HIGH TRACTION ROOFING UNDERLAYMENT

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation in part of International patent application No. PCT/EP24/52667, having an international filing date of Feb. 2, 2024, which claims the benefit of priority to U.S. provisional patent application No. 63/443,241 filed on Feb. 3, 2023 and U.S. provisional patent application No. 63/579,171 filed on Aug. 28, 2023, and this application also claims the benefit of priority to U.S. provisional patent application No. 63/685,392 filed on Aug. 21, 2024; the entirety of all prior applications are hereby incorporated by reference herein.

BACKGROUND OF THE INVENTION

Field of the Invention

The invention relates to high traction roofing underlayment having a fabric on an exposed side to provide better traction for workers on a roof.

Background

Roofing underlayment is used to provide a layer of additional resistance for moisture to pass through the roof into the building and may be non-breathable synthetic material. The roofing underlayment is applied over the plywood and shingles are mechanically attached to the roof, such as by roofing nails through the shingle, through the roofing underlayment and into the plywood. Roof underlayment may be configured with a surface adhesive strip that is configured to bond with the adhesive layer of another piece of roof underlayment when overlapped on a roof. Roofing underlayment can be low friction or slippery, especially when wet and this can lead to falls and injury. Many roofs are configured at an angle and therefore there is a high propensity for falls.

Some roof underlayment has sand attached to the surface side of the underlayment to provide additional friction and traction for those walking on the underlayment. The sand does not effectively stick to the underlayment and provides only marginal improvements in traction. The underlayment with a sand or particle coating is therefore slippery and dangerous, especially in wet conditions.

SUMMARY OF THE INVENTION

The invention is directed to a high traction roof underlayment comprising a barrier layer and a traction layer configured on a surface or exposed side when configured on a roof and may have an adhesive layer configured on a roof side and configured for bonding to a roof surface. The traction layer may be a fabric having fibers and may be woven or a non-woven fabric. A traction layer may preferably be a non-woven as these materials are less expensive than woven material and can provide a high friction for traction on the surface side of an underlayment. An exemplary fabric may be a fleece fabric that is woven and then brushed to produce a napped surface. Fleece is typically made with synthetic polymer fibers, such as polyester, but can be made with natural fibers, such as wool.

The traction layer may include a fabric having fibers and may be woven or a non-woven fabric and includes a traction layer that may be a continuous or discontinuous layer. A fabric layer of the traction layer may preferably be a non-woven as these materials are less expensive than woven material and can provide some traction and may be well suited for bonding to the traction layer on the surface side of an underlayment. A fabric layer of the traction layer may be embossed to produce a non-uniform thickness and the friction layer or a high friction material, such as varnish or an elastomeric material, may be attached to the peaks or raised portions of the embossed fabric layer. A fabric layer of the traction layer may be a friction material and more particularly a high friction material having a coefficient of friction as defined herein to prevent slipping. A fabric layer may be or include a meltblown layer that may form a meltblown fabric layer being made of a high melt flow polymer that may have a low molecular weight and therefore be a high friction material.

An exemplary traction layer may include a discontinuous traction layer that has gaps between portions of the traction layer. The traction layer may include bands or bands of high friction material separated by gaps between the bands. The bands may extend along the length of the high traction roof underlayment, wherein the bands run across the roof to provide effective contact with a shoe that may begin to slip down along the high traction roof underlayment. The high traction roof underlayment is typically provided in a roll of high traction roof underlayment having a length wrapped into a roll and a width. The roll of high traction roof underlayment is rolled across a roof with a first edge along a top or elevated on a pitched roof over a second edge. The bands of high friction material may extend along the length of the roll such that if traction is lost, the foot would have to traverse over bands of high friction material to better aid in regaining traction and footing to prevent falls. A roll of high traction roof underlayment may have a length of about 5 m or more, about 10 m or more, about 25 m or more and any range between and including the values provided.

The traction layer may also include discrete high friction material that is surround by a gap in the traction layer. Openings or gaps in the traction layer may promote moisture to run off or out of the high friction material and thereby improve traction. Also, strips or bands or discrete high friction portions may dry out more quickly after becoming wet from precipitation. Furthermore, discontinuous and discrete high friction material has reduced weight over a continuous layer and this is desired.

A band of high friction material and the gaps therebetween may a width of about 10 mm or more, about 20 mm or more, about 30 mm or more, about 50 mm or more and any range between and including the width values provided. A discrete high friction material may occupy an area of about 100 mm² or more, about 250 mm² or more, about 1 cm², about 5 cm² or more, about 10 cm² or more and any range between and including the area values provided. Again, a smaller area may enable better drainage and may enable the high friction material to dry out quickly. However, a large enough area may be preferred to provide adequate traction, such as at last 250 mm² or more. A traction layer may be very thin when being a high friction material coating, or a meltblown layer and may have a thickness of about 1 micrometers (μm) or more, about 2 μm or more, about 5 μm or more, about 20 μm or more, about 100 μm or more and any range between and including the thickness values provided. When the traction layer includes raised portions, the traction layer including these raised portions may have a height or thickness of about 1 mm or more, about 2 mm or more, about 4 mm or more, about 5 mm or more and any range between and including the thickness values provided. A large thickness may not be required to greatly increase traction and a lower thickness reduces weight, which is desirable, therefore thinner is preferred.

The friction layer of the traction layer of the high traction roof underlayment may be a continuous friction layer, discontinuous friction layer or a discrete friction layer. A continuous friction layer may form a film of high friction material on the high traction roof underlayment and may be bonded to the barrier layer or to a fabric layer. A discontinuous friction layer has opening or apertures in the friction layer and may include elongated friction portions that may crisscross each other to form a grid or may be some other pattern. A grid of bands of high friction material forms a discontinuous friction layer that may be contiguous, wherein the friction material is connected across the grid pattern. A discrete friction layer has discrete friction portions that are not connected to other friction portions, wherein the discrete fiction portions have a closed perimeter. A discrete friction layer has friction material configured as discrete areas, such as dots or other discrete geometric portions, including, but not limited to diamonds, polygonal shapes, and the like.

A preferred friction layer may be an interconnecting pattern of elongated high friction material, or bands of traction layer material. A strand of high friction material is elongated having a length that is five times or more, and in most cases ten times or more the width of the strand. A strand of high friction material may extend continuously across the high traction roof underlayment. An interconnecting pattern may form discrete openings in the interconnecting pattern and may be a grid pattern. The grid pattern may include a first series of bands of high friction material and second series of stands of high friction material that is configured substantially orthogonally to the first series of bands of high friction material, or within about 20 degrees of orthogonal, to form a grid. The bands of high friction material may have a width of about 2 mm or more, about 4 mm or more, about 6 mm or more, about 8 mm or more and any range between and including the values provided. The distance between adjacent elongated high friction bands may be at least the same as the width of one of the bands of high friction material forming the cell or opening in the grid and may be twice the width or more, or about five times the width or more, or ten times the width or more, or even 20 times the width or more. A grid pattern of bands of high friction material may be preferred as it may be more durable to abrasion and prevent peeling of the high friction material from the base material, the fabric layer or the barrier layer.

