Abstract:
Provided is a nonwoven surface preparation or cleaning material comprising melamine fibers and a process for preparing the material. The nonwoven material, in one embodiment, comprises from 20 to 100% by weight melamine fibers. Other synthetic and natural fibers can be used in conjunction with the melamine fibers. However, it is the melamine fibers which are important, and the actual amount can be varied based on the nature of the surface to be cleaned, cleaning difficulty and material cost.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to U.S. provisional application Ser. No. 61/755,201, filed Jan. 22, 2013 and 61/889,803, filed Oct. 11, 2013, which applications are incorporated herein by reference. To the extent appropriate, a claim of priority is made to each of the above disclosed applications. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to nonwoven surface preparation and cleaning materials. More specifically, the present invention relates to nonwoven surface preparation and cleaning materials comprising melamine fibers. 
         [0004]    2. Related Art 
         [0005]    Nonwoven cleaning pads are well known. For example, U.S. Pat. No. 1,852,114 discloses a renewable surface dust cloth that is composed of a plurality of thin, fibrous, loosely compacted layers. 
         [0006]    U.S. Pat. No. 8,152,929 describes cleaning a surface by rubbing the surface with a non-abrasive fabric comprised of a multitude of nonwoven polyester fibers which are bound together in the form of a sheet with a binder. The binder consists of an ethylene-vinyl chloride copolymer. The nonwoven polyester fibers have a diameter which is within the range of from 10 micrometers to about 50 micrometers. The polyester fibers can be polyethylene terephthalate fibers or polyethylene naphthalate fibers. 
         [0007]    The use of lofty, fibrous, nonwoven abrasive products for scouring surfaces such as the soiled surfaces of pots and pans is also well known. These products are typically lofty, nonwoven, open mats formed of fibers which are bonded together at points where they intersect and contact each other. 
         [0008]    U.S. Pat. No. 5,458,962 describes a flexible and resilient, fibrous surface treating article comprising an open, lofty, nonwoven fibrous web formed of entangled fibers bonded together at points where they contact one another by a binder. The binder generally comprises a copolymer of an acrylate monomer and an acrylamide monomer, a crosslinked reaction product of a polyol and a melamine crosslinking-agent, and a reaction product of a urea derivation and formaldehyde. 
         [0009]    Low-density abrasive products can be formed of randomly dispersed staple fibers which are bonded together at points of contact with a binder that contains abrasive particles. The staple fibers typically have been crimped and are laid down by equipment such as a “Rando Webber” web-forming machine (marketed by the Curlator Corporation of Rochester, N.Y. and described in U.S. Pat. Nos. 2,541,915; 2,700,188; 2,703,441 and 2,744,294) to form a lofty open mat. One very successful commercial embodiment of such an abrasive product is that sold under the trade designation “Scotch-Brite” by the 3M Company of St. Paul, Minn. Low-density abrasive products of this type can be prepared by the method disclosed by Hoover et al in U.S. Pat. No. 2,958,593. 
         [0010]    The low-density abrasive products described above may also be formed of webs or mats of continuous fibers. For example, in U.S. Pat. No. 4,227,350, Fitzer discloses a low-density abrasive product comprising a uniform cross-section, generally flat-surfaced, open, porous, lofty web of autogenously bonded, continuous, undulated, interengaged filaments. The web of Fitzer is formed by downwardly extruding a plurality of thermoplastic organic filaments into a quench bath. As the filaments enter the quench bath, they begin to coil and undulate, thereby setting up a degree of resistance to the flow of the molten filaments, causing the molten filaments to oscillate just above the bath surface. The spacing of the extrusion openings from which the filaments are formed is such that, as the molten filaments coil and undulate at the bath surface, adjacent filaments touch one another. The coiling and undulating filaments are still sufficiently tacky as this occurs, and, where the filaments touch, most adhere to one another to cause autogenous bonding to produce a lofty, open, porous, handleable filament web. The web, so formed, is then impregnated with a tough binder resin which adherently bonds the filaments of the web together and also bonds a multitude of abrasive granules, uniformly dispersed throughout the web, to the surface of the filaments. 
