EP1022977A1

EP1022977A1 - Cleaning implement

Info

Publication number: EP1022977A1
Application number: EP98953489A
Authority: EP
Inventors: David Robert Zint; Kevin Timothy Burnam
Original assignee: Procter and Gamble Co
Current assignee: Procter and Gamble Co
Priority date: 1997-10-15
Filing date: 1998-10-14
Publication date: 2000-08-02
Also published as: JP2001519189A; CN1282227A; WO1999018838A1

Abstract

The subject invention includes cleaning implements comprising a resilient absorbent core material (40, 60) snugly surrounded by open-cell plastic mesh material (41, 42, 43, 44, 61, 62). The plastic mesh material, when fully expanded, has a basis weight of from about 3.4 g/m2 to about 34g/m2, and an average strand count of from about 0.8/cm to about 20/cm. At least about 50 % of the surface of the absorbent core material is covered by at least layers of the mesh material. The subject invention also involves kits comprising such cleaning implements, and a container of detergent cleaning product.

Description

CLEANING IMPLEMENT

TECHNICAL FIELD

The subject invention involves an implement for cleaning hard surfaces, especially eating and cooking utensils, which has an absorbent core with a surface cover material.

BACKGROUND OF THE INVENTION

It is an object of the subject invention to provide cleaning implements which help provide a large volume of suds and long-lasting suds when used in conjunction with a detergent wash solution for cleaning hard surfaces.

It is a further object of the subject invention to provide cleaning implements which have a surface covering material suitable for the type of cleaning desired: gentle cleaning of scratchable surfaces, abrasive cleaning of scratch-resistant surfaces, etc.

It is also an object of the subject invention to provide a convenient kit of a subject cleaning implement along with a container of detergent cleaning product.

SUMMARY OF THE INVENTION

The subject invention involves a cleaning implement comprising a resilient absorbent core material snugly surrounded by open-cell plastic mesh material, the plastic mesh material when fully expanded having a basis weight of from about 3.4 g/m2 to about 34 g/m^ and an average strand count of from about 0.8/cm to about 20/cm, at least about 50% of the surface of the absorbent core material being covered by at least three layers of the mesh material.

The subject invention also involves a kit comprising such cleaning implement and a container of detergent cleaning product.

BRIEF DESCRIPTION OF THE DRAWINGS

While the specification concludes with claims particularly pointing out and distinctly claiming the subject invention, it is believed the invention will better be understood from the following description taken in conjunction with the accompanying drawings:

Fig. 1 illustrates an exemplary section of fully-expanded diamond-shaped open-cell mesh material;

Fig. 2 illustrates an exemplary section of fully-expanded hexagonal-shaped open-cell mesh material after stretching a diamond-shaped cell mesh material; Fig. 2A illustrates an enlarged exemplary view of a node of the mesh material of Fig. 2;

Fig. 3 is a schematic illustration of testing procedures for measuring an open- cell mesh's resistance to an applied weight, which is useful in characterizing the flexibility of the open-cell mesh material;

Fig. 4 is a perspective view of a preferred subject invention implement.

Figs. 4A and 4B are two cross-sectional views of the implement of Fig. 4 in which the thickness of the mesh material layers is exaggerated for clarity.

Fig. 5 is a perspective view of a preferred subject invention implement.

Figs. 5 A and 5B are two cross-sectional views of the implement of Fig. 5 in which the thickness of the mesh material layers is exaggerated for clarity.

Fig. 6 shows pleated mesh material on a wicket, illustrating how an exemplary implement can be made.

Fig. 6A is a cross-sectional view of the pleated mesh material of Fig. 6. DETAILED DESCRIPTION OF THE INVENTION

The subject invention cleaning implements comprise a core material which is absorbent and resilient. The absorbency of the core material allows it to act as a reservoir for a detergent cleaning solution. The resiliency of the core material allows one to force cleaning solution out of the core material by squeezing it during use. The core material is also flexible, so that the implement can conform to the shape of the surface of the object being cleaned. This flexibility and resiliency of the core material enables intimate contact between the surface of the cleaning implement and that of the object being cleaned for good cleaning performance.

Preferred absorbent, resilient materials useful as core materials for the subject cleaning implements include sponge-type materials. Sponges are available made from many different materials including cellulose, polyester, polyurethane, other plastics, and natural sponges. Preferred sponge materials useful as core materials for the subject cleaning implements include polyurethane, and cellulose.

The subject cleaning implements comprise an open-cell plastic mesh material which substantially surrounds the core material. The plastic mesh material need not be bonded to the core material, although such bonding can optionally be present. There is preferably a snug fit of the core material within the surrounding mesh material, such that the core material, which is generally of a particular shape, remains in place within the mesh material. Thus, it is optional but preferred that the mesh material compress the core material a small amount to help hold the core material in place within the mesh covering. Conversely, the slightly compressed core material exerts a small outward pressure on the mesh material which helps hold the mesh material in its fully-expanded configuration. (The fully-expanded configuration of the mesh material is described more completely hereinbelow.)

It is preferred that the mesh material not compress the core material to a large extent, so that the core material retains its flexibility and its ability to act as a reservoir for cleaning solution. Therefore, it is preferred that within the surrounding mesh material, the absorbent core material is compressed no more than to the extent that it retains at least about 60% of its water absorption capacity compared to when it is not compressed at all, more preferably retains at least about 80%, more preferably still retains at least about 90%, of such absorption capacity. It is preferred that the core material is compressed no less than to the extent that it retains at most about 100% of such absorption capacity, also preferably retains at most about 95%, also preferably retains at most about 90%, of such absorption capacity.

