EP2297506A1

EP2297506A1 - Pre-applied waterless adhesive on hvac facings with sealable flange

Info

Publication number: EP2297506A1
Application number: EP09774408A
Authority: EP
Inventors: Jerry Parks
Original assignee: Owens Corning Intellectual Capital LLC
Current assignee: Owens Corning Intellectual Capital LLC
Priority date: 2008-07-03
Filing date: 2009-07-01
Publication date: 2011-03-23
Also published as: CA2729768A1; MX2010014449A; CN102124262A; US20100000170A1; WO2010002958A1

Abstract

A fibrous insulation product (10) having at least one facing material (12) adhered thereto is provided. The facing includes a pre-applied waterless, thin-film adhesive (7), (125) that is thermoplastic and heat activated. Accordingly, the facing may be repaired or repositioned in the field with the use of a hot applicator. In at least one embodiment, the fibrous insulation (10) product is a duct board (147) formed of an insulation layer (14) with a vapor barrier (130) adhered to a first major surface and a fibrous web (5), (132) adhered to a second major surface. The vapor barrier is preferably wider than the insulation layer (14) to form a sealing flange (134). The waterless, thin-film adhesive may be placed on a sealing flange (134) and heat sealed without the use of hand applied foil tape. The waterless, thin-film adhesive reduces odor potential and improves fiberglass recovery. In addition, the waterless, thin-film adhesive requires less energy to cure than a water-based adhesive, thereby reducing cost.

Description

PRE-APPLIED WATERLESS ADHESIVE ON HVAC FACINGS WITH

SEALABLE FLANGE

TECHNICAL FIELD AND INDUSTRIAL APPLICABILITY OF THE INVENTION

The present invention relates generally to rotary fiberglass insulation, and more particularly, to fibrous insulation products faced with one or more facing materials having thereon a waterless, pre-applied thin-film adhesive, including HVAC product facings with a sealable flange.

BACKGROUND OF THE INVENTION

Ducts and conduits are used to convey air in building heating, ventilation, and air conditioning (HVAC) systems. Often these ducts are formed of sheet metal, and, as a result, do not possess good thermal or acoustical properties. In order to enhance these properties, the ducts are lined with a flexible thermal and sound insulating material. Duct insulation used in HVAC systems typically includes a facing layer adhered to an insulation layer. Often the facing layer acts as, or is, a vapor barrier. The fibrous duct insulation is typically formed of a suitable organic or inorganic material such as fiberglass. Typical fiberglass duct boards or duct liners are constructed of a fiberglass insulation layer having a density from about 1.0 to about 7.0 pounds per cubic foot (pcf) and a thickness from about 0.5 to about 3.0 inches. The facing material is commonly affixed to the fibrous insulation by an adhesive. Non-limiting examples of adhesive materials used in conjunction with fibrous insulation are set forth below.

U.S. Patent No. 4,738,998 to Uffiier, et al. discloses thermal insulating articles that include a laminate of thermal insulation and a flexible jacket material. The insulation and the jacket material are adhered to each other by a hot melt adhesive that consists essentially of an asphalt, an ethylene-vinyl acetate copolymer, and a wax.

U.S. Patent No. 5,106,446 to DiRado, et al. teaches a hot melt adhesive for insulation assemblies for HVAC systems that includes (1) 10-50% of an isotactic thermoplastic polybutylene-1 /ethylene copolymer containing from about 5.5-10% by weight ethylene, (2) 20-50% of a tackifier, (3) 15-50% of an amorphous diluent having a softening point greater than 90 ⁰C, (4) 0-2% of an antioxidant, and (5) 0-5% of a wax.

U.S. Patent No. 5,277,955 to Schelhorn, et al, discloses an insulation assembly for insulating buildings. The insulation assembly includes a low density, binderless mineral fiber batt enclosed by an exterior layer or cover. In one embodiment, the exterior layer is a heated polyethylene layer that is applied directly to the fibrous glass batt. The heated polyethylene serves as an adhesive layer that joins the film to the mineral fiber batt.

U.S. Patent No. 6,986,367 to Toas, et al. discloses an insulation product for installing around ducts that includes a fibrous insulation board and a reinforcement fabric. The insulation board and reinforcement fabric are laminated together using an adhesive material. The adhesive material may be a removable adhesive, a permanent adhesive, or a repositionable adhesive. Examples of suitable adhesives include water-based adhesives, hot melt glues, a liquid adhesive, or a tape.

U.S. Patent Publication No. 2005/0031819 to Mankell, et al. discloses a duct board or duct liner that is formed of (1) a fibrous material bound by a resinous binder, (2) an outer facing layer adhered to an outer surface of the insulating layer, and (3) a water repellant mat facer adhered to an interior surface of the insulating layer opposite the outer surface. A liquid adhesive is utilized to adhere the outer facing layer and the mat facer to the insulation layer.

U.S. Patent Publication No. 2005/0272338 to Shaffer teaches a faced fibrous insulation product that has a mat on one or more surfaces of a fibrous insulation. The mat facing includes a pre-applied adhesive that is heat activated to provide adhesion to the fibrous insulation. A low melting point adhesive and a relatively higher temperature melting point adhesive are distributed on a surface of the mat facing and heated to a temperature above the melting point of the low melting adhesive to adhere the high melting point adhesive to the mat facing. Suitable low melting point adhesives include polyethylene, ethylene vinyl acetate, and other polymer adhesives. Examples of high melting point adhesives include polyamide adhesives and phenolic powders.