         [0011]    Additionally, fibrous polishing and/or abrading materials can be prepared from continuous or substantially continuous synthetic filaments by the method disclosed by Zimmer et al. in U.S. Pat. No. 3,260,582. In this method crimped or curled continuous filaments are straightened out under tension into a substantially parallel relationship with one another, uniformly coated while under tension, with an adhesive which may or may not contain abrasive particles, interlocked one with another by release of such tension and then set in a permanently interlocked and lofty, open, three-dimensional state by curing or setting up the adhesive. 
         [0012]    U.S. Pat. No. 5,025,596 describes a low-density nonwoven abrasive pad for scouring surfaces. The pad is comprised of a multiplicity of continuous, crimped thermoplastic organic filaments. The pad is made by arranging the filaments into an open lofty array, bonding substantially all of the filaments together at a first and second bond site, and then cutting the array at the bond sites such that each bond is divided into at least two bond area segments with each bond area segment having the filament array bonded therein in a unitary structure. 
         [0013]    Another type of cleaner is a foam-like material consisting of a formaldehyde-melamine-sodium bisulfite copolymer known as melamine foam. It is a component of the commercial Magic Eraser® cleaning product. The open cell foam is microporous and its polymer substance is very hard, so that when used for cleaning it works like extremely fine sandpaper, getting into tiny grooves and pits in the object being cleaned. On a larger scale, the material feels soft. However, if the surface being cleaned is not sufficiently hard, it may be finely scratched by the melamine material. The foam wears away, rather like a pencil eraser, leaving behind a slight residue. 
       SUMMARY OF THE INVENTION 
       [0014]    Provided is a nonwoven surface preparation or cleaning material, e.g., a floor buffing pad, polishing pad or a wipe, comprising melamine fibers. The nonwoven surface preparation or cleaning material, in one embodiment, comprises from 20 to 100% by weight melamine fibers. Other synthetic and natural fibers can be used in conjunction with the melamine fibers. However, it is the melamine fibers which are important, and the actual amount can be varied based on the nature of the surface to be cleaned, the cleaning difficulty expected, and the material cost. 
         [0015]    In one embodiment, there is provided a method for preparing the nonwoven cleaning material. The process comprises the steps of carding melamine fibers with a carding machine and then hydroentangling the carded melamine fibers. The carding machine is a particular carding machine that has no main roll cylinder, only a number of smaller cylinders. This type of carding machine reduces breakage of the melamine fibers and results in a much better cleaning material. In another embodiment, the method for preparing the nonwoven material comprises carding and then needlepunching a web comprising melamine fibers. In another embodiment, the method for preparing the nonwoven material comprises wetlaying the melamine fibers, generally in combination with other fibers. 
         [0016]    Among other factors, the present invention is based upon the recognition that melamine fibers can be successfully used in a surface preparation or cleaning material, such as a pad or wipe, with excellent results. The material can be effectively and efficiently made using a number of methods, such as a spunlace nonwoven process or a needlepunch process. The cleaning material need only be wet with water to provide an effective cleaner of dirt, soap scum, etc. No other cleaning chemicals are required, but can be used as desired. The cleaning material can be free of surfactants, cleaning detergents and binders. Such melamine fiber cleaning materials are significantly lower in cleaning cost, per use and are even more durable than melamine foam block cleaners. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURE OF THE DRAWING 