Open-cell plastic mesh materials useful as cover materials for the subject cleaning implements are known. Such materials are preferably made by extrusion processes resulting in a continuous sheet or tube of substantially planar mesh material. "Substantially planar" does not mean that the mesh material is necessarily a flat sheet, since, as indicated, it is often produced in a tubular shape; it means that the mesh material can be oriented into a flat sheet having a substantial length and width and very small thickness (e.g., by cutting along the length of the tube produced and pulling the cut sides in opposite directions until the mesh material is flat). By "open-cell" it is meant that the mesh material comprises openings surrounded by interconnected strands of plastic. The strands and openings are preferably in a regular, repeated pattern. The "cell" of the open-cell mesh material refers to a single opening of the mesh which is surrounded by contiguous strands of plastic. Cells of a given mesh material are preferably all substantially the same size and shape, but different mesh materials can have different sizes and shapes of cells.

The direction of the mesh material which is parallel to the length of the tube produced, or to the sides of the sheet produced, is known as the "machine direction" (MD). The direction of the mesh material in the plane of the mesh but perpendicular to the machine direction is known as the "transverse direction" (TD).

A process of manufacturing an open-cell mesh materials for use as a part of a subject implement involves the selection of an appropriate resin material, which can include polyolefms, polyamides, polyesters, and other appropriate materials which produce a durable and functional mesh. Low density polyethylene (LDPE, a polyolefin), linear low density polyethylene (LLDPE), polyvinyl ethylacetate, high density polyethylene (HDPE), or mixtures thereof, are preferred to produce the mesh materials described herein, although other resin materials can be substituted provided that the resulting mesh material conforms with the physical parameters defined herein. LDPE is the most preferred resin for the subject mesh materials.

In addition to the resins described above, adjunct materials are commonly added to the resins in making the extruded mesh materials. Mixtures of pigments, dyes, brighteners, heavy waxes and the like are common additives in making the extruded mesh materials described herein.

To produce an open-cell mesh material, the selected resin is fed into an extruder by any appropriate means. Extruder and screw feed equipment for production of synthetic webs and open-cell meshes are known and available in the industry.

After the resin is introduced into the extruder it is melted so that it flows through extrusion channels and into the die, as will be discussed in greater detail below. Resin melt temperatures vary depending upon the resin selected. The material's Melt Index is a standard parameter (ASTM Method D1238) for correlating extrusion die temperatures to the viscosity of the extruded plastic as it flows through the die. Melt Index is defined as the viscosity of a thermoplastic polymer at a specified temperature and pressure; it is a function of the molecular weight. Specifically, Melt Index is the number of grams of such a polymer that can be forced through a 0.0825 inch (2J0 mm) diameter orifice in 10 minutes at 190°C by a pressure of 3045 g/cm2.

A Melt Index of from about 2 to about 14 for LDPE and other resins is preferred for manufacturing the mesh described herein; a Melt Index of at least about 4 is more preferred, at least about 6 is more preferred still; a Melt Index of at most about 10 is more prefeπed, at most about 8 is more preferred still. If resin materials other than LDPE are used, the Melt Index might be varied, as appropriate. The temperature range of operation of the extruder can vary substantially between the temperature at which the resin melts and the temperature at which the resin degrades.

For making the diamond or hexagonal open-cell mesh materials of Figs. 1 and 2, a liquefied resin can be extruded through two counter-rotating dies, which are common to the industry. U.S. Patent Nos. 3,957,565 of Livingston & Melin and 4,020,208 of Mercer & Martin, for example, describe processes for extruding tubular plastic mesh materials using counter-rotating dies, such disclosures being hereby incorporated herein by reference. A counter-rotating die has an inner and outer die, and both have channels cut longitudinally around their outer and inner circumferences respectively, such that when resin flows through the channels, fibers are extruded. Individual fibers, e.g., F, as seen in Fig. 1, are extruded from each channel of the inner die as well as each channel of the outer die to form mesh section 10. As the two dies are rotated in opposite directions relative to one another, the channels from the outer die align with the channels of the inner die, at predetermined intervals. The liquefied resin is thereby mixed as two channels align, and the two fibers (e.g., F, as seen in Fig. 1) being extruded are bonded together until the extrusion channels of the outer and inner die are misaligned due to continued rotation. As the inner die and outer die rotate counter-directionally to each other, the process of successive alignment and misalignment of the channels of each die occurs repeatedly. The point at which the channels align and two fibers are bonded together is commonly referred to as a "node" (e.g., N of Fig. 1).

The "die diameter" is measured as the inner diameter of the outer die or the outer diameter of the inner die. These two diameters must be essentially equal to avoid stray resin from leaking between the two dies. The die diameter affects the final diameter of the tube of mesh being produced, although die diameter is only one parameter which controls the final diameter of the mesh tube. Although it is believed that a wide variety of die diameters, preferably between about 2 cm and about 15 cm, are suitable for manufacturing the meshes described herein, die diameters are more preferably at least about 3 cm, also more preferably still at least about 6 cm; and are more preferably at most about 10 cm, more preferably still at most about 8 cm, also more preferably at most about 5 cm.

The extrusion channels can likewise be varied among a variety of geometric configurations known to the art. Square, rectangular, D-shaped, quarter-moon, semicircular, keyhold, and triangular channels are all shapes known to the art, and can be adapted to produce the mesh described herein. Rectangular-shaped channels are preferred for the subject mesh materials, although other channels also provide acceptable results.

After the tube of mesh is extruded from the counter-rotating dies, it can be characterized as having diamond-shaped cells when viewed relative to the machine and transverse directions (Fig. 1) where each of the four corners of the diamond is an individual node N and the four sides of the diamond are four, separately formed filament segments F. The mesh tube is then pulled over a cylindrical mandrel where the longitudinal axis of the mandrel is essentially parallel to the longitudinal axis of the counter-rotating dies, i.e., the machine direction (MD as shown in Fig. 1). The mandrel serves to put circumferential pressure on the web, thus expanding it somewhat in the TD; this also insures good contact of the filaments where they cross, and secure formation of the nodes at such points. Typically the mandrel is immersed in a vat of water, oil or other quench solution, which is typically about 25°C or less; this serves to cool and solidify the extruded mesh.