A high friction material is a material with a static coefficient of friction against stainless steel surface as defined by a Coefficient of Friction (COF) test under ASTM D1894 of about 0.35 or more, about 0.40 or more, about 0.5 or more, about 0.60 or more, and any range between and including the static coefficients of friction provided. A test block or sled for ASTM 1894 from The Universal Grip Company, Salem, MA is used in the testing and is the second surface against the material tested. The traction layer and/or a friction layer of the traction layer, such as friction material, and/or a meltblown layer may have a COF according to ASTM D1894 of about 0.35 or more, about 0.40 or more, about 0.5 or more, about 0.60 or more, and any range between and including the static coefficients of friction provided.

A high friction material may be a varnish, an elastomeric material such as a urethane or silicone.

A high friction material may have a thickness of about 5 μm or less, 10 μm or less, or about 0.01 mm or more, about 0.1 mm or more, about 0.25 mm or more, about 0.5 mm or more and any range between and including the values provided. The thinner the layer the less weight the high friction material adds to the high traction roof underlayment. A high friction material may be coated onto the barrier layer or onto a fabric layer and may be a wash-coat, a solution of friction material in a fluid carrier, the friction material may be dissolved in a liquid carrier or may be a suspension of solid particles in the liquid carrier.

A traction layer may only cover a portion of the surface side of the high traction roof underlayment and may cover about 100% or less, about 95% or less of the area, about 80% or less, about 75% or less, about 50% or less, about 35% or less, about 25% or less of the area and any range between and including the values provided. A high area of coverage may provide improved slip resistance but may be more expensive and may make the underlayment much heavier, which may make it more difficult to move onto a roof and manipulate on a roof. Also, a high coverage of the traction layer would be more expensive. For these reasons a coverage of about 50% or less is preferred and 35% or less areal coverage is even more preferred. For higher coverage areas of the friction material, the thickness of the friction material may be very thin, such as less than 0.01 mm, or about 10 μm or less, for example and the friction material may be applied by a coating.

The adhesive on the roof side of the high traction roof underlayment may be a continuous adhesive layer, discontinuous or a discrete adhesive layer. A continuous adhesive layer forms a film of adhesive on the high traction roof underlayment and may be bonded to the barrier layer. A discontinuous adhesive layer has opening or apertures in the adhesive layer and may include elongated adhesive portions that may crisscross each other or some other pattern. A discrete adhesive layer has discrete adhesive portions that are not connected to other adhesive portions, or put another way, a discrete adhesive layer or portion has a closed perimeter.

A high traction roof underlayment may have a traction layer that is water resistant and/or water repellant to prevent liquid water from absorbing into the traction layer. A traction layer may be made of water repellant materials, or materials that do not absorb water, such as a polymer, or an elastomer, such as silicone. A traction layer may include a hydrophobic coating such as on or within a fabric layer of the traction layer, wherein the fabric is coated with a hydrophobic material to prevent water from absorbing into the fabric layer of the traction layer. Also, the traction layer may include a hydrophobic coating, such as on the surface of the traction layer or on the friction layer of the traction layer. Also, the high friction material may also be inherently hydrophobic such as a silicone high friction material.

The high traction roof underlayment may also be a self-adhering underlayment that includes an activator layer on the surface side that is configured to activate and bond with the adhesive when configured in contact on a roof. The activator layer may be a strip configured proximal an edge of the self-adhering underlayment, such that a second piece of self-adhering underlayment will overlay and contact this activator layer strip when installed on a roof. The activator layer may be configured to chemically react with the adhesive layer to enable adhesion between the layers. The activator layer may comprise a chemical that chemically bonds with the adhesive layer. The activator layer may not be a tacky adhesive and therefor a release liner for the activator layer may not be required. An activator layer may be non-tacky as defined as not adhering when pressed against the barrier layer of the self-adhering underlayment comprises for one minute with a pressure 70 kPa.

An exemplary high traction underlayment comprises a barrier layer, and an adhesive layer for bonding to a roof. The barrier layer may include a structural component such as a woven or non-woven fabric or scrim and a water barrier component, such as a polymer coating or film layer attached to the structural component. In an exemplary embodiment, the structural component is a woven material and the water barrier component is a coating of polymer on the woven structural component.

A barrier layer may be or include a water barrier component that may be selected based on the application and location of use. Very wet areas may require a more substantial or thicker water barrier component while more arid locations may require minimal water barrier thickness. A water barrier component may include a polymer coating or a polymer film that may be olefin, polypropylene, polyethylene, polyester, polyurethane and the like. The polymer films may be continuous films and may be tensilized to increase the modulus. The polymer films may be uniaxially oriented, wherein they are tensilized in one direction, the machine direction, or they may be biaxially oriented, wherein they are tensilized in both the machine direction and cross-machine direction. The polymer films may have a thickness of about 50 μm or less, about 25 μm or less, about 10 μm or more, about 1 mm or more, or even about 2 mm or more. The polymer films may extend substantially across the entire high traction roof underlayment and may be configured between a traction layer and an adhesive layer. A high traction roof underlayment may include one barrier layer that is a film or two barrier layers and both may be polymer films to ensure no water penetration through the thickness of the high traction roof underlayment. A first polymer film barrier layer may be bonded to a second polymer film barrier layer by a scrim, a lightweight netting material that may have a melting temperature at least 5° C. below or 10° C. or more below the melting temperature of the polymer films of the barrier layer.

A high traction underlayment may be a solid layer to prevent liquid water passage but may have a high moisture vapor transmission rate (MVTR) to enable moisture in the house to pass through the housewrap to prevent mold. An exemplary high traction underlayment may include a high MVTR layer including urethane, copolyester elastomer, microporous PP or PE, ethyl/ethylacrylate copolymer, ethyl/methylacrylate copolymer, and the like. This MVTR layer may be configured as the water barrier component. The moisture vapor transmission rate (MVTR) through the high traction underlayment according to ASTM E96-00 may be about 2.0 perm or more, about 3.0 perm or more, about 4.0 perm or more, and even at least 5.0 perm or more.