         [0017]    The FIGURE of the drawing illustrates a card configuration for carding melamine fibers in the preparation of a nonwoven melamine fiber cleaning material in accordance with the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0018]    The invention relates to a cleaning or surface preparation substrate containing melamine fibers combined with other fibers in a spunlace needlepunch or wet laid nonwoven process. Fibrous melamine is well suited for use in a wide variety of surface preparation, scrubbing, cleaning and wiping applications including household, janitorial, food service, industrial, medical, dental, automotive, flooring or any other end uses where a pliable and effective removal or cleaning substrate is needed. While this substrate can be produced from a variety of fabric formations including airlaid, wetlaid, stitch bond, melt blown and others, a preferred needlepunch nonwoven configuration comprises melamine fibers blended with fibers like viscose rayon, Tencel®, polyester, nylon, wood pulp, polypropylene, bicomponents and others. 
         [0019]    Melamine is an organic base and a trimer of cyanamide, with a 1,3,5-triazine skeleton. Melamine fiber is a manufactured fiber in which the fiber-forming substance is a synthetic polymer composed of at least 50% by weight of a cross-linked melamine polymer. Melamine fibers are commercially available from Basofil® of North Carolina. Melamine fiber is a heat resistant fiber based on melamine chemistry, with a 400° F. (200° C.) continuous operating temperature. Typical fiber lengths are in the 5-100 mm range and the average diameter is about 15 μm. For a spunlace or needlepunch nonwoven configuration, the fiber length is generally in the 25-100 mm range, most commonly around 50 mm. Fiber lengths can be supplied in the range of from 5-25 mm average length, which are more suitable for wetlaid and airlaid processing. 
         [0020]    The present invention relates to a cleaning material or substrate containing melamine fibers. Generally, the cleaning material comprises from 20-100 wt % melamine fibers, e.g., from 20 to 80 wt % melamine fibers. In one embodiment, the cleaning material comprises from 30-70 wt % melamine fibers, e.g., from 40 to 60 wt % melamine fibers. The melamine fibers can be combined with other fibers. The other fibers can include rayon, Tencel®, bicomponent, polyesters, woodpulp, polyolefins such as polypropylene, cotton, jute, bamboo or nylon fibers. In one embodiment, the cleaning material comprises 50 wt % melamine fibers and 50 wt % polyester fibers. In another embodiment, the cleaning material comprises 50 wt % melamine fibers, 30 wt % viscose fibers and 20 wt % polyester fibers. In another embodiment, the cleaning material comprises 20 wt % melamine fibers, 30 wt % weight viscose fibers and 50% by weight polyester fibers. In another embodiment, the cleaning material comprises 65 wt % melamine fibers and 35 wt % cellulose (e.g., viscose fiber, etc.). In another embodiment, the cleaning material comprise 65 wt % melamine fiber, 25 wt % cellulose (e.g., viscose fiber, etc.) and 10 wt % polyester fiber. 
         [0021]    In one embodiment, the outer surface of the cleaning material has a visual texture or pattern that may provide an aesthetic and/or functional benefit for a user. One functional benefit that may be provided by the pattern is to improve surface preparation or the cleaning efficacy of the material. Examples of suitable visual patterns include, but are not limited to, dots, dashes, wavy lines and herringbone lines. 
         [0022]    The basis weight of the nonwoven cleaning material, e.g., pad or wipe, is generally in the range of about 20-1200 g/square meter. This is suitable for spunlace, airlaid, needlepunch, wetlaid or other fabric formation technologies. In one embodiment, the nonwoven material has a basis weight in the range of from 40-150 g/square meter, e.g., 40-110g/square meter, which is quite suitable for spunlace and wetlaid configurations. In another embodiment, the nonwoven material has a basis weight in the range from 70-1200 g/square meter, or 300-600 g/square meter, or 800-1200 g/square meter, which basis weights are quite suitable for needlepunched configurations. 
         [0023]    Melamine fibers are the critical ingredient that delivers unique surface preparation or cleaning properties. Prior to use, the invention needs only to be wet with water to provide an effective cleaner of dirt, soap scum, rust, baked on food, and other soils from surfaces like glass, tile, metal, wood, vinyl, etc. No other cleaning chemicals are required but may be combined with the invention cleaning material to further enhance cleaning of certain surfaces. Many conventional “wet” wipes are pre-moistened with surfactants and detergents to enhance cleaning “Dry” wipes are often used in conjunction with a chemical cleaner at the point of application. The invention can eliminate the need and cost of the aqueous cleaning chemicals, their packaging and transportation. However, they can also utilize such added chemicals if desired. 
         [0024]    Melamine fiber substrates are also significantly lower in cleaning cost/use and are more durable than melamine foam block cleaners. Therefore, the invention can save money at initial purchase and over the useful cleaning life of the product. 
         [0025]    While melamine has been blended with rayon, wood pulp, bicomponents and polyesters to date, melamine fiber may also be blended with various synthetic and cellulosic fibers like: polypropylene, cotton, jute, bamboo, nylons and others to enhance absorbency, resiliency, compression resistance, thickness, softness, toughness, strength, abrasion resistance and other properties. The critical melamine fiber component has shown good cleaning and surface enhancement properties with as little as 20% by weight of the blend. Samples can be made with up to 80%, and even 100% melamine fibers. Outside active layers comprising 100% melamine fibers have been successful in layered materials. 
         [0026]    Among the polyolefins, polyethylene and polypropylene fibers are quite suitable. Among the polyesters, polyethylene terephthalate (PET), polybutylene terephthalate (PBT) and/or polypropylene terephthalate (PPT) are quite suitable. 
         [0027]    A spunlace nonwoven configuration is one preferred for the cleaning material. The spunlace nonwoven configuration is of particular applicability to a wipe cleaning material. The method of preparing the spunlace nonwoven involves carding the melamine fibers with a carding machine, followed by hydroentangling the fiber. 
         [0028]    Since carding melamine fibers can be quite difficult at normal production rates, a process for producing a lightweight, nonwoven web containing a high percentage of melamine fibers is used. This process requires a specific carding configuration whereby no main carding cylinder is used. This process reduces melamine fiber breakage as demonstrated by the retention of the average fiber length even when 50% melamine is used in the blend. 
         [0029]    What is provided is a process for producing a web containing high % levels of a melamine fiber (e.g., from Basofil®) and a broad range of products that can be produced from such materials. The product made from melamine fibers has some unique properties related to surface preparation, cleaning and wiping, however the fiber production process produces a fiber which can be very difficult to process through conventional means. Described below is one manner in which a hydroentangled version of this product can be produced, and exemplary product formulations. 
         [0030]    Melamine fiber through its production process has a wide range of fiber length and can be quite brittle, consequently the fiber can be very difficult to process. Accordingly the conditions under which such a fiber can be carded and hydroentangled at high speeds are consequently quite unique. Products were produced using a very specific card arrangement (see  FIG. 1 ) whereby no main carding cylinder is utilized. 
         [0031]    An example of such a card machine is the Erko EWK 413. This card configuration allows for a limited reduction in the fiber length of the melamine fiber, with a before carding average fiber length of about 41 mm and an after carding average fiber length of about 38 mm for a 50% melamine fiber material. 
         [0032]    This card type has no main roll cylinder, instead it has a number of small cylinders. Consequently, there are significantly less worker and stripper rolls used and there is much less working of the fibers to open them. This dramatically reduces breakage of the melamine fiber. The roll speeds are lower on this card configuration once again leading to less damage of the melamine fiber, but also to less flying fibers in the card as a whole. The clearances between rolls are generally wider on this card configuration. The wire clothing used is the same as that used on cotton cards which means the teeth are much less aggressive again meaning less breakage of the relatively brittle melamine fiber. 
         [0033]    In one example, the carding and hydroentangling of the melamine fiber was carried out with the following basic formulations: 
         [0034]    50% melamine—30% Viscose—20% PET at a basis weight of 50 gsm and 100 gsm 
         [0035]    20% melamine—30% Viscose—50% PET at a basis weight of 50 gsm and 100 gsm 
         [0036]    The hydroentangling conditions involved waterjet hydroentangling. The finished product properties for these webs are provided below. 
         [0000]    
       
         
               
               
               
               
               
             
               
               
               
               
               
             
           
               
                   
               
               
                   
                   
                   
                 BW 
                 MD TS 
               
               
                 BW 
                 BLEND 
                 STRUCTURE 
                 (g/m 2 ) 
                 (N.5 cm) 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 50 
                 50% Melamine/30% 
                 Big Dot 
                 53.4 
                 58.45 
               
               
                   
                 VIS/20% PET 
               
               
                 100 
                 50% Melamine/30% 
                 Big Dot 
                 108.5 
                 138.6 
               
               
                   
                 VIS/20% PET 
               
               
                 50 
                 20% Melamine/30% 
                 Big Dot 
                 51 
                 60.8 
               
               
                   
                 VIS/50% PET 
               
               
                 100 
                 20% Melamine/30% 
                 Big Dot 
                 106 
                 143.3 
               
               
                   
                 VIS/50% PET 
               
               
                   
               
             
          
         
       
     
         [0000]    
       
         
               
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
             
           
               
                   
               
               
                 MD Elong 
                 MD TS 
                 MD Elong 
                 CD TS 
                 CD Elong 
                 CD TS 
                 CD Elong 
                 Thickness 
                   
               
               
                 @Max (%) 
                 (N.5 cm) 
                 @Max (%) 
                 (N.5 cm) 
                 @Max (%) 
                 (N.5 cm) 
                 @Max (%) 
                 @ 0.5 kPa 
                 Absorption 
               
             
          
           
               
                 DRY 
                 WET 
                 DRY 
                 WET 
                 (mm) 
                 Capacity (%) 
               
               
                   
               
             
          
           
               
                 25..7 
                 46.95 
                 33.42 
                 15.93 
                 106.8 
                 16.59 
                 107 
                 0.9 
                 1347 
               
               
                 33.19 
                 110.2 
                 38.26 
                 28.44 
                 96.06 
                 29.13 
                 97.57 
                 1.45 
                 1100 
               
               
                 43.64 
                 54.64 
                 47.87 
                 20.79 
                 122.2 
                 19.06 
                 119.9 
                 1.01 
                 1535 
               
               
                 36.41 
                 132.4 
                 41.55 
                 32.08 
                 113.7 
                 34.75 
                 108 
                 1.45 
                 1100 
               
               
                   
               
             
          
         
       
     
         [0037]    In another example, the following spunlace nonwoven samples were prepared using the carding and hydroentangling method described above. 
         [0000]    
       
         
               
             
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
             
           
               
                   
               
               
                 Spunlace Nonwoven Samples 
               
             
          
           
               
                   
                 Basis 
                 % 
                   
                   
                 Hydro 
                   
               
               
                 Sample 
                 Weight 
                 Mela- 
                 % 
                 % 
                 entangling 
               
               
                 No. 
                 (GSM) 
                 mine 
                 Rayon 
                 Polyester 
                 pressure 
                 Pattern 
               
               
                   
               
             
          
           
               
                 1 
                 40 
                 50 
                   
                 50 
                 Standard 
                 Smooth 
               
               
                 2 
                 50 
                 50 
                 30 
                 20 
                 Standard 
                 Big dot 
               
               
                 3 
                 100 
                 50 
                 30 
                 20 
                 Standard 
                 Big dot 
               
               
                 4 
                 50 
                 20 
                 30 
                 50 
                 Standard 
                 Big dot 
               
               
                 5 
                 100 
                 20 
                 30 
                 50 
                 Standard 
                 Bid dot 
               
               
                 6 
                 100 
                 50 
                 30 
                 20 
                 Standard 
                 Natural 
               
               
                 7 
                 70 
                 50 
                 35 
                 15 
                 Standard 
                 Big dot 
               
               
                 8 
                 70 
                 50 
                 35 
                 15 
                 High 
                 Herring- 
               
               
                   
                   
                   
                   
                   
                   
                 bone 
               
               
                 9 
                 70 
                 65 
                 35 
                 — 
                 Standard 
                 HB 
               
               
                 10 
                 70 
                 65 
                 35 
                 — 
                 High 
                 HP 
               
               
                 11 
                 100 
                 65 
                 35 
                 — 
                 High 
                 BD 
               
               
                 12 
                 100 
                 65 
                 35 
                 — 
                 Standard 
                 HB 
               
               
                 13 
                 100 
                 50 
                 50 
                 — 
                 High 
                 HB 
               
               
                 14 
                 100 
                 50 
                 50 
                 — 
                 Standard 
                 BD 
               
               
                 15 
                 70 
                 65 
                 35 
                 — 
                 Standard 
                 BD 
               
               
                 16 
                 70 
                 65 
                 35 
                 — 
                 Standard 
                 HB 
               
               
                 17 
                 70 
                 65 
                 25 
                 10 
                 Standard 
                 BD 
               
               
                 18 
                 70 
                 65 
                 25 
                 10 
                 Standard 
                 HB 
               
               
                   
               
             
          
         
       
     
         [0038]    A needlepunch nonwoven configuration is also a preferred configuration for the cleaning material. This configuration finds particular applicability for surface preparation or scrubbing pads. The needlepunch nonwoven configuration is prepared by carding and needlepunching a fibrous web comprising melamine fibers. Layers of fibers, comprising the same or different fibers, can also be needlepunched to create the nonwoven cleaning material. The needling can be from one side or both sides of the nonwoven. 
         [0039]    In one example the following needlepunch samples were prepared by intimately blending, carding and needlepunching fibers, as indicated in the Table below. The Table indicates the composition of the nonwoven webs for each sample, Nos. 1-9. 
         [0000]    
       
         
               
             
               
               
               
               
               
               
               
               
             
           
               
                   
               
               
                 Needlepunch Nonwoven Samples (Intimate Blend) 
               
             
          
           
               
                 Sam- 
                 Basis 
                 % 
                 % 
                   
                   
                   
                   
               
               
                 ple 
                 Weight 
                 Mela- 
                 Ray- 
                 % 
                 &amp; 
               
               
                 No. 
                 (GSM) 
                 mine 
                 on 
                 Polyester 
                 Bico 
                 Needling 
                 Structure 
               
               
                   
               
               
                 1 
                 850 
                 50 
                   
                 35 
                 15 
                 Light 
                 Intimate 
               
               
                   
                   
                   
                   
                   
                   
                   
                 blend 
               
               
                 2 
                 850 
                 65 
                   
                 20 
                 15 
                 Light 
                 Intimate 
               
               
                   
                   
                   
                   
                   
                   
                   
                 blend 
               
               
                 3 
                 850 
                 65 
                   
                 20 
                 15 
                 Standard 
                 Intimate 
               
               
                   
                   
                   
                   
                   
                   
                   
                 blend 
               
               
                 4 
                 850 
                 65 
                 25 
                   
                 10 
                 Standard 
                 Intimate 
               
               
                   
                   
                   
                   
                   
                   
                   
                 blend 
               
               
                 5 
                 850 
                 65 
                 25 
                   
                 10 
                 Standard 
                 Intimate 
               
               
                   
                   
                   
                   
                   
                   
                   
                 blend 
               
               
                 6 
                 850 
                 65 
                   
                 15 (2.25 
                 20 
                 Standard 
                 Intimate 
               
               
                   
                   
                   
                   
                 denier) 
                   
                   
                 blend 
               
               
                 7 
                 850 
                 65 
                   
                 20 (60 
                 20 
                 Standard 
                 Intimate 
               
               
                   
                   
                   
                   
                 denier) 
                   
                   
                 blend 
               
               
                 8 
                 490 
                 65 
                   
                 35 
                   
                 Single 
                 Intimate 
               
               
                   
                   
                   
                   
                 (3 denier 
                   
                 side 
                 blend 
               
               
                   
                   
                   
                   
                 x 3″) 
               
               
                 9 
                 490 
                 65 
                   
                 35 
                   
                 Both 
                 Intimate 
               
               
                   
