Three dimensional structures useful as cleaning sheets

ES 2 202 256 T3

DESCRIPTION

Scented cleaning sheets.

Field of the invention

This invention relates to scented cleaning sheets particularly suitable for removing and trapping dust, lint, hair, sand, food scraps, grass and the like.

Background of the invention

The use of non-woven sheets for dry-type dusting is known in the art. Such sheets typically use a fiber composite where the fibers are bonded by adhesive, entanglement, or other forces. See, for example, US Patent Nos. 3,629,047 and 5,144,729. To provide a durable wipe clean sheet, reinforcing means have been combined with staple fibers in the form of a continuous filament or net structure. See, for example, US Patent Nos. 4,808,467, 3,494,821, and 4,144,370. Furthermore, to provide a product capable of withstanding the rigors of the wiping process, prior nonwoven sheets have employed fibers tightly bonded by one or more of the forces mentioned above. Although durable materials are obtained, such strong bonding can adversely impact the materials' ability to collect and retain particulate dirt. In an effort to address this issue, U.S. Patent 5,525,397 to Shizuno et al. Describes a cleaning sheet comprising a network polymeric layer and at least one nonwoven layer, in which the two layers are slightly hydroentangled. in order to provide a sheet that has a low entanglement coefficient. The resulting sheet is said to provide mechanical strength and durability, as well as improved dust collection performance because the composite fibers are slightly hydroentangled. Sheets that have a low entanglement coefficient (ie, no more than 500 µm) are said to offer better cleaning performance because a higher degree of fibers is available to contact dirt.

Although the sheets disclosed in US Patent No. 5,525,397 are alleged to address some of the problems with prior nonwoven cleaning sheets, those sheets appear to have a generally uniform basis weight, at least in macroscopic terms. ; and they are essentially of uniform gauge, again in macroscopic terms. That is, the usual and expected basis weight, and gauge fluctuations and variations can occur randomly, as a result of fluid pressure differentials during hydroentanglement. However, the structure should not be considered to comprise discrete regions that differ relative to basis weight. For example, if in microscopic terms the basis weight of a gap between fibers were measured, an apparent basis weight of zero would result when, in fact, unless an opening had been measured in the nonwoven structure, the basis weight of said region is greater than zero. Such fluctuations and variations are a normal and expected result of the hydroentangling process. Nonwovens having such variations, including those described in US Patent No. 5,525,397, will be interpreted by the skilled craftsman as having essentially uniform basis weight and gauge, in macroscopic terms. The result of a sheet having a uniform base weight is that the material is not particularly suitable for picking up and trapping dirt of one size, shape, etc. various. US-3619251 describes the use of a pure cotton fabric impregnated with mineral spirits to effectively wipe clean, for example, floor surfaces and slates. This known cleaning element can include a perfume to counteract the unpleasant odor released by mineral spirits when the cleaner is used. The mineral spirits composition includes wax in a percentage of 43% and aromatic benzene in a percentage of 15.9%.

There is a continuing need to provide cleaning sheets that offer improved soil removal.

It is the objective of the invention to provide cleaning sheets with additives, especially those that improve the adhesion of dirt to the substrate, and especially for those sheets described below, with different basis weights and / or three-dimensional structure, said combinations having special benefits in behavior, and providing such combinations improved benefits. In particular, the sheets of the invention incorporate a perfume.

Summary of the invention

The present invention relates to a cleaning sheet for dry-type dust cleaning, comprising an additive selected from the group consisting of surfactants, wax, oil or mixtures thereof, and a perfume, being present the additive on said cleaning sheet in a percentage from 0.1 to 8%, by weight of said cleaning sheet. Preferred sheets have at least two regions, the regions being distinguished by basis weight. In particular, the cleaning sheet comprises one or more high basis weight regions having a basis weight of between about 30 to about 120 g / m2.², and one or more low basis weight regions, in which the low basis weight region (s) have a basis weight that does not exceed about 80% of the basis weight of the region (s) ( regions) of high basis weight. In a preferred aspect, the first region is relatively high basis weight and comprises an essentially continuous network. The second region comprises a plurality of mutually discrete regions of relatively low basis weight and which are circumscribed by the first high basis weight region. In particular, a preferred cleaning sheet comprises a continuous region having a basis weight

ES 2 202 256 T3 from about 30 to about 120 g / m² , and a plurality of discontinuous regions circumscribed by the high basis weight region, wherein the discontinuous regions are located in a non-random repeating pattern and have a basis weight that does not exceed about 80% of the basis weight of the continuous region.

In one embodiment, the cleaning sheet will have, in addition to regions that differ relative to basis weight, substantial macroscopic three-dimensionality. As used herein, the term "macroscopic three-dimensionality", when used to describe three-dimensional cleaning sheets, means that the three-dimensional pattern is actually visible to the naked eye when the perpendicular distance between the viewer's eye and the blade plane is approximately 12 ''. In other words, the three-dimensional structures of the present invention are cleaning sheets that are not flat, since one or both surfaces of the sheet are in multiple planes, in which the distance between those planes is observable to the naked eye when the structure is viewed from approximately 12 inches. In contrast, the term "flat" refers to cleaning sheets that have fine-scale surface aberrations on one or both sides, with surface aberrations not actually being visible to the naked eye when the perpendicular distance between the viewer's eye and the Flat of band is approximately 12 '' or greater. In other words, on a macroscopic scale, the observer would not observe that one or both surfaces of the sheet are in multiple planes in order to be three-dimensional. The macroscopically three-dimensional structures of the present invention optionally comprise a scrim material, which upon heating and then cooled, contracts to provide a macroscopic three-dimensional structure. Other materials that provide shrinkage forces in order to provide three-dimensionality are discussed below. Macroscopic three-dimensionality is described herein in terms of "mean height differential", which is defined in memory as the mean distance between contiguous peaks and valleys of a given sheet surface, as well as the "mean peak-to-peak distance ”, Which is the average distance between contiguous peaks on a given surface. Macroscopic three-dimensionality is also described in terms of the "Surface Topography Index" of the surface (s) to the outside of the cleaning sheet; The Surface Topography Index is the relationship obtained by dividing the Average Height Differential of a surface by the Average Peak-to-Peak Distance of that surface. In one embodiment, both surfaces toward the outside of the sheet will have the described Average Peak-to-Peak Distance and Surface Topography properties. Procedures for measuring Average Peak-to-Peak Distance and Average Height Differential are described in detail below, in the Test Procedure section.

The sheets of this invention and similar sheets, especially those that contain additives in small percentages, as described herein, and especially those in which the additive is substantially uniformly fixed over at least one continuous zone, can be used in processes. improved to clean and to provide desirable consumer and user benefits of the blades, some of these benefits being ones that are not intuitively apparent to a consumer, as detailed below. Therefore, it is desirable to package the sheets, either in the form of rolls, with perforations to help separate the sheets, or with means to separate the sheets into useful lengths, and / or package them in packages that inform the consumer of the procedures and / or the enhanced benefits that can be obtained, especially those benefits that are not intuitively obvious to the consumer. Cleaning sheets with additives, including those with desirable small percentages of said additives, preferably substantially uniformly fixed, at least in one or more zones, provide in combination, special benefits in performance, and such combinations can provide improved benefits, especially when the sheets have the desirable structures set forth in the specification.