U.S. Patent Publication No. 2005/0272338 to Shaffer discloses a faced fibrous insulation product that has a fibrous web on one or more surfaces of a fibrous insulation layer. The mat facing includes a pre-applied adhesive that is heat activated to provide adhesion to the fibrous insulation layer. Particles of the adhesive are distributed on a surface of the fibrous web and heated to a temperature above the temperature of the melting point of the adhesive to adhere the adhesive powder to the fibrous nonwoven web. Examples of suitable adhesives include polyethylene, polypropylene, ethylene vinyl acetate, polyamides, epoxies, urethane, melamine, and phenolic powders.

U.S. Patent Publication No. 2006/0083889 to Schuckers discloses a duct board that is formed of a fibrous duct board layer, an adhesive material, and a second insulating board layer. The adhesive material may be any adhesive material that adheres the fibrous duct board and the second insulating board layer. Examples of suitable adhesives include a hot melt glue or a water-based adhesive.

Although there are numerous types of adhesives known in the art, water-based adhesives are conventionally utilized to adhere the facing layer to the fibrous insulation. However, water-based adhesives present numerous problems, such as surface foil corrosion and the stimulation of trimethylamine (TMA), which produces an undesirable odor. In addition, an enormous amount of energy is required to remove the water and cure the water-based adhesive. Accordingly, there exists a need in the art for a fibrous insulation product that can be utilized as a duct liner and which is formed using an adhesive that is easy to use, is inexpensive, requires minimal energy to cure, and eliminates the need for expensive foil tape. SUMMARY OF THE INVENTION

It is an object of the present invention to provide a faced insulation product that includes at least one facing layer adhered to a major surface of an insulation layer. The facing layer is formed of a facing material that has thereon a pre-applied waterless, thin- film adhesive. The waterless, thin-film adhesive is thermoplastic and heat activated. In at least one embodiment, the waterless, thin-film adhesive is a polyethylene copolymer. Due to the thermoplastic nature of the waterless, thin-film adhesive, the facing material may advantageously be repositioned or repaired in the field by the application of heat. The facing material may be any facing material that is suitable for a fibrous insulation product, such as a nonwoven mat, web, or veil, or a vapor barrier. Application of the waterless, thin-film adhesive to the facing layer(s) reduces the time associated with curing the adhesive. In particular, the waterless, thin-film adhesive requires much less energy to cure than conventional water-based adhesives, which, in turn, may result in a reduction in manufacturing costs. Additionally, the lack of water in the waterless, thin- film adhesive helps to reduce or eliminate detrimental effects to the insulation product typically caused by water-based adhesives, such as surface foil corrosion and the stimulation of trimethylamine (TMA) and its associated odor.

It is another object of the present invention to provide a fibrous duct board that has facing materials on first and second major surfaces of an insulation layer, a sealing flange, and optionally, male and female shiplap edges. In one exemplary embodiment, a first facing material is a vapor barrier positioned on a first major surface of a fibrous insulation layer and a second facing material is a non-woven fibrous web positioned on a second, opposing major surface of the fibrous insulation layer. Desirably, the first facing layer is wider than the insulation layer and projects beyond the insulation layer along a transverse edge thereof to form a sealing flange. In addition, the first facing layer may be applied to the fibrous insulation layer in an offset manner such that a transverse edge of the first facing layer extends beyond a corresponding transverse edge of the fibrous insulation layer to form a male shiplap edge, from which the sealing flange extends. The facing materials have thereon a pre-applied waterless, thin-film adhesive. In a preferred embodiment, the waterless, thin-film adhesive is a polyethylene copolymer. The waterless, thin- film adhesive seals the sealing flange and thus reduces, or even eliminates, the need for foil tape or staples, which are conventionally used in the industry. Because foil tape is expensive and time consuming to apply, the use of the waterless, thin- film adhesive saves both time and money. Additionally, the sealing flange may be securely and easily bonded in the field, such as with a hot iron, and may be repositioned due to the thermoplastic nature of the waterless, thin- film adhesive.

It is yet another object of the present invention to provide a method of forming a fibrous insulation product, such as a duct board, duct liner, or duct wrap. A waterless, thin- film adhesive is pre-applied to a facing material to form a facing layer. The facing layer having the pre-applied waterless, thin-film adhesive thereon is adhered to a major surface of a fibrous insulation layer by heating the facing material and the fibrous insulation layer to a temperature at or above the melting point of the waterless, thin- film adhesive for a time sufficient to adhere the facing to the fibrous insulation layer. In exemplary embodiments, a first facing layer is adhered to a first major surface of the fibrous insulation layer and a second facing layer is adhered to a second major surface of the fibrous insulation layer. The first facing layer may be wider than the insulation layer to project beyond the insulation layer along a transverse edge thereof to form a sealing flange. The waterless, thin-film adhesive is thermoplastic and heat activated. In preferred embodiments, the waterless, thin- film adhesive is a polyethylene copolymer.

It is an advantage of the present invention that the waterless, thin- film adhesive may be pre-applied to a sealing flange of a duct board and sealed by the application of heat without the use of tape or staples.

It is another advantage of the present invention that less energy is required to cure the waterless, thin-film adhesive compared to water-based adhesives. It is yet another advantage of the present invention that the waterless, thin- film adhesive may reduce or eliminate the use of foil tape conventionally used to seal duct sealing flanges.

It is also an advantage of the present invention that the waterless, thin- film adhesive reduces surface foil corrosion and permits a better adhesion of foil tape and duct board foil, if such foil tape is utilized.

It is still another advantage of the present invention that the waterless, thin- film adhesive may be evenly or substantially evenly applied to the facer material.

It is a further advantage of the present invention that the facing material having thereon the pre-applied waterless, thin-film adhesive may advantageously be repaired or repositioned in the field with the use of a hot applicator.

It is yet another advantage of the present invention that the waterless, thin- film adhesive exhibits a constant or nearly constant weight distribution across the facing.

It is a feature of the present invention that the waterless, thin- film adhesive is thermoplastic and heat activated.