                   
                   
                   
                 (3 denier 
                   
                 sides 
                 blend 
               
               
                   
                   
                   
                   
                 x 3″) 
               
               
                   
               
             
          
         
       
     
         [0040]    Roll good manufacture of needlepunch nonwovens starts with fiber opening and carding. Intimate blends typically comprise 30-70% of staple length melamine fiber as the active cleaning ingredient which is blended with other manmade and cellulosic fibers. Cellulosic fibers (like rayon, cotton, flax etc.) can be added at levels of 10-50% to increase absorbency. Polyester and polypropylene fibers from 3-200 denier can be added for increased compression resistance, tensile strength, durability, thickness, cost reduction, and other reasons. In one embodiment, melt colored polyester or polypropylene fibers can be blended at 10-50% to give the substrate color across the palette range. Basis weight ranges from 70-1200 grams/square meter (gsm) with a preferred weight of 300-900 gsm. Fabric thickness varies from 3-7 mm. Depending on the needling density and the end use application, thickness and basis weight might increase or decrease beyond the ranges above. For example, a melamine fiber containing floor buffing pad might be 25 mm thick. 
         [0041]    In another example, different layers of fibers were needlepunched to create cleaning materials. The compositions of the various layers needlepunched are noted in the Table below. The structure, number of layers and whether the needling was from one side only or from both sides, is also indicated for each sample, Nos. 10-15. 
         [0000]    
       
         
               
             
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
             
           
               
                   
               
               
                 Needlepunch Nonwoven Samples (Layered) 
               
             
          
           
               
                   
                 Basis 
                   
                   
                   
                   
                   
               
               
                 Sample 
                 weight 
                   
                   
                   
                 Needling 
               
               
                 No. 
                 (GSM) 
                 Layer 1 
                 Layer 2 
                 Layer 3 
                 Density 
                 Structure 
               
               
                   
               
             
          
           
               
                 10 
                 215 
                 100% 
                 — 
                 — 
                 70 
                 Single 
               
               
                   
                   
                 melamine 
                   
                   
                 strokes 
                 layer 
               
               
                 11 
                 1100 
                 200 gsm 
                 700 gsm 
                 200 gsm 
                 70 
                 Tri-layer 
               
               
                   
                   
                 melamine 
                 6 denier 
                 melamine 
                 strokes 
               
               
                   
                   
                   
                 polyester 
               
               
                 12 
                 115 
                 100% 
                   
                   
                 95 
                 Single 
               
               
                   
                   
                 melamine 
                   
                   
                 strokes 
                 layer 
               
               
                 13 
                 930 
                 115 gsm 
                 700 gsm 
                 115 gsm 
                 95 
                 Tri-layer; 
               
               
                   
                   
                 melamine 
                 6 denier 
                 melamine 
                 Strokes 
                 Single side 
               
               
                   
                   
                   
                 polyester 
                   
                   
                 needled 
               
               
                 14 
                 880 
                 115 gsm 
                 700 gsm 
                 115 gsm 
                 95 
                 Tri-layer; 
               
               
                   
                   
                 melamine 
                 6 denier 
                 Melamine 
                 Strokes 
                 Both sides 
               
               
                   
                   
                   
                 polyester 
                   
                   
                 needled 
               
               
                 15 
                 312 
                 115 gsm 
                 135 gsm 
                 115 gsm 
                 95 
                 Tri-layer; 
               
               
                   
                   
                 melamine 
                 3 denier 
                 melamine 
                 Strokes 
                 Both sides 
               
               
                   
                   
                   
                 polyester 
                   
                   
                 needled 
               
               
                   
               
             
          
         
       
     