Brief description of the drawings

Figure 1 is a schematic plan view illustration of a three-layer embodiment of a cleaning sheet of the present invention, in which the second layer comprises a scrim material having filaments running parallel to the side and end edges. of the sheet, in which a portion of the first layer is shown cut away, and in which the surface characteristics of the first layer are omitted for clarity.

Figure 2 is an illustration of the type shown in Figure 1 depicting an alternate embodiment of the present invention in which the second layer filaments are inclined at an angle of approximately 45 degrees relative to the end and side edges of the cleaning sheet.

Figure 3 is a schematic plan view illustration of the photograph of Figure 5 showing the texture of the macroscopically three-dimensional outer surface of the first layer, and particularly the ridges that extend over the outer surface of the first layer.

Figure 4 is a cross-sectional illustration of the sheet, taken parallel to one of the second layer filaments and showing parts of the filament that extend intermediate between the filament intersections, the parts of the filament that are not attached to the first layer, as well as portions of the filaments that extend intermediate between the filament intersections which are not bonded to the third layer.

Figure 5 is a photomicrogram showing the macroscopically three-dimensional surface texture of the first layer and, in particular, the elongated ridges on the surface. The scale in figure 5 is in inches.

Figure 6 is an enlarged photomicrogram of the type shown in Figure 5, showing an elongated ridge having branches extending in different directions.

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Figure 7 is a Scanning Electron Photomicrogram providing a perspective view of the macroscopically three-dimensional surface of the first layer.

Figure 8 is a Scanning Electron Photomicrogram of a cross section of the cleaning sheet showing parts of filaments extending intermediate between filament intersections, which parts of the filaments are not attached to the first layer.

Figure 9 is a Scanning Electron Photomicrogram showing the bonding of the first and third layers to the second layer at the filament intersections.

Figure 10 is a photograph (magnified 12 times) of a cleaning sheet of the present invention, depicting the continuous high basis weight region and a plurality of discrete low basis weight regions.

Figure 11 is a plan view of the sheet represented in Figure 10, to facilitate the study of the differences in basis weight of the sheet.

Detailed Description of the Invention I. Definitions

As used herein, the term "comprising" means that the various components, ingredients, or steps can be used together in practicing the present invention. Accordingly, the term "comprising" encompasses the more restrictive terms "consisting essentially of" and "consisting of".

As used herein, the term "hydroentangled" generically means a process for making a material in which a layer of loose fibrous material (eg, polyester) is supported on an apertured textured member and is subjected to water pressure differentials large enough to cause individual fibers to mechanically entangle to provide a weave. The apertured texturing member may be formed, for example, from a woven screen, a perforated metal plate, etc.

As used herein, the term "Z dimension" refers to the dimension orthogonal to the length and width of the cleaning sheet of the present invention, or a component thereof. The Z dimension normally corresponds to the thickness of the sheet.

As used herein, the term "XY dimension" refers to the plane orthogonal to the thickness of the cleaning sheet, or to a component thereof. The X and Y dimensions typically correspond to the length and width, respectively, of the sheet or one of a sheet component.

As used herein, the term "layer" refers to a member or component of a cleaning sheet whose primary dimensions are XY, that is, along its length and width. It should also be understood that the term layer is not necessarily limited to single layers or sheets of material. In this way the layer can comprise laminates or combinations of several continuous sheets or bands of the type of materials required. Accordingly, the term "layer" includes the terms "layers" and "layered".

For the purposes of the present invention, a "top" layer of a cleaning sheet is a layer that is relatively remote from the surface to be cleaned (ie, in the accessory context, relatively closer to the accessory handle. during use). Conversely, the term "bottom" layer means a cleaning sheet layer that is relatively closer to the surface to be cleaned (ie, in the accessory context, relatively further away from the accessory handle during use).

All percentages, ratios, and proportions used herein are by weight unless otherwise specified.

II. Cleaning sheets

The present invention relates to a dry-type dust cleaning cleaning sheet, useful for removing dust, lint, hair, grass, sand, food debris and other matter of type, size, consistency, etc. diverse, from a variety of surfaces. Preferably, the cleaning sheets will demonstrate improved cleaning performance in consumer panel tests.

Due to the ability of cleaning sheets to reduce, or eliminate, by various means, including contacting and retaining, dust, lint, and other airborne matter, from surfaces, as well as from the air, the sheets will provide a greater reduction in the percentages of said materials on surfaces and in the atmosphere, compared to other products and practices for similar cleaning purposes. This ability is especially evident in sheets containing additives as described herein. Even US Patent No. 5,525,397 sheets can provide this benefit, albeit at a lower level than preferred specification structures, and therefore it is important to provide this information on packaging, or associated with packaging,

ES 2 202 256 T3 in order to encourage the use of the sheets, including those of the aforementioned patent No. 5,525,397, especially on non-traditional surfaces such as upholstery, curtains, carpets, clothing, etc., where, normally , the dust sheets have not been used. The use of a small percentage of additive, uniformly bound on at least one continuous zone of the sheet in an amount effective to improve the adherence of dirt, especially particles, and especially those particles that cause allergic reaction, provides a surprising degree control over the adhesion of dirt. At least in those areas where the additive is present on the sheet, the small percentage is important for such use, since, unlike traditional dust cleaning operations where oils are applied as liquids, or as a spray, there is much less danger of creating a visible stain, especially on such non-traditional surfaces, when using the blade. Preferred structures also provide benefits by trapping larger particles rather than wearing them down to smaller sizes.

Consumers with allergies especially benefit from the use of memory sheets, especially preferred structures, since allergens are typically in powder form and it is especially desirable to reduce the percentage of small particles that can be breathed. For this benefit, it is important to use the sheets regularly, and not just when soiling is visually apparent, as in prior art procedures.

to. Multiple base weights

The present invention relates to a cleaning sheet having at least two regions, where the regions are distinguished by basis weight. In particular, the cleaning sheet comprises one or more high basis weight regions having a basis weight of from about 30 to about 120 g / m2.² (preferably from about 40 to about 100 g / m², more preferably from about 50 to about 90 g / m², even more preferably from about 60 to about 80 g / m²) and one or more low basis weight regions, in which the low basis weight region (s) have a basis weight that is not more than about 80% of the basis weight of the high basis weight region (s). In this regard, preferred cleaning sheets comprise a continuous high basis weight region and a plurality of discontinuous regions circumscribed by the continuous high basis weight region, in which the discontinuous regions are arranged in a repeating pattern. non-random and has a basis weight no greater than about 80% of the basis weight of the continuous region.

Preferably, the low basis weight region (s) of the cleaning sheet will have a basis weight of not more than about 60%, more preferably not more than about 40%, and even more preferably not more. to about 20%, of the basis weight of the high basis weight region (s). The cleaning sheets will preferably have an aggregate basis weight of from about 20 to about 110 g / m2.², more preferably from about 40 to about 100 g / m², even more preferably from about 60 to about 90 g / m². With regard to the low basis weight region (s), it is preferred that the basis weight is not zero in such regions, such that macroscopic apertures are present. This is because dirt will be allowed to fully penetrate through the cleaning sheet, and will not be retained inside. In other words, the sheet entrapment percentage will not be optimized in such situations.