The mandrel can be a variety of diameters, although it will be chosen to correspond appropriately to the extrusion die diameter. The mandrel is preferably larger in diameter than the die diameter to achieve the desired secure node formation and desired stretch of filaments in the TD, but the mandrel must also be small enough in diameter to avoid damaging the integrity of the mesh through overstretching. The ratio of mandrel diameter to die diameter is preferably at least about 1.1, more preferably at least about 1.3, more preferably still at least about 1.4, and is preferably at most about 2, more preferably at most about 1.8, more preferably still at most about 1.6.

The tube of mesh material is preferably stretched longitudinally in the machine direction (MD) of the mesh; this aligns the polymer molecules in the filaments or filaments and nodes, imparting desired strength and flexibility properties to the mesh material. Depending on a number of factors, including the polymer the mesh is made from, the temperature to which the mesh has been cooled, the speed and amount of stretch applied to the mesh; either the filaments alone, or both the filaments and nodes of the mesh are stretched. If the filaments alone are stretched, the mesh material continues to look like that of Fig. 1.

Preferably both the filaments and nodes of the mesh are stretched. The geometric configuration of the mesh cells can also vary significantly depending on how the tube of mesh is viewed. Thus, the geometric cell descriptions are not meant to be limiting but are included for illustrative purposes only. As the nodes of the diamond cell mesh are stretched, they can be transformed from small, ball-like objects (e.g., N of Fig. 1) to longer, thinner filament-like nodes (e.g., 12 of Figs. 2 and 2A). The cells are thereby also transformed from a diamond-like shape to hexagonal-shape wherein the stretched nodes 12 form two sides of the hexagon, and the four individual filament segments F form the other four sides of the hexagon. Preferably the mesh is taken-up faster than it is produced, which supplies the desired longitudinal, or machine direction, stretching force. Typically a take-up spool is used to accumulate the finished mesh product. As should be apparent, there are a variety of process parameters (e.g., resin feed rate, die and mandrel diameters, channel design, die rotation speed, quench temperature, stretch amount and speed, and the like) that affect mesh parameters such as cell shape, basis weight and cell count.

Although the production of open-cell mesh materials in a tube configuration through the use of counter-rotating dies, as described above, is preferred for the mesh materials useful in making the subject invention implements, alternative processing means are known. For example, U.S. Patent No. 4,123,491 of Larsen, the disclosure of which is hereby incorporated herein by reference, shows the production of a sheet of open cell mesh wherein the filaments produced are essentially perpendicular to one another, forming essentially rectangular cells when viewed relative to the machine and transverse directions. The resulting mesh material is preferably stretched in both the MD and TD after production, to provide alignment of the polymer molecules in the mesh filaments.

Yet another alternative for manufacturing extruded open-cell mesh materials is described in U.S. Patent No. 3,917,889 of Gaffhey & Larsen, the disclosure of which is hereby incorporated herein by reference. This reference describes the production of a tubular extruded mesh, wherein the filaments extruded in the machine direction are essentially perpendicular to filaments or bands of plastic material which are periodically formed transverse to the machine direction. The material extruded transverse to the machine direction can be controlled such that thin filaments or thick bands of material are formed. As was the case with the mesh manufacturing procedures described above, the tubular mesh manufactured according to this reference is preferably stretched both circumferentially (TD) and longitudinally (MD) after extrusion.

One parameter of importance of the open-cell mesh materials useful for the subject implements is the "basis weight". Since the mesh materials are substantially planar, basis weight is determined as the weight per unit area of the mesh material. However, care must be taken to define the unit area of the mesh material. This is because the mesh materials are flexible and by expanding or contracting them in different directions, the weight per unit area is dramatically changed. For example, the diamond or hexagonal mesh materials of Figs. 1 or 2 can be elongated in the machine direction such that the cell angles pointing in the machine direction approach 0°, such that the cells collapse to virtually no width in the transverse direction. In fact, because of the MD stretching typically applied to such mesh materials when they are produced, they are generally supplied in such a "collapsed" state in the TD (i.e., angles which point in the MD (14 in Figs. 1, 2 and 2A) are about 0°), and require a small force in the TD to expand them in that direction and "open" the cells.

The basis weight of the open-cell mesh materials is determined by measuring the area of the mesh when it is "fully-expanded". A fully-expanded mesh material is one where the mesh material is expanded in both the machine and transverse directions such that, while none of the plastic strands are actually stretched and made longer, they are fully straightened. For mesh materials having a rectangular cell shape, the mesh material is expanded in the machine and transverse directions until the strand sides of the rectangles are straight and parallel to these directions. For, the mesh materials of Figs. 1 and 2, they must be expanded the proper distances in the machine and transverse direction so that the four plastic strands that meet at each intersection in the mesh material of Fig. 1 are straight and form four 90° angles, and the three strands which meet at each intersection in the mesh shown in Fig. 2 are straight and form three 120° angles.

The mesh materials useful for the subject implements have a basis weight of at least about 3.4 g/m2, preferably at least about 6 g/m2, more preferably at least about 8 g/m2, more preferably still at least about 10 g/m2; and a basis weight of at most about 34 g/m2, preferably at most about 20 g/m2, more preferably at most about 15 g/m2, more preferably still at most about 12 g/m2.