A high traction underlayment may be a solid layer to prevent liquid water passage but may have a high moisture vapor transmission rate (MVTR) to enable moisture in the house to pass through the housewrap to prevent mold. An exemplary self-adhering underlayment may include a high MVTR layer including urethane, copolyester elastomer, microporous PP or PE, ethyl/ethylacrylate copolymer, ethyl/methylacrylate copolymer, and the like. This MVTR layer may be configured as the water barrier component. The moisture vapor transmission rate (MVTR) through the self-adhering underlayment according to ASTM E96-00 may be about 2.0 perm or more, about 3.0 perm or more, about 4.0 perm or more, and even at least 5.0 perm or more.

An adhesive layer may be coupled to the barrier layer on the roof side to enable direct attachment to the exterior roof surface of a building. An adhesive layer may extend substantially over the entire roof surface of the high traction roof underlayment, or over at least 90% of the surface area. An adhesive layer may be a pressure sensitive adhesive that is configured in a continuous layer or as a discontinuous layer, such as dots or a grid or adhesive. The adhesive release liner is configured over the adhesive layer to prevent adhesion of adjacent layers when in a roll form.

A high traction roof underlayment may include a meltblown layer on the surface side to produce the traction layer, or friction layer of a traction layer to prevent slips and falls when working on a pitched roof. The meltblown layer includes meltblown fibers forming a meltblown layer including or consisting of meltblown fibers which may form a non-woven fabric layer on the surface side. An exemplary traction layer consists of meltblown fibers configured on the surface side. A traction layer may include a plurality of layers of meltblown layers that are layered one layer atop another layer. A first layer of meltblown material may have a first orientation of meltblown fibers and a second layer or meltblown material may have a second orientation of meltblown fibers, wherein the first orientation may be configured at an offset angle from the second layer, such as about 20 degrees or more, about 45 degrees or more, or about 90 degrees, or substantially orthogonal between about 80 and 100 degrees.

An exemplary traction layer is a random arrangement of meltblown fibers that extend in a variety of directions and not in a pattern. The individual meltblown fibers of standard meltblown materials may have a diameter of about 0.1 μm or more, about 0.5 μm or more, about 1 μm or more, about 2 μm or more, about 3 μm or more, about 4 μm or more, about 5 μm or more, about 7.5 μm or more, or event 10 μm or more, and any range such as from about 0.5 μm to about 5 μm or more, between and including the diameter values provided. Note that the meltblown fibers may not be circular in cross-section and diameter may refer to the maximum cross-sectional, or cross-length dimension or a meltblown fiber. Meltblown fibers of the present invention may be much larger than standard meltblown or spunbonded fibers that have a diameter in the range of 15 to about 35 μm. The size range of the meltblown fibers in the meltblown layer may be larger than other meltblown materials, as the size uniformity may not be critical for this traction layer, as it may be for filtration and other applications. Larger average meltblown fiber diameters are believed to provide improved traction. A preferred average meltblown fiber diameter of the meltblown material may be 20 μm or more, about 25 μm or more, about 30 μm or more or even 40 or 50 μm or more and any range between and including the average fiber diameters provided.

The meltblown fiber layer may include fiber clusters, or nodes of intersections of many fibers that form a larger mass. These fiber clusters may have a size (length and/or width) that is about 2 mm or more, about 5 mm or more, about 10 mm or more, about 25 mm or more, or even 50 mm or more and any range between and including the sizes provided. The fiber clusters have a higher density, mass per area, than the surrounding meltblown fibers, wherein a ratio of the density to the surrounding meltblown fibers is about 2:1 or more, about 3:1 or more, about 5:1 or more and any range between and including the ratios provided. The fiber clusters may be elongated having a length that is much greater than a width, with a ratio of length to width of about 4:1 or more, 5:1 or more, about 6:1 or more or even 10:1 or more and any range between and including the ratios provided. The clusters may overlap each other or intersect each other which may provide improved traction. The clusters may be spaced randomly across the surface layer and may only make up a small portion of the area of the surface layer or meltblown layer and have an areal concentration as about 35% or less, about 25% or less, about 15% or less, about 10% or less, or even 5% or less, and any range between and including the area values provided. A meltblown layer may include a cluster areal density of about 50/929 cm² (1 ft²) or more, about 75/929 cm² (1 ft²) or more, about 100/929 cm² (1 ft²) or more, about 250/929 cm² (1 ft²) or more and any range between and including the cluster areal densities provided. A high areal density of the clusters may provide improved traction. The areal density of the clusters for this application may be much higher than meltblown fiber layers for other applications that typically try to reduce the cluster density and size. For filtration applications for example, the clusters increase flow resistance which is not desirable.

A traction layer and/or the meltblown layer may include additives, such as solids to increase the number of fiber clusters or shots. An exemplary additive is calcium carbonate that may be added to the polymer before meltblowing the meltblown layer to promote agglomeration of the polymer and formation of the shots and fiber clusters.

A meltblown material may have both fiber clusters and also shots, an agglomerate of the meltblown polymer that may have an aspect ratio of less than about 5:1, a size (in plane of the meltblown material) of 100 μm or more and an areal density of about 20 per 929 cm² (sqft) or more.

The exemplary meltblown fibers are made with polymers, such as homopolymers, that have a melt flow index of about 400 Melt Flow Rate (MFR) or more, about 750 MFR or more, about 1,000 MFR or more, about 1500 MFR or more, about 2,000 MFR or more, about 2,500 MFR or more, and any range between and including the MFR values provided. The MFR testing conditions are the standard for type of polymer tested. The homopolymer may be a standard isotactic homopolymer such as a homopolymer of polypropylene, or may be a copolymer of polypropylene that is formulated to have a lower melt temperature than a homopolymer of polypropylene. Lower melting temperatures may result in a meltblown layer that is more tacky and therefore provides better traction. Some polymers used for producing the meltblown layer may be atactic polypropylene, which has no melting point. These atactic polymers may be tacky are room temperature or about 23° C. Other suitable polymers for the meltblown fiber layer include polyethylene, polyamide, poly 1-butene, elastomeric polymers including but not limited to, styrenic block copolymers, polyurethane and the like. Also, blends of polymers may be used to provide the desired fiber diameter and high friction.

The exemplary meltblown fibers may be bicomponent fibers or multicomponent fibers, having two or more polymer types within the fiber. A fiber may be a core-shell type fiber having a first polymer in a core and a second polymer configured around the core. A fiber may be a pie type fiber having different polymers configured around the outer perimeter of the fiber. A fiber may have two or more fibers intermixed randomly within the fiber. A fiber may have a bicomponent side-by-side configuration with a first polymer extending on one side and a second polymer on an opposing second side, or adjacent the first polymer, which may cause curing.