It is another feature of the present invention that the lack of water in the waterless, thin-film adhesive reduces odors that commonly occur with water-based, liquid adhesives.

It is a further feature of the present invention that facing materials having thereon a pre-applied layer of the waterless, thin-film adhesive may be adhered to one or more surfaces of a fibrous insulation layer.

It is yet another feature of the present invention that the waterless, thin-film adhesive may be positioned on the facing material and adhered thereto via the application of heat.

The foregoing and other objects, features, and advantages of the invention will appear more fully hereinafter from a consideration of the detailed description that follows. It is to be expressly understood, however, that the drawings are for illustrative purposes and are not to be construed as defining the limits of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

The advantages of this invention will be apparent upon consideration of the following detailed disclosure of the invention, especially when taken in conjunction with the accompanying drawings wherein:

FIG. 1 is a schematic illustration of a facing layer formed of a fibrous web having thereon a waterless, thin- film adhesive according to one embodiment of the present invention;

FIG. 2 is a schematic illustration of a manufacturing line for producing a faced fibrous insulation product in which the faced insulation product is rolled by a roll-up device according on an exemplary embodiment of the present invention;

FIG. 3 is a schematic illustration similar to that of FIG. 2, but showing an alternate embodiment of the manufacturing line of FIG. 2 where the faced insulation product is cut into panels according to another exemplary embodiment of the present invention;

FIG. 4 is a schematic illustration depicting an alternate embodiment of the manufacturing line of FIG. 3 in which the facer is applied to a top surface of an uncured pack of glass fibers;

FIG. 5 is a perspective view, partially cut away, of a faced insulation product having a facing material on one major surface thereof according to at least one embodiment of the present invention;

FIG 6A is a schematic illustration of a faced fibrous insulation product having a sealing flange extending beyond a transverse edge of the fibrous insulation layer;

FIG. 6B is a schematic illustration of the insulation product depicted in FIG. 6A being folded and used as a duct wrap;

FIG. 6C is a schematic illustration of a faced fibrous insulation product similar to that of FIG. 6A, but having a thinner insulation layer;

FIG. 6D is a schematic illustration of the insulation product depicted in FIG. 6C being folded into a duct liner;

FIG. 7 is a schematic illustration of a manufacturing line for producing a faced fibrous insulation product in which the faced insulation product has a facing material on a first and second major surface according on one exemplary embodiment of the present invention; FIG. 8 is a perspective view, partially cut away, of a faced insulation product having a facing material on two major surfaces thereof according to at least one embodiment of the present invention;

FIG. 9 is a schematic illustration depicting an alternate embodiment of the manufacturing line of FIG. 7 in which the faced insulation product is bisected and rolled into two separate rolls by roll-up devices;

FIG. 1OA is schematic illustration depicting an alternative process of forming a faced fibrous insulation product in a post-curing oven or off-line process using a heated platen to adhere the facing material to the fibrous insulation;

FIG. 1OB is a schematic illustration of an alternative process of forming a faced fibrous insulation product in a post-curing oven or off-line process using a heated roller to adhere the facing material to the fibrous insulation;

FIG. 11 is a schematic illustration of an alternative process of forming the faced fibrous insulation product in a post-curing oven or off-line process using a heated caterpillar to adhere the facing to the fibrous insulation;

FIG. 12 is a perspective view of a duct board according to at least one exemplary embodiment of the present invention;

FIG. 13 is a schematic illustration of a duct board similar to that of FIG. 12 but including grooves to permit folding of the duct board into a predetermined shape according to at least one exemplary embodiment of the present invention;

FIG. 14 is a schematic illustration of a duct board folded into an air duct according to at least one exemplary embodiment of the present invention;

FIG. 15 is a perspective view of a duct board according to at least one exemplary embodiment of the present invention, the duct board incorporating male and female shiplap edges and a sealing flange;

FIG. 16 is a schematic illustration of a duct board similar to that shown in FIG. 15 but incorporating grooves to facilitate folding of the duct board into a predetermined shape; and

FIG. 17 is a schematic illustration of a duct board as depicted in FIG. 16 but folded into an air duct with the shiplap edges engaging at the joint between the opposing ends of the duct board. DETAILED DESCRIPTION AND PREFERRED EMBODIMENTS OF THE INVENTION

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, the preferred methods and materials are described herein. All references cited herein, including published or corresponding U.S. or foreign patent applications, issued U.S. or foreign patents, and any other references, are each incorporated by reference in their entireties, including all data, tables, figures, and text presented in the cited references.

In the drawings, the thickness of the lines, layers, and regions may be exaggerated for clarity. It is to be noted that like numbers found throughout the figures denote like elements. It will be understood that when an element is referred to as being "on," another element, it can be directly on or against the other element or intervening elements may be present. The terms "facing" and "facing material" may be used interchangeably herein.

The present invention relates to a waterless, thin-film adhesive that is pre-applied to a facing material. The facing with the pre-applied adhesive may subsequently be adhered to surfaces of fibrous insulation materials to form duct boards for HVAC systems. In addition, the waterless, thin-film adhesive may be placed on a sealing flange of a duct board and heat sealed without the use of hand applied foil tape. The waterless, thin-film adhesive reduces odor potential, improves fiberglass recovery, and reduces manufacturing and production costs.