When the open-cell mesh materials useful for the subject implements are fully-expanded as defined above, each cell of the mesh has either two or three pairs of parallel sides. The "cell size" of a mesh material is the average of the dimensions between the two or three pairs of parallel strands for each cell. a n additional preference for mesh materials useful for the subject invention implements is that the greatest of these dimensions between parallel cell sides be no more than about 3 times the smallest of these dimensions, preferably the greatest of these dimensions is no more than about 2 times the smallest of these dimensions, more preferably still the greatest of these dimensions is no more than about 1.5 times the smallest of these dimensions, still more preferably the greatest of these dimensions is no more than about 1.2 times the smallest of these dimensions. The cell size of the open-cell mesh materials useful for the subject implements is at least about 0.5 mm, preferably at least about 1 mm, more preferably at least about 2 mm, more preferably still at least about 3 mm, still more preferably at least about 4 mm, and is at most about 10 mm, preferably at most about 8 mm, more preferably at most about 7 mm, more preferably still at most about 6 mm, still more preferably at most about 5 mm.

.Another parameter of the open-cell mesh materials is the "strand count" or "cell count" (as defined herein they are the same). The strand or cell count is taken in all directions perpendicular to the strands of the mesh. For mesh materials having strands perpendicular to the MD or TD when the mesh is fully expanded (rectangular cell mesh, or TD in the mesh of Fig. 2), the count is simply taken along a line in the direction of interest across such perpendicular strands; counting either the strands or cells crossed results in the same count (except for possible rounding differences). For mesh materials with strands not perpendicular to the MD and TD (all strands in the mesh of Fig. 1, or F strands in the mesh of Fig. 2), the count is taken along a line which is perpendicular to these strands, counting either the strands or the cells crossed. For most mesh materials, such as those of Figs. 1 and 2, the strand count in every direction is about the same, and an average of the two (e.g., for mesh of Fig. 1) or three (for mesh of Fig. 2) strand counts ("average strand count" or "average cell count") can be used to describe the mesh material.

The average strand count or average cell count of the open-cell mesh materials useful for the subject implements is at least about 0.8/cm, preferably at least about 1.0/cm, more preferably at least about 1.2/cm, more preferably still at least about 1.4/cm, still more preferably at least about 1.5/cm; and is at most about 20/cm, preferably at most about 8/cm, more preferably at most about 5/cm, more preferably still at most about 3/cm, still more preferably at most about 2.2/cm, also preferably at most about 1.8/cm.

The good sudsing achieved by the subject implements requires good flexibility of the strands of the mesh material. One way to achieve good flexibility is to have thin strands of material, which is largely determined by the basis weight and strand count of the mesh. However, the flexibility is also affected by the properties of the plastic material itself.

It has been determined that a standardized test of mesh material flexibility, for mesh material with diamond or hexagonal shaped cells produced as a tube of mesh material, such as those of Figs. 1 and 2, can be performed as described herein and as depicted in Fig. 3. The resulting measurement of flexibility is defined herein as Initial Stretch. As schematically illustrated in Fig. 3, the procedure for determining Initial Stretch begins by hanging a mesh tube 20 from a test stand horizontal arm 22, which in turn is supported by a vertical support member 24 and which is in turn attached to a test stand base 26.

As was described above, when the open cell mesh is extruded from a counter-rotating die, the mesh is formed in a tube. The tube of mesh 20 for testing should be 6.0 inches (15.2 cm) in length, as indicated by length 28. Six inches was chosen, along with a 50.0 gram weight, as an arbitrary standard for making the measurement. As will be apparent, other standard conditions could have been chosen. However, in order to compare Initial Stretch values for different meshes, it is preferred that the standard conditions chosen and described herein be followed uniformly.

As is illustrated in Fig. 3, a standardized weight, is suspended from a weight support member 30, which has a weight support horizontal arm 32 placed through and hung from mesh tube 20. It is critical that the total combined weight of the support member 30 and the standardized weight together equal 50 grams. Distance 34 illustrates the "Initial Stretch", and is the distance which mesh tube 20 stretches immediately after the weight has been suspended from it. A linear scale 36 is preferably used to measure distance 34.

The Initial Stretch is, of course, dependent on the die diameter and the mandrel diameter. It can be used to compare different mesh materials made using dies and mandrels of the same diameter. For example, for mesh useful for making implements of the subject invention made on a machine with a die diameter of 7 cm and a mandrel diameter of 10.5 cm, the mesh material preferably has an Initial Stretch value which is at least about 30 cm, more preferably at least about 33 cm, still more preferably at least about 35 cm, also preferably at least about 36 cm; and is preferably at most about 43 cm, more preferably at most about 39 cm, more preferably still at most about 37 cm, also preferably at most about 36 cm.

The dependence of the Initial Stretch of a mesh material on die and mandrel diameters can be eliminated by dividing the Initial Stretch by the mandrel diameter. This provides an "Initial Stretch Ratio" which is useful in comparing mesh materials made with different dies and mandrels. Mesh materials useful for the subject implements preferably have an Initial Stretch Ratio which is at least about 2.8, more preferably at least about 3J, more preferably still at least about 3.3; and preferably is at most about 4J, more preferably at most about 3.7, more preferably still at most about 3.5.

The resilient property of open-cell mesh material can be measured by suspending a larger standardized weight (i.e., 250 grams, as shown in Fig. 3) from the mesh sample 20, and subtracting the distance 34 from the distance 35. It is critical that the total combined weight of the support member plus the larger standardized weight equal 250 grams. The result is directly proportional to the resilience level of the mesh and is termed "Resilience". For mesh materials used in making the subject implements, Resilience, for mesh materials made by equipment having a die diameter of 7 cm and a mandrel diameter of 10.5 cm, is preferably at least about 34 cm, more preferably at least about 38 cm, more preferably still at least about 40 cm, also preferably at least about 41 cm; and is preferably at most about 48 cm, more preferably at most about 44 cm, more preferably still at most about 42 cm, also preferably at most about 41 cm.

