Abstract:
A sound control mat, comprising: a resilient layer of extruded polymer monofilaments, and a fiberglass scrim adhered to the resilient layer. A floor assembly employing the foregoing sound control mat is disclosed.

Description:
TECHNICAL FIELD 
     This invention relates to sound control mats. The sound control mats are useful for noise control with flooring systems. 
     BACKGROUND 
     Three-dimensional products are used with floor systems for reducing impact noise. 
     SUMMARY 
     This invention relates to a sound control mat, comprising: a resilient layer of extruded polymer monofilaments, the polymer monofilaments being heat welded at junctions to form a matrix of tangled monofilaments, the resilient layer having a machine direction, a cross-direction, a first side and a second side, the resilient layer comprising a plurality of waves forming a repeating pattern of peaks and valleys, the waves extending in the machine direction and the cross-direction, the average ratio of the width of the waves, as measured in the cross-direction, to the length of the waves, as measured in the machine direction, being at least about 2:1; and a fiberglass scrim overlying the second side of the resilient layer, the scrim comprising a plurality of fiberglass strands, the resilient layer being heat welded to the fiberglass scrim. 
     This invention also relates to a floor assembly, comprising: a sub-flooring layer; a top-flooring layer overlying the sub-flooring layer; and the above-indicated sound control mat positioned between the sub-flooring layer and the top-flooring layer, the resilient layer contacting the sub-flooring layer, the scrim contacting the top-flooring layer. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the annexed drawings like parts and features have like references. A number of the drawings are schematic illustrations which may not necessarily be drawn to scale. 
         FIG. 1  is a schematic illustration of a sound control mat within the scope of the invention, the sound control mat comprising a resilient layer and a fiberglass scrim, part of the resilient layer being cut away to show the scrim. 
         FIG. 2  is a schematic illustration of the sound control mat illustrated in  FIG. 1  with the mat turned over and rotated 90°, the scrim being shown in greater detail. 
         FIG. 3  is a side elevation of the sound control mat illustrated in  FIG. 2 , this side view showing the resilient layer with a repeating pattern of peaks and valleys extending in the machine direction. 
         FIG. 4  is a side elevational view of a flooring system within the scope of the invention, the flooring system comprising a sub-flooring layer, a top flooring layer overlying the sub-flooring layer, and the sound control mat illustrated in  FIGS. 1-3  and  5  positioned between the sub-flooring layer and the top flooring layer, the resilient layer of the sound control mat contacting the sub-flooring layer, and the scrim of the sound control mat contacting the top-flooring layer. 
         FIG. 5  is a schematic illustration of the sound control mat illustrated in  FIGS. 1-4  wherein the sound control mat is shown in the form of a roll. 
     
    
    
     DETAILED DESCRIPTION 
     All numerical ranges disclosed in the specification and claims may be combined in any manner. It is to be understood that unless specifically stated otherwise, references to “a,” “an,” and/or “the” may include one or more than one, and that reference to an item in the singular may also include the item in the plural. All combinations specified in the claims may be combined in any manner. 
     The term “machine direction” refers to the direction of the flow of polymer from an extruder when forming the inventive sound control mat. 
     The term “cross-direction” refers to the direction that is oriented 90° from the machine direction. 
     The expression, “a plurality of waves forming a repeating pattern of peaks and valleys” is used herein to refer to the shape of the resilient layer of the inventive sound control mat. The waves, as viewed from a side edge of the mat, may have a sinuous configuration or a serpentine configuration. The waves, in their illustrated embodiment, are shown in  FIGS. 1-5 . In the illustrated embodiment, the waves have irregularities as a result of the fact that the resilient layer is made from a plurality of extruded polymer monofilaments that are entangled, and some of the waves may have edges and/or dimensions that are slightly different than other waves in the resilient layer. The average ratio of the width of the waves, as measured in the cross-direction, to the length of the waves, as measured in the machine direction, is at least about 2:1, and may be at least about 10:1. 
     The term “scrim” is used herein to refer to a thin layer of fiberglass strands. The layer of fiberglass strands may be a woven layer. 