A roof layer of the high traction roof underlayment, a layer configured more proximal to a roof surface may also include bicomponent fibers and may be spunbonded fibers that are bicomponent fibers or multicomponent fibers, having two or more polymer types within the fiber. A fiber may be a core-shell type fiber having a first polymer in a core and a second polymer configured around the core. A fiber may be a pie type fiber having different polymers configured around the outer perimeter of the fiber. A fiber may have two or more fibers intermixed randomly within the fiber. A fiber may have a bicomponent side-by-side configuration with a first polymer extending on one side and a second polymer on an opposing second side, or adjacent the first polymer, which may cause curing

A meltblown fiber may have a circular or substantially circular cross-sectional shape or may be flat or planar in shape and form tapes, or ribbons, or may have an irregular cross-sectional shape.

The high traction roof underlayment is configured to provide improved traction for walking on a roof surface, especially a pitched roof surface and may provide high friction even when wet or with dirt and debris on the surface of the high traction roof underlayment. A static coefficient of friction of traction layer as tested against itself according to ASTM 1894-14, may be effectively high, such as about 0.35 or more, about 0.5 or more, about 0.75 or more, about 1.0 or more, about 1.25 or more, and any range between and including the values provided. ASTM 1894-14, updated on Mar. 6, 2023 is hereby incorporated by reference herein. While OSHA does not have a standard for the friction coefficient of walking surfaces, In the appendix under rule No. 1910.22 the document states:

• • “2. Slip Resistance. A reasonable measure of slip-resistance is static coefficient of friction (COF). A COF of 0.5, which is based upon studies by the University of Michigan and reported in the “Work Surface Friction: Definitions, Laboratory and Field Measurements, and a Comprehensive Bibliography,” is recommended as a guide to achieve proper slip resistance. A COF of 0.5 is not intended to be an absolute standard value. A higher COF may be necessary for certain work tasks, such as carrying objects, pushing or pulling objects, or walking up or down ramps.”

The areal mass or weight of the meltblown layer per unit surface area may be high enough to provide enough area for traction and friction, such as about 5 g/m² or more or about 10 g/m² or more and may be low weight to prevent excessive weight that is not required, and therefore may be about 25 g/m² or less, or even about 20 g/m² or less, or any range between and including the areal mass values provided such as from about 5 g/m² to about 20 g/m². A preferred mass is about 10 g/m² to about 15 g/m². The meltblown layer may be applied directly to the roof underlayment and therefore may be applied at a low areal mass since it is supported by the underlayment. Alternatively, a meltblown layer may be a stand-along layer or meltblown non-woven fabric that is subsequently coupled to the high traction roof underlayment such as by melt bonding or by use of an adhesive.

A meltblown layer may be configured on a meltblown support to enable the meltblown material to then be attached to the high traction roof underlayment, such as to a barrier layer. An exemplary meltblown support is a lightweight spunbonded material having an areal mass of about 50 g/m² or less, and preferably about 25 g/m² or less, or even about 20 g/m² or less, any range between and including the values provided. A traction layer may include a spunbonded fabric layer, a non-woven fabric layer, with a meltblown layer on the spunbonded fabric layer and exposed to form a friction layer of the traction layer. Furthermore, a high friction material may be coated onto the composite fabric layer of the spunbonded fabric layer and meltblown layer to provide additional friction and slip resistance.

The traction layer, which may be the meltblown layer bonded to the meltblown support, such as the spunbonded material, may be bonded to a barrier layer of the high traction roof underlayment and may be bonded using an embossed heated processing roll that imparts raised portions and depressed portions to the high traction layer. The raised portions may further be coated with friction material through a transfer roll process wherein the raised portions contact a roll coated with a thin layer of the friction material, such as a elastomeric material or varnish as described herein. Also, a hydrophobic coating may be applied to a barrier layer or the high traction roof underlayment before bonding the traction layer thereto.

The high traction roof underlayment may include a first barrier layer and a second barrier layer that may be separated by a thin coupling layer, such as a scrim layer. A scrim layer in a lightweight porous layer that typically has a grid pattern of polymeric material. Also, a high traction roof underlayment may have an adhesive layer on the roof side for bonding to a roof surface and a release liner configured over the adhesive layer to enable the high traction roof underlayment to be rolled up in a roll. The release liner would have to be removed before application of the high traction roof underlayment to a roof surface.

A meltblown material is different from a spunbond material due to their manufacturing process. Spunbond involves extruding continuous filaments that are laid down on a conveyor belt, while meltblown uses high-velocity air to blow molten polymer, such as polypropylene, creating fine fibers with a random arrangement and with fiber clusters and shots that may increase traction. Meltblown materials may have a higher concentration of void areas than a spunbonded material due to the processing.

A roof underlayment may include a meltblown discontinuous fiber (as defined by industry standard) or other fiber such as microfibers or nanofibers that are distinct in size from the standard continuous fibers. A microfiber has a diameter or cross-length dimension of less than about 500 μm. A nanofiber has a diameter or cross-length dimension of about 0.01 to 0.1 μm. These smaller fibers do not contribute significantly to the tensile strength of an underlayment but may contribute to walkability. They may also impart information visually, such as indicators of moisture or temperature ranges. The meltblown component is also characterized by a non-uniform distribution on the surface such that if these fibers are a different color, the nonuniformity is visually apparent from a distance of up to 6.1 m (20 ft).

The meltblown component can be added in a single process with production of the continuous fiber, or it can be added to a previously bonded layer of continuous fiber in a second process.

Moisture vapor transmission rate through the high traction roof underlayment may be measured using ASTM E96-00 (Last Updated: Aug. 16, 2017), Water Vapor Transmission. ASTM E96 tests and evaluates the water vapor transfer through semi-permeable and permeable samples.

An exemplary high traction underlayment may comprise a barrier layer, and an adhesive layer for bonding to a roof. The barrier layer may include a structural component such as a woven or non-woven fabric or scrim and a water barrier component, such as a polymer coating or film layer attached to the structural component. In an exemplary embodiment, the structural component is a woven material and the water barrier component is a coating of polymer on the woven structural component.

A water barrier component may be selected based on the application and location of use. Very wet areas may require a more substantial or thicker water barrier component while more arid locations may require minimal water barrier thickness. A water barrier component may include a polymer coating or a polymer film that may be olefin, polypropylene, polyethylene, polyester, polyurethane and the like. The polymer films may be tensilized to increase the modulus. The polymer films may be uniaxially oriented, wherein they are tensilized in one direction, the machine direction, or they may be biaxially oriented, wherein they are tensilized in both the machine direction and cross-machine direction.