The facing material is not particularly limited, and may be any facing material that is suitable for a fibrous insulation product, such as a nonwoven mat, web, or veil, or a vapor barrier such as a foil/skrim/Kraft (FSK), Kraft/asphalt, or polymer and foil/scrim/Kraft layers. FIG. 1 depicts a facer with a waterless, thin-film adhesive adhered thereto according to one embodiment of the present invention. As shown in FIG. 1, the facer 12 may include a fibrous web 5 and a waterless, thin-film adhesive 7 adhered to a major surface of the fibrous web 5. The fibrous web 5 may be formed from fibers such as, but not limited to, glass fibers, mineral wool, rock wool, polymer fibers, synthetic fibers, and/or natural fibers. As used in this application, the term "natural fiber" is meant to indicate plant fibers extracted from any part of a plant, including, but not limited to, the stem, seeds, leaves, roots, or bast. Desirably, the fibrous web 5 is formed of organic fibers such as rayon, polyethylene, polypropylene, nylon, polyester, and mixtures thereof. Continuous fibers and/or multi-component fibers such as bicomponent or tricomponent polymer fibers may also be utilized in forming the web 5. The bicomponent fibers may be formed in a sheath-core arrangement in which the sheath is formed of first polymer fibers that substantially surround a core formed of second polymer fibers. Although the web 5 is preferably a non-woven web formed by conventional dry-laid processes, other materials such as point bonded, woven, and other non- woven materials such as needled, spunbonded, or meltblown webs may be used. A binder, flame-retardants, pigments, and/or other conventional additives may also be included in the fibrous web 5. Optionally, the web 5 may be treated with a fungicide and/or bactericide either during or after manufacturing. Similarly, the waterless, thin-film adhesive may be heat bonded to a vapor barrier (for example, FSK layer) and subsequently applied to a fibrous insulation product.

The waterless, thin-film adhesive is thermoplastic and heat activated. The thickness of the waterless, thin-film adhesive is desirably as small as possible so long as the adhesive has sufficient bond strength and meets such required standards such as ASTM E84 Flame and Smoke certifications. In exemplary embodiments, the waterless, thin-film adhesive has a thickness less than or equal to about 60 microns, from about 6.0 to about 30.0 microns, or from about 10 microns to about 15 microns. The waterless, thin- film adhesive is applied to the facing material via the application of heat. For instance, the waterless, thin-film adhesive may be positioned on the facing material and then adhered to the facing material by heating the facing material with a hot plate or other suitable heating device (for example, an oven). The facing material may similarly be adhered to a fibrous insulation layer by heating the facing material and the fibrous insulation to a temperature at or above the melting point of the waterless, thin-film adhesive for a time sufficient to adhere the facing to the fibrous insulation layer. Non-limiting examples of suitable adhesives include an ethylene copolymer, polyurethane, ethylene vinyl acetate (EVA), amorphous polyolefin, polyethylene, low density polyethylene (LDPE), cellophane, polyethylene terephthalate (PETP), polyvinyl chloride (PVC) nylons, polypropylene, polystyrene, polyamides, and cellulose acetate. Additionally, the waterless, thin-film adhesive may incorporate pre-engineered components to address requirements set forth according to ASTM E 184 (Flame and Smoke certification), color pigmentation, static guards, and/or pre-designed scavengers.

The lack of water in the thin-film adhesive helps to reduce odors that commonly occur with water-based, liquid adhesives. Because the thin-film adhesive is thermoplastic and heat activated, the facing may advantageously be repaired or repositioned in the field with the use of a hot applicator. Conventional adhesives are thermoset and do not allow for easy re-application of the facing layer(s). In addition, the thin-film adhesive may be evenly or substantially evenly applied to the facing material, unlike conventional liquid adhesives which are commonly unevenly applied to the facing material. Further, there is a reduction in down time due to the optimization of the application of the waterless, thin- film adhesive. Unlike the waterless, thin-film adhesive, water-based adhesives require constant monitoring. Further, the waterless, thin-film adhesive may reduce or eliminate the use of foil tape conventionally used to seal duct sealing (closing) flanges.

The facing with the pre-applied waterless, thin- film adhesive may be applied to one or more surfaces of a fibrous insulation layer to form a faced insulation product. The facing provides improved surface quality, high and controlled adhesion, and is easily manufactured. The pre-applied facing may be input into the glass fiber forming section of a fibrous insulation production line as shown in FIG. 2. It is to be appreciated that although glass fiber insulation is discussed herein, mineral wool, rock wool, polymer fibers, synthetic fibers, and/or natural fibers may alternatively or additionally be utilized in forming the insulation. Fibrous glass insulation products are generally formed of matted glass fibers bonded together by a cured thermoset polymeric material. The manufacture of glass fiber insulation products may be carried out in a continuous process by fiberizing molten glass and immediately forming a fibrous glass batt on a moving conveyor.

Turning to FIG. 2, glass may be melted in a tank (not shown) and supplied to a fiber forming device such as a fiberizing spinner 15. The spinners 15 are rotated at high speeds. Centrifugal force causes the molten glass to pass through the holes in the circumferential sidewalls of the fiberizing spinners 15 to form glass fibers. Single component glass fibers of random lengths may be attenuated from the fiberizing spinners 15 and blown generally downwardly, that is, generally perpendicular to the plane of the spinners 15, by blowers 20 positioned within a forming chamber 25. The blowers 20 turn the fibers downward to form a veil or curtain 30. Non- limiting examples of glass fibers that may be utilized in the present invention are described in U.S. Patent No. 6,527,014 to Aubourg; U.S. Patent No. 5,932,499 to Xu et al; U.S. Patent No. 5,523,264 to Mattison; and U.S. 5,055,428 to Porter, the contents of which are expressly incorporated by reference in their entirety. The glass fibers, while in transit in the forming chamber 25 and while still hot from the drawing operation, are sprayed with an aqueous binder composition by suitable spray applicators 35 so as to result in a distribution of the binder composition throughout the formed uncured pack 40. Water may also be applied to the glass fibers in the forming chamber 25, such as by spraying, prior to the application of the binder composition to at least partially cool the glass fibers. Although any conventional binder such as phenol- formaldehyde and urea-formaldehyde may be used, the binder is desirably a low formaldehyde binder composition, such as a polycarboxylic based binder, a polyacrylic acid glycerol (PAG) binder, or a polyacrylic acid triethanolamine (PAT binder). Suitable polycarboxy binder compositions for use in the instant invention include a polycarboxy polymer, a crosslinking agent, and, optionally, a catalyst. Such binders are known for use in connection with rotary fiberglass insulation. Examples of such binder technology are found in U.S. Patent Nos. 5,318,990 to Straus; 5,340,868 to Straus et ah; 5,661,213 to Arkens et ah; 6,274,661 to Chen et ah; 6,699,945 to Chen et ah; and 6,884,849 to Chen et ah, each of which is expressly incorporated entirely by reference. The binder may be present in an amount from about 2% to about 25% by weight of the total product, and preferably from about 5% to about 20% by weight of the total product, and most preferably from about 10% to about 18% by weight of the total product.