In these embodiments where a continuous high basis weight region surrounds discrete low basis weight regions, it is preferred that at least about 5% of the total surface area of ​​the cleaning sheet will be the low basis weight regions. More preferably at least about 10%, still more preferably at least about 15%, still more preferably at least about 20%, still more preferably at least about 30% of the total surface area of ​​the cleaning sheet will be the low basis weight regions. In these embodiments where discrete high basis weight regions are surrounded by a continuous low basis weight region, it is preferred that at least about 5% of the total surface area of ​​the cleaning sheet will be the discrete high basis weight regions. More preferably, at least about 10%, still more preferably at least about 15%, still more preferably at least about 20%, still more preferably at least about 30%, of the total surface area of ​​the sheet of cleaning will be the low basis weight regions.

In those preferred embodiments that have a continuous high basis weight region surrounding discrete low basis weight regions, the discrete low basis weight regions may be entangled in, or may be aligned in, in either or both the X and Y directions. Preferably, the essentially continuous high basis weight network forms a textured network circumferentially contiguous to the discrete low basis weight regions, although, as noted, small transition regions may be accommodated.

It will be apparent to one skilled in the art that there may be small transition regions that have a basis weight intermediate between the basis weights of the high basis weight region (s) and the basis weight region (s). low, transition regions that by themselves may not be significant enough in area to be considered as comprising a basis weight other than the basis weights of any contiguous region. Said transition regions are within known manufacturing variations and are inherent in the manufacture of a structure according to the present invention. It will also be recognized that within a given region (whether high or low basis weight), fluctuations and variations in the ordinary or expected basis weight may occur when said given region is considered to have a basis weight. For example, if in microscopic terms, the basis weight of

ES 2 202 256 T3 a gap between fibers, an apparent basis weight of zero will occur when, in fact, the basis weight of said region is greater than zero. Again, such fluctuations and variations are a normal and expected result of the manufacturing process.

Figure 10 is a photograph of a portion of a preferred nonwoven sheet of the present invention having a continuous high basis weight region surrounding discrete low basis weight regions. Although no reference numerals are shown, it is seen that the continuous high basis weight region appears as the light lattice and the low basis weight regions are the darkest discrete regions. Figure 11 is a plan view of a portion of a non-woven sheet 10 to further depict this aspect of the sheet shown in Figure 10. In particular, in Figure 11, the non-woven sheet 10 has a region 12 continuous high basis weight and discrete low basis weight regions 14. In this representative illustration, an optional scrim material is not shown. Although the lower weight regions 14 are depicted as having essentially the same size and having a single well-defined shape, these regions may have different sizes to facilitate entrapment of particles of varying size and shape. Also, it will be recognized that the shape of the low basis weight regions 14, and consequently the continuous high basis weight region 12, can vary throughout the structure.

Differences in basis weights (within the same structure 10) between the high and low basis weight regions 12 and 14 of at least 20% are considered to be significant, and define distinct regions for purposes of the present disclosure. For a quantitative determination of basis weight in each of regions 12 and 14, and for a quantitative determination of the differences in basis weight between said regions 12 and 14, a quantitative procedure can be used, such as hypoenergetic X-ray image analysis as described in US Patent No. 5,277,761, issued to Phan et al. on January 11, 1994. This procedure is also applicable where the high and low basis weight regions are not arranged in a continuous / discrete pattern such as that shown in Figure 2.

The relative area of ​​the low basis weight regions and the high basis weight region can be measured quantitatively using image analysis techniques. An information software platform to allow such measures is the following:

Information software is developed using Optimas 6.1 macro language, a commercial image analysis information software package available from Optimas Corp. (Bothell, Washigton).

Input images

The input to the program are the images of the leaves acquired by optical microscope. These images are digitized in 8 bit monochrome gray. The size of the images is 512 pixels x 486 pixels. In physical measurements, the image is approximately a 14.5mmx11.0mm area.

Image analysis

Each digital image is analyzed using the same procedure as outlined above.

Step 1: select a region of interest (ROI) in the image.

(This is done because the illumination is not uniform over the entire image. Therefore, a boundary around the edges is omitted from the analysis. The same region of interest is selected for all images).

Stage 2: run a 3 x 3 mean calculation filter within the ROI.

(The averaging filter reduces noise in digital images.)

Stage3: Automatically calculate the gray level threshold (T) to segment depot zones.

(Pores appear dark in images. Use the GetAutoThreshold function provided by the Optimas macro language to isolate dark areas within the ROI. Of the many opinions provided by GetAutoThreshold to select a threshold, the “Search for minimum in region about de mean ”, is believed to provide the best results. See the Optimal 6.11 Online Help on GetAutoThreshold).

Step 4: select the threshold to be from zero (0) to 10.0 and identify all pixels that have gray values ​​within these limits to be pores.

(The threshold automatically chosen by GetAutoThreshold can be further decremented by 10levels of gray.)

Stage 5: create pore zone objects.

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Stage 6: for each pore zone extract its size in square millimeters and diameter of the circle with an equivalent area of ​​square millimeter.

Output results

The image analysis output is written to an Excel spreadsheet. The output for each image contains the threshold, the number of pore zones found, the percentage of total pore area to total ROI area, and a list of individual pore sizes and equivalent diameters.

Applicants have found that by introducing macroscopic zones of discrete regions of relatively low basis weight, selected and optimized with respect to physical dimensions, such as size and height, and / or basis weight, into the cleaning sheet, it is possible to create sheets that provide the removal and enhanced entrapment of large materials such as sand, grass, food scraps, and other solids of relatively large size and varying shapes and consistency. At the same time, the relatively high basis weight region provides for the removal and entrapment of smaller materials such as fine dust, fluff, dust, and the like. Relative to preferred sheets having a continuous high basis weight region surrounding a plurality of low basis weight regions, although differences in basis weight are an important aspect, the relative size of discrete basis weight regions is also important. under. Applicants have found that in relation to the collection and entrapment of large particulate dirt, such as sand and small food scraps, it is preferred that the area of ​​a substantial number of the individual low basis weight regions be between about 0, 02 up to about 0.5 mm² , more preferably from about 0.08 to about 0.4mm² , even more preferably from about 0.1 to about 0.3 mm² . It is also preferred that the longest dimension of a certain substantial number of the individual discrete low basis weight is in the range of from about 100 to about 1,200 microns, more preferably from about 250 to about 1,000 microns. Although the skilled artisan will recognize that the size of the individual low basis weight regions may be larger or smaller, depending on the desired end use of the product, these ranges are preferred for typical house cleaning. It may also be desirable to include discontinuous regions of varying sizes on a single cleaning sheet. By using a non-woven material in the manufacture of the cleaning sheet, it can be made using a textured belt having varying aperture sizes. In addition to having relatively low basis weights, it is preferred that the discontinuous regions of the cleaning sheet have a relatively smaller gauge (ie, thickness in the Z direction) than the continuous high basis weight region. This further enhances the blade's ability to trap large particles that are trapped by the structure. Without wishing to be bound by theory, Applicants believe that the low basis weight regions provide sufficient space between fibers for larger particles to be contained. Furthermore, the smaller gauge in these regions keeps the larger particles further away from the surface of the structure, thereby reducing the level of contact that the entrapped particles have during further washing of the surface being cleaned.

With regard to gauge differences, it is preferred that the gauge difference between the discontinuous regions and the continuous region is at least about 25%. More preferably, the gauge difference will be at least about 40%, even more preferably at least about 55%. A means of measuring the caliber of the corresponding regions is described in the Assay Procedures section.

The cleaning sheets of the present invention will preferably exhibit elongation, particularly in the CD direction, which will improve their formability, when used as a standalone product or when used in combination with a cleaning accessory. In this regard, these structures will preferably have a CD elongation value at 500 g at least about 10%, more preferably at least about 20%, more preferably at least about 35%, even more preferably at least about 45%. %, and even more preferably 60%.

As highlighted above, the hydroentangling process is not new. However, the preferred cleaning sheets of the present invention comprise a hydroentangled fiber composite, in which the texturing member (also referred to as the shaping belt) used in hydroentangling processes has a structure that provides the desired basis weight differential between continuous and discontinuous regions, as well as a desired gauge differential between these regions, in the structure formed thereon. Although the selection of the specific texturing member is not critical, it is important that the member have sufficient opening capacity (ie, opening size) to provide for the macroscopic differences in basis weight between the continuous and discontinuous regions of the cleaning sheet. In this regard, the texturing member will preferably have from about 15 to about 60 openings per inch to provide a total of about 20 to about 45 percent open area. In a particularly preferred embodiment, the shaping belt will be formed from polyester fibers (filaments) arranged in the MD and CD direction. A preferred strap has the following characteristics:

Mesh:

MD 23 strands / inch

CD 17 strands / inch

Filament diameter (inch) - CD and MD 0.24 polyester Air permeability (feet³ / min) 685

ES 2 202 256 T3 where MD refers to the Machine Direction of the entangling process, and CD refers to the perpendicular direction (Cross Direction) of the entangling process. A belt having these characteristics is available from Albany International, Engineered Fabrics Division, Appleton, Wisconsin, as a 23C belt.

The cleaning sheets of the present invention can be manufactured, using either a woven process or not, or by forming operations using molten materials deposited in forms, especially on belts, and forming operations involving mechanical actions / modifications carried out on films. . Structures are fabricated by any number of procedures (eg, rotary bond, fusion, resin bond, air-through bond, etc.), once the essential three-dimensional and basis weight requirements are known. However, preferred structures are nonwoven, and especially those formed by hydroentangling as is well known in the art, as they provide highly desirable open structures. Therefore, the preferred cleaning sheets are non-woven structures having the characteristics described herein. Materials particularly suitable for forming the preferred nonwoven cleaning sheet of the present invention include, for example, natural cellulose as well as synthetic products such as polyolefins (for example, polyethylene and polypropylene), polyesters, polyamides, synthetic cellulose (for example, RAYON^®), and mixtures thereof. Also useful are natural fibers, such as cotton, or blends thereof and those obtained from various cellulose sources. The preferred starting materials for making the hydroentangled fiber sheets of the present invention are synthetic materials, which may be in the form of carded, spun, fused, air-laid, or other structures. Particularly preferred are polyesters, especially carded polyester fibers. The degree of hydrophobicity or hydrophilicity of the fibers is optimized depending on the desired purpose of the sheet, in terms of the type of dirt to be removed, the type of additive that is provided, when an additive is present, biodegradability, availability and combinations of these considerations. In general, the most biodegradable materials are hydrophilic, but the most effective materials tend to be hydrophobic.

The cleaning sheets can be formed from a single fibrous layer, but are preferably a composite of at least two different layers. Preferably, the sheets are not made woven via a hydroentangling process. In this regard, prior to hydroentangling discrete layers of fibers, it may be desired to slightly hydroentangle each of the layers prior to hydroentangling the layers and prior to bonding.

In a particularly preferred embodiment of the present invention, to enhance the integrity of the final sheet, it is preferred to include a polymeric network (referred to herein as a "chambray" material) that is positioned with the fibrous material, for example, by lamination via heat or chemical means such as adhesives, via hydroentanglement. The scrim materials useful herein are described in detail in US Pat.

States No. 4,636,419. The cambrays can be formed directly in the extrusion die or they can be made from extruded films by fibrillating or embossing, followed by stretching and splitting. The scrim can be obtained from a polyolefin such as polyethylene or polypropylene, copolymers thereof, poly (butylene terephthalate), polyethylene terephthalate, Nylon 6, Nylon 66 and the like. Chambray materials are available from various commercial sources. A preferred scrim material useful in the present invention is a polypropylene scrim available from Conwed Plastics (Minneapolis, Minnesota).

b. Optional macroscopic three-dimensionality

As noted above, in one embodiment the multiple basis weight cleaning sheets will also be macroscopically three-dimensional. These sheets are preferably relatively open structures compared to, for example, paper towels. In one such preferred embodiment, the macroscopically three-dimensional cleaning sheets have a first surface and a second surface and comprise a scrim or other shrinkable material. In such a preferred embodiment, the cleaning sheet has a first surface facing outward and a second surface facing outward, and comprises a shrinkable material (preferably a scrim), in which the Average Peak-to-Peak Distance of at least one surface facing outside is preferably from about 1 mm and the Surface Topography Index of this (s) surface (s) is preferably from about 0.01 to about 5. Procedures for measuring Average Peak-to-Peak Distance and Average Height Differential are described in detail in the Test Procedure section, below.

Regardless of the configuration of the cleaning blades, the Average Peak-to-Peak Distance of the at least one surface outward will preferably be at least about 1mm, more preferably at least about 2mm, and even more preferably at least about 3mm. . In one embodiment, the Average Peak-to-Peak Distance is from about 1 to about 20mm, particularly from about 3 to about 16mm, more particularly from about 4 to about 12mm. The Surface Topography Index of at least one surface outward will preferably be from about 0.01 to about 10, preferably from about 0.1 to about 5, more preferably from about 0.2 to about 3, even more preferably from about 0 , 3 to about 2. At least one outward facing surface will preferably have an Average Height Differential of at least about 0.5mm, more preferably at least about 1mm, and even more preferably at least about 1.5mm. The Average Height Differential of the at least one surface outward will typically be from about 0.5 to about 6mm, more typically from about 1 to about 3mm.

ES 2 202 256 T3

All Figures 1-9 depict aspects of cleaning sheets that have macroscopic three-dimensionality. Although it is understood that these sheets also have different basis weight regions, as discussed above and shown in Figures 10 and 11, this aspect of the sheets is not shown or discussed with reference to Figures 1 -9.

FIG. 1 illustrates a macroscopically three-dimensional, multilayer cleaning sheet 20 in accordance with the present invention. The cleaning sheet 20 includes side edges 22 and end edges 24. The side edges 22 extend generally parallel to the length of the sheet 20, and the end edges 24 extend generally parallel to the width of the sheet. Optionally, sheet 20 may include an edge seal 26 that extends around the perimeter of the sheet. Such an edge seal 26 can be formed by heating, by use of adhesives, or by a combination of heating and adhesives.

The cleaning sheet 20 includes a first layer 100 and a second layer 200. Preferably, the cleaning sheet also includes a third layer 300. The second layer 200 may be located between the first layer 100 and the third layer 300. In the figure 1, a portion of the first layer 100 is shown cut away to reveal the underlying portions of the second 200 and third 300 layers.

The first layer 100 can be formed from woven materials, nonwovens, paper webs, foams, wadding, and the like, such as those known in the art. Particularly preferred materials are nonwoven webs having randomly distributed fibers or filaments as in "air-laid" or certain "wet-set" processes, or with a degree of orientation, as in certain "wet-set" or "carded". The fibers or filaments of the first layer 100 can be natural, or of natural origin (for example, cellulose fibers such as pulp fibers, cotton linters, rayon and bagasse fibers), or synthetic (for example, polyolefins, polyamides or polyesters). The third layer 300 can be substantially the same as the first layer 100, or alternatively, it can be of a different material and / or structure.

In one embodiment, the first layer 100 and the third layer 300 may each comprise a hydroentangled web of nonwoven synthetic fibers having a denier of less than about 4.0, preferably less than about 3.0, more preferably less than about 2, 0 grams, per 9,000 meters of fiber length. A suitable first layer 100 (as well as a suitable third layer 300) is a hydroentangled web of polyester fibers having a denier of about 1.5 grams or less per 9,000 meters of fiber length, and the web having a basis weight of about 30 grams per square meter. A suitable band is available from PGI Nonwovens of Benson, North Carolina under the designation PGI 9936.

The second layer 200 is discontinuously bonded to the first layer 100 (and to the third layer 300 if present) and provides for the meeting of the first layer by shrinkage of the second layer. The shrinkage mechanism includes, among others, the heat shrinkage and elastic properties of the second layer. As discussed above, in such an embodiment, the second layer 200 comprises a network-like arrangement of filaments having openings defined by contiguous filaments. Alternatively, the second layer could be in the form of a polymeric film, which may optionally have openings through it; To provide the requirement for a shrinkage mechanism, such films must have sufficient elasticity to provide the function of bundling, which results in the three-dimensional surface. The film may be embossed in such a way as to provide surface depressions instead of, or in addition to, openings. In another alternative, the shrinkage effects can be generated by the inclusion of fibers that contract on heating and re-cooling. In this approach, certain fibers will not contract, but since they are mechanically associated with the shrinkable fibers, the entire sheet will "wrinkle" during shrinkage of the shrinkable fibers, to the extent that such fibers are included in a sufficient percentage.

In the illustrated embodiments, the second layer comprises a network-like arrangement of filaments that includes a first plurality of filaments 220, and a second plurality of filaments 240. The filaments 220 extend generally parallel to each other, and the filaments 240 extend. they extend generally parallel to each other and generally perpendicular to filaments 220. The filaments extend between filament intersections 260. The intersecting, contiguous filaments 220 and 240 define apertures 250 in the second layer 200. The contiguous intersecting filaments 220 and 240 define apertures 250 in the second layer 200. The intersections of filament and apertures 250 are arranged in a pattern-like pattern. a lattice that repeats generically in a non-random way.

The second layer 200 may comprise a polymeric network (referred to herein as "scrim material"). Suitable scrim materials are described in US Patent No. 4,636,419. The scrim can be obtained from a polyolefin, such as polyethylene or polypropylene, or copolymers thereof, poly (butylene terephthalate), polyethylene terephthalate, Nylon 6, Nylon 66 and the like, and mixtures thereof.

The scrim material is preferably attached to layers 100 and 300 through lamination by heat or by chemical means, such as adhesives. Preferably, the filaments of the chambray material contract relative to layers 100 and 300 upon heating, such that the contraction of second layer 200 groups layers 100 and 300 together and imparts a macroscopic three-dimensional texture to the outer surfaces of the layers. 100 and 300, as described in more detail below.

A particularly suitable scrim material useful when the second layer 200 is a heat activated metal reinforcing net available from Conwed Plastics of Minneapolis, Minnesota as the brand name reinforcing net.

ES 2 202 256 T3

THERMANET^®, which has a polyrolinel / EVA resin, 2-sided adhesive, and is 3 strands per inch by 2 strands per inch in size before contracting, for example, when heated. After heating, the second layer 200 can have between about 3.5 and 4.5 filaments per inch by between about 2.5 to 3.5 filaments per inch.

By "double sided adhesive" it is meant that the EVA (Ethyl Vinyl Acetate Adhesive) adhesive is present on both sides of the filaments. The activation temperature of the EVA is generally around 85 ° C. During lamination of layer 200 to the polyester fibers of layers 100 and 300, the EVA adhesive is activated to provide the bond between the filaments of layer 200 and the fibers of layers 100 and 300. Without being limited in theory, it is believed that by exerting pressure with a relatively low pressure eg less than 3.4023 Pa and more preferably less than 1.70115 Pa for a relatively short time (eg less than about 30 seconds), the filaments of layer 200 are not continuously bonded to the nonwovens of layers 100 and 300. This discontinuous bonding, together with the shrinkage of the polypropylene filaments upon heating, provides enhanced texture of the outward surfaces of layers 100 and 300.

In Figure 1, the filaments 220 extend generally parallel to the side edges 22 and the length of the sheet 20. Similarly, the filaments 240 extend generally parallel to the end edges 24 and the width of the sheet 20.

Alternatively, the filaments 220 may be inclined at an angle of between about 20 and about 70 degrees relative to the length of the sheet 20 and the side edges 22, and more preferably between about 30 degrees and about 60 degrees. The filaments 240 may be inclined at an angle of between about 20 and about 70 degrees relative to the width of the sheet 20 and end edges 24, and more preferably between about 30 degrees and about 60 degrees.

Figure 2 shows an embodiment of the present invention in which the filaments 220 are inclined at an angle of approximately 45 degrees relative to the side edges 22 (angle A in Figure 2), and in which the filaments 240 are inclined at an angle of approximately 45 degrees from the end edges 24 (angle B in Figure 2). Such a distribution provides the advantage that the angled orientation of the filaments 220 and 240 relative to the length and width of the sheet 20 allows deformation of the network structure of the layer 200 parallel to the edges 22 and 24. Said deformation provides the blade with elastic-like behavior parallel to the length and width of the blade.

By "spring-type behavior" is meant that the element in question can be elongated by applying tension in one direction to have an elongated dimension measured in this direction which is at least 120 percent of the relaxed dimension of the original element in this direction, and that when the elongation stress is no longer applied, the element recovers up to 10 percent of its relaxed dimension.

An important aspect of one embodiment of the present invention is that the first layer 100 is intermittently attached to the second layer 200. In particular, the first layer 100 may be intermittently attached to the second layer 200 at intersections 260 of filament, while parts of the filaments 220, parts of the filaments 240 or parts of both filaments 220 and 240 intermediate between the filament intersections 260, remain unbonded to the first layer 100.

Accordingly, the surface texture of the outer surface first layer 100 is not limited by the geometry of the apertures, in the filament-like arrangement, but is decoupled from the non-random repeating geometry of the apertures 250. Similarly, third layer 300 may be intermittently bonded to second layer 200 to provide surface texture similar to the outer surface of third layer 300.

The surface texture of the first layer 100 is omitted in Figures 1 and 2 for clarity. The surface texture is shown in Figures 3-8.

Figure 3 provides a schematic illustration of the surface texture of the first layer 100 shown in the photograph of Figure 5. Figure 4 provides a cross-sectional illustration of the surface texture of the first layer 100 and the third layer 300. Figure 5 is a photomicrogram showing the macroscopically three-dimensional surface texture of the first layer 100. Figure 6 is an enlarged photomicrogram showing the three-dimensional surface of the first layer 100. Figure 7 is a scanning electron photomicrogram that provides a perspective view of the three-dimensional surface of the first layer 100. Figure 8 is a photomicrogram of electronic scanning of a cross section of the sheet.

