US20100285298A1 - Anti-microbial carpet underlay and method of making - Google Patents

Abstract

A method for making antimicrobial rebonded carpet pad includes mixing zinc pyrithione with a polyol to form an antimicrobial polyol mixture concentrate, blending the antimicrobial polyol mixture concentrate with a binder stream, mixing the binder with foam particles and curing the binder. The percentage of zinc pyrithione mixed with the polyol and the addition ratio of the antimicrobial polyol mixture concentrate with the binder stream are selected to provide an overall concentration of zinc pyrithione in the binder of at least about 7500 ppm. The particles and binder are cured into a block and sliced to form carpet pad.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS
• This continuation application is related to and claims priority under 35 U.S.C. §120 to co-pending U.S. patent application Ser. No. 11/627,610, filed Jan. 26, 2007 and entitled “Anti-Microbial Carpet Underlay and Method of Making,” which claims benefit under 35 U.S.C. §120 as a Divisional Application of U.S. patent application Ser. No. 10/840,309, filed May 6, 2004, entitled “Anti-Microbial Carpet Underlay and Method of Making,” which claims the benefit under 35 U.S.C. §119 of U.S. provisional application Ser. No. 60/506,688 filed Sep. 26, 2003 and entitled “Anti-Microbial Carpet Pad and Method of Making,” all of which are hereby incorporated herein by reference for all purposes.
FIELD OF THE INVENTION
• This invention relates to antimicrobial rebonded carpet underlay and more particularly to a method of making such underlay by mixing an anti-microbial agent in binder used to make the rebonded carpet underlay.
BACKGROUND OF THE INVENTION
• Carpet, especially wall-to-wall carpet, is normally installed with an underlay, often in the form of a foam pad or cushion. Moisture, dirt, food particles, and other debris tend to filter through the carpet to the pad. These conditions provide a breeding ground for various bacteria and mold that may produce undesirable odors, cause degradation of the carpet and/or pad, and/or contribute to a poor indoor air quality environment for occupants of the premises.
• A typical carpet pad consists of ground polyurethane foam particles of a specific size range that are rebonded back together to form a continuous foam pad of various densities and thickness. Typically, carpet pad ranges in density from four to eight pounds per cubic foot. Rebonded pad is made from recycled polyurethane foam, typically from scraps of foam reclaimed from padding used in furniture, bedding, and automobile seating. The scraps are often of different sizes and colors. The rebonded foam is produced by grinding or chopping the scraps, mixing the chopped scraps with a binder, curing the binder, and slicing the resulting block of rebonded foam particles into a desired pad thickness. The binder may typically form ten percent of the weight of the final rebonded pad. Various films or webs may be bonded to one or both sides of the pad for various purposes.
SUMMARY OF THE INVENTION
• A method of making antimicrobial rebonded carpet pad includes mixing zinc pyrithione with a polyol to form an antimicrobial polyol mixture concentrate, and blending the antimicrobial polyol mixture concentrate with a binder stream used to make rebonded carpet pad.
• In an embodiment, the percentage of zinc pyrithione mixed with the polyol and the addition ratio of the antimicrobial polyol mixture concentrate with the binder stream are selected to provide an overall concentration of zinc pyrithione in the binder of at least about 7500 ppm.
• In one embodiment, an antimicrobial carpet underlay comprises a rebonded pad comprising particles of foam joined together with a binder prepared according the described method.
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 is a cross sectional view of a carpet underlay according to one embodiment of the present invention.
• FIG. 2 is a block diagram of a binder mixing system used in making rebonded pad for testing the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
• FIG. 1 is a cross sectional illustration of anantimicrobial carpet underlay10 which may be made according to one embodiment of the present invention. Theunderlay10 includes a rebondedpad portion12 including a number of small pieces offoam14 bonded together bybinder16. Thefoam pieces14 may typically be ground or chopped scraps of polyurethane foam used in making furniture. Theunderlay10 may also include afilm18 bonded to at least one surface of thepad12, in this case the upper surface of thepad12. Thefilm18 is typically preferred to facilitate laying carpet on top of theunderlay10 and for resisting the flow of fluids into thepad12, e.g. when fluids are spilled on carpet installed over thepad12. Afilm18 may also be laminated to the lower side of thepad12 if desired. In the present invention, thecarpet underlay10 is resistant to the growth of bacteria and mold on and within theunderlay10. This antimicrobial resistance is achieved by adding an effective amount of an antimicrobial compound to thepad12 and/or to thefilm18, as described in more detail below.