The glass fibers having the uncured resinous binder adhered thereto may be gathered and formed into an uncured pack 40 on the facer 12 on an endless forming conveyor 45 within the forming chamber 25 with the aid of a vacuum (not shown) drawn through the insulation pack 40 from below the forming conveyor 45. It is to be noted that throughout this application, facers 12, 16 are facing materials having thereon a pre-applied waterless, thin-film adhesive as described herein. The facer 12 is supplied to the conveyor 45 by roll 90. The residual heat from the glass fibers and the flow of air through the insulation pack 40 and facer 12 during the forming operation are generally sufficient to volatilize a majority of the water from the binder before the glass fibers exit the forming chamber 25, thereby leaving the remaining components of the binder on the fibers as a viscous or semi-viscous high-solids liquid.

The coated uncured pack 40, which is in a compressed state due to the flow of air through the pack 40 in the forming chamber 25, and the facer 12 are then transferred out of the forming chamber 25 under exit roller 50 to a transfer zone 55 where the insulation pack 40 vertically expands due to the resiliency of the glass fibers. The expanded uncured pack 40 and facer 12 are then heated, such as by conveying the pack 40 through a curing oven 60 where heated air is blown through the insulation pack 40 and facer 12 to evaporate any remaining water in the binder, cure the binder and the adhesive, rigidly bond the fibers together in the insulation pack 40, and adhere the facer 12 to the insulation pack 40. The facer 12 and the insulation pack 40 are heated to a temperature at or above the temperature of the above the waterless, thin- film adhesive for a time period sufficient to at least partially melt the waterless, thin- film adhesive and bond the adhesive to the insulation pack 40. Specifically, heated air is forced though a fan 75 through the lower oven conveyor 70, the insulation pack 40 and the facer 12, the upper oven conveyor 65, and out of the curing oven 60 through an exhaust apparatus 80. The cured binder imparts strength and resiliency to the faced insulation product 10. It is to be appreciated that the drying and curing of the binder and the waterless, thin-film adhesive may be carried out in either one or two different steps. Also, in the curing oven 60, the uncured pack 40 may be compressed by upper and lower foraminous oven conveyors 65, 70 to form the faced fibrous insulation product 10 having a predetermined thickness.

The faced fibrous insulation 10 then exits the curing oven 60 and may be rolled by roll-up device 82 for storage and/or shipment. The faced fibrous insulation product 10 may subsequently be unrolled and cut or die pressed to form fibrous insulation parts (for example, duct boards). Alternatively, as depicted in FIG. 3, the faced fibrous insulation product 10 may be cut to a predetermined length by a cutting device such as a blade or knife 83 to form panels 84 of the faced fibrous insulation. The panels 84 may be stacked or bagged by a packaging apparatus 86. If desired, channels or grooves, such as v-shaped grooves, may be formed in the inner surface of the fibrous insulation product 10 for folding or bending the fibrous insulation product 10 into a duct liner, as is discussed in more detail below.

In an alternate embodiment depicted in FIG. 4, an uncured pack 40 is formed as described in detail above with respect to FIG. 2. Once the uncured pack 40 is formed and exits the forming chamber 25, a facer 12 is applied to a top surface of the uncured pack 40 from roll 90. The facer 12 and the uncured pack 40 enter the curing oven 60 where heated air is forced though a fan 75 through the lower oven conveyor 70, the insulation pack 40 and the facer 12, the upper oven conveyor 65, and out of the curing oven 60 through an exhaust apparatus 80. As the faced fibrous insulation product 10 exits the oven 60, it may be cut into panels 84 by the cutting device 83 and collected by the gathering apparatus 86. Alternatively, the faced fibrous insulation product 10 may be rolled by a roll-up device (not illustrated) for storage and/or shipment. As illustrated in FIG. 5, the faced insulation product 10 formed by the processes depicted in FIGS. 2, 3, and 4 include a fibrous insulation layer 14 and a facing material 12 affixed to a major surface of the insulation layer 14. In a related embodiment, the facer 12 may be applied to one surface of the fibrous insulation 14 where the facer 12 is larger than the fibrous insulation 14 and drapes over the edges of the insulation layer 14 to face one or more of the minor surfaces of the fibrous insulation 14.