Referring to Figures 3-8, parts of the first layer 100 are contracted together by the second layer 200 relative to the first layer 100. This meeting provides the first layer 100 with a macroscopically three-dimensional surface as illustrated in Figures 3. -8. Similarly, the third layer 300 can be contracted together from the second layer 200, to provide the third layer 300 with a macroscopically three-dimensional surface.

The three-dimensional surface of the first layer 100 has relatively high peaks 105 and relatively depressed valleys 107. The third layer has peaks 305 and valleys 307. In Figure 4, the peaks of layer 100 are indicated by reference numerals 105A and 105B, and the valleys of layer 100 are indicated by reference numerals

ES 2 202 256 T3

107A and 107B. Similarly, the peaks of layer 300 are labeled 305A and 305B, and the valleys are labeled 307A and 307B. Peaks 105 provide elongated ridges 120 on the exterior facing surface of the first layer 100, and peaks 305 provide elongated ridges 320 on the exterior facing surface of the third layer 300.

The macroscopic three-dimensionality of the outer surface of the first layer 100 can be described in terms of the "Average Height Differential" of a contiguous peak and valley, as well as in terms of the "Average Peak-to-Peak Distance" between contiguous peaks. The height differential relative to a peak pair 105A / valley 107A is the distance H in FIG. 4. The peak-to-peak distance between a contiguous pair of peaks 105A and 105B is indicated as distance D in FIG. 4. The “Average Height Differential” and “Average Peak-to-Peak Distance” for the blade are measured and set forth in the Test Procedures section. The “Surface Topography Index” from the surface to the outside is the relationship obtained by dividing the Average Height Differential of the surface by the Average Peak-to-Peak Distance of the surface.

Without being limited in theory, the Surface Topography Index is believed to be a measure of the efficiency of the macroscopically three-dimensional surface in receiving and containing material in the valleys of the surface. A relatively high value of the Average Height Differential for a given Average Peak-to-Peak Distance provides deep and narrow valleys that can trap and retain materials. Consequently, a relatively high value of the Surface Topography Index is believed to indicate effective capture of materials during cleaning.

The cleaning sheets of the present invention have the characteristic that parts of the filaments 220, parts of the filaments 240, or parts of both filaments 220 and 240, of the second layer 200 are not attached to the first layer 100. Referring to Figure 4, a portion of a filament 220, extending intermediate between the filament intersections 260A and 260B, is not bonded to the first layer 100. The part of the filament 220 that is not bonded to the first layer 100 is indicated by the reference numeral 220U. A gap between the filament 220 and the first layer 100 provides an intermediate hollow space 180 between the first layer 100 and the filament 200. Similarly, portions of filament 220, which extend intermediate between filament intersections 260, are not bonded to third layer 300, thereby providing an intermediate hollow space 380 between third layer 300 and filament 220.

Figures 7 and 8 also illustrate this feature of sheet 20. In Figure 7, ridges 120 and 320 are visible on the outward facing surfaces of both first and third layers 100 and 300, respectively. In Figure 8, a filament 220 is seen extending between two filament intersections 260. The part of the filament that extends between the two filament intersections is spaced from the first layer, to which it is not attached.

The ridges 120 are shown in plan in Figures 3 and 5. At least several of the ridges 120 extend transversely to at least one strand of the second layer 200. In Figure 4, the ridge 120 corresponding to peak 105A extends transversely to at least one filament 220.

Because the ridges extend transversely to one or more strands, the ridges may have a length greater than the maximum distance between 260 contiguous strand intersections (the distance between contiguous strand intersections after layer 200 shrinkage and layer grouping 100 and 300). In particular, the length of the ridges 120 may be greater than the maximum dimension of the openings 250 of Figure 1 (ie, greater than the length of the diagonal extending transversely to the rectangular openings 250). The length of a mountain range 120 is indicated by the letter L in Figure 3. The length L is the distance in a straight line between two ends of a mountain range 120, the ends of the mountain range 120 being those points where a mountain range 120 ends in a valley 107.

The value of L may be at least about 1.0 centimeters, more preferably at least about 1.5 centimeters for some ridges 120. In one embodiment, at least some ridges 120 have a length L of at least about 2.0 centimeters. The length L can be at least twice the distance between contiguous filament intersections.

For example, in order to determine the length of ridges 120 relative to the distance between contiguous filament intersections, the cleaning sheet 20 may be moistened and placed on a light table or other suitable source of backlighting. Such backlighting, together with moistening the cleaning sheet, can be used to make the filament intersections of layer 200 visible through layer 100, such that the lengths of ridges 120 relative to the distance between intersections of filament can be measured with a scale.

The elongated ridges provide deformable and flexible cleaning elements to enhance the removal of material from the surface to be cleaned. In contrast, if the second layer filaments were continuously attached to the first and third layers, then any textural characteristics of the first and third layers would be confined to the area associated with the openings 250 in the second layer 200.

At least some ranges elongated in a different direction from at least some of the other ranges. Referring to Figure 3, each of the ridges 120A, 120B, and 120C extend in one direction

IS 2 202 256 T3 different. Consequently, the blade is effective in picking up material when the blade is used for cleaning in different directions.

Figures 3 and 6 also illustrate that at least some ridges 120 may have branches that extend in different directions. In Figure 3, a ridge 120 is shown to have three branches 123A, 123B, and 123C, extending in different directions. Similarly, figure 6 shows a mountain range 120 that has at least three branches labeled 123A, 123B, and 123C.

The first 100 and third 300 layers are firmly bonded to the second layer 200 at the filament intersections 260. Figure 9 illustrates the bonding of fibers from both layers 100 and 300 to the second layer at a filament intersection 260.

Referring to Figures 4, 7 and 8, the peaks 105 of the first layer 100 are generically offset from the peaks 305 of the third layer in the plane of sheet 20. For example, in Figure 4, the peak 305A of the third layer does not lie directly below the peak 105A, but is generically aligned with the valley 107A associated with the peak 105A. . Accordingly, the peaks 105 of the first layer are generally aligned with valleys 307 of the third layer, and the peaks 305 of the third layer are generally aligned with valleys 107 of the first layer.

The present invention also includes a process for making multilayer cleaning sheets. A first non-woven layer, a second layer comprising a network-like filament arrangement, and a third non-woven layer are provided. The first layer is adjacent to an upper surface of the second layer, face to face with the second layer. The third layer is adjacent to a lower surface of the second layer, face to face with the second layer.

The first layer and the third layer are intermittently attached to discrete separate portions of the second layer, such that portions of the filaments that extend between filament intersections remain unbound to the first layer, and such that said portions of the filaments that extend between the filament intersections remain unbound to the third layer. The second layer is contracted relative to the first layer and the third layer to provide a macroscopically three-dimensional outwardly clustered surface of the first layer, and a macroscopically three-dimensional outwardly clustered surface of the first layer of the third layer. The joining and collapsing stages can occur simultaneously or sequentially.

The step of intermittently bonding the second layer to the first layer and the third layer may comprise the step of hot pressing the first layer, the second layer and the third layer at a relatively low pressure for a relatively short period of time. to avoid relatively continuous bonding of the second layer to the first and second layers.

