FLOOR SANDING SPONGE PADS

RELATED APPLICATION

This application is a claims the benefit of U.S. Provisional Application No. 61/068,619, filed on March 7, 2008. The entire teachings of the above application(s) are incorporated herein by reference.

BACKGROUND OF THE INVENTION

Floors are finished with a variety of materials to protect the surface from physical or chemical damage. The process of finishing a floor often requires the several sequential applications of coating material. To adequately protect the floor surface, the coating contains chemicals that, once cured, repel or prevent other chemicals from directly contacting and damaging the floor surface. However, this repellent property of the coating material can make intercoat adhesion in the subsequent applications of the coating difficult. Mechanical abrasion therefore is necessary to ensure proper adhesion of additional coating applications. Additionally, intercoat abrasion is utilized to remove grain raise, bubbles, and other debris that may have dried into the surface of the coating. Abrasion is most commonly accomplished via sanding with fine grain paper.

Intercoat abrasion is a process for providing a consistent scratch pattern that will ensure adherence of subsequent coating layers, but not diminish the overall appearance of the floor surface. Ideally, the intercoat abrasion step will produce fine scratches that will promote bonding between applied coats, but will not be visible following the application of subsequent coats.

Currently, intercoat abrasion is performed by using a nylon non-woven pad in conjunction with a coated abrasive that is attached to the non-woven pad via either a pressure sensitive adhesive or a hook-and-loop attachment. Alternatively, a sanding screen can be used. However, using two products in combination is problematic. The result of a combination of two products may not be obvious based upon the function of each product used separately, creating several issues for the user. First, the use of two products in conjunction requires the proper initial selection of each individual product. However, variables such as floor type, finish, and equipment used prevents a straightforward combination of the two products. In addition, the number of coated abrasive strips to be added to the pad may not be readily apparent to the user. Another issue with the current products and methods is the inadvertent scratching from the swarf being trapped between the equipment and floor.

Therefore, there is a need for a product and method for abrading the intercoat layers during floor finishing, which can reduce or eliminate one or more of the above-mentioned problems.

SUMMARY OF THE INVENTION

The present invention generally relates to floor sanding sponges, and to methods using such floor sanding sponge products.

A floor sanding sponge comprising at least one abrasive surface supported by a porous backing, wherein the abrasive surface defines openings that provide, in conjunction with the porous backing, fluid communication from the abrasive surface through the porous backing to an opposite side of the sponge. In another embodiment, the abrasive surface and the porous backing define coterminous openings.

The porous backing includes either an open or closed cell foam material. In another embodiment, the foam material can be either a polyurethane or a polyethylene. In another embodiment, the porous backing includes a laminated scrim, which can be a flame laminated scrim.

An abrasive article backing surface can be used to fix the abrasive article to the porous backing. In one embodiment, an adhesive can be used to attach the

abrasive surface to the porous backing. In another embodiment, a hook-and-loop fastener can be used to attach the abrasive surface to the porous backing.

The sponge includes at least one adhesive surface. In another embodiment, the sponge includes two abrasive surfaces, each abrasive surface being on an opposite side of the sponge. In another embodiment, at least one abrasive surface of the sponge defines a pattern. The abrasive surface includes at least one abrasive component that is selected from the group consisting of 60 grit, 80 grit, 100 grit, 150 grit and 180 grit.

In one embodiment, the sponge has a circular shape, and has a diameter in a range of between, for example, about 12 inches and about 20 inches. In yet another embodiment, the sponge has a diameter in a range of between about 15 inches and

18 inches.

A method for sanding a floor includes abrading a surface with a floor sanding sponge having at least one abrasive surface supported by a porous backing, wherein the abrasive surface defines openings that provide, in conjunction with the porous backing, fluid communication from the abrasive surface through the porous backing to an opposite side of the sponge.

In another embodiment, the surface being abraded has a floor treatment. In another embodiment, the floor treatment is a urethane. In one embodiment of the method, the surface is abraded by manually directing the floor sanding sponge across the surface. In another embodiment, the surface is abraded by automated abrasion of the surface.

Many benefits result in the floor sanding sponge disclosed herein. First, the floor sanding sponge disclosed herein will perform the duty of both the nylon non- woven pad/coated abrasive in one product. Second, the sponge material provides a compliancy or "give" to the sanding product that allows the grain to push up into the foam instead of into the flooring, providing a softer and finer scratch pattern, resulting in better appearance of the floor surface. Another advantage, the sponge pad can be rinsed out and reused, prolonging the life of the product. In addition, the vacuum hole configuration allows more efficient sanding dust removal, preventing inadvertent scratching and undesired shorting the lifetime of the abrasive material.

BRIEF DESCRIPTION OF THE DRAWINGS

The Figure is a plan view of one embodiment of a floor sanding sponge of the invention.