• In one embodiment, an effective biocide, or antimicrobial, compound known as zinc pyrithione (e.g. the material sold under the trademark ZINC OMADINE by Arch Chemicals Inc.) is incorporated into rebondedcarpet pad12 by the following method. The chemical name for this compound is Bis(1-hydroxy-2(1H)-pyridinethionato-O,S)-(T-4)Zinc. The zinc pyrithione in powdered form is mixed with a triol polyol of a molecular weight typically ranging from 3000 to 3500 to form a 20% strength antimicrobial/polyol mixture concentrate. Then, the 20% antimicrobial/polyol mixture concentrate is added to a binder stream at a 3.90% to 6.50% addition level to render a zinc pyrithione concentration of between 7500 to 12500 ppm in thebinder16. The antimicrobial/polyol mixture concentrate and binder stream are preferably held at between about 90 and about 100 degrees F. during mixing and use. Thebinder16 is typically composed of ⅓ aromatic oil, ⅓ triol polyol, and ⅓ polymeric MDI. The binder is added to ground foam particles, mixed together, compressed, injected with steam, and dried in the form of a large block of rebonded foam particles. The block is then sliced into thicknesses suitable for carpet pad, e.g. three-eighth to five-eighth inch, to produce the rebondedfoam pad12. The binder to ground foam weight ratio is approximately 1:10. The final concentration of Zinc Pyrithione in the rebondedpad12 is therefore from about 750 ppm to about 1250 ppm.
• If desired, the particular concentration of zinc pyrithione in the antimicrobial/polyol mixture concentrate may be selected to be more or less than the 20% concentration used in this embodiment. The addition level of the antimicrobial/polyol mixture concentrate in thebinder16 may then be adjusted to achieve a zinc pyrithione concentration of at least about 7500 ppm and preferably between about 7500 to about 12500 ppm in thebinder16.
• If desired, abinder16 to ground foam weight ratio of more or less than 1:10 may be used. If other ratios are used, the particular concentration of zinc pyrithione in the antimicrobial/polyol mixture concentrate and/or the addition level of the antimicrobial/polyol mixture concentrate in thebinder16 may then be adjusted to achieve a final concentration of Zinc Pyrithione in the rebondedpad12 from about 750 ppm to about 1250 ppm.
• FIG. 2 illustrates a mixing system used in makingbinder16 for testing the present invention. A method for makingbinder16 will be described with reference toFIG. 2. A mix tank20 included a thirty-gallon drum and a vortex type mixer. Eighty pounds of polyol and twenty pounds of powdered zinc pyrithione were placed in tank20 and mixed for at least three hours. Atransfer pump22 was used to pump the mixture from mix tank20 to arun tank24, which also includes a vortex mixer. The antimicrobial/polyol mixture concentrate in therun tank24 was mixed constantly during production. If the mixer is turned off for any significant period of time, it should be restarted at least two hours prior to use in production of rebondedpad12.
• During production of rebondedpad12, a variable speed Watson Marlowpump26 was used to flow the antimicrobial/polyol mixture concentrate from therun tank24 at a controllable rate. The rate is controlled by acontrol panel28 and avariable frequency drive30. The discharge side ofpump26 is connected to the vacuum side of abinder pump32. Atank34 of binder also has an outlet connected to the vacuum side of abinder pump32. The discharge side ofpump32 is connected to astatic mixer36. Theoutlet38 ofmixer36 is coupled to a blender wherepolyurethane particles14 are mixed withbinder16 to produce the finished rebondedpolyurethane pad12.
• During the operation of the system ofFIG. 2, it is preferred that the antimicrobial/polyol mixture concentrate in the mix tank20 andrun tank24 be maintained at a temperature of between about 90 and about 100 degrees F. during mixing and production operations. Likewise, thebinder tank34 is preferable maintained within the same temperature range.
• It is sometimes desirable to includelaminating film18 on one or both surfaces ofcarpet pad12. For example, such afilm18 may facilitate laying and stretching of carpet by allowing the carpet to slide easily on top of thepad12 and avoiding undesirable movement or buckling of thepad12. The film may also prevent fluids spilled on carpet from penetrating into thepad12. In one embodiment of the present invention, anantimicrobial laminating film18 is laminated onto one or both surfaces of a carpet pad. The carpet pad may or may not include an antimicrobial compound as disclosed above.
• Theanti-microbial laminating film18 of this embodiment inhibits the growth of certain bacteria and fungus when used in combination with prime polyurethane foam pad or rebondedpolyurethane foam pad12 as carpet underlay. The anti-microbial film may be thermally laminated to the top and/or bottom surfaces of prime polyurethane foam pad or re-bonded polyurethaneflexible foam pad12 where it acts as a barrier to inhibit the growth of microbes that accumulate on the surfaces of carpet underlay. Thisfilm18 may also inhibit the growth of microorganisms in other products where this film can be used as a lamination barrier.
• In this embodiment, a 0.45 to 0.50 mil monolayer blownfilm18 includes between 500 and 1500 ppm of the antimicrobial compound zinc pyrithione (e.g. the material sold under the trademark ZINC OMADINE by Arch Chemicals Inc.). The chemical name for this compound is Bis(1-hydroxy-2(1H)-pyridinethionato-O,S)-(T-4)Zinc. The zinc pyrithione powder is incorporated at 10% by weight into a LLDPE, linear low density polyethylene, resin concentrate supplied by PolyChem Alloy, Inc. under the trademark POLYSEPT 554Z. The chemical description of the resin concentrate is Mercaptopyridine-N-oxide in Polypropylene. This resin concentrate has a specific melt index of 20 grams/10 mins. and 0.93 density. About 1% to about 3% by weight of this concentrate is then blended with a LLDPE/Copolymer resin mixture. Due to thermal breakdown of zinc pyrithione during processing of the film, the initial 10% concentration of zinc pyrithione in the concentrate may be effectively reduced to less than 6%. After mixing with the resin mixture and processing it into a film, the net effective concentration of zinc pyrithione in the processed film is about 500 ppm to 1500 ppm. Suitable copolymer resins may be EVA, EMA, or EMAA. The copolymer resin consists of approximately 60-70% by weight of the total mixture. The remaining mixture is 30-40% LLDPE by weight, including the 1-3% LLDPE concentrate treated with zinc pyrithione. The blended resins may then be extruded at between 450 and 550 degrees F. with a blow up ratio, i.e. bubble diameter to die diameter, of between 1.8 and 2.5:1. It is preferred that the extrusion temperature be kept below 500 degrees F. to minimize thermal breakdown of the zinc pyrithione.