Again this measurement can be normalized for mesh materials made with different dies and mandrels by dividing it by the mandrel diameter to determine the "Resilience Ratio" for the mesh. Mesh materials useful for the subject implements preferably have a Resilience Ratio which is at least about 3.2, more preferably at least about 3.6, more preferably still at least about 3.8; and is preferably at most about 4.6, more preferably at most about 4.2, more preferably still at most about 4.0.

The process typically used for manufacture of the preferred diamond-shaped and hexagonal-shaped open-celled mesh materials useful for the subject implements typically results in a mesh that is very contracted in the transverse direction and somewhat elongated in the machine direction. Although such mesh material can be readily expanded by pulling it gently in the transverse direction, its natural resiliency tends to make it contract once this force in the transverse direction is released.

It is preferred that the open-celled plastic mesh materials of Figs. 1 and 2, when used for making the subject implements, be close to their fully-expanded state. Such mesh materials can be relaxed in their fully-expanded state by gently pulling them in the TD until they reach their fully-expanded state, and holding them in that state at an elevated temperature (but below the melt temperature of the plastic) until the mesh material relaxes and remains fully-expanded without the TD force. For the preferred LDPE mesh materials, this can be achieved, for example, by holding them in their fully-expanded state for about 15 minutes at about 60°C. Similarly, other mesh materials useful for the subject implements can be relaxed at or near their fully-expanded state by holding them in that state at temperatures and for periods of time which are readily determined for each experimentally.

For the subject invention cleaning implements, at least about 50% of the surface of the core material is covered by three or more layers of the plastic mesh material. As used herein, "surface" of the core material means its external surface. Preferably at least about 70% of the surface of the core material is covered by three or more layers of the mesh material; more preferably still at least about 90% of the surface of the core material is so covered. Most preferably, substantially all of the surface of the core material is covered by three or more layers of the mesh material (although the surrounding mesh material typically has several seams where the layers of mesh material are adhered or melted together, such that the layers cannot be separated at such seams).

Where there are multiple layers of mesh material covering the core material of the subject implements, the number of such layers of mesh material at any given point on the surface of the implement can vary substantially, depending on how the implement is made. The average number of layers of mesh material covering the surface of the core material of the implements is preferably at least 3, more preferably at least about 4, more preferably still at least about 6, still more preferably at least about 8, also preferably at least about 10, also preferably at least about 12. The average number of layers of the mesh material covering the surface of the core material of the implement is preferably at most about 40, more preferably at most about 32, more preferably still at most about 25, still more preferably at most about 20, also preferably at most about 16, also preferably at most about 12.

In order for the subject implements to provide good and long-lasting suds generation when used in conjunction with a detergent cleaning solution, many of the outer layers of the mesh material must be readily movable relative to the layers beneath it, over a substantial portion of the surface area of the implement. It is believed that the good sudsing benefit provided by the implement requires that many of the layers of mesh material be movable relative to the layers beneath them, a distance at least about equal to the cell size of the mesh. Such relative movement of the mesh layers can be facilitated by the way the implements are made.

The size and shape of the subject cleaning implements are not critical to achieving the good sudsing characteristics described above. Since the subject cleaning implements are primarily use for hand cleaning of surfaces, especially eating and cooking utensils, it is desirable that the implements be a convenient size and shape for hand use. Many different geometric solid shapes are possible for the implements.

It is also desirable that the subject implements be readily manufactured from commercially available sponge and plastic mesh materials. Sponges can be obtained in most any size and shape. The plastic mesh materials are most conveniently available as tubes of set diameter and indefinite length.

Preferred subject cleaning implements are made using sponge core materials which are approximately rectangular solid in shape. Such core material is preferably surrounded by multiple layers of plastic mesh material, which generally results in a rounding of corners and edges, such that the resulting cleaning implement is pillow- shaped as shown in Figs. 4 and 5.

Cleaning implements of the subject invention are preferably from about 5 cm to about 20 cm long, from about 4 cm to about 15 cm wide, and from about 2 cm to about 10 cm deep. Such pillow-shaped implements are more preferably at least about 7 cm long; more preferably still at least about 9 cm long; and are more preferably at most about 15 cm long, more preferably still at most about 11 cm long. Such implements are more preferably at least about 6 cm wide, more preferably still at least about 7 cm wide; and more preferably at most about 10 cm wide, more preferably still at most about 9 cm wide. Such implements are more preferably at least about 3 cm deep, more preferably still at least about 4 cm deep; and are more preferably at most about 7 cm deep, more preferably still at most about 6 cm deep.

The multiple layers of plastic mesh material which surround the absorbent core material can be accomplished by many different configurations and ways of layering such mesh material. Regardless of how the plastic mesh material is layered around the core material, it is preferable that the layers of mesh material be attached together at intervals, so that the layers are not completely free to move relative to adjacent layers. While some attachment of the layers is desirable, it is preferable that substantial portions of the implement have layers of mesh material which are not attached to one another, in order to achieve the relative movement of the layers needed for the good suds generation described above. To achieve this, it is preferred that point or line bonds be used to attach the mesh material layers together. It is preferred that such bonds be at least about 2 cm apart, more preferably at least about 4 cm apart, more preferably still at least about 5.5 cm apart, still more preferably at least about 7 cm apart, and that they preferably are at most about 20 cm apart, more preferably at most about 15 cm apart, more preferably still at most about 11 cm apart, still more preferably at most about 9 cm apart.