     The term “resilient layer” refers to the fact that when the inventive sound control mat is installed in the above-identified inventive floor assembly, the resilient layer may give or attenuate in response to impacting forces contacting the top flooring layer. This give or attenuation is believed to be due, at least in part, to the construction of the resilient layer with its plurality of waves in the form of a repeating pattern of peaks and valleys. This give or attenuation has the effect of creating a sound break or “spring” between the flooring layers. This may result in the sub-flooring layer receiving less of an impact from vibration which in turn may lower the level of sound heard by occupants in rooms above and/or below the inventive floor assembly. 
     Referring to  FIGS. 1-5 , the inventive sound control mat, in its illustrated embodiment, comprises sound control mat  10  which includes resilient layer  30  and fiberglass scrim  60 . The mat  10  has a machine direction, which is indicated by the arrow  12 , and a cross-direction, which is indicated by the arrow  14 . The machine direction  12  is the direction in which polymer monofilaments  32  used to make the resilient layer  30  flow out of an extruder and onto a substrate during the formation of the mat  10 . The cross-direction  14  is the direction that is oriented 90° from the machine direction  12 . 
     The resilient layer  30  is formed from a plurality of the extruded polymer monofilaments  32 . The monofilaments  32  are welded at junctions to form a matrix  34  of the polymer monofilaments  32 . The resilient layer  30  has a first side  40  and a second side  42 . The resilient layer  30  comprises a plurality of waves  35  which provide a repeating pattern of peaks  36  and valleys  38 . Each wave  35  has a pair of legs  44  and  46  extending from the peaks  36  to the valleys  38 . The legs  44  and  46  are heat welded to the fiberglass scrim  60  at points of contact  62 . The average distance in the machine direction  12  from one point of contact  62  to the next point of contact  62  may be in the range from about 0.25 to about 3 inches, and in one embodiment in the range from about 0.5 to about 0.75 inches. The average ratio of the width of each wave  35 , as measured in the cross-direction  14 , to the length of each wave  35 , as measured in the machine direction  12 , from one point of contact  62  to the next point of contact  62 , may be at least about 2:1, and in one embodiment at least about 10:1, and in one embodiment in the range from about 16:1 to about 100:1, and in one embodiment in the range from about 16:1 to about 25:1, and in one embodiment in the range from about 50:1 to about 100:1. 
     The resilient layer  30  may have a thickness with a major dimension A in the range from about 0.1 to about 1 inch, and in one embodiment from about 0.2 to about 0.8 inch. The resilient layer  30  may have a thickness with a minor dimension B in the range from about 0.01 to about 0.04 inch, and in one embodiment in the range from about 0.02 to about 0.03 inch. The resilient layer  30  may have from about 25 to about 400 polymer monofilaments  32  per foot as measured along the cross-direction  14  of the mat  10 , and in one embodiment from about 75 to about 150 polymer monofilaments  32  per foot. The polymer monofilaments  32  may have an average diameter in the range from about 1 to about 4 mils, and in one embodiment from about 2 to about 3 mils. 
     The resilient layer  30  may be made from any thermoplastic polymer that provides the desired properties of strength and resilience when used in the inventive floor assembly. The resilient layer  30  may be made of a polyolefin, polyamide, polyester, polyvinylchloride (PVC), or a mixture of two or more thereof. The polyolefin may comprise polyethylene, polypropylene, or a mixture thereof. The polyamide may be a Nylon. 
     The fiberglass scrim  60  overlies the second side  42  of the resilient layer  30 . The resilient layer  30  is heat welded to the fiberglass scrim  60  at the points of contact  62 . The fiberglass scrim  60  may comprise a fiberglass layer  64  and a polymer coating  66 . The fiberglass layer  64  may be a woven layer. The fiberglass layer  64  has a plurality of fiberglass strands  68  extending parallel to one another in the machine direction  12 , and a plurality of fiberglass strands  70  extending parallel to one another in the cross-direction  14 . The fiberglass strands  66  and  70  intersect one another at angles of about 90°. The strands  68  and  70  may be referred to as yarns. The strands  68  and  70  may be aligned in a side-by-side configuration or in an over/under configuration. The polymer coating  66  provides a binding to hold the strands  68  and  70  together in the scrim  60 . 