• It is apparent that zinc pyrithione powder may be incorporated at more or less than 10% by weight into the resin concentrate. If other addition levels are selected, the percentage of the concentrate blended with the LLDPE/Copolymer resin mixture may be adjusted to achieve a net effective concentration of zinc pyrithione in the processed film of from about 500 ppm to 1500 ppm.
• The anti-microbial treated film may be thermally laminated (e.g. at about 250-450 degrees F., 0.5 sec dwell time) to one or both sides of a prime polyurethane foam pad orrebonded pad12 which may typically be from about three-eighth inch to about five-eighth inch thick or other desired thickness. Other laminating methods may be used if desired, e.g. by use of an adhesive. The anti-microbial film may be laminated to an anti-microbial treated pad or non-anti-microbial treated pad. The anti-microbial film may also be laminated to another anti-microbial treated or untreated film for lamination to anti-microbial treated pad or non-anti-microbial treated pad.
• Biocidal effectiveness of therebonded carpet pad12 and/orfilm18 according the present invention may be determined by measuring inhibition of growth of bacterial and/or fungus using AATCC (American Association of Textile Chemists and Colorists) 174, ASTM E2180-1, and ASTM D 3273 test protocols compared to non-treated control standards. The AATCC 174 protocol was developed for determining the antimicrobial activity of new carpet materials.
• A number of specimens ofcarpet underlay10 were made by methods described above, with various concentrations of zinc pyrithione in thebinder16 andfilm18 for testing to determine levels that provide an effective antimicrobial effect. The specimens included afilm18 on one side as illustrated inFIG. 1. This allowed testing of the foam side of the specimens to indicate antimicrobial effect of thepad12 withoutfilm18 and testing of the film side to indicate antimicrobial effect of thepad12 withfilm18. The AATCC 174 test method provides for testing both unwashed and washed samples. Washed samples were treated according to the AATCC 138 protocol. The test results are summarized as follows.
• The AATCC 174 test method includes three parts. Part I is a qualitative test for antibacterial activity. Test specimens are placed into contact with a nutrient agar which has been streaked with a bacterial culture. The specimens are then incubated. After incubation, a clear area of interrupted growth underneath and along the sides of the test specimen indicates antibacterial activity of the specimen. Standard strains of bacteria are used, withStaphylococcus aureusandKlebsiella pneumoniaebeing the representative organisms.
• In the AATCC 174, Part I tests various washed and unwashed specimens were tested. An unwashed foam side specimen with 751 ppm of zinc pyrithione passed the test with a one millimeter zone of inhibition forKlebsiella pneumoniaeand a two millimeter zone of inhibition forStaphylococcus aureus. All unwashed and washed foam side specimens with a concentration of 1096 ppm or more of zinc pyrithione inhibited the growth ofKlebsiella pneumoniaefrom underneath and along the sides of the specimen.
• The AATCC 174, Part II test provides a quantitative procedure for the evaluation of the degree of antibacterial activity. Test specimens are inoculated with the test microorganisms. After incubation, the bacteria are eluted from specimens by shaking in 100 milliliters of liquid. The number of bacteria present in the liquid is determined and the percent reduction produced by the specimen is calculated.
• In the AATCC 174, Part II tests, washed foam side specimens containing 751 and 1096 ppm of zinc pyrithione provided a 90% reduction in the numbers of bothStaphylococcus aureusandKlebsiella pneumoniae. In all unwashed and washed film and foam side specimens containing a concentration of 500 ppm or more of zinc pyrithione in the film and 1096 ppm of zinc pyrithione in the pad, there was a reduction of at least 66% inStaphylococcus aureuswith an average reduction of 92%.
• The AATCC 174, Part III protocol provides a qualitative test for antifungal activity. Specimens are subjected to the growth of a common fungus,Aspergillus niger, on Sabouraud Dextrose agar. Prewet specimens are inoculated and incubated at 28 degrees C. for seven days. Specimens are then assessed for growth of the fungus.
• In the AATCC 174, Part III tests, washed and unwashed foam side samples with a concentration of 1096 ppm of zinc pyrithione in the pad produced no observable fungus growth. No growth was observed on washed and unwashed film side samples when the concentration of zinc pyrithione in the film was 1500 ppm or greater.