DETAILED DESCRIPTION OF THE INVENTION The floor sanding sponge pads (also referred to as "sponge pads") of the invention are designed to sand both raw (unfinished) or treated (finished with stain, sealer, polyurethane, etc.) floors in order to smooth out the surface roughness, but still apply a sufficient surface texture to allow the subsequent application of finish to properly adhere. In one embodiment, the sponge pads use a foam sponge base that is coated on both sides with abrasive grain. In another embodiment, the sponge pads can be cut into specific shapes, mainly discs, but sometimes sheets, and used in conjunction with floor sanding machines to perform the sanding application.

As used herein "porous backing" is derived from solid foam material. Foam materials can be classified as either "open cell" or "closed cell" based on pore structure. Open cell foams contain pores that are connected to each other and form an interconnected network, with air filling the spaces in the material. Closed cell foams do not have interconnected pores. Normally the closed cell foams have higher compressive strength due to their structures. In one embodiment the foam is bun stock and roll stock open cell polyurethane. In an alternative embodiment, closed cell polyethylene is used for the foam material.

Abrasive particles or agglomerates of abrasive particles useful in the invention can be of any conventional abrasive material utilized in the formation of abrasive products. Examples of suitable abrasive materials for use in the invention include diamond, corundum, emery, garnet, chert, quartz, sandstone, chalcedony, flint, quartzite, silica, feldspar, pumice and talc, boron carbide, cubic boron nitride, fused alumina, ceramic aluminum oxide, heat treated aluminum oxide, alumina zirconia, glass, silicon carbide, iron oxides, tantalum carbide, cerium oxide, tin oxide, titanium carbide, synthetic diamond, manganese dioxide, zirconium oxide, and silicon nitride. The abrasive materials can be oriented or can be applied to the substrate without orientation (i.e., randomly), depending upon the particular desired properties of the coated abrasive tools. In choosing appropriate abrasive particles or

agglomerates of abrasive particles, characteristics, such as size, hardness, compatibility with workpieces and heat conductivity, are generally considered. Abrasive particles or agglomerates of abrasive particles useful in the invention typically have a particle size ranging from about 0.1 micrometer and about 1,500 micrometers, such as from about 10 micrometers to about 1000 micrometers.

"Abrasive article backing surface," as that phrase is used herein, refers to a backing surface to which an abrasive article can be fixed. The abrasive article backing surface can be, for example, a plain surface, a gripping surface, such as, e.g.., a hook-and-loop system, or an adhesive surface. The abrasive article backing surface can be adapted for affixation to a particular style of abrasive article. Thus, in one embodiment, an abrasive article includes a hook or loop fastener component and the abrasive article backing surface includes a compatible hook or loop fastener component. In another embodiment, roller coating is used to adhere the abrasive material to the foam material with a paint roller. In an alternative embodiment, antiloading composition (also known as a no fill) coating and proprietary grains can be added to the sponge pad. Examples of antiloading compositions are describe in more detail in the U.S. Patent No. 7,195,658 and US. Patent Application Serial Nos. 11/492,614, 11/726,848 and 1 1/726,849, which are incorporated herein by reference. In one embodiment, the abrasive article backing surface defines a plurality of openings in conjunction with the porous backing. The term "opening," as used herein, refers to an opening such as hole, for example, a circular, rectangular, triangular, or ring-shaped opening. For example, the openings can be arc-shaped. The openings defined by the abrasive article backing surface can be symmetrically arranged about the abrasive article backing surface. The backing surface can include openings generally symmetric about one or more axes of symmetry. For example, a disc-shaped abrasive article backing surface can include openings (e.g., circular, rectangular, triangular, ring-shaped, elongated, or arc- shaped openings) that can be generally radially symmetric. A rectangular backing surface could include openings generally symmetric about, for example, a longitudinal axis of symmetry.

The abrasive surface defines openings that provide, in conjunction with the porous backing, fluid communication from the abrasive surface through the porous

backing to an opposite side of the sponge. Preferably, the openings are configured such that swarf produced during an abrasion process can be effectively transported through the abrasive article backing surface's openings to reach a support tool's dust extraction system. The shape of the sponge may be modified to conform to the restraints of the drivers utilized by the particular floor sander. The sponge made can be cut to conform to any size drive pad being used in the method. In one embodiment, the sponge may be circular. In another embodiment, the diameter may range from 15 inches to 20 inches. In another embodiment, the diameter of the sponge is 16 inches.

The floor sanding sponges will work with pad drivers known in the art. Said pad drivers can be thin non -woven pads attached to the drive pad assembly via small hooks. The floor sanding sponges can be attached to the pad drivers and held in place by the weight of the machine. Vacuum holes can be stamped into the sponge to aid in dust collection, although sponges can be used without vacuum holes. The holes provide a place for excess sanding dust to collect. The floor sander is then equipped with a dust shroud that encompasses drive pad to contain the dust and a dust port to allow attachment to a vacuum. In one embodiment, the vacuum holes allow the dust to be removed from the sanding surface through the dust collection of the internal or external sanding machine. In another embodiment, the swarf removal can be facilitated by vacuum hole design and grain application.