A preferred configuration for the subject implements is to have a number of substantially smooth layers of mesh material surrounding the core material, much like having a number of pillow cases on a single pillow. Such an implement is depicted in Figs. 4, 4A and 4B. Fig. 4 is a perspective view of pillow-shaped implement 50 having top 53, bottom 54, sides 51 and 52, ends 55 and 56, and overall dimensions of length L, width W, and depth D. Fig. 4A is a cross-sectional view of implement 50 taken along line 4A-4A in a plain perpendicular to length L. Fig. 4B is a cross-sectional view of implement 50 taken along line 4B-4B of Fig. 4 in a plain perpendicular to width W.

Figs. 4A and 4B depict sponge core material 40 surrounded by four substantially smooth layers of plastic mesh material 41, 42, 43 and 44. All four layers of mesh material are bonded together by line bonds achieved by heat sealing or adhesive resulting in four seams 45, 46, 47 and 48. Seam 45 runs along the entire length of side 51 from end 55 to end 56 about midway between the top 53 and bottom 54 of implement 50; similarly seam 46 runs along the entire length of side 52. Seam 47 runs along the entire width of end 55 from side 51 to side 52 approximately midway between top 53 and bottom 54 of implement 50; similarly seam 48 runs along the entire width of end 56.

Implement 50 can be made using sponge core material 40 which is substantially a rectangular solid having dimensions slightly smaller than those of finished implement 50. The mesh material used to make implement 50 is preferably taken from tubular-shaped stock mesh material as described hereinabove, the mesh material preferably having a circumference of the tube, when the mesh material is fully-expanded, of approximately 2W+2D (although tubes having larger circumferences can be used). The tubular mesh material is then formed into concentric tubular layers which are substantially smooth, each layer preferably having a length slightly greater than L. This can be done by cutting multiple lengths of the tubular material, each slightly greater than L in length, and placing them one inside the other until the desired number of layers of mesh material (for implement 50, four layers) form the desired number of concentric tubes one inside the other. Alternatively, this layering of concentric tubes of mesh material can be accomplished by turning a length of the tube of mesh material slightly greater than L in length inside out and folding it back over the remainder of the tube and repeating this until the desired number of layers (4 for implement 50) are achieved.

It is convenient to form the multiple layers of mesh over an expansion object (e.g., a wicket or mandrel) which holds the concentric tubes of mesh such that the mesh is fully-expanded. While the mesh is so held in its fully-expanded configuration, it is preferably placed at an elevated temperature for the length of time needed to allow the mesh material to relax, such that it will remain in its fully- expanded state when it is removed from the expansion object. Alternatively, the mesh material could be fully-expanded and relaxed prior to layering it into the concentric tubes.

It is preferred that side seams 45 and 46 bond all the layers of the mesh together, and that they be made after the layers of concentric tubes of mesh are relaxed. (Seams 45 and 46 could be made prior to such relaxation.) The seams can be made by heat sealing the layers of mesh material together or by adhering them together using adhesive. Heat sealing can be achieved by using ultrasonic, or other known methods.

If the circumference of the concentric layers of tubular mesh materials is approximately equal to 2W+2D, the layered tubes are ready for the next step, once side seams 45 and 46 are completed. If this circumference is substantially greater than 2W+2D, seams 45 and 46 can be used to make concentric tubes of mesh having this desired circumference by simply sealing them along the appropriate lines parallel to the length of the tubes, and then cutting off any excess material beyond these seams. To avoid wasting mesh material, it is preferred tubes of mesh material be selected which have circumferences which are approximately an even multiple of the desired circumference (2W+2D) of the implements being made. If the circumference of the mesh is two or more times 2W+2D, concentric tubes of mesh material for two or more implements can be made side by side by making one or more wide sealed seam(s) parallel to the tube length, and cutting along the middle of such seam (or alternatively by making two narrow sealed seams close together and cutting between them).

The procedure described above results in one or more items of concentric layers of tubular mesh material having a circumference, when the mesh is fully expanded, of approximately 2W+2D, and a length slightly greater than L. If side seams 45 and/or 46 protrude or are rougher on the outside of the multiple-layered tube of mesh than on the inside, it is preferable to turn the tube inside out, such that the smoother side of the seams is on the outside. This is because implement 50 is often gripped along sides 51 and 52 when in use, and it is more comfortable to grip a smooth seam.

The rectangular solid core material 40 is now inserted into the multi-layered mesh tube, end first, until it is entirely swrounded by the mesh tube. Side seams 45 and 46 of the mesh tube are preferably aligned with sides 51 and 52 of core 40. Because the length of the multiple-layered mesh tube is slightly longer than that of core 40, core 40 can be situated such that it is entirely within the mesh tube -and end seams 47 and 48 can be made along ends 55 and 56, such that core 40 is entirely encased within the mesh material and implement 50 is completely formed. End seams 47 and 48 can be heat seals or adhesive seals similar to side seams 45 and 46. .Any excess mesh material beyond end seams 47 and 48 is preferably cut away.

It is readily recognized that the multi-layered mesh tubes could be made substantially longer than length L of a single implement, such that two or morp implements could be made from one multi-layered mesh tube.

Another preferred configuration for the subject implements is to have one or more pleated layers of the mesh material surrounding the core material. Such an implement is depicted in Figs. 5, 5 A and 5B. Fig. 5 is a perspective view of pillow- shaped implement 70 having top 73, bottom 74, sides 71 and 72, ends 75 and 76, and overall dimensions of length L, width W, and depth D. Fig. 5 A is a cross- sectional view of implement 70 taken along line 5 A-5 A in a plain perpendicular to length L. Fig. 5B is a cross-sectional view of implement 70 taken along line 5B-5B of Fig. 5 in a plain perpendicular to width W.

Figs. 5A and 5B depict sponge core material surrounded by two pleated layers of plastic mesh material 61 and 62. The pleated layers of mesh material are bonded together by line bonds achieved by heat sealing or adhesive, resulting in four seams 65, 66, 67 and 68. Seam 65 runs along the entire length of side 71 from end 75 to end 76 about midway between top 73 and bottom 74 of implement 70; similarly seam 66 runs along the entire length of side 72. Seam 67 runs along the entire width of end 75 from side 71 to side 72 approximately midway between top 73 and bottom 74 of implement 70; similarly seam 68 runs along the entire width of end 76.