     The fiberglass strands  68  and  70  may each comprise a plurality of fiberglass filaments. The fiberglass filaments may be combined with filaments of another material, for example, a polymer such as polyester. The average diameter of the fiberglass strands  68  and  70  may be in the range from about 10 to about 200 mils, and in one embodiment in the range from about 20 to about 40 mils. The number of fiberglass strands  68  extending in the machine direction  12  may be in the range from about 1 to about 20 strands per inch of scrim  60  as measured in the cross-direction  14 , and in one embodiment in the range from about 6 to about 10 strands per inch, and in one embodiment about 7 or 8 strands per inch. The number of fiberglass strands  70  extending in the cross-direction  14  may be in the range from about 1 to about 20 strands per inch of scrim  60  as measured in the machine direction  12 , and in one embodiment in the range from about 6 to about 10 strands per inch of scrim as measured in the machine direction  12 , and in one embodiment about 7 or about 8 strands per inch. 
     The polymer coating  66  may comprise any coating that is sufficient to bind the strands  68  and  70  and provide the scrim  60  with the dimensional stability, strength and flexibility characteristics required for use in the sound control mat  10 . The polymer coating  66  may provide a polymer layer  71  extending between the strands  68  and  70 . The polymer layer  71  may be sufficient to make the fiberglass scrim  60  water or moisture impermeable. The strands  68  and  70  may be embedded in the polymer layer  71 . The polymer layer  71  may overlie one or both sides of the strands  68  and  70 . The polymer coating may be made of a polyolefin, polyvinyl alcohol, polyvinylchloride (PVC), polyacrylate, styrene-butadiene rubber, or a mixture of two or more thereof. The polyolefin may comprise polyethylene, polypropylene, or a mixture thereof. The polymer coating may be formed using a plastisol, such as a PVC plastisol. The term “plastisol” is used herein to refer to a suspension of polymer particles in a plasticizer. 
     The scrim  60  may have a thickness in the range from about 5 to about 20 mils, and in one embodiment from about 10 to about 15 mils. 
     An example of a scrim that may be used is available from Saint-Gobain Technical Fabrics under Product Number GD8811/V38/V38. This scrim is made of fiberglass yarn. The pattern is 8×7.5 yarns per inch. The tensile strength is 64×60 pounds per inch. The weight of this scrim is 3.45 ounces per square yard. The polymer coating used to form the scrim is a PVC plastisol (a suspension of polyvinyl chloride particles in a plasticizer). 
     The sound control mat  10  may have a weight in the range from about 1 to about 5 ounces per square foot, and in one embodiment in the range from about 2 to about 4 ounces per square foot, and in one embodiment in the range from about 1.5 to about 2.5 ounces per square foot. The mat  10  may have a porosity in the range from about 75 to about 98%, and in one embodiment in the range from about 90 to about 95%. The mat  10  may have any length and width that is suitable for the desired end use. The length, as measured in the machine direction  12 , may be, for example, from about 25 to about 200 feet, and in one embodiment from about 50 to about 100 feet. The width, as measured in the cross-direction  14 , may be, for example, in the range from about 3 to about 8 feet, and in one embodiment from about 3.5 to about 4.5 feet. 
     The sound control mat  10  may be supplied in the form of roll  90  to facilitate transport of the mat  10  and installation of the mat at the job site. The roll  90  is illustrated in  FIG. 5 . When forming the roll  90 , the mat  10  may be rolled in the machine direction  12 . The scrim  60  may be on the outside as illustrated in  FIG. 5  when the mat  10  is rolled, or alternatively, the scrim  60  may be on the inside. The diameter of the roll  90  may be of any dimension suitable for providing the desired length of mat  10 . For example, the roll  90  may have a diameter in the range from about 10 to about 36 inches, and in one embodiment in the range from about 20 to about 25 inches. 