A high traction underlayment may be waterproof to prevent liquid water passage but may have a high moisture vapor transmission rate (MVTR) to enable moisture in the house to pass through the housewrap to prevent mold. An exemplary high traction underlayment may include a high MVTR layer including urethane, copolyester elastomer, microporous PP or PE, ethyl/ethylacrylate copolymer, ethyl/methylacrylate copolymer, and the like. This MVTR layer may be configured as the water barrier component. The moisture vapor transmission rate (MVTR) through the high traction underlayment according to ASTM E96-00 may be about 2.0 perm or more, about 3.0 perm or more, about 4.0 perm or more, and even at least 5.0 perm or more.

An adhesive layer may be coupled to the barrier layer on the roof side to enable direct attachment to the exterior roof surface of a building. An adhesive layer may extend substantially over the entire roof surface of the high traction roof underlayment, or over at least 90% of the surface area. An adhesive layer may be a pressure sensitive adhesive that is configured in a continuous layer or as a discontinuous layer, such as dots or a grid or adhesive. The adhesive release liner is configured over the adhesive layer to prevent adhesion of adjacent layers when in a roll form.

The high traction roof underlayment may comprise a number of layers including at least one layer of meltblown which may be configured on or extend through another layer to be exposed on a walking surface for traction. The construction may include one or more spunbonded layers. An exemplary high traction roof underlayment may have a construction of a spunbonded layer(S) proximal a roof surface and meltblown layer (M) on a walking or exposed surface, (SM), or a plurality of spunbonded layers proximal a roof surface (SS) and a meltblown layer on a walking surface, or (SSM). Other construction may include SSSM, with three layers of spunbonded, SSMM, SSMS with a spunbonded layer over the meltblown layer on the walking surface, SSMMS, SSSSM and other combinations.

An exemplary high traction roof underlayment may include a woven fabric, foil, film or netting material to provide additional structural support and strength and/or permeation properties. A film may be used to control moisture vapor transmission through the high traction roof underlayment.

The meltblown fibers may be deposited directly over a spunbonded layer to produce a meltblown layer on the spunbonded layer and this may be done in-line on a machine.

The high traction roof underlayment may include an adhesive on a roof surface for application and adhering to a roof surface. An adhesive or adhesive layer may also have a release liner configured thereover that requires removal before adhering to a roof surface. The adhesive may include a bitumen based adhesive, acrylic adhesive and/or a butyl based adhesive.

The high traction roof underlayment may be configured as a flooring underlayment, a drywall applications, geomembrane, industrial packaging and the like.

An exemplary high traction roof underlayment may include a plurality of layers that may be produced by extrusion coating, adhesive lamination, liquid coating, thermal calendaring, thermal lamination, adhesive lamination and the like.

Definitions

Moisture vapor transmission rate through the barrier composite may be measured using ASTM E96-00 (Last Updated: Aug. 16, 2017), Water Vapor Transmission. ASTM E96 tests and evaluates the water vapor transfer through semi-permeable and permeable samples.

The summary of the invention is provided as a general introduction to some of the embodiments of the invention and is not intended to be limiting. Additional example embodiments including variations and alternative configurations of the invention are provided herein.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

The accompanying drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention, and together with the description serve to explain the principles of the invention.

FIG. 1 shows a cross sectional view of layers of roof underlayment of the prior art including a release liner over the adhesive layer.

FIG. 2 shows a perspective view of the prior art roof underlayment with the release liner removed and being attached to a roof with the adhesive layer on the roof side of the roof underlayment being bonded to the roof and to the other underlayment in the overlap region.

FIG. 3 shows a cross sectional view of layers of an exemplary high traction roof underlayment that includes a traction layer on the surface side configured to provide improved traction and an adhesive layer on the roof side with a release liner configured thereover to prevent adhesion to the adjacent layer in the roll configuration.

FIG. 4 shows a cross sectional side view of two pieces of exemplary high traction roof underlayment being attached together by the adhesive layer and being attached to the roof by the adhesive layer.

FIG. 5 shows a perspective view of the high traction underlayment with the adhesive release liners removed from the adhesive layer and the adhesive layer of a first high traction underlayment being attached to the traction layer of the second high traction underlayment.

FIG. 6 shows a cross sectional view of layers of roof underlayment of the prior art including a release liner over the adhesive layer and a second surface adhesive liner over a surface adhesive strip configured to bond to the adhesive layer when the configured on a roof.

FIG. 7 shows a perspective view of the prior art roof underlayment with both release liners removed and being attached to a roof with the surface adhesive strip bonding to the adhesive layer on the roof side of the roof underlayment.

FIG. 8 shows a cross sectional view of layers of an exemplary roll of high traction roof underlayment that is a self-adhering roof underlayment that includes an activator layer on a surface side configured to activate the adhesive on the adhesive layer on the roof side of the self-adhering roof underlayment.

FIG. 9 shows a cross sectional side view of two pieces of exemplary self-adhering roof underlayment being attached together on a roof with the activator layer contacting the adhesive.

FIG. 10 shows a perspective view of the self-adhering underlayment with both the adhesive release liners removed from the adhesive layer and the adhesive layer of a first self-adhering underlayment being attached to the activator layer of the second self-adhering underlayment.

FIG. 11 shows a surface view of a high traction roof underlayment having a discontinuous traction layer with the high friction material extending in strips or bands across the length and between a first edge and opposing second edge.

FIG. 12 shows a surface view of a high traction roof underlayment having a discontinuous traction layer with the high friction material configured in as discrete high friction areas with gaps extending around the discrete high friction material.

FIG. 13 shows a cross sectional view of layers of roof underlayment of the prior art including a fabric traction layer on the surface of the underlayment.

FIG. 14 shows a perspective view of the prior art roof underlayment being attached to a roof with the adhesive layer on the roof side of the roof underlayment being bonded to the roof and a second underlayment overlapping the first underlayment region.

FIG. 15 shows a surface side view of an exemplary high traction roof underlayment having a discrete friction layer bonded to a fabric layer to form the traction layer.

FIG. 16 shows a cross sectional view of the exemplary high traction roof underlayment shown in FIG. 15 having a traction layer, a barrier layer and an adhesive layer on a roof side of the high traction roof underlayment.

FIG. 17 shows a surface side view of an exemplary high traction roof underlayment having a discrete friction layer bonded to an embossed fabric layer to form the traction layer.

FIG. 18 shows a cross sectional view of the exemplary high traction roof underlayment shown in FIG. 17 having a traction layer, a barrier layer and an adhesive layer on a roof side of the high traction roof underlayment.

FIG. 19 shows a surface side view of an exemplary high traction roof underlayment having a discontinuous friction layer bonded to a fabric layer to form the traction layer.

FIG. 20 shows a cross sectional view of the exemplary high traction roof underlayment shown in FIG. 19 having a traction layer, a barrier layer and an adhesive layer on a roof side of the high traction roof underlayment.