• Inhibitory mold activity was also tested by the ASTM E2180-01 test method. Good inhibitory activity forAspergillus nigerwas observed when film side specimens had a total minimum combined concentration of 1600 ppm of zinc pyrithione. The total combined concentration is the sum of the concentration in thepad12 of a specimen and the concentration in thefilm18 of the specimen. The tests indicate that a minimum of 500 ppm may be preferred in thefilm18, with a preferred complement minimum of 1100 ppm in thepad12. Alternatively, a minimum concentration of 750 ppm may be preferred in thepad12 with a preferred complement minimum of 850 ppm in thefilm18. Good results were achieved for some, but not all, specimens with a total combined concentration of 1251 ppm, i.e. 751 ppm in thepad12 and 500 ppm in thefilm18. Therefore, the preferred minimum combined concentration is about 1600 ppm.
• Mold susceptibility tests were also performed under the ASTM D3273 test method. NoAspergillus nigermold colonization was observed onfilm18 side specimens when the specimens had a total minimum combined concentration of about 1600 ppm zinc pyrithione. The tests indicate that a minimum of 500 ppm may be preferred in thefilm18, with a preferred complement minimum of 1100 ppm in thepad12. Alternatively, a minimum concentration of 750 ppm may be preferred in thepad12 with a preferred complement minimum of 850 ppm in thefilm18.
• The above described tests indicate that an effectiveantimicrobial carpet underlay10 can be made by incorporating 7500 to 12500 ppm of zinc pyrithione into binder used to bind foam particles to make rebonded carpet pad. The net concentration in thefoam pad12 is from 750 to 1250 ppm of zinc pyrithione when the binder to foam weight is 1:10. If different ratios of binder to foam are used, it is preferred to adjust the concentration in the binder stream to achieve at least about 750 ppm of zinc pyrithione in thefinal foam pad12.
• The tests also indicate that an effective antimicrobial film can be made by incorporating 500 to 1500 ppm of zinc pyrithione in thefilm18. As noted above, the initial concentration is preferably adjusted to account for thermal degradation which occurs during film processing. Thus, the initial ten percent concentration of zinc pyrithione in the resin concentrate may be reduced to an effective five to six percent after processing.
• The tests also show that when both afoam pad12 and afilm18 including a biocide are combined to form a carpet underlay, lower concentrations of zinc pyrithione may be used than may be necessary if only thepad12 or thefilm18 contains the biocide. In general, in a carpet underlay having a biocide treatedpad12, but anuntreated film18, thepad12 preferably has a biocide concentration near the upper end of the range tested, e.g. at least about 1100 to 1250 ppm of zinc pyrithione. For an underlay having anuntreated pad12, and a treatedfilm18, thefilm18 preferably has a biocide concentration near the upper end of the range tested, e.g. at least about 1100 to 1500 ppm of zinc pyrithione. When both thepad12 andfilm18 are treated, it is preferred that the combined concentrations forfoam pad12 andfilm18 be at least about 1600 ppm.
• In the above disclosure, the concentrations of biocide in thefoam pad12 andfilm18 have been discussed in terms of ranges having a lower limit and an upper limit. It is apparent that it is preferred to include concentrations at or above the lower limits to achieve an effective antimicrobial activity in the products. That is, concentrations above the ranges tested should also be effective. Concentrations should be kept below a level at which the biocide may affect the mechanical integrity of the product. Since the biocide is a relatively high cost part of the product, normal practice should be to avoid using more of the biocide than is needed to achieve effective biocidal or antimicrobial activity.
• The particular choice of an effective amount of the biocide also depends upon the particular application in which the carpet pad will be used. In some applications, there is a requirement that carpet products exhibit effective antimicrobial activity after being washed. For those applications, it may be desirable to use a concentration at or near the upper limits of the ranges given above. In the tests reported above, the specimens at the upper ends of the ranges provided effective antimicrobial activity after washing. If the application does not require washing, a lower concentration of biocide provides an effective biocidal activity.
• In the above description of making therebonded foam pad12, zinc pyrithione was initially mixed in powder form with a polyol. The resulting mixture is basically a suspension of particles in a liquid. As noted in the description ofFIG. 2, it is desirable to continuously operate a mixer inrun tank24 to insure that the zinc pyrithione remains uniformly mixed with the polyol. It may be desirable to first dissolve the zinc pyrithione in a fluid which is miscible with a polyol. Such a process is described in U.S. Pat. No. 5,114,984 issued to Branch et al. on May 19, 1992. In that patent, a pyrithione salt is dissolved in an alkanolamine which is miscible with a polyol, which the Branch patent indicates may then be used to make an antimicrobially effective polyurethane. Such a solution of zinc pyrithione in polyol may also be suitable for mixing with the binder described above for use in the present invention.
• While the present invention has been disclosed in terms of specific structures, chemical compositions and mixtures, and methods of making carpet underlay, it is apparent that various changes and substitutions of materials and steps may be made within the scope of the present invention as defined by the appended claims.