In one embodiment, the three layers can be joined using a BASIX B400 hand press manufactured by HIX Corp. of Pittsburg, Kansas. The three layers are joined by exerting pressure in the hand press at a temperature of approximately 183.33 ° C for approximately 13 seconds. The manual press has a regulation to vary the clearance, and the pressure, provided by the press. The regulation can be varied as desired to provide the desired texture in layers 100 and 300.

c. Additive and perfume

The cleaning performance of any of the cleaning sheets of the present invention is further enhanced by treating the fibers of the sheet, especially surface treatment, with an additive selected from the group consisting of surfactants, wax, oil or mixtures. of the same, which enhance the adherence of the soil to the blade. Additionally, the additive provides a means for incorporating and fixing perfumes, especially those that are soluble or dispersible in the additive. Said additives are added to the cleaning sheet in a percentage sufficient to enhance the ability of the sheet to adhere dirt. Said additives are applied to the cleaning sheet in an added percentage of at least about 0.1%, more preferably at least about 0.5%, more preferably at least about 1%, even more preferably at least about 3%, even more preferably at least about 4%, and up to 8% by weight. A preferred added percentage is from about 4 to about 8%, and more preferably from about 4 to about 6% by weight. In a preferred embodiment the additive is a wax or a mixture of an oil (eg mineral oil, petroleum jelly, etc.) and a wax. Suitable waxes include various types of hydrocarbons, as well as esters of certain fatty acids (eg, saturated triglycerides) and fatty alcohols. They can be obtained from natural sources (eg, animal, vegetable or mineral) or they can be synthesized. Mixtures of these various waxes can also be used. Some representative animal and vegetable waxes that can be used in the present invention include beeswax, carnauba, whale white, lanolin, shellac wax, candelilla wax, and the like. Representative waxes from mineral sources that can be used in the present invention include petroleum-based waxes, such as paraffin, petroleum, and microcrystalline wax, and fossil or ground waxes, such as white refined ozokerite wax, yellow refined ozokerite wax, yellow wax. ozokerite white and the like. Representative synthetic waxes that can be used in the present invention include ethylenic polymers such as polyethylene wax, chlorinated naphthalenes such as "Halowax", hydrocarbon type waxes made by Fischer-Tropsch synthesis, and the like.

ES 2 202 256 T3

When using a mixture of mineral oil and wax, the components will preferably be mixed in an oil to wax ratio of from about 1:99 to about 7: 3, more preferably from about 1:99 to about 1: 1, even more preferably from about 1:99 to about 3: 7 by weight. In a particularly preferred embodiment, the oil to wax ratio is approximately 1: 1, by weight, and the additive is applied in an added percentage of approximately 5% by weight. A preferred mixture is a 1: 1 mixture of mineral oil wax and paraffin.

In particular, enhanced cleaning performance is achieved when multiple basis weights, macroscopic three-dimensionality, and additives are provided on a single cleaning sheet. As discussed below, these low percentages are especially desirable when the additives are applied at an effective percentage and preferably substantially uniformly to at least a discrete continuous area of ​​the sheet. The use of preferred lower percentages, especially additives that improve dirt adhesion to the sheet, provide surprisingly good cleaning, airborne dust removal, consumer preferred prints, especially tactile prints, and, in addition to perfumes, the additive can provide a means of incorporating and fixing perfumes, pest control ingredients, antimicrobials, including fungicides, and a group of other beneficial ingredients, especially those that are soluble, or dispersible, in the additive. These benefits are for example only. Low percentages of additives are especially desirable where the additives can have adverse effects on the substrate, packaging, and / or surfaces being treated.

The application medium for these additives is preferably applied to at least a substantial amount of the additive at points on the sheet that are "within" the sheet structure. It is a special advantage of three-dimensional and / or multi-basis weight structures that the amount of additive that is in contact with the skin and / or surface to be treated, and / or the packaging, is limited, such that materials that otherwise could cause damage, or interfere with the function of the other surface, could only cause limited or no adverse effects. The presence of the additives within the structure is very beneficial as the soil that adheres within the structure is much less likely to be removed by the subsequent cleaning action.

The invention also encompasses packages containing cleaning sheets, the packages being associated with information that will inform the consumer, through words and / or images, that the use of the sheets will provide cleaning benefits including removal and / or trapping of dirt ( e.g. dust, lint, etc.) and this information may comprise claiming superiority over other cleaning products. In a highly desirable variation, the packaging carries information that informs the consumer that use of the cleaning sheet provides reduced levels of dust and other airborne matter in the atmosphere. It is very important that the consumer is aware of the potential use of the sheets on non-traditional surfaces, including fabrics, pets, etc., to ensure that all the benefits of the sheets are realized. Accordingly, the use of packaging associated with information that will inform the consumer, through words and / or images, that the use of the compositions will provide benefits such as improved cleaning, reduction of particulate soils in the air, etc. As discussed above, it is important. The information can be included, for example, in the advertising of all normal communication media, as well as text and icons on the packaging, or on the sheet itself, to inform the consumer.

The above products that do not comprise the preferred memory structures can be used to provide the benefits on a smaller scale, and to the extent that these benefits have not been previously recognized, they should be included in the information provided. Otherwise, the consumer will not get the full value of the improved performance over conventional products or practices.

In a particularly preferred embodiment, a cleaning sheet is prepared:

introducing a first layer of carded polyester (for example, 19 g / m² basis weight) on a carrier belt, laying a mesh chambray material on top of the first layer, and laying a randomized second layer of continuous carded polyester web (28 g / m2² basis weight) over the top of the mesh chambray material. (It should be recognized that either or both of the first and second layers may be formed from multiple layers of carded polyester). The three-layer composite is then hydroentangled onto a belt-forming mesh consisting of strands or filaments running in the MD and CD directions. This results in hydroentangling of the two carded layers of fiber, as well as entanglement of each of the fibrous layers with the chambray material. The entangled compound is then subjected to heat during the drying process, which results in approximately a 20% shrinkage of the sheet in the CD direction. This shrinkage results in the bottom layer, which has an estimated basis weight of 23.75 g / m² , and the top layer, which has an estimated basis weight of 35 g / m² . After the final cut, the sheet is coated on both surfaces with 5%, of the dry weight of the sheet, of a mixture of mineral oil and paraffin wax (1: 1 w / w ratio). The aggregate basis weight of the sheet (including the chambray material), after coating, is approximately 64-68 g / m² .

III. Cleaning accesories

In another aspect, the present invention relates to a cleaning accessory comprising the cleaning sheets discussed above. In another aspect the cleaning accessory comprises:

to. a handle; Y

ES 2 202 256 T3

b. a removable cleaning sheet comprising one or more high basis weight regions having a basis weight of from about 30 to about 120 g / m2² , and one or more low basis weight regions, in which the low basis weight region (s) have a basis weight that is not more than 80% of the basis weight of the region (s) ( regions) of high basis weight.

As discussed above, in this aspect of the invention, it is preferred that the cleaning accessory blade have a continuous region surrounding discrete regions that differ relative to basis weight. It is particularly preferred where the continuous region has a relatively higher basis weight than the discrete regions. The appearance of the accessory sheet may also have macroscopic three-dimensionality.

The accessory and, separately, the cleaning sheet of the present invention are designed to be compatible with all hard surface substrates, including wood, vinyl, linoleum, non-wax floors, ceramic, FORMICA^®, porcelain and the like.

The handle of the cleaning accessory comprises any long, durable material that provides ergonomically convenient cleaning. The length of the handle will be dictated by the end user of the accessory.