In another embodiment, a laminated scrim is attached to one side of the sponge to give the foam material extra strength. In another embodiment, the laminated scrim material is flame laminated scrim.

A "floor treatment" refers to the coating of a floor surface with stain, sealant, or other such material that would protect the floor from chemical and physical damage. In one such embodiment, a floor treatment can be a wax, urethane or polyurethane coating. The method of this invention is designed to work in conjunction with either rotary or orbital floor sanders. The floor sanding sponge disclosed in this method can be adapted for use on any machine regardless of motor type. Any machine specifically designed for floor sanding applications can be used with the floor

sanding sponge of this invention. The sponge is designed to work in situations where an abrasive screen or non-woven pad would be abrading coats of finish on wood floors.

The Figure depicts one embodiment of a floor sponge pad of the invention, where the floor sponge pad is cut into a disc 10 and arc-shaped openings 12 are radially stamped into the sponge material.

EXEMPLIFICATION

The following non-limiting examples represent various embodiments of a floor sanding sponge pad of the invention and methods to use the floor sanding sponge pads.

Example 1

A %" foam from Rempac Foam Corporation (Clifton, New Jersey) is covered with aluminum oxide (A/O) abrasive grain. The grain is applied to the 1/4" foam by using gravity to coat a resin system that locks the grain in place. The material is then cut into a 16" disc with six dye-cut vacuum holes. The vacuum holes allow the finish dust that is sanded off the floor to be collected by the vacuum system on the buffer.

Example 2

Materials. Sol-Gel (SG) coated, A/O coated between coat pads. Grits tested were 100 grit for the SG, and 100, 120, 150 and 180 grit for the A/O. Testing was conducted using a standard 16" diameter rotary floor buffer, equipped with dust collection. Products tested were compared against existing pad and coat system of Norton 16' Maroon Conditioning Pad part #6626100020566 and Norton Aluminum Oxide Pressure Sheet Rolls (PSA) in 150, 180 and 220 grit.

Floor Sanding Method. The floor sanding sponge was used on a test floor of approximately 400 square feet. The floor was sanded, stained, and finished with two coats of Lenmar Rapid Seal Polyurethane, and two coats of BonaKemi Mega water- based urethane. The floor was divided into several sections to test each product by abrading after each coat of finish was applied. The products were then evaluated after each section was abraded, and after each coat of finish was applied.

Product Evaluation. The products were evaluated on loading (comparison to the PSA); smoothness (ability to remove grain raise, bubbles, hairs, and debris from the previous coat of finish); aggressiveness (ability to abrade the finish without removing too much finish or cutting through the finish and sanding through the stain); and scratch pattern (quality of scratch pattern).

Conclusion. Both the SG and A/O products performed extremely well in all areas of evaluation. All products had minimal loading and were comparable to the PSA Sheet Roll.

The SG pad in 100 grit and the A/O pads in 100 and 120 grit performed best in abrading sealer coats of finish, which tended to require the removal of more bubbles, debris, and raised wood fibers. The SG pad was the most aggressive; removing the most finish of all the products tested; yet still left a fine scratch pattern, and did not cut through the finish or stain. The A/O pads in 150 and 180 grit performed best on the finish coats where there was minimal debris to remove, the least amount of finish was removed, and the finest scratch pattern was required. Multiple areas in the floor consisted of high spots and overwood. While these areas would typically be prone to cutting through the finish or stain, neither the SG nor A/O products in any of the grits tested cut through the finish in these areas. All the products left a very fine scratch pattern, and no highlighted scratches or swirls were visible following finish coat application. Even though the finish had been abraded with multiple grits in different sections, the finish appeared uniform across its entirety.

Example 3 Materials. SG coated in 60 and 100 grit, A/O coated between coat pads in

100 and 120 grit. Testing was conducted using a standard 16" floor buffer.

Floor Sanding Method. The floor sanding sponge was used on a test floor with an existing polyurethane finish that was approximately 15 years old. Four separate areas of 100, 150, 150, and 200 square feet were tested. The two 150 square feet areas were rated as in poor condition, with paint spills, deep scratches, and heavily worn areas throughout. The 100 and 200 square foot areas were in fair condition and contained areas of normal wear and scratching. The floors were sanded, stained, and finished with two coated of BonaKemi Mega Semi-Gloss

urethane. The products were then evaluated after each section was abraded, and after each coat of finish was applied.

Conclusion. Thee 100 and 120 grit A/O pads were used in the 100 and 200 square feet areas, respectively, and both performed well. Both pads removed surface scratches and left behind a fine scratch pattern, without wearing out. The 60 and 100 grit SG pads were used in the two 100 square feet areas. Both also left a fine scratch pattern while removing the paint stains, deep scratches, and worn spots, without wearing out. The finish was uniform throughout the four areas, although each area had been abraded with different grits in each room. EQUIVALENTS

While this invention has been particularly shown and described with references to example embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims.