USE OF CONDUCTIVE FIBERS TO DISSIPATE STATIC ELECTRICAL CHARGES IN UNBONDED LOOSEFILL INSULATION MATERIAL

Abstract

An unbonded loosefill insulation material including a multiplicity of discrete, individual tufts formed from a plurality of insulative fibers and a plurality of conductive fibers mixed with the insulative fibers is provided. The conductive fibers are configured to dissipate static electrical charges.

Description

BACKGROUND

In the insulation of buildings, a frequently used insulation product is unbonded loosefill insulation material. In contrast to the unitary or monolithic structure of insulation batts or blankets, unbonded loosefill insulation material is a multiplicity of discrete, individual tufts, cubes, flakes or nodules. Unbonded loosefill insulation material can be applied to buildings by blowing the unbonded loosefill insulation material into insulation cavities, such as sidewall cavities or an attic of a building.

In certain instances, the individual tufts forming portions of the unbonded loosefill insulation material can develop static electrical charges. The static electrical charges can cause the individual tufts to bind together in a manner that degrades the insulative characteristics of the applied unbonded loosefill insulation material.

The static electrical charges can develop during various steps of the processes for manufacturing the unbonded loosefill insulation material as well as during various steps during the application of the unbonded loosefill insulation material into the building cavities. For example, in certain instances, static electrical charges can form during the manufacturing process as the unbonded loosefill insulation material is conducted from one process center to another process center through ductwork. In another example, static electrical charges can form during a conditioning or “fluffing” process within a blowing insulation machine. In still other instances, static electrical charges can form during the distribution process as the conditioned unbonded loosefill insulation material is passed from the blowing insulation machine to an insulation cavity through a distribution hose.

In an effort to control and dissipate the formation of static electrical charges, manufacturers of unbonded loosefill insulation material have coated the exterior surfaces of the fibers forming the unbonded loosefill insulation material with chemical materials having anti-static properties. In certain instances, the chemical anti-static coatings utilize moisture in the air to dissipate the static electrical charges. However, it has been found that the chemical anti-static coatings are less effective in conditions of relatively low humidity.

It would be advantageous if the unbonded loosefill insulation material could have improved anti-static characteristics.

SUMMARY OF THE INVENTION

The above objects as well as other objects not specifically enumerated are achieved by an unbonded loosefill insulation material including a multiplicity of discrete, individual tufts formed from a plurality of insulative fibers and a plurality of conductive fibers mixed with the insulative fibers. The conductive fibers are configured to dissipate static electrical charges.

According to this invention there is also provided a method of manufacturing unbonded loosefill insulation material configured for distribution in a blowing insulation machine. The method includes the steps of forming tufts of fibrous insulation materials and mixing conductive fibers with the fibrous insulation materials. The conductive fibers are configured to dissipate static electrical charges.

According to this invention there is also provided a method of insulating a building cavity using a blowing insulation machine. The method includes the steps of receiving and conditioning loosefill insulation material from a package of compressed loosefill insulation material, the loosefill insulation material having a mixture of fibrous insulation material and conductive fibers and distributing the conditioned loosefill insulation material into the building cavity using the blowing insulation machine. The conductive fibers are configured to dissipate static electrical charges.

According to this invention there is also provided a method of insulating a building cavity using a blowing insulation machine. The method includes the steps of using the blowing insulation machine to condition and distribute fibrous loosefill insulation material into the building cavity and mixing conductive fibers with the fibrous loosefill insulation material. The conductive fibers are configured to dissipate static electrical charges.

Various objects and advantages of the use of conductive fibers to dissipate static electrical charges in unbonded loosefill insulation material will become apparent to those skilled in the art from the following detailed description of the preferred embodiment, when read in light of the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic representation, in elevation, of a process for manufacturing unbonded loosefill insulation material.

FIG. 2a is a perspective view of a first embodiment of a conductive fiber.

FIG. 2b is a plan view of a second embodiment of a conductive fiber.

FIG. 2c is a plan view of a third embodiment of a conductive fiber.

FIG. 2d is a plan view of a fourth embodiment of a conductive fiber.

FIG. 2e is a plan view of a fifth embodiment of a conductive fiber.

FIG. 3 is a graph comparing the change in static for various forms of anti-static material at a relative humidity level of 29%.

FIG. 4 is a graph comparing the change in static for various forms of anti-static material at a relative humidity level of 21%.

FIG. 5 is a graph comparing the percentage of color loss over time for insulative fibers having chemical anti-static material and insulative fibers mixed with conductive fibers, both under constant lighting.

DETAILED DESCRIPTION OF THE INVENTION

The present invention will now be described with occasional reference to the specific embodiments of the invention. This invention may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for describing particular embodiments only and is not intended to be limiting of the invention. As used in the description of the invention and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise.

Unless otherwise indicated, all numbers expressing quantities of dimensions such as length, width, height, and so forth as used in the specification and claims are to be understood as being modified in all instances by the term “about.” Accordingly, unless otherwise indicated, the numerical properties set forth in the specification and claims are approximations that may vary depending on the desired properties sought to be obtained in embodiments of the present invention. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical values, however, inherently contain certain errors necessarily resulting from error found in their respective measurements.

The description and figures disclose the use of conductive fibers to dissipate static electrical charges (hereafter “static charges”) in unbonded loosefill insulation material (hereafter “insulation material”). Generally, the conductive fibers include electrically conductive materials and are configured to dissipate static charges without the use moisture in the air. The conductive fibers are mixed with the fibers forming the loosefill insulation material in sufficient quantities to provide effective dissipation of static charges.

The terms “unbonded loosefill insulation material” or “loosefill material” or “insulation material”, as used herein, is defined to mean any conditioned insulation material configured for distribution in an airstream. The term “unbonded”, as used herein, is defined to mean the absence of a binder. The term “conditioned”, as used herein, is defined to mean the shredding of the loosefill material to a desired density prior to distribution in an airstream. The terms “static electrical charges or static charges”, as used herein, is defined to mean an imbalance of electric charges within or on the surface of the insulation material.

Referring now to FIG. 1, one non-limiting example of a process for manufacturing mineral fibers for use as loosefill insulation material is shown generally at 10. For purposes of clarity, the manufacturing process 10 will be described in terms of glass fiber manufacturing, but the manufacturing process 10 is applicable as well to the manufacture of fibrous products of other mineral materials, such as the non-limiting examples of rock, slag and basalt.

Referring again to FIG. 1, molten glass 16 is supplied from a forehearth 14 of a furnace 12 to rotary fiberizers 18. The molten glass 16 is formed from various raw materials combined in such proportions as to give the desired chemical composition.

The fiberizers 18 receive the molten glass 16 and subsequently form veils 20 of glass fibers 22 and hot gases. The flow of hot gases can be created by optional blowing mechanisms, such as the non-limiting examples of an annular blower (not shown) or an annular burner (not shown), configured to direct the veils 20 of glass fibers 22 in a given direction, usually in a downward manner.

The veils 20 are gathered and transported to downstream processing stations. While the embodiment illustrated in FIG. 1 shows a quantity of two rotary fiberizers 18, it should be appreciated that any desired number of rotary fiberizers 18 can be used.

In one embodiment, the glass fibers 22 are gathered on a conveyor 24 such as to form a blanket or batt 26. The batt 26 is transported by the conveyor 24 to further processing stations (not shown). In other embodiments, the glass fibers 22 and hot gases are collected by a gathering member 28. The gathering member 28 will be discussed in more detail below.

Referring again to FIG. 1, spraying mechanisms 30 can be configured to spray fine droplets of water onto the hot gases in the veils 20 to help cool the flow of hot gases. The spraying mechanisms 30 can be any desired structure, mechanism or device sufficient to spray fine droplets of water onto the hot gases in the veils 20 to help cool the flow of hot gases.

Optionally, the glass fibers 22 can be coated with a lubricant after the glass fibers are formed. In the illustrated embodiment, a series of nozzles (not shown) are positioned in a ring 34 around the veil 20 at a position below the rotary fiberizers 18. The nozzles are configured to supply a lubricant (not shown) on the glass fibers 22 from a source 36. The lubricant is configured to prevent damage to the glass fibers 22 as the glass fibers 22 move through the manufacturing process 10 and come into contact with various apparatus as well as other glass fibers 22. The lubricant can also be useful to reduce dust in the ultimate product. The application of the lubricant is controlled by a valve 38 such that the amount of lubricant being applied can be precisely controlled. In the embodiment illustrated in FIG. 1, the lubricant is a silicone compound having no or low VOCs (volatile organic compounds). The term “low VOC”, as used herein, is defined to mean a VOC content of less than 1.0%. However, the lubricant can also be other materials or combinations of materials, such as for example an oil emulsion having a low VOC. In the illustrated embodiment, the lubricant is applied in an amount of about 1.0 percent oil by weight. However, in other embodiments, the amount of the lubricant can be more or less than about 1.0 percent oil by weight.

Referring again to FIG. 1 and specifically to the portion of FIG. 1 where the glass fibers 22 and hot gases are collected by the gathering member 28, it should be noted that since this portion of the manufacturing process 10 is being used to form loosefill insulation material, a binder material is not applied to the glass fibers 22 in order to make a binderless product. However, it should be appreciated that insignificant amounts of binder could be applied to the fibers 22 as desired depending on the specific application and design requirements of the resulting loosefill insulation material.

As discussed above, the glass fibers 22 and hot gases can be collected by the gathering member 28. The gathering member 28 is shaped and sized to easily receive the glass fibers 22 and hot gases. The gathering member 28 is configured to divert the glass fibers 22 and hot gases to a duct 40 for transfer to one or more processing stations for further handling. The gathering member 28 and the duct 40 can be any generally hollow pipe members that are suitable for receiving and conveying the glass fibers 22 and hot gases. In the embodiment shown in FIG. 1, a rotary fiberizer 18 is associated with an individual gathering member 28 such that the glass fibers 22 and hot gases are received directly into the gathering member 28. Alternatively, a single gathering member 28 can be adapted to receive the glass fibers 22 and hot gases from multiple fiberizers 18 (not shown). Although the manufacturing process 10 is shown with a gathering member 28, it is to be understood that the gathering member 28 is optional, and the glass fibers 22 and hot gases can be directed from the rotary fiberizers 18 to other downstream operations (not shown).

Referring again to FIG. 1, the glass fibers 22 created by the rotary fiberizer 18 are intercepted by the gathering member 28 at a point beneath the rotary fiberizer 18 and the spraying mechanisms 30. An entrance section 42 is positioned at an upper end of the gathering member 28. The entrance section 42 is configured to facilitate collection of the glass fibers 22 and hot gases in the veil 20. In the illustrated embodiment, the entrance section 42 has a funnel-shape or a frusto-conical shape. In other embodiments, the entrance section 42 can have other shapes sufficient to efficiently collect the glass fibers 22 and hot gases in the veil 20. As discussed above, the glass fibers 22 and hot gases continue to flow through the gathering member 28 to other downstream operations. Non-limiting examples of downstream operations include cutting, sizing and bagging.

Referring again to the embodiment illustrated in FIG. 1, the duct 40 is configured to have a minimal number of directional changes such that the flow of glass fibers 22 and hot gases can be efficiently transferred from the rotary fiberizer 18 to a rotary forming apparatus 32.

In the illustrated embodiment, the momentum of the flow of the hot gases will cause the glass fibers 22 to continue to flow through the gathering member 28 and the duct 40 to the rotary forming apparatus 32, where the entrained glass fibers 22 are separated from the flow of hot gases. Alternatively, or additionally, there can be other mechanisms or devices (not shown) configured to draw or push the glass fibers 22 towards the rotary forming apparatus 32.

As shown in FIG. 1, a header system 40 is positioned between the rotary forming apparatus 32 and the fiberizer 18. The header system 40 is configured as a chamber in which the glass fibers 22 and hot gases flowing from the plurality of rotary fiberizers 18 can be combined while controlling the characteristics of the resulting combined flow. In certain embodiments, the header system 40 can include a control system (not shown) configured to combine the flows of the glass fibers 22 and hot gases from various fiberizers 18 and further configured to direct the resulting combined flows to various rotary forming apparatus 32. Such a header system 40 can allow for maintenance and cleaning of certain rotary fiberizers 18 without the necessity of shutting down the remaining rotary fiberizers 18 while one rotary fiberizer 18 is not operating. Optionally, the header system 40 can incorporate any desired means for controlling and directing the glass fibers 22 and flows of hot gases.

Referring again to FIG. 1, an air flow exhaust duct 38 is connected to the rotary forming apparatus 32. The air flow exhaust duct 38 is configured to exhaust hot gases separated from the glass fibers 22 in the rotary forming apparatus 32. In the illustrated embodiment, the exhaust duct 38 includes an optional fan (not shown) configured to draw the glass fibers 22 towards the rotary forming apparatus 32.

From the rotary forming device 32, the separated fibers are transported to other downstream operations, such as for example, bagging operations, via a transfer duct 44. As with the duct 40 described above, the transfer duct 44 can be a generally hollow pipe or other conduit suitable for handling the separated glass fibers 22.

As discussed above, it is desirable to mix conductive fibers with the glass fibers 22 to dissipate static charges in the unbonded loosefill insulation material, blankets or batts. Referring first to the instance where the glass fibers 22 are gathered on a conveyor 24 and blankets or batts 26 are formed, the resulting blankets and batts 26 are passed under one or more dispensers 50 for the application of conductive fibers 52 to an upper surface 54 of the blanket or batt 26. While the illustrated embodiment shows one dispenser 50, it should be understood that any number of dispensers 50 can be used. The dispenser 50 can be any desired structure, device or mechanism suitable for depositing conductive fibers 52 onto the upper surface 54 of the blanket or batt 26.

Subsequent downstream operations (not shown), including but not limited to milling operations, needling operations, compression operations, bagging operations and the like can be used to mix the conductive fibers 52 positioned on the upper surface 54 of the blanket or batt 26 with the glass fibers 22 forming the blanket or batt 26. The resulting blanket or batt can have conductive fibers 52 substantially and uniformly distributed throughout the blanket or batt.

Referring again to FIG. 1 and now to the instance where the glass fibers 22 and hot gases are collected by the gathering member 28 and transferred through the duct 40 to the rotary forming apparatus 32, the rotary forming apparatus 32 separates the glass fibers 22 from the flow of hot gasses. The glass fibers 22 are then transported to downstream operations via an air stream, in a direction as indicated by direction arrow A, within a transfer duct 44. The air stream can be created by any desired device, such as the non-limiting examples of a vacuum or a fan, positioned upstream or downstream from the transfer duct 44.

An insertion device 60 can be positioned adjacent to the transfer duct 44. The insertion device 60 is configured to insert conductive fibers 52, via insertion duct 62, into the air stream within the transfer duct 44 such that the conductive fibers 52 mix with the glass fibers 22. While the illustrated embodiment shows one insertion device 60, it should be understood that any number of insertion devices 60 can be used. The insertion device 60 can be any desired structure, device or mechanism suitable for inserting conductive fibers 52 into the air stream within the transfer duct 44 such that the conductive fibers 52 mix with the glass fibers 22.

After the conductive fibers 52 are mixed with the glass fibers 22 within the transfer duct 44, the mixture of the glass fibers 22 and the conductive fibers 52 are conveyed via the transfer duct 44 to subsequent downstream operations. The resulting mixture of the glass fibers 22 and the conductive fibers 52 can have a substantially and uniformly distributed quantity of conductive fibers 52.

While the embodiment shown in FIG. 1 illustrates the insertion of the conductive fibers 52, 62 respectively by the dispenser 50 and insertion device 60, it should be appreciated that the conductive fibers 52, 62 can be dispensed or inserted into or mixed with the glass fibers at other locations in the mineral fiber manufacturing process 10. In non-limiting examples, the insertion device 60 can be positioned such as to insert conductive fibers 62 into the flow of glass fibers passing through the gathering member 28 or the duct 40. In another example, an insertion device or a dispenser can be positioned to insert conductive fibers 52, 62 into the glass fibers forming the veil 20 such that the conductive fibers mix with the veil 20. In another example, an application of conductive fibers can be inserted into any desired portion of a forming hood (not shown) such that the conductive fibers mix throughout formed glass fibers. In yet another example, an insertion device or a dispenser can be positioned to insert conductive fibers 52, 62 into the glass fibers during downstream operations, such as for example bagging operations.

It is further contemplated that the conductive fibers can be mixed with the glass fibers during processes other than the illustrated manufacturing process 10. As one example of a non-manufacturing process, a blowing insulation machine can be used to distribute a mixture of glass fibers and conductive fibers. Referring now to FIGS. 6 and 7, a blowing insulation machine is illustrated generally at 210. The blowing insulation machine 210 includes a chute 214 and a lower unit 212. The chute 214 includes an inlet end 216, configured to receive a package of compressed loosefill insulation material (not shown). The lower unit 212 includes a plurality of shredders 224, an agitator 226 and a discharge mechanism 228. A distribution hose 246 can be connected to the discharge mechanism 228 and configured to receive an air flow containing conditioned loosefill insulation material exiting the blowing insulation machine 210. A nozzle 250 can be positioned at an end of the distribution hose 246 and configured to direct the conditioned loosefill insulation material into an insulation cavity (not shown).

Referring again to FIGS. 6 and 7, the blowing insulation machine can be configured in a variety of manners to distribute a mixture of glass fibers and conductive fibers. In a first example, conductive fibers can be inserted into the inlet end 216 of the chute 214 from a dispenser 252 simultaneously with the loading of the compressed glass fibers into the inlet end 216 of the chute 214, such that the conductive fibers mix with the expanding glass fibers. The dispenser 252 can have any desired structure, such as for example an insertion duct 253 configured to connect the inlet end 216 of the chute 214 with the dispenser 252. The dispenser 252 can be incorporated into the blowing insulation machine 210 in any desired manner. In a second example, conductive fibers can be inserted into the flow of the glass fibers as the glass fibers are conditioned by the shredders 224 or conditioned by the agitator 226. In this example, a dispenser 260 can be positioned to insert conductive fibers within the blowing insulation machine such that the conductive fibers mix with the glass fibers during the conditioning process. The dispenser 260 can have any desired structure, such as for example an insertion duct 261 configured to connect the flow of the glass fibers in the shredders or agitator with the inserted conductive fibers. The dispenser 260 can be incorporated into the blowing insulation machine 210 in any desired manner.

In a third example, conductive fibers can be inserted into the flow of the conditioned glass fibers as the conditioned glass fibers exit the blowing insulation machine 210 through a discharge mechanism 228, such that the conductive fibers mix with the conditioned glass fibers during the exiting process. In this example, a dispenser 270 can be positioned to insert conductive fibers within the blowing insulation machine such that the conductive fibers mix with the glass fibers within the discharge mechanism 228. The dispenser 270 can have any desired structure, such as for example an insertion duct 271 configured to connect the flow of the conditioned glass fibers within the discharge mechanism 228 with the inserted conductive fibers. The dispenser 270 can be incorporated into the blowing insulation machine 210 in any desired manner.

In a fourth example, conductive fibers can be inserted into the air stream containing the conditioned glass fibers as the conditioned glass fibers flow through the distribution hose 246, such that the conductive fibers mix with the conditioned glass fibers. In this example, a dispenser 280 can be positioned to insert conductive fibers into the distribution hose 246 such that the conductive fibers mix with the glass fibers within the distribution hose 246. The dispenser 280 can have any desired structure, such as for example an insertion duct 281 configured to connect the air stream containing the conditioned glass fibers within the distribution hose 246 with the inserted conductive fibers. The dispenser 280 can be incorporated into the distribution hose 246 in any desired manner.

In a final example, conductive fibers can be inserted into the air stream containing the conditioned glass fibers as the conditioned glass fibers flow through the nozzle 250, such that the conductive fibers mix with the conditioned glass fibers. In this example, a dispenser 290 can be positioned to insert conductive fibers into the nozzle 250 such that the conductive fibers mix with the glass fibers within the nozzle 250 or as the glass fibers exit the nozzle 250. The dispenser 290 can have any desired structure, such as for example an insertion duct 291 configured to connect the air stream containing the conditioned glass fibers within the nozzle 250 with the inserted conductive fibers. The dispenser 290 can be incorporated into the nozzle 250 in any desired manner. While the examples discussed above illustrate several methods of using a blowing insulation machine to distribute a mixture of glass fibers and conductive fibers, it should be appreciated that in other embodiments, a blowing insulation machine can be used in other manners to distribute a mixture of glass fibers and conductive fibers.

One non-limiting example of blowing insulation machine is illustrated by U.S. Pat. No. 7,712,690, issued to Owens Corning Intellectual Capital, LLC on May 11, 2010 and incorporated herein in its entirety. However, it should be appreciated that other blowing insulation machines could be used. It should be appreciated that this application contemplates the mixing of the conductive fibers with the glass fibers at any desired point during or after the manufacture of the glass fibers.

The downstream operations can further include compression of the glass fibers 22 in packages of compressed loosefill material. The packages of compressed loosefill material are ready for transport from an insulation manufacturing site to a building that is to be insulated. The compressed loosefill material can be encapsulated in a bag. The bags can be made of polypropylene or other suitable material. During the packaging of the loosefill material, it is placed under compression for storage and transportation efficiencies. Typically, the loosefill material is packaged with a compression ratio of at least about 10:1.

Referring again to FIG. 1, the conductive fibers 52 are incorporated into blankets or batts 26 or into loosefill material to provide effective dissipation of static charges. One non-limiting example of a conductive fiber is the No-Shock® Antistatic Fiber marketed by Ascend Performance Materials LLC, headquartered in Houston, Tex. However, it should be appreciated that other conductive fibers can be used.

Whether the conductive fibers 52 are incorporated into blankets or bats 26 or into loosefill material, the conductive fibers 52 are incorporated in sufficient quantities such as to provide effective dissipation of static charges. In the illustrated embodiment, the quantity of conductive fibers 52 mixed with the glass fibers is in a range of from about 0.1 pounds per 100 pounds of glass fiber to about 0.5 pounds per 100 pounds of glass fiber. However, in other embodiments, the quantity of conductive fibers 52 can be less than about 0.1 pounds per 100 pounds of glass fiber or more than about 0.5 pounds per 100 pounds of glass fiber.

Referring again to FIG. 1, optionally a coloring material (not shown) may be added to the air stream transporting the glass fibers 22 within the transfer duct 44. In certain embodiments, the coloring material is added by a color insertion device 70 positioned adjacent to the transfer duct 44. The color insertion device 70 is configured to insert coloring material, via color insertion duct 72, into the air stream within the transfer duct 44 such that the coloring material mixes with the glass fibers 22 and imparts the color to the glass fibers 22. While the illustrated embodiment shows one color insertion device 70, it should be understood that any number of color insertion devices 70 can be used. The insertion device 70 can be any desired structure, device or mechanism suitable for inserting coloring material into the air stream within the transfer duct 44 such that the coloring material mixes with the glass fibers 22. It should be appreciated that the coloring material can be any desired material and can be either in dry or wet form. While the color insertion device 70 is shown as being positioned downstream from the rotary forming apparatus 32, it should also be appreciated that the color insertion device 70 can be positioned in other locations sufficient to provide a mixing of the coloring material with the glass fibers flowing within the air stream, including within other transfer ducts.

Referring now to FIG. 2a, a first embodiment of a conductive fiber 52 is illustrated. The conductive fiber 52 includes a sheath 64 and a core 66. Generally, the sheath 64 is configured as a protective covering for the core 66 and the core 66 is configured to dissipate static charges. In the illustrated embodiment, the sheath 64 has a circular cross-sectional shape. However, it should be appreciated that in other embodiments, the sheath 64 can have other cross-sectional shapes, such as for example a hexagonal cross-sectional shape sufficient to provide a protective covering for the core 66.

Referring again to FIG. 2a, the sheath 64 has an outer diameter ODS, an inner diameter IDS and a wall thickness TW. The outer diameter ODS of the sheath 64 is of sufficient size such that the conductive fibers 52 are of no greater source of particulate matter than the glass fibers 22 comprising the finished loosefill insulation material. In one embodiment, the glass fibers 22 can have a diameter in a range of from about 10 HT to about 20 HT and the outer diameter ODS of the sheath is in a range of from about 20 HT to about 50 HT. However, in other embodiments, the glass fibers 22 can have a diameter less than about 10 HT or more than about 20 HT and the outer diameter ODS of the sheath can be less than about 20 HT or more than about 50 HT such that the conductive fibers 52 are of no greater source of particulate matter than the glass fibers 22 comprising the finished loosefill insulation material.

The inner diameter IDS of the sheath 64 is sized to be substantially equal to a core diameter DC such that the core 66 fills a passage formed by the inner diameter IDS of the sheath 64. The diameter DC of the core 66 will be discussed in more detail below.

The wall thickness TW of the sheath 64 is in a range of from about 5 HT to about 10 HT. In other embodiments, the wall thickness TW can be less than about 5 HT or more than about 10 HT such that the sheath 64 provides a protective covering for the core 66.

In the embodiment illustrated in FIG. 2a, the sheath 64 is manufactured from a nylon-based polymer. However, in other embodiments, the sheath 64 can be manufactured from other desired materials, including the non-limiting example of polyester, sufficient to provide a protective covering for the core 