The handle will preferably comprise at one end a support head to which the cleaning blade can be removably attached. For ease of use, the support head can be pivotally attached to the handle using known joint sets. Any suitable means can be used to attach the cleaning sheet to the support head, as long as the cleaning sheet remains attached during the cleaning process. Examples of fasteners include fasteners, brackets, and clips (for example, VELCRO^®), and similar. In a preferred embodiment, the support head will comprise means for gripping the sheet on its upper surface to keep the sheet mechanically attached to the head during the rigors of cleaning. However, the gripping medium will promptly release the sheet for proper removal and disposal.

The cleaning sheets useful in the cleaning accessory of the present invention are as described above.

IV. Test procedures

A. Gauge procedure

To prevent structural alteration of the sample, the sample must be cryofractured to provide a cross-sectional image of the high and low basis weight regions. The microscopic image of the cross section of the sample can be used to determine relative differences in caliper between regions.

B. Average Height Differential

The Mean Height Differential is determined using an optical microscope (eg, Zeiss Axioplan, Zeiss Company, Germany), equipped with a Z-dimension measuring device (eg, Microcode II, sold by Boeckeler Instruments). This procedure involves locating a peak or valley region of the leaf, focusing the microscope, and zeroing the measuring device in the Z dimension. The microscope is then moved to a contiguous valley or peak region, respectively, and the microscope is refocused. The instrument display indicates the difference in height between this peak / valley or valley / peak pair. This measurement is repeated at least 10 times, in random places on the sheet, and the Average Height Differential is the average of these measurements.

C. Average Peak-to-Peak Distance

A single light microscope can be used to measure Average Peak-to-Peak Distance. The amplification used would be sufficient to truly measure the distance between two contiguous peaks. This measurement is repeated at least 10 times at random places on the sheet, and the Average Peak-to-Peak Distance is the average of these measurements.

D. Elongation CD at 500 g

The CD elongation is an average of the percentage of elongation that a test sample exhibits under a load of 500 g. CD elongation can be measured using a Sintech Renew Instron 7310 (which includes Testworks software package) with a 100 N load cell. Using this instrument a load versus% displacement curve is generated. The test parameters are as follows:

Sample width = 30 mm

Gauge length = 100 mm

Crosshead speed = 300 mm / min

From the generated curve, the computer program obtains the% displacement (% elongation) at a load of 500 g. This is reported as CD elongation at 500 g.

ES 2 202 256 T3

V. Representative examples

Examples of cleaning sheets of the present invention are illustrated below. Wherever applicable, the mechanical properties of sheets are summarized in Table I. Wherever applicable, enhanced three-dimensionality is indicated in Table II.

Example 1

This example illustrates the combination of carded webs and a scrim (ie, a polypropylene filament net) to make a cleaning sheet of the present invention. Two continuous webs of carded polyester fiber are prepared with a scrim in between. The combination of the two carded webs and the scrim is then placed on top of an apertured forming belt (23C square wave available from Albany International, Division of Tissue Engineering, Appleton, Wisconsin) and hydroentangled and dried. The water entanglement process causes the fibers to tangle with each other and entangle with the scrim, while at the same time causing the fibers to separate and provide two different basis weight regions. During the drying process, the hydroentangled sheet becomes a "cushioned" sheet (that is, greater three-dimensionality is achieved), as a result of the shrinkage of the polypropylene scrim relative to the polyester nonwoven material. This material is designated as Example 1 in Table I and Table II.

As a preferred optional step, the nonwoven sheet is surface coated (eg, by painting, spraying, etc.) with 5%, by weight, of a 1: 1 mixture of mineral oil and paraffin wax. This treated sheet is designated as Example 1A in Table 1.

As another preferred optional step, the entangled nonwoven sheet can be subjected to further heating, for example in a press at 180 ° C for 10 seconds. (This heating can be done before or after adding the surface treatment, but it is preferably done before or after applying the additive). This even provides an enhanced three-dimensionality, similar to that of the sheet described in Example 3. This sheet is indicated as example 1B in Table 1 and Table 2.

Example 2

This example illustrates the hydroentangling of two layers of carded fibers (polyester), in which no scrim material is located between the two fibrous layers. The fabric belt and both hydroentanglement and drying conditions are similar to Example 1. This material is indicated as Example 2 in Table 1.

Example 3

A cleaning sheet according to the present invention includes a first layer 100, a second layer 200, and a third layer 300. The first layer 100 and the third layer 300 each comprise a hydroentangled web of polyester fibers having a basis weight of about 30 grams per square meter. The second layer comprises the reinforcement net of the brand THERMANET^®, described above, having a polypropylene / EVA resin, two-sided adhesive, and a size of 3 strands per inch by 2 strands per inch prior to shrinkage of the second layer. The second layer 200 is between the first layer 100 and the third layer 300 on a BASIX B400 manual press. The three layers are pressed together in the hand press at a stabilization temperature of approximately 183.33 ° C for approximately 13 seconds.

Comparative Example A

Comparative Example A illustrates a nonwoven sheet having a uniform basis weight. A forming belt with fine apertures (eg, 100 mesh) can be used to make this sheet. The combination of carded web and scrim was hydroentangled and dried. The fabric strap provides a very even basis weight to the blade due to the very fine openings in the strap. The non-woven sheet is surface coated (eg by printing, spraying, etc.) with 5% by weight of a 1: 1 mixture of mineral wax and paraffin.

Comparative Example B

Comparative Example B illustrates a nonwoven sheet that has a uniform basis weight and is generally flat. The sheet is commercially available from Kao Corporation, Tokyo, Japan, as QUICKLE^®.

ES 2 202 256 T3

TABLE 1

<td>Example no.</td><td>Added chemical (%)</td><td>Density (g / cm³)</td><td>Weight base (gsm)</td><td>Caliber (one thousand)</td><td>CD tension (g / 30mm)</td><td>CD elongation at 500 g (%)</td><td>MD tension (g / 30m)</td><td>MD elongation at 500 g (%)</td>

<td> 1</td><td> 0</td><td> 0,07</td><td> 63</td><td> 36</td><td> 3620</td><td> 6,5</td><td> &gt; 10.000</td><td> 3,3</td>

<td>1A</td><td> 5</td><td> 0,07</td><td> 66</td><td> 39</td><td> 2418</td><td> 6,9</td><td> 7594</td><td> 3,5</td>

<td>1 B</td><td> 5</td><td> 0,04</td><td> 136</td><td> 127</td><td> 4437</td><td> 11,2</td><td> &gt; 10.000</td><td> 9,8</td>

<td> 2</td><td> 0</td><td> 0,06</td><td> 63</td><td> 42</td><td> 6188</td><td> 31</td><td> &gt; 10.000</td><td> 9,6</td>

<td>Compatibility. TO</td><td> 5</td><td> 0,11</td><td> 68</td><td> 24</td><td> 2643</td><td> 5,5</td><td> 7633</td><td> 1,9</td>

N = 3 for all measurements.

TABLE II

<td>Example no.</td><td>Height Differential Average (mm)</td><td>Average Peak Distance to Peak (mm)</td><td>Surface Topography Index</td>

<td> 1</td><td> 0,74</td><td> 0,89</td><td> 0,8</td>

<td>1 B</td><td> 1,4</td><td> 3</td><td> 0,5</td>

<td> 3</td><td> 1,8</td><td> 3</td><td> 0,6</td>

<td>Comparison B</td><td> 0,14</td><td> 0,85</td><td> 0,16</td>