FIG. 21 shows a surface side view of an exemplary high traction roof underlayment having a discontinuous friction layer of crisscrossing friction material bonded to a fabric layer to form the traction layer.

FIG. 22 shows a cross sectional view of the exemplary high traction roof underlayment shown in FIG. 21 having a traction layer, a barrier layer and an adhesive layer on a roof side of the high traction roof underlayment.

FIG. 23 shows a first high traction roof underlayment is bonded to the roof and second high traction roof underlayment has a release liner over the adhesive layer that is configured for removal to enable attachment of the second high traction roof underlayment to the first high traction roof underlayment.

FIG. 24 shows a perspective view of a high traction roof underlayment being attached to a roof with the adhesive layer on the roof side of the roof underlayment being bonded to the roof and a second underlayment overlapping the first underlayment region and being bonded to the roof.

FIG. 25 shows a Scanning Electron Micrograph (SEM) image of an exemplary meltblown layer.

FIG. 26 shows a probability distribution of the fiber diameters of the meltblown layer shown in FIG. 25. FIGS. 25 and 26 are from the Journal of Materials Science 53(9) article, “Turbulent air flow field in slot-die melt blowing for manufacturing microfibrous nonwoven materials” May 2018, Sheng Xie, et al.

FIG. 27 shows a photograph of an exemplary meltblown layer.

FIG. 28 shows an optical micrograph of an exemplary meltblown layer of meltblown material having fiber clusters and also shots, an agglomerate of the meltblown polymer.

FIG. 29 shows an exemplary traction layer comprising two meltblown layers of meltblown fibers having fiber orientations that are offset an offset angle.

FIG. 30 shows a cross-sectional view of high traction roof underlayment that includes a meltblown layer on a surface side that may have fiber clusters and shots of meltblown polymer that improve traction.

Corresponding reference characters indicate corresponding parts throughout the several views of the figures. The figures represent an illustration of some of the embodiments of the present invention and are not to be construed as limiting the scope of the invention in any manner. Some of the figures may not show all of the features and components of the invention for ease of illustration, but it is to be understood that where possible, features and components from one figure may be included in the other figures. Further, the figures are not necessarily to scale, some features may be exaggerated to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

As used herein, the terms “comprises,” “comprising,” “includes,” “including,” “has,” “having” or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Also, use of “a” or “an” are employed to describe elements and components described herein. This is done merely for convenience and to give a general sense of the scope of the invention. This description should be read to include one or at least one and the singular also includes the plural unless it is obvious that it is meant otherwise.

Certain exemplary embodiments of the present invention are described herein and are illustrated in the accompanying figures. The embodiments described are only for purposes of illustrating the present invention and should not be interpreted as limiting the scope of the invention. Other embodiments of the invention, and certain modifications, combinations and improvements of the described embodiments, will occur to those skilled in the art and all such alternate embodiments, combinations, modifications, improvements are within the scope of the present invention.

FIG. 1 shows a cross sectional view of layers of roof underlayment 312, 312′ of the prior art. Each layer of the roof underlayment has a barrier layer 317, 317′ and an adhesive release liner 319 that is configured between the adhesive layer 318 of one layer and the barrier layer 317′ of the other layer of roof underlayment 312′. The barrier layer is on the surface side 604 and the adhesive layer 318 is on the roof side 606.

FIG. 2 shows a perspective view of the prior art roof underlayment with both release liners removed and the second roof underlayment 312′ attached to a roof 310 by the adhesive layer 318′ on the roof side 606 of the roof underlayment. The barrier layer 317 of each piece of underlayment is exposed to the surface for walking thereon and may be slippery.

Referring now to FIGS. 3 to 5, an exemplary high traction roof underlayment system 400 includes high traction roof underlayment 602, 602′ each having a barrier layer 322, 322′ an adhesive layer 330, 330′ on the roof side 606 and a fabric layer 420, 420′ on a surface side 604. The barrier layer may include a structural component 324 for strength and a water barrier component 326 to prevent water passing through the high traction roof underlayment. An adhesive release liner 339, 339′ is configured over the adhesive layers 330, 330′ respectively when in a rolled configuration, as shown in FIG. 3. The fabric layer 420 may have high friction and may be a woven or non-woven.

As shown in FIG. 4, the two pieces of exemplary high traction roof underlayment 602, 602′ are being attached together on a roof 310 with the fabric layer 420 on the surface side 604. The first high traction roof underlayment 602 has a width 305 from a first edge 308 to second edge 308′.

As shown in FIG. 5, the first piece of high traction underlayment 602 is being overlapped on the second piece of high traction roof underlayment 602′ such that the fabric layer 420′ of the second piece of high traction roof underlayment 602′ is contacting the adhesive layer 330 of the first piece of high traction roof underlayment 602. The fabric layer 420 may be configured to bond to the adhesive layer and provide a strong bond between the first piece of high traction roof underlayment and second piece of high traction roof underlayment.

FIG. 6 shows a cross sectional view of layers of roof underlayment 312, 312′ of the prior art including a barrier layer 317 and an adhesive release liner 319 over the adhesive layer 318 and a second surface adhesive liner 314 over a surface adhesive strip 316 configured on the surface side 604 to bond to the adhesive layer 318 of a layered piece of roof underlayment when applied on a roof.

FIG. 7 shows a perspective view of the prior art roof underlayment shown in FIG. 6, with both release liners removed and being attached to a roof 310 with the surface adhesive strip 316 bonding to the adhesive layer 318 on the roof side 606 of the roof underlayment.

Referring now to FIGS. 8 to 10, a roll of high traction roof underlayment 301 includes layers of high traction roof underlayment 602, 602′ that are rolled over each other. The high traction roof underlayment layers shown are self-adhering roof underlayment 300, 300′ having a barrier layer 322, an adhesive layer 330 on the roof side 606 and a fabric layer 420, 420′ and activator layer 340 on a surface side 604. The barrier layer may include a structural component 324 for strength and a water barrier component 326 to prevent water passing through the self-adhering roof underlayment. An adhesive release liner 339 is configured over the adhesive layer when in a rolled configuration, as shown in FIG. 8. The activator layer 340′ of the second high traction roof underlayment 602′ may have an activator chemical 341′ that is configured to chemically react with an adhesive 331 of the adhesive layer 330 of the first high traction roof underlayment 602 and may cross-link with the adhesive of the adhesive layer.