     The process for making the sound control mat  10  may include the steps of extruding the polymer monofilaments  32  onto a substrate to form the resilient layer  30 . The substrate may have a surface with a repeating pattern of peaks and valleys extending in the machine direction that is complimentary to or a “negative” shape corresponding to the repeating pattern of peaks and valleys formed in the resilient layer  30 . The polymer monofilaments  32  may become entangled and heat welded to form a matrix  34  of tangled monofilaments. The fiberglass scrim  60  may then be placed in contact with the resilient layer  30  while the resilient layer  30  is in a sufficiently tacky state to allow the resilient layer  30  to be heat welded to the fiberglass scrim  60  at points of contact  62 . 
     The sound control mat  10  may be used in forming the inventive floor assembly which, in its illustrated embodiment, is shown in  FIG. 4 . Referring to  FIG. 4 , the inventive floor assembly comprises floor assembly  100  which includes sub-flooring layer  110 , top flooring layer  120  overlying the sub-flooring layer  110 , and sound control mat  10  positioned between the sub-flooring layer  110  and the top flooring layer  120 . The resilient layer  30  is in contact with the sub-flooring layer  110 . The scrim  60  is in contact with the top flooring layer  120 . The sub-flooring layer  110  may be made of any conventional sub-flooring material, for example, concrete, steel, wood, and the like. The top flooring layer  120  can also be made of any conventional top-flooring material including, for example, wood, gypsum concrete, and the like. The top flooring layer  120  may optionally have a finish flooring layer overlying the top flooring layer. The finish flooring layer, not shown in the drawings, may be made of any finish flooring layer material, for example, wood, linoleum, ceramic tile, and the like. 
     The resilient layer  30  may be of sufficient strength to support a top-flooring layer  120  with a weight in the range up to about 25 pounds per square foot, and in one embodiment in the range from about 5 to about 25 pounds per square foot, and in one embodiment in the range from about 8 to about 15 pounds per square foot. 
     An advantage of the inventive floor assembly  100  is that the sound control mat  10  gives or attenuates in response to impacting forces contacting the top flooring layer  120 . This provides the effect of creating a sound break or spring between the flooring layers  120  and  110 . This may result in the sub-flooring layer  110  receiving less of an impact from vibration which in turn may lower the level of sound heard by occupants in rooms above and/or below the floor assembly  100 . 
     When the top flooring layer  120  comprises a poured floor, such as a gypsum concrete floor, the scrim  60  may become partially or completely embedded in the flooring layer  120 , and this embedding may enhance the flexural strength of the flooring layer  120 . 
     While not wishing to be bound by theory, it is believed that the mat  10  exhibits enhanced strength and resiliency, as well as enhanced sound attenuation properties, due to the shape of the resilient layer  30  with its plurality of waves forming a repeating pattern of peaks and valleys, and the construction of the fiberglass scrim  60 . When installed in the floor assembly  100 , resilient layer  30  gives or attenuates in response to impacting forces contacting the top flooring layer  120 . This has the effect of creating a sound break or spring between the flooring layers  110  and  120 . The sub-flooring layer  110  receives a reduced level of vibrational impact which in turn lowers the level of sound heard by occupants above or below the floor assembly  100 . This give or attenuation is believed to be due, at least in part, to the shape of the waves  35  in the resilient layer  30 . The peaked sections of waves  35  may at least partially give or depress in response to impacting forces contacting the top flooring layer  120  and then spring back once the impacting forces have ceased. This give or attenuation puts an outward stress on the legs  44  and  46  of the waves  35 , which in turn transmits stress to the fiberglass scrim  60 . The shape of the waves  35  with their extended width to length ratios of at least about 2:1 enhance the strength and stability of the resilient layer  30 . The fiberglass scrim  60  provides the mat  10  with strength, stability and reinforcement. Because of the construction of the scrim  60  with multiple strands  68  and  70 , the scrim  60  may give or stretch in response to the stress applied to it from the legs  44  and  46  of the waves  35  of the resilient layer  30 . In this way the scrim  60  may mimic the movements of the resilient layer  30  when the mat  10  is subjected to vibrational impact. 
     While the invention has been explained in relation to various embodiments, it is to be understood that various modifications thereof will become apparent to those skilled in the art upon reading this specification. Therefore, it is to be understood that the invention provided herein is intended to cover such modifications as may fall within the scope of the appended claims.