a brush in accordance with an embodiment of the present invention.

DESCRIPTION OF THE INVENTION

Various embodiment of the present invention provides brush cleaning elements and a method for manufacturing a brush. The following description provides specific details of certain embodiments of the invention illustrated in the drawings to provide a thorough understanding of those embodiments. It should be recognized, however, that the present invention can be reflected in additional embodiments and the invention may be practiced without some of the details in the following description.

The various embodiments including the example embodiments will now be described more fully with reference to the accompanying drawings, in which the various embodiments of the invention are shown. The invention may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the sizes of components may be exaggerated for clarity.

It will be understood that when an element or layer is referred to as being “on,” “connected to,” or “coupled to” another element or layer, it can be directly on, connected to, or coupled to the other element or layer or intervening elements or layers that may be present. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. Spatially relative terms, such as “strips,” “brush”, “cleaning elements” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the structure in use or operation in addition to the orientation depicted in the figures.

Embodiments described herein will refer to plan views and/or cross-sectional views by way of ideal schematic views. Accordingly, the views may be modified depending on simplistic assembling or manufacturing technologies and/or tolerances. Therefore, example embodiments are not limited to those shown in the views but include modifications in configurations formed on basis of assembling process. Therefore, regions exemplified in the figures have schematic properties and shapes of regions shown in the figures exemplify specific shapes or regions of elements, and do not limit the various embodiments including the example embodiments.

The subject matter of example embodiments, as disclosed herein, is described with specificity to meet statutory requirements. However, the description itself is not intended to limit the scope of this patent. Rather, the inventors have contemplated that the claimed subject matter might also be embodied in other ways, to include different features or combinations of features similar to the ones described in this document, in conjunction with other technologies. Generally, the various embodiments including the example embodiments relate to brush cleaning elements and method of manufacturing a brush.

The present invention is a series of manufacturing steps to manufacture higher quality and reliability brush elements. The process includes different brush elements prepared separately for the bonding process. Firstly, a long strip of a hot melt adhesive is applied on predetermined location of the brush elements. The brush elements are then de-taped to expose the tacky adhesive. Two or more brush elements are bonded together in various desired configurations. Then the brush elements are subject to the heat press process where high temperature and pressure is applied to permanently bond the brush elements. Subsequently, excess material is trimmed off using customized cutting fixtures and defect checks are performed. Finally, the brush cleaning element are attached to vacuum cleaner brush bars. Referring to Fig. 1 a process flow diagram 100 depicting a brush manufacturing process is shown in accordance with an embodiment of the present invention. The process includes raw brush material preparation 102, a prebonding process of placing, aligning and excursion of brush material 104, a bonding process of de-taping brush material, application of heat and pressure 106, a post bonding process of trimming excess brush material, checking and testing the brush material 108 and assembling the brush material on brush bar 110.

In an exemplary embodiment, a flowchart 100a depicting the brush manufacturing method is provided as shown in Fig. 1A. The method includes the steps of S102a applying at least one adhesive tape each on a plurality of brush materials. In S104a removing the adhesive tape from each of the plurality of brush materials to be bonded. In 106a assembling the brush materials in multiple profiles. In S108 heat pressing the brush materials for bonding into a single piece with secured joints and in S 110a fixing of the bonded materials to a brush bar.

In an embodiment, one or more of the plurality of brush material is of different material.

In an embodiment, the brush strips of different material arranged in multiple profiles are bonded together using compression rollers and heaters that soften and melt the adhesive at a pressure of 0.25-0.75 MPa and temperature range of 115-145 degree C.

In an embodiment, a complete brush strip consisting of different brush materials bonded in multiple configurations is attached to a brush bar using customized fixtures and equipment.

In an embodiment, the hot melt adhesive strip to be applied on brush material is shown in Fig. 2. The adhesive includes a top covering tape 202, a bottom covering tape 204, hot melt adhesive layer 206, adhesive gauge 208 and adhesive width 210.

In an embodiment, the brush material for manufacturing a brush is shown in Fig. 3. The brush material 300 includes a base 302 and a cleaning surface 304.

In a related embodiment, the brush material spool 300a is shown in Fig. 3a. In another related embodiment, a plurality of brush materials 300b are stacked together as shown in Fig. 3b. The brush material shows weft 306, a first wrap 308 and a second wrap 310.