As shown in FIG. 8, the two pieces of exemplary self-adhering roof underlayment 300, 300′ are being attached together on a roof 310 with the activator layer 340′ on the surface side 604′ of the second piece of self-adhering roof underlayment 602′ contacting the adhesive layer 330 on the roof side 606 of the first piece of self-adhering roof underlayment 300. The activator layer will activate the adhesive to bond to the activator layer. The adhesive layer 330′ of the second piece of self-adhering roof underlayment 602′ is bonded to the roof 310. The first piece of self-adhering roof underlayment also has an activator strip that is configured to bond to the adhesive layer of a third piece of self-adhering roof underlayment when configured over the second piece of self-adhering roof underlayment.

As shown in FIG. 9, the activator layer 340 has a width 345 that may be a proportion of the overall width 305 from a first edge 308 to a second opposing edge 308′ of the high traction roof underlayment 602, such as about 20% or less, about 10% or less, or 5% or less. Put another way, the width of the activator layer may be about 10 mm or more, about 20 mm or more, about 30 mm or more, about 50 mm or more, about 100 mm or less and any range between and including the values provided.

As shown in FIG. 10, the first piece of high traction roof underlayment 602 is being overlapped on the second piece of high traction roof underlayment 602′ such that the activator layer 340′ of the second piece of high traction roof underlayment 602′ is contacting the adhesive layer 330 of the first piece of self-adhering roof underlayment 602. Note that both the adhesive release liners are removed from the adhesive layer.

Referring now to FIGS. 11 and 12, a high traction roof underlayment 602 may have a discontinuous fabric layer 421 that may have gaps 430 between portions of the fabric layer. As shown in FIG. 11, the discontinuous fabric layer 421 includes bands of fabric 422 that extend along the length of the high traction roof underlayment 602 with gaps extending a gap width 435 between the bands of the fabric 422. The gaps and bands of fabric are elongated having a length that is at least five times greater than the width. The bands of fabric 422 have a width 425 and this width may be configured to provide adequate friction for a person walking on the high traction roof underlayment 602 when on a roof. Also, as shown in FIG. 11, the fabric layer 420 may be configured an upper offset distance 427 from the edge 308, a top edge when configured on a roof, wherein the surface adhesive strip 316 and surface release liner 314 are configured. Put another way, the fabric layer 420 may be offset from the top edge to allow room for the surface adhesive strip 316 and surface release liner 314. Likewise, the fabric layer 420 may be configured a lower offset distance 429 from the edge 308′, a lower or bottom edge when the high traction roof underlayment 602 is configured on a roof.

As shown in FIGS. 12, the high traction roof underlayment 602 has a discontinuous fabric layer 421 with discrete fabric layers 424 and gaps 430 that extend around the discrete fabric layers 424. This configuration may provide effective traction and may also prevent water from gathering on the surface as there is drainage between the discrete fabric layers or areas. The high friction fabric 426 has a length 423 along a length axis 616 of the high traction roof underlayment 602.

FIG. 13 shows a cross sectional view of layers of roof underlayment 312, 312′ of the prior art. Each layer of the roof underlayment has a traction layer 315, 315′ on a surface side 604, 604′, a barrier layer 317, 317′, and an adhesive 318, 318′, on a roof side 606 that bonds to the roof. The barrier layer is configured between the adhesive and the traction layer. The bottom edge 309 of the first roof underlayment 312 overlaps the top edge 307′ of the second piece of roof underlayment 312′. The top edge 307 of the first piece of underlayment is configured above the bottom edge when the roof underlayment is configured on a pitched roof.

FIG. 14 shows a perspective view of the prior art roof underlayment 312, 312′ being attached to a roof 310 by the adhesive layer 318 on the roof side 606 of the roof underlayment. The traction layer 315 of each piece of underlayment is exposed to the surface on the surface side 604 for walking thereon and can become slippery especially when wet.

Referring now to FIGS. 15 to 21, an exemplary high traction roof underlayment 612 has a traction layer 636 that includes traction layer 636 including a friction layer 630 on a surface side 604 of the underlayment. The friction layer 630 may be bonded to a fabric layer 650, which may be a non-woven fabric 654. Also, the fabric may be an embossed fabric layer 652, having raised areas that extend up from compressed areas. The friction layer 630 is discontinuous on the surface and may include discrete friction portions having a bound or closed perimeter, such as dots or diamonds. The traction layer 636 may be bonded to the barrier layer 617 and an adhesive layer 618, containing an adhesive 619, may be bonded to the barrier layer on the roof side 606 of the high traction roof underlayment 612.

As shown in FIGS. 15 to 20, the traction layer 636 may include a hydrophobic coating 628, which may be configured on the friction layer 630 and/or on a fabric layer 650. As shown in FIGS. 15, 17, 19 and 21, a hydrophobic coating 628 is configured on the traction layer 636 and may be configured on the friction layer 630, such as on the discrete friction layer 632, and a hydrophobic coating 628′ is configured on the fabric layer 650, such as a coating on the fibers of a non-woven fabric.

As shown in FIGS. 15 and 16, a traction layer 636 includes a discrete friction layer 632 having discrete dots of friction material 638 having a closed perimeter, wherein each discrete dot of friction material does not contact the other discrete dots. As shown in FIG. 4, the friction layer 630 is raised up from the fabric layer 650 and the fabric layer is bonded to the barrier layer 617. The adhesive layer 618 is bonded to the barrier layer on the roof side 606 of the high traction roof underlayment 612.

As shown in FIGS. 17 and 18, a traction layer 636 includes a discrete friction layer 632 having discrete dots of friction material 638 having a closed perimeter, wherein each discrete dot of friction material does not contact the other discrete dots. As shown in FIG. 18, the fabric layer 650 is an embossed fabric layer 652 having raised portions 653 and depressed portions 655. The friction layer 630 is configured or bonded to the raised portions 653 of the embossed fabric layer 652 and the fabric layer is bonded to the barrier layer 617. The adhesive layer 618 is bonded to the barrier layer on the roof side 606 of the high traction roof underlayment 612.

As shown in FIGS. 19 and 20, a traction layer 636 includes a discontinuous friction layer 634 having elongated bands 635 of friction material 638 that extend across the underlayment to form rows of friction material. The friction material 638 is bonded to the fabric layer 650. As shown in FIG. 20, the friction layer 630 is raised up from the fabric layer 650 to form groves in the friction layer which may effectively channel water to run off the underlayment. The rows may be configured to extend from a position proximal a top edge 613 toward a bottom edge 615 of the underlayment, or across the width of the high traction roof underlayment 612, or orthogonal to the length axis 616 of the high traction roof underlayment 612. The fabric layer is bonded to the barrier layer 617. The adhesive layer 618 is bonded to the barrier layer on the roof side 606 of the high traction roof underlayment 612.