         [0042]    Generally, this layered configuration offers greater debris removal or cleaning efficacy since more melamine fiber is at the user interface rather than buried inside the structure. Preferentially putting the more expensive melamine fiber at the surface has the second benefit of reducing overall raw material cost of the fabric. Roll goods are comprised of 2 or more layers consolidated by needlepunch in the forms: 
         [0043]    A/B 
         [0044]    A/B/A 
         [0045]    Where, layer A has high fiber melamine content (50-100%) on the active or outsides on the fabric. Basis weight of this layer is generally 70-200 gsm. 
         [0046]    Layer B does not contain melamine fiber and could be another carded fiber nonwoven, scrim, film, foam, etc. This layer can be comprised of low cost (recycled or inexpensive) fibers and/or functional fibers that increase: thickness, compression resistance, resilience, absorbency, abrasiveness, softness, durability, stretch, etc. Layer B might also be rendered more antimicrobial through additives or treatment. Basis weight for this layer might range from 100-700 gsm depending on the type of material used and end user requirements. 
         [0047]    Overall thickness typically ranges from 3-7 mm. Total basis weight is typically 300-900 gsm. Thickness and weight could extend beyond these ranges depending on end user requirements. 
         [0048]    In one example, cleaning materials were made by using a conventional wet laying technique. The composition of each wetlaid sample, Nos. 1-3, are indicated in the Table below. 
         [0000]    
       
         
               
             
               
               
               
               
               
               
               
             
           
               
                   
               
               
                 Wetlaid Samples 
               
             
          
           
               
                   
                 Basis 
                 % 
                   
                 % 
                   
                 % Binder 
               
               
                 Sample 
                 weight 
                 Mela- 
                   
                 wood 
                   
                 (Poly vinyl 
               
               
                 No. 
                 (GSM) 
                 mine 
                 % Rayon 
                 pulp 
                 % Bico 
                 alchohol) 
               
               
                   
               
               
                 1 
                 50 
                 50 
                 40 
                 — 
                 — 
                 10 
               
               
                   
                   
                   
                 4.5 den 
               
               
                   
                   
                   
                 x ¼″) 
               
               
                 2 
                 50 
                 65 
                 — 
                 — 
                 35 
                 — 
               
               
                   
                   
                   
                   
                   
                 (2 den 
               
               
                   
                   
                   
                   
                   
                 x ¼″) 
               
               
                 3 
                 50 
                 50 
                   
                 40 
                   
                 10 
               
               
                   
               
             
          
         
       
     
         [0049]    Short cut melamine fiber ranging from 5-25 mm in length is dispersed in water using dispersants and possibly viscosity modifiers. This shortcut melamine fiber could then be blended with wood pulp, rayon (1.5-5 denier×¼″), bicomponents and other shortcut fibers that reduce cost and deliver functional benefits as described prior. The thoroughly mixed furnish is then formed into a roll good in a typical wetlay nonwoven process. Basis weights typically range from 40-80 gsm. The resulting sheet or fabric has low tensile strength which might be desirable where quick dissociation is needed for disposal. However, in most applications, greater strength is needed and can be gained by: 
         [0050]    a) thermal bonding of sheets containing bicomponent fibers (2 denier×¼″) 
         [0051]    b) adding polyvinyl alcohol (PVOH) or other strength aids 
         [0052]    The melamine fiber cleaning material of the present invention has many advantages as a cleaning material, either pad or wipe. The material can be sold as a wet or dry wipe, resulting in great packaging flexibility. Chemical free cleaning is offered, as one only needs to add water. Also, the cleaning material itself can be free of surfactants, chemical cleaners and binders. The triboelectric properties of the cleaning material are exceptional, thereby allowing the wipe to pick up and hold small particles. As noted before, cost advantages are realized by using the present cleaning material. One can blend other fibers with the melamine fibers to tailor performance characteristics. The cleaning material can also be effectively used as part of a laminate or composite structure, if so desired. 
         [0053]    While the foregoing written description of the invention enables one of ordinary skill to make and use what is considered presently to be the best mode thereof, those of ordinary skill will understand and appreciate the existence of variations, combinations, and equivalents of the specific embodiment, method, and examples herein. The invention should therefore not be limited by the above described embodiment, method, and examples, but by all embodiments and methods within the scope and spirit of the invention.