Referring to Fig. 4, a hot-melt pressure sensitive adhesive production machine assembly 400 is shown in accordance with an embodiment of the present invention. The machine assembly 400 includes a holt- melt adhesive spool 402, a hot melt adhesive strip double sided tape 404 moving by an upper roller 406a, lower roller 406b, a bottom covering tape 408, a hot melt adhesive without covering tape 410 passing between a supply conduct containing heating element 412 and strip feeding mechanism 414, hot melt adhesive 416 passing between an upper roller 418a and a lower roller 418b, a brush material spool 420 strip passing between the upper roller 418a and the lower roller 418b enabling application of the hot melt adhesive 416 on the brush material spool strip to form a pre -bonded brush material 422 strip rolling to form a spool 424.

In an embodiment the tapes are polyurethane adhesive tapes of various dimensions, physical properties and shapes that are applied on various brush materials such as polyamide or PAN at specific locations.

Referring to Fig. 5, a front view of hot-melt pressure sensitive adhesive production machine 500 is shown in accordance with an embodiment of the present invention. The machine includes adhesive dispense nozzle 502, a first guard rail 504 and a second guard rail 506, a platform 508, an adhesive landing zone 510, an adhesive edge zone 512, and brush material 514 on the machine.

In an embodiment, pre-bonding brush material (600, 600a) are shown in Fig. 6 and 6a. The pre-bonding provides brush cleaning surface 602, a brush bar attaching surface/bmsh base 604, hot melt pressure sensitive adhesive 606 and adhesive bonded to surface 608. Further the pre-bonded material (600a) includes brush cleaning surface weft (602a), brush bristles (604a), brush base wrap (606a), stitching (608a) and hot melt pressure sensitive adhesive bonding location (610a). Referring to Fig. 7, a de-taping (700) of the brush material is shown in accordance with an embodiment of the present invention. The de-taping includes adhesive tape 702, brush material 704 and hot melt adhesive tacky surface 704. Each of the tape covers applied on the plurality of brush materials are removed using de-taping fixtures and equipment.

In an embodiment, referring to Fig. 8, 8a and 8b, bonding (800, 800a, 800b) elements for joining multiple brush materials is provided. The bonding includes first roller (802, 802a), second roller (804, 804a), a first brush material (806, 806a) and a second brush material (808, 808a) between the first and second roller. The first and second roller enables bonding of the first and second brush material to form a single piece (810).

In an exemplary embodiment, the brush materials are bonded in multiple profiles (900, 1000, 1100, 1200) i.e with various configurations as shown in Fig. 9, 10, 11 and 12. The bonding provides a first brush material (902, 1002, 1102, 1202) bonded to a second brush material (904, 1004, 1104, 1204) forming a hot melt adhesive joint (906, 1006, 1106, 1206). The assembling of two of more of the plurality of brush strips in multiple profiles include configurations such as parallel or perpendicular or oblique angled or in other geometric arrangement to each other.

In an embodiment, the bonded brush material is trimmed and shear (1300) as shown in the Fig. 13 providing a working platform with a trimmer assembly for cutting the strips into the desired dimensions of the present invention. The trimming includes trim blade 1302 configured to trim excess brush material strips, a trimmed corner 1304 and a shear force of 30N applied in opposite directions to each other. The desired dimensions of the material by trimming is obtained using customized trimming fixtures and equipment.

In an embodiment, referring to Fig. 14, a brush 1400 is provided with a first brush material 1402, a second brush material 1404 bonded to the first brush material and placed on a brush bar 1406.

In one aspect of the invention, the carrier film is unwound from the film roll. Both sides have the hot-melt adhesive. The material is extruded from the production machine. One side has the covering film removed to expose a tacky surface. The opposite surface still has the covering film intact. The exposed side of the adhesive tape is placed on the desired location of the brush substrate. The opposite surface, still covered with the film material, is to be used for bonding the second the second brush substrate. The first process is completed when the predetermined brush substrate surface is covered with the adhesive film. The hot melt adhesive production equipment has an extrusion devise, rollers for the tensioning and circulation of the film roll, cooling device and a heating device.

It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the claims.