Claims (30)

1. A method for making rebonded carpet pad, comprising:

mixing an antimicrobial compound with a polyol to form an antimicrobial polyol mixture concentrate;

blending the antimicrobial polyol mixture concentrate with a binder stream to form binder;

selecting a percentage of the antimicrobial compound mixed with the polyol and an addition ratio of the antimicrobial polyol mixture concentrate with the binder stream to provide an effective concentration of the antimicrobial compound in the binder;

mixing the binder with foam particles; and

forming the mixture of binder and foam particles into a pad;

wherein the antimicrobial compound is approximately uniformly dispersed in the binder, there is substantially no antimicrobial compound in the foam particles, and the antimicrobial compound in the binder renders the carpet pad as a whole effectively antimicrobial.

2. The method ofclaim 1, wherein the antimicrobial compound comprises zinc pyrithione.

3. The method ofclaim 1, wherein the antimicrobial compound is zinc pyrithione, and wherein the effective concentration of zinc pyrithione in the binder is at least about 7500 ppm.

4. The method ofclaim 3, wherein mixing antimicrobial compound with a polyol to form an antimicrobial polyol mixture concentrate further comprises:

mixing zinc pyrithione with a triol polyol to a 20% strength antimicrobial polyol mixture concentrate, and

blending the 20% strength antimicrobial polyol mixture concentrate with a binder stream at least a 3.90% addition level.

5. The method ofclaim 4, further comprising blending the 20% strength antimicrobial polyol mixture concentrate with a binder stream at about a 3.90% to 6.5% addition level.

6. The method ofclaim 3, wherein the ratio of binder to foam particles is about 1:10 and results in an overall concentration of zinc pyrithione in the carpet pad of at least about 750 ppm.