In one or more exemplary embodiment, the faced insulation product 10 may be utilized as a duct liner or duct wrap. For example, a duct liner or duct wrap may be formed from the insulation products described above where the insulation layer 14 has thereon a single facer 12 that is wider than the insulation layer 14 along a transverse edge to form a flange 134. In preferred embodiments, the facer 12 is a foil/scrim/Kraft layer. As shown in FIGS. 6a and 6b, the duct wrap 145 may be formed of a facer 12 including a flange 134 adhered to an insulation layer 14 by a waterless, thin- film adhesive 125. The duct wrap 145 may be wrapped around a sheet metal duct 137 and the edges of the duct wrap 145 sealed by the sealing flange 134. Specifically, the sealing flange 134 may be adhered or bonded to the adjoining surface of the facing layer 12 (for example, a foil/scrim/Kraft layer) by heat and pressure due to the pre-applied waterless, thin-film adhesive 125. Although the flange 134 is depicted at the middle of a wall of the metal duct 137, one skilled in the art will recognize that the location of the sealing flange 134 on the final assembly, including the duct liner 147 described below, could be at a corner of the duct 137, or at other locations, depending on the location of the grooves 144 within the insulation product 10.

Turning to FIGS. 6c and 6d, a duct liner 147 having a facing 12 with a flange 134 adhered to a fibrous insulation layer 14 is illustrated. The duct liner 147 may be folded into a shape substantially similar to the shape of the duct into which it is to be inserted (for example, a substantially square shape as shown in FIG. 6d) and inserted into a sheet metal to form a duct assembly (not illustrated). The duct wrap 145 and duct liner 147 enhance the thermal efficiency of duct work in a building and reduce noise associated with the movement of air through the air duct.

Alternatively, facing materials may be applied to both major surfaces of the fibrous insulation 14, as shown in FIG. 7. In one exemplary embodiment, molten glass (not illustrated) is supplied to fiberizing spinners 15 that are rotated at high speeds to force the molten glass through holes in the circumferential sidewalls of the fiberizing spinners 15 and form glass fibers. Blowers 20 direct a gas stream in a substantially downward direction to impinge the attenuated fibers, turning them downward, to form a veil or curtain 30. The fibers may be sprayed with an aqueous binder by suitable spray applicators 35. The glass fibers having the uncured resinous binder adhered thereto may then be gathered and formed into an uncured pack 40 on a perforated endless conveyor 45 within the forming chamber 25. The coated uncured pack 40, which is in a compressed state due to the flow of air through the pack 40 in the forming chamber 25 is then transferred out of the forming chamber 25 under exit roller 50 to a transfer zone 55 where the insulation pack 40 vertically expands due to the resiliency of the glass fibers.

As the uncured pack 40 exits the forming chamber 25, facing materials 12, 16 are positioned on the top and bottom major surface of the uncured pack. It is to be appreciated that the facing materials 12, 16 may be the same or different. For example, one of the facing layers may be a fibrous web and the other facing layer may be a vapor barrier. The facing materials 12, 16 are fed to the uncured pack 40 from rolls 90 and 92, respectively. The expanded uncured pack 40 and facers 12, 16 are then heated in a curing oven 60 where heated air is blown through the insulation pack 40 and facers 12, 16. It is contemplated that facer 12 may alternatively be supplied to the conveyor 45 prior to the formation of the uncured pack 40 such that the fibers formed from the spinners 15 are deposited onto the facer 12. Heated air is forced though a fan 75 through the lower oven conveyor 70, the insulation pack 40 and the facers 12, 16, the upper oven conveyor 65, and out of the curing oven 60 through an exhaust apparatus 80. Also, in the curing oven 60, the uncured pack 40 may be compressed by upper and lower foraminous oven conveyors 65, 70 to form a faced fibrous insulation product 10 having a predetermined thickness. The double-faced fibrous insulation product 10 then exits the curing oven 60 and may be rolled by roll-up device 82 for storage and/or shipment. The faced fibrous insulation product 10 may subsequently be unrolled and cut or die pressed to form fibrous insulation parts. Channels or grooves, such as v-shaped grooves, may optionally be formed in the inner surface of the fibrous insulation product 10 for folding or bending the fibrous insulation product 10 into a duct liner. FIG. 8 depicts such a double-faced fibrous insulation product 10 in which a facer 12 is positioned on a first major surface of the fibrous insulation 14 and a second facing material 16 is positioned on a second major surface of the fibrous insulation 14.

The presence of water, dust, and/or other microbial nutrients in the faced insulation product 10 may support the growth and proliferation of microbial organisms. Bacterial and/or mold growth in the insulation product may cause odor and discoloration of the insulation product and deterioration of the vapor barrier properties of Kraft paper. To inhibit the growth of unwanted microorganisms such as bacteria, fungi, and/or mold in the faced insulation product 10, the facing materials 12, 16 and/or the fibrous insulation 14 may be treated with one or more anti-microbial agents and/or biocides. The anti-microbial agents and/or biocides may be added during manufacture or in a post manufacture process of the fibrous insulation product. In addition, flame retardants, pigments, colorants, and/or other conventional additives may be included in the faced insulation product 10.

Application of the waterless, thin- film adhesive to the first and second facing layers 12, 16 reduces the time associated with drying and bonding (curing) the adhesive, both to the facing layers 12, 16 and to the fibrous insulation product 10. Conventional adhesives are water-based and require an enormous amount of heat energy to flash off the water during the curing of the adhesive. The waterless, thin-film adhesive requires much less energy to cure, which may result in a reduction in manufacturing costs. Additionally, the lack of water in the waterless, thin- film adhesive helps to reduce or eliminate the detrimental effects to the insulation typically caused by water-based adhesives, such as, but not limited, to surface foil corrosion and the stimulation of trimethylamine (TMA) and its associated odor. In addition, the waterless, thin-film adhesive exhibits a constant or nearly constant weight distribution across the facing, unlike conventional water-based adhesives which commonly have inconsistent weight across the facing material due to equipment malfunction or the inherent uneven application of the water-based adhesive. The reduction of surface foil corrosion permits a better adhesion of tape and duct board foil, if such tape is utilized.