As shown in FIGS. 21 and 22, a traction layer 636 includes a discontinuous friction layer 634 having elongated bands of friction material 638 that crisscross each other on the underlayment to form a grid of friction 639 material. Bands extend along the length axis 616 and across the width from a position proximal to a top edge 613 towards a bottom edge 615 of the high traction roof underlayment. The friction material 638 is bonded to the fabric layer 650. As shown in FIG. 22, the friction layer 630 is raised up from the fabric layer 650 to form a grid in the friction layer which may provide a very effective friction pattern and may be most durable, wherein abrasion of the grid is less likely to peel away a portion of the friction material. The fabric layer 650 is bonded to the barrier layer 617. The adhesive layer 618 is bonded to the barrier layer on the roof side 606 of the high traction roof underlayment 612.

Referring to any of FIGS. 15 to 22, the fabric layer 650 may include a meltblown layer 500 as described herein and the meltblown layer may be configured on a non-woven fabric layer that may be embossed to form a discrete friction material or layer, discontinuous friction material or layer, bands of friction material and/or a grid of friction material.

As shown in FIG. 23, a first high traction roof underlayment 612, is bonded to the roof 310 by the adhesive layer 618 and a second high traction roof underlayment 612′ has a release liner 670 configured over the adhesive layer 618′. The release liner 670 is configured for removal from the adhesive layer 618′ to expose the adhesive 618′ on the roof side 606′ of the second high traction roof underlayment 612′. The second high traction roof underlayment 612′ can then be attached to the roof and to the first high traction roof underlayment. The bottom edge 615 of the second high traction roof underlayment 612′ overlaps the top edge 613′ of the first piece of high traction roof underlayment 612′. The top edge 613′ of the first piece of roof underlayment is configured above the bottom edge 615 of the second high traction roof underlayment when the roof underlayment is configured on a pitched roof 310.

As shown in FIG. 24, an exemplary high traction roof underlayment 612 is being attached to a roof 310 with the adhesive layer 618 on the roof side 606 of the roof high traction roof underlayment. A first high traction roof underlayment 612 is being bonded to the roof 310 and to a second high traction roof underlayment 612′ that is already bonded to the roof. The traction layer 636 is configured on a surface side 604 of the high traction roof underlayment to improve traction and prevent falls resulting in injury.

Referring now to FIGS. 25 and 27, an exemplary meltblown layer 500, a traction layer 636 of the high traction roof underlayment includes a plurality of meltblown fibers 520 that are randomly oriented. The meltblown layer 500 also has fiber clusters 550 that are larger masses of the meltblown polymer and serve as interconnects for the meltblown fibers. FIG. 26 shows a probability distribution of the fiber diameters of the meltblown layer shown in FIG. 25. The mean fiber diameter is 18 μm with a distribution up to 60 μm or more for some fiber diameters. FIG. 25 and FIG. 26 are from the Journal of Materials Science 53(9) article, “Turbulent air flow field in slot-die melt blowing for manufacturing microfibrous nonwoven materials” May 2018, Sheng Xie, et al, incorporated by reference herein.

FIG. 27 shows photograph of an exemplary meltblown layer 500 that has a dashed area that is 25.4 cm×25.4 cm (10 in×10 in) and has meltblown fibers 520 that are pigmented to show their general shape and size as well as void area 540, void of meltblown material, wherein the void areas have at least a 12.7 mm (0.5 in) diameter gap between meltblown material as indicated by the dashed circle. These void areas may occupy a significant area of the meltblown layer such as about 25% or more, about 35% or more, about 50% or more, and may have an areal concentration of at least 10/25.4 cm×25.4 cm (10 in×10 in) area of the meltblown layer. The meltblown layer 500 may be configured on a meltblown support layer 570, such as a spunbonded layer 572 as shown. The fiber clusters 550 are elongated forming interconnected striations. Also shown are shots 560 as described herein. The meltblown layer may form the traction layer 636 of the high traction roof underlayment 612.

FIG. 28 shows a magnified photograph of an exemplary meltblown layer 500 with a scale bar of 1 mm shown. The meltblown layer 500 has fiber clusters 550 and also shots 560, an agglomerate of the meltblown polymer that may have an aspect ratio of length to width of less than about 5:1, a size (in plane of the meltblown material) of 200 μm or more and an areal density of about 20 per 929 cm² (1 ft²) or more. The shot is outlined in a dashed oval for clarity. The fiber clusters 550 have an aspect ratio of 4:1 or more, such as about 10:1 as shown by reference number 550. The meltblown layer 500 is on a meltblown support layer 570, which is a spunbonded polymer.

FIG. 29 shows a traction layer 636 comprising a first meltblown layer 500 having meltblown fibers 520 is a first orientation and a second meltblown layer 500′ that has meltblown fibers 520 in a second orientation configured at offset angle from the first meltblown layer. The orientation of each meltblown fiber visible in a scanning electron micrograph taken at 1000× magnification may be determined and the average orientation may be determined and compared with the average orientation of all the visible meltblown fibers in the second meltblown layer of meltblown fibers. The general average or orientation is indicated by the bold arrow on the image.

As shown in FIG. 30, an exemplary high traction roof underlayment 612 includes a meltblown layer 500 on a surface side 604 that may have fiber clusters 550 and shots 560 of meltblown polymer that improve traction. The meltblown polymer may be a low molecular weight polymer that has a higher coefficient of friction than higher molecular weight polymers. The meltblown layer may be on a meltblown support 570, such as a spunbonded layer as described herein and form the traction layer 636, a fabric layer 420 having an effective coefficient of friction to prevent slipping. The meltblown may be bonded to a barrier layer 617 directly, and a scrim layer 580 may bond the first barrier layer to a second barrier layer 617′. The high traction roof underlayment 612 may include an adhesive layer 618, such as a pressure sensitive adhesive, and a release layer 660 on the roof side 606. The adhesive layer is configured for adhering the high traction roof underlayment 612 to a roof surface. The fabric layer 650, such as the meltblown layer 500 may be an embossed fabric layer 652 or otherwise processed to form raised portions 653 and depressed portions 655 forming the traction layer 636 of the high traction roof underlayment. Note that the meltblown layer alone, without further embossing or without raised and depressed portions may effectively form the traction layer 636, as the meltblown layer may provide an effective coefficient of friction. Also, a friction material 638 may be configured on the surface side 604 to provide additional traction and the friction material may form a friction layer over the meltblown layer 500. The friction material may form a friction layer 630 that may be a discrete friction layer 632 wherein the friction material 638 is configured on the raised portions 653 as shown.

It will be apparent to those skilled in the art that various modifications, combinations and variations can be made in the present invention without departing from the scope of the invention. Specific embodiments, features and elements described herein may be modified, and/or combined in any suitable manner. Thus, it is intended that the present invention cover the modifications, combinations and variations of this invention provided they come within the scope of the appended claims and their equivalents.