Implement 70 can be made from the same materials as implement 50 of Figs. 4, 4 A and 4B. The primary difference in making implement 70 compared to implement 50, is that the tubular mesh material is gathered into pleats, and two pleated tubular layers of mesh material are placed one inside the other to form concentric pleated tubular layers. The pleats are held permanently in position at seams 65, 66, 67 and 68.

A particularly preferred cellular mesh material useful for making implements 50 and 70 above is Vexar (code no. 940809-1) available from Conwed Plastics, Inc. of Minneapolis, MN. It is made from LDPE, and is a hexagonal open-cell mesh material as depicted in Fig. 2. It has a basis weight of 12 g/m2, a cell size of 5 mm (the dimension between all three parallel strands for each cell being about equal), an average strand count of 1.8/cm, an Initial Stretch Ratio of 3.4, and a Resilience Ratio of 3.9.

The mesh material described in the previous paragraph is relatively soft and is particularly suitable for cleaning dishes and implements where the residue from food being cleaned off the dishes and implements is not tightly bound to their surfaces. This relatively soft mesh material on the outer surface of the subject implements does not provide an implement suitable for hard scrubbing.

A subject invention implement which is somewhat better suited for hard scrubbing can be made by using a mesh material made from a harder plastic, such as HDPE. Somewhat better hard scrubbing is also achieved by using a mesh material having a diamond open-cell configuration with rounded nodes as depicted in Fig. 1.

Materials suitable for scrubbing of hard surfaces which are an open-mesh or open-weave, such that aqueous fluids can pass through them, are known. Such scrubbing materials are typically made of nylon or other tough synthetic, or/and may include metallic strands woven into the scrubbing material. Subject invention implements as described above can have a layer of such hard-scrubbing material as the outer surface of the implement, in order to achieve an implement which provides good sudsing due to the multiple layers of relatively soft open-cell mesh materials which cover the core material, and good scrubbing ability due to the outer layer of such hard-scrubbing material.

The following non-limiting example provides further information regarding the making of implements of the subject invention. It described a process for making an implement such as that shown in Figs. 5, 5 A and 5B.

Example

The particular preferred tube-shaped cellular plastic mesh material described above is used for making the example implements. As received from the manufacturer, the mesh material is substantially completely collapsed in the transverse direction. A length of mesh material weighing 18/g is cut from the stock material; it is about 1.8/m in length. One open end of the mesh tube is slipped over a wire wicket having parallel sides 30 cm apart, thus forcing the mesh material to be fully expanded. When fully expanded, the tube of mesh material has a circumference of 60 cm. The mesh material is bunched or pleated on the wicket, the pleats being substantially parallel to one another, each pleat being about 1 cm to about 3 cm deep. The bunched or pleated mesh material on the wicket is about 13 cm in length. A second 18/g piece of mesh material is cut from the stock material. It is pulled over the same wicket, and is bunched or pleated on top of the first piece of mesh material in a similar manner. (See Figs. 6 and 6A.)

The wicket with the two layers of pleated mesh material on it is placed in a room at 60oC for 15 minutes. This relaxes the mesh material in its fully expanded configuration.

The mesh material on the wicket is removed from the 60oC room, and the layers of mesh material are heat sealed together, using an ultrasonic sealer, along four lines parallel to the length of the mesh tubes (perpendicular to the direction of the pleats). This is depicted in Figs. 6 and 6A. Pleated layers 61 and 62 of mesh material are on wicket 80. Heat seal lines 65 and 85 are made close to the side legs of wicket 80, and heat seal lines 66 and 86 are made close together near the center of the mesh material tubes midway between the legs of wicket 80, This results in two connected, side-by-side, layered, pleated mesh tubes 90 and 91 with open ends 81, 82, 83 and 84.

The mesh material is removed from wicket 80 and cut along a line between the close-together heat seal lines 66 and 86, resulting in two separate mesh tubes which are open at each end. Each of these tubes will be used to make one implement. Excess mesh beyond the heat seals can be trimmed off and discarded. Mesh tube 90 is turned inside out, putting rough heat seals 65 and 66 on the insides of pleated, multi-layered tube 90.

Urethane sponge is used as the core material for the example implement. A rectangular solid piece of urethane sponge about 11.3 cm x 7.5 cm x 2.5 cm is placed in the middle of pleated, layered mesh tube 90, such that the 7.5 cm x 2.5 cm ends of the sponge are perpendicular to (and are seen through) open ends 81 and 82 of mesh tube 90, and heat-sealed seams 65 and 66 along the sides of mesh tube 90 are each about in the middle of, and parallel to, the lengths of the 11.3 cm x 2.5 cm sides of the sponge. If necessary to achieve a good fit, the sponge can be trimmed slightly. Open ends 81 and 82 of pleated, layered mesh tube 90 are heat sealed closed, forming seams 67 and 68 on the two ends 75 and 76 of implement 70, each end seam running from one side seam 65 to the other 66. .Any excess mesh material beyond end seams 67 and 68 can be trimmed off and discarded.

.Another aspect of the subject invention is a kit comprising a container of detergent product along with a subject invention implement. Particularly preferred are such kits wherein the detergent product is a liquid or gel product which is particularly useful for hand cleaning of eating and cooking implements. Such kits include, for example, a bottle of liquid dishwashing detergent with a box containing implement 70 of Fig. 5 attached to the neck of the bottle.