In an alternative embodiment shown in FIG. 9, an uncured pack 40 is formed as described in detail above with respect to FIG. 7. Once the uncured pack 40 is formed and exits the forming chamber 25, facers 12, 16 are applied to a top and bottom major surface of the uncured pack 40 from rolls 90, 92. It is contemplated that facer 12 may instead be supplied to the conveyor 45 prior to the formation of the uncured pack 40 such that the fibers formed from the spinners 15 are deposited onto the facer 12. The facers 12, 16 and the uncured pack 40 enter the curing oven 60 where heated air is forced though a fan 75 through the lower oven conveyor 70, the insulation pack 40 and the facers 12, 16, the upper oven conveyor 65, and out of the curing oven 60 through an exhaust apparatus 80. As the double-faced fibrous insulation product 10 exits the oven 60, it may be bisected by a bisect saw 94 or other suitable cutting device and rolled into two rolls by an upper roll- up device 96 and a lower roll-up device 98. The product thus formed is an insulation product having thereon a facer 12 on one major surface thereof, such as is depicted in FIG. 5.

FIGS. 1OA and 1OB show alternate methods of forming the faced insulation product 10 in a post-curing or off-line process using a heated platen 100 (FIG. 10A) and a heated roller 102 (FIG. 10B). Here, the facing material 12 is unrolled from roll 90 onto the cured insulation layer 14. The heated platen 100 or heated roller 102 at least partially melts the waterless, thin-film adhesive that has been pre-applied to the facing material as described above to adhere the facer 12 onto the insulation layer 14.

FIG. 11 illustrates an alternative post-cure method of forming the double-faced fibrous insulation product 10 utilizing a heated caterpillar 110. The heated caterpillar 110 has a heated upper belt 112 that rotates around a first upper belt roller 114 and a second upper belt roller 116 to compress the fibrous insulation layer 14 against a heated lower belt 120 that rotates around a first lower belt roller 122 and a second lower belt roller 124. The upper belt 112 presses facing 12 to an upper surface of the cured fibrous insulation layer 14 and the lower belt 120 presses facing 16 to a lower surface of the insulation layer 14 for a time sufficient to heat the waterless, thin-film adhesives to adhere facing layers 12, 16 to the fibrous layer 14 and form the fibrous insulation product 10.

In one exemplary embodiment, the fibrous insulation product 10 is a duct board having facing materials on first and second major surfaces of an insulation layer, a sealing flange, and optionally, male and female shiplap edges. The facing materials are formed of an outer surface layer, such as, but not limited to, a vapor barrier, and an inner surface layer formed of a nonwoven fibrous web, veil, or mat. One example of a duct board 128 according to the present invention is depicted in FIGS. 12-14. In this exemplary embodiment, a first facing layer 130 is a vapor barrier positioned on a first major surface of the fibrous insulation layer 14 and is affixed to the first major surface by a waterless, thin-film adhesive 125. A second facing layer 132 may be a fibrous web, such as the web described in detail above, which is affixed to a second major surface of the fibrous insulation layer 14 by a waterless thin-film adhesive 127. The waterless, thin-film adhesives 125, 127 may be the same or different, but are both thermoplastic in nature. It is to be appreciated that the vapor barrier and the fibrous web forming the first and second facing layers 130, 132 each correspond to one of facer 12 or facer 16 described in detail above.

Turning to FIGS. 13 and 14, the duct board 128 may be formed into an air duct 135 by folding the duct board 128 into a generally rectangular shape such that the second facing layer 132 faces an interior portion thereof and the first facing layer (for example, vapor barrier) is positioned on an exterior surface of the air duct 135. It is to be appreciated that although a square air duct is shown, the air duct may be formed into a non-square shape, such as a rectangular, round, or oval air duct, as would be understood by those of skill in the art. The second facing layer 132 facilitates air flow through the duct and reduces or eliminates the occurrence of flyaway glass fibers from the insulation layer 14. To facilitate bending of the duct board 128, grooves 144 may be cut or otherwise formed into the duct board 128 at even intervals where the duct board 128 is to be folded to permit the duct board 128 to be folded along the grooves 144 and formed into the air duct 135. The sealing flange 134 may be adhered or bonded to the adjoining surface of the first facing layer 132 (for example, a foil/scrim/Kraft layer) by heat and pressure due to the pre-applied waterless, thin- film adhesive 125.

In an alternate embodiment, shown in FIGS. 15-17, the first facing layer 130 is wider than the insulation layer 14 and projects beyond the insulation layer 14 along a transverse edge to form a sealing flange 134 extending from a male shiplap edge 140. The first facing layer 130 may be applied to the fibrous layer 14 in an offset manner such that a transverse edge of the first facing layer 130 extends beyond a corresponding transverse edge of the fibrous insulation layer 14 to form the male shiplap edge 140. An opposing transverse edge of the insulation layer 14 is thus formed into a female shiplap edge 142. The duct board 128 may also be formed such that one or both of the longitudinal edges also form a shiplap edge (not depicted). As illustrated in FIG. 16, grooves 144 may be cut into the duct board to facilitate bending of the duct board into an air duct 135.

Once the duct board 128 is folded, as shown in FIG. 17, the male and female shiplap edges 140, 142 are mated and sealing flange 134 covers the interface of the male and female shiplap edges 140, 142. As with the embodiment set forth above, the sealing flange 134 may be adhered or bonded to the adjoining surface of the first facing layer 132 (for example, a foil/scrim/Kraft layer) by heat and pressure due to the pre-applied waterless, thin- film adhesive 125.

The waterless, thin- film adhesive seals the sealing flange 134 without tape or staples and thus reduces, or even eliminates, the need for foil tape or staples, which are conventionally used in the industry. Because foil tape is expensive and time consuming to apply, the use of the waterless, thin- film adhesive saves both time and money. Additionally, the sealing flange 134 may be securely and easily bonded in the field, such as with a hot iron, and may be repositioned due to the thermoplastic nature of the waterless, thin-film adhesive.