7. The method ofclaim 1, wherein the antimicrobial compound is zinc pyrithione, and the overall concentration of zinc pyrithione in the carpet pad is between about 750 and about 850 ppm.

8. The method ofclaim 7, wherein forming the mixture of binder and foam particles into a pad comprises shaping the mixture of binder and foam particles into a block, curing the binder, and slicing the block to form carpet pad of a substantially uniform thickness between about ⅜ and about ⅝ inch.

9. The method ofclaim 2, further comprising laminating a film to at least one side of the carpet pad.

10. The method ofclaim 9, wherein the film comprises an effective amount of an antimicrobial compound.

11. The method ofclaim 10, wherein the antimicrobial compound of the film comprises zinc pyrithione, and wherein the minimum combined concentration of zinc pyrithione in the pad and the film is about 1600 ppm.

12. The method ofclaim 10, wherein the film is an 0.45 to 0.5 mil monolayer blown film, the antimicrobial compound of the film comprises zinc pyrithione, the pad comprises a concentration of zinc pyrithione from about 750 to about 1250 ppm, and the film comprises a concentration of zinc pyrithione from about 500 to about 1500 ppm.

13. The method ofclaim 12, further comprising:

forming the 0.45 to 0.5 mil monolayer blown film; and

thermally laminating the film to at least one side of the pad.

14. The method ofclaim 2, wherein blending the antimicrobial polyol mixture concentrate with the binder stream forms a binder comprising about ⅓ aromatic oil, about ⅓ triol polyol, and about ⅓ polymeric MDI.

15. The method ofclaim 2, wherein blending the antimicrobial polyol mixture concentrate with binder stream comprises pumping the antimicrobial polyol mixture concentrate and binder stream from separate lines through a static mixer for discharge onto the foam particles.

16. The method ofclaim 15, wherein the binder is not held after the polyol mixture concentrate is blended with the binder stream, but is sprayed from the discharge line directly onto the foam particles.

17. The method ofclaim 16, wherein despite the fact that the antimicrobial is not uniformly distributed throughout the carpet pad, the carpet pad as a whole is effectively antimicrobial.

18. A carpet underlay for use beneath carpeting comprising a pad, comprising:

foam particles bound together with a binder comprising an effective amount of an antimicrobial compound;

wherein the antimicrobial compound is approximately uniformly dispersed in the binder, there is substantially no antimicrobial compound in the foam particles, and the antimicrobial compound in the binder renders the carpet pad as a whole effectively antimicrobial.

19. The carpet underlay ofclaim 18, wherein the antimicrobial compound of the binder comprises zinc pyrithione.

20. The carpet underlay ofclaim 19, wherein the binder comprises at least about 7500 ppm of the antimicrobial compound.

21. The carpet underlay ofclaim 19, wherein the pad comprises between about 750 and about 850 ppm of the antimicrobial compound.

22. The carpet underlay ofclaim 19, further comprising a film laminated to the pad.

23. The carpet underlay ofclaim 22, wherein the film is a 0.45 to 0.5 mil monolayer blown film, and the film comprises an effective amount of an antimicrobial compound.

24. The carpet underlay ofclaim 22, wherein the film comprises at least about 500 ppm of zinc pyrithione.

25. The carpet underlay ofclaim 18, further comprising a film, wherein the film comprise an effective amount of antimicrobial compound.

26. The carpet underlay ofclaim 24, wherein the concentration of zinc pyrithione in the pad plus the concentration of zinc pyrithione in the film comprises at least about 1600 ppm.

27. A carpet underlay, comprising:

a foam pad, and

a laminating film comprising an effective amount of an antimicrobial compound, wherein the laminating film is laminated to the foam pad, such that the film provides

effective antimicrobial protection to the foam pad.

28. The carpet underlay ofclaim 27, wherein the antimicrobial compound comprises zinc pyrithione, and the laminating film comprises at least about 500 ppm of zinc pyrithione.

29. The carpet underlay ofclaim 27, wherein the foam pad comprises foam particles bound together with a binder comprising an effective amount of an antimicrobial compound.

30. The carpet underlay ofclaim 29, wherein the antimicrobial compound of the film is zinc pyrithione, the antimicrobial compound of the binder is zinc pyrithione, and the concentration of zinc pyrithione in the pad plus the concentration of zinc pyrithione in the film comprises at least 1600 ppm.

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