Test Procedure Suds From Scrubbing Test

The test is designed to resemble the direct application method of dish washing. The test is designed to quantitatively determine the amount of suds generated by a dishwashing implement via scrubbing. The quantities of suds generated by different implements can be compared. A measured amount of water is applied to the surface of the implement, followed by a measured amount of liquid dishwashing product. The inside of a beaker is then scrubbed for 25 strokes, using a metronome to pace the strokes. The resulting suds are carefully transferred to a modified graduated cylinder and the suds volume is measured. A measured amount of soil is applied to the implement, and the beaker scrubbing and suds collection steps are repeated. The soil application, scrubbing, suds collection steps are repeated until no more suds are generated. The total amount of suds generated and total number of scrubbing steps during the test is recorded for each implement.

Equipment and Materials:

Implements - to be evaluated by the test.

100 ml graduated cylinder with its base removed and replaced by a mesh-screen cap - the mesh screen cap allows water to escape the cylinder while trapping suds for measurement.

50 ml graduated cylinder - to apply water to the surface of the implement.

3 cc syringe - to inject liquid dishwashing product onto the implement's surface.

1000 ml beaker - for use as the surface on which the implement scrubs.

Liquid dishwashing product - preferably Dawn from the Procter & Gamble Company

Standardized test soil. Procedure:

1. Prior to the start of the test, std. test soil, which is stored in a freezer, is thawed and warmed to about 21°C.

2. Water of desired hardness and temperature is prepared and placed in a water bath to maintain its temperature - 7gpg hardness and 38°C are preferred for the test.

3. Implements to be tested are washed prior to testing in water at the same hardness and temperature as will be used for the test.

4. A metronome is set at 100 bpm.

5. 50 ml of test water is applied to the implement. Next, 2g of dishwashing liquid is applied to the surface of the implement in the same area where the water was applied.

6. Using the metronome to pace the strokes, the inside of the 1000 ml beaker is scrubbed for 25 strokes.

7. The resulting suds are carefully removed from the surface of the implement by lightly scraping it along the edge of the beaker, so that the suds drain into the beaker. The suds are transferred from the beaker to the 100 ml modified graduated cylinder, and the suds volume is measured.

8. Using the same implement, 50 ml test water is added to the same area as before; then 2 ml soil is applied to the same area. The scrubbing, suds collection and suds measurement are repeated.

9. The water addition, soil addition, beaker scrubbing, suds collection, and suds measurement are repeated until no more suds are generated by the scrubbing step.

Results:

A. The total amount of suds collected from all the beaker scrubbing/sud collection sequences is the suds volume for the implement tested. B. The number of scrubbing steps before a suds volume of 0 is reached is the suds mileage for the implement tested.

C. Typically, the procedure is repeated three more times, so that four trials can be averaged for each implement tested.

While particular embodiments of the subject invention have been described, it will be obvious to those skilled in the art that various changes and modifications of the subject invention can be made without departing from the spirit and scope of the invention. It is intended to cover, in the appended claims, all such modifications that are within the scope of this invention.

Claims

WHAT IS CLAIMED IS:

1. A cleaning implement characterized by comprising a resilient absorbent core material snugly surrounded by open-cell plastic mesh material, the plastic mesh material when fully expanded having a basis weight of from 3.4 g/m2 to 34 g/m2 and an average strand count of from 0.8/cm to 20/cm, preferably the basis weight of the mesh material is from 5 g/m2 to 20 g/m2, and the average strand count is from 1.2/cm to 5/cm, more preferably the basis weight of the mesh material is from 8 g/m2 to 12 g/m2, and the average strand count is from 1.4/cm to 3/cm; at least 50% of the surface of the absorbent core material being covered by at least three layers of the mesh material.

2. The implement of Claim 1 characterized wherein the mesh material plastic is selected from the group consisting of low density polyethylene, high density polyethylene, polyvinyl ethylacetate, and mixtures thereof, the plastic having a Melt Index of from about 2 to about 14, preferably the mesh material plastic is low density polyethylene having a Melt Index of from 4 to 10.

3. The implement of Claim 1 or 2 characterized wherein the average number of layers of mesh material covering the surface of the core material is from 4 to 20, with at least 3 layers covering at least 70% of the surface of the core material.

4. The implement of Claim 3 characterized wherein the implement has a geometric solid shape having a length of from 5 cm to 20 cm, a width of from 4 cm to 15 cm, and a depth of from 2 cm to 10 cm; and the layers of mesh material are attached together at seam or point bonds, the bonds having a distance between them on average of from 4 cm to 15 cm.

5. The implement of Claim 4 characterized wherein the average number of layers of mesh material covering the surface of the core material is from 6 to 16.

6. The implement of Claim 1 characterized wherein the average number of layers of mesh material covering the surface of the core material is from 4 to 20, with at least 3 layers covering at least 70% of the surface of the core material; and wherein the mesh material plastic is selected from the group consisting of low density polyethylene, high density polyethylene, polyvinyl ethylacetate, and mixtures thereof, the plastic having a Melt Index of from 4 to 10.

7. The implement of Claim 1, 3 or 6 characterized wherein the implement has an additional outer covering of a mesh material which comprises nylon or metallic fibers.

8. The implement of Claim 1 characterized wherein the mesh material has a cell shape which is hexagonal or diamond; and wherein the mesh material plastic is selected from the group consisting of low density polyethylene, high density polyethylene, polyvinyl ethylacetate, and mixtures thereof, the plastic having a Melt Index of from 2 to 14.

9. The implement of Claim 8 characterized wherein the average number of layers of mesh material covering the surface of the core material is from 4 to 20, with at least 3 layers covering at least 70% of the surface of the core material; and wherein the mesh material plastic is low density polyethylene having a Melt Index of from 4 to 10.

10. A kit characterized by comprising a container of detergent product, and an implement of any one of the preceding Claims.