The invention of this application has been described above both generically and with regard to specific embodiments. Although the invention has been set forth in what is believed to be the preferred embodiments, a wide variety of alternatives known to those of skill in the art can be selected within the generic disclosure. The invention is not otherwise limited, except for the recitation of the claims set forth below.

Claims

Having thus described the invention, what is claimed is:

1. A faced fibrous insulation product (10) comprising: a fibrous insulation layer (14) having first and second opposed major surfaces; and a first facing layer (12) adhered to said first major surface, said first facing layer having thereon a first pre-applied waterless, thin-film adhesive (125), wherein said first facing layer is adhered to said first major surface of said fibrous insulation layer by heating said fibrous insulation layer and said first facing layer to a temperature at or above the melting point of said first pre-applied waterless, thin- film adhesive.

2. The faced insulation product of claim 1 , wherein said first pre-applied waterless, thin- film adhesive is selected from the group consisting of a polyethylene copolymer, polyurethane, ethylene vinyl acetate, amorphous polyolefm, polyethylene, low density polyethylene, cellophane, polyethylene terephthalate, polyvinyl chloride, nylons, polypropylene, polystyrene, polyamides and cellulose acetate.

3. The faced insulation product of claim 1, wherein said first facing layer is a vapor barrier and said first facing layer extends beyond said fibrous insulation layer to form a sealing flange (134).

4. The faced insulation product of claim 3, wherein said insulation product contains a plurality of grooves (144) to permit folding of said insulation product into one of a duct liner or a duct wrap (147).

5. The faced insulation product of claim 3, wherein said first pre-applied thin- film adhesive is thermoplastic and said first facing layer and said sealing flange may be repaired or repositioned with the application of heat.

6. The faced insulation product of claim 3, wherein said first pre-applied waterless, thin- film adhesive is substantially evenly applied to said fibrous insulation layer.

7. The faced insulation product of claim 1, further comprising a second facing layer (16) adhered to said second major surface of said fibrous insulation layer, said second facing layer having thereon a second pre-applied waterless, thin-film adhesive.

8. The faced insulation product of claim 7, wherein said first and second facing layers are selected from the group consisting of a vapor barrier, a nonwoven mat, web and veil.

9. A fibrous duct board comprising: a fibrous insulation layer (14) having a first and second opposing major surfaces; a first facing layer (130) adhered to said first major surface, said first facing layer having thereon a first pre-applied waterless, thin-film adhesive (125), wherein said first facing layer is wider than said insulation layer such that said first facing layer extends beyond an edge of said fibrous insulation layer to form a sealing flange (134); and a second facing layer (16, 132) adhered to said second major surface, said second facing layer having thereon a second pre-applied waterless, thin- film adhesive, wherein said first and second facing layers are adhered to said fibrous insulation layer by heating said fibrous insulation layer, said first facing layer, and said second facing layer a temperature at or above the melting points of said first and second waterless, thin- film adhesive.

10. The fibrous duct board of claim 9, further comprising male and female shiplap (140,142) edges, said sealing flange extending from said male shiplap edge.

11. The fibrous duct board of claim 9, wherein said first and second pre-applied waterless, thin- film adhesive are substantially evenly applied to said fibrous insulation layer

12. The fibrous duct board of claim 9, wherein said first and second pre-applied waterless, thin- film adhesive is selected from the group consisting of a polyethylene copolymer, polyurethane, ethylene vinyl acetate, amorphous polyolefm, polyethylene, low density polyethylene, cellophane, polyethylene terephthalate, polyvinyl chloride, nylons, polypropylene, polystyrene, polyamides and cellulose acetate.

13. The fibrous duct board of claim 9, wherein said first and second pre-applied thin- film adhesives are thermoplastic and said first and second facing layers may be repaired or repositioned with the application of heat.

14. The fibrous duct board of claim 9, wherein said first facing layer is a vapor barrier and said second facing layer is selected from the group consisting of a nonwoven fibrous web, veil and mat.

15. A method of forming a faced fibrous insulation product (10) comprising: pre-app lying a first waterless, thin-film adhesive (125) to a first facing material to form a first facing layer (12); forming a pack of fibers having an uncured binder thereon; applying said first facing layer to a first major surface of said pack of fibers; heating said first facing material and said pack of fibers to cure said binder and at least partially melt said first waterless, thin-film adhesive to form a faced insulation product.

16. The method of claim 15, further comprising: pre-app lying a second waterless, thin-film adhesive (127)to a second facing material to form a second facing layer (16); applying said second facing layer to a second major surface of said pack of fibers; at least partially melting said second waterless, thin-film adhesive to adhere said second facing layer to said pack of fibers, wherein said first and second waterless, thin-film adhesives may be the same or different.

17. The method of claim 16, wherein said step of applying said first facing layer positions said first facing layer to extend beyond said pack of fibers to form a sealing flange (134).

18. The method of claim 17, further comprising: forming grooves in said faced insulation product (144); folding said insulation product along said grooves into a duct liner(147); and heating said sealing flange to seal said sealing flange against a first portion of said insulation product to secure the formation of said duct liner.

19. The method of claim 16, wherein said first and second waterless, thin- film adhesives are selected from the group consisting of a polyethylene copolymer, polyurethane, ethylene vinyl acetate, amorphous polyolefm, polyethylene, low density polyethylene, cellophane, polyethylene terephthalate, polyvinyl chloride, nylons, polypropylene, polystyrene, polyamides and cellulose acetate.

20. The method of claim 16, wherein said first and second thin-film adhesives are thermoplastic and said first and second facing layers may be repaired or repositioned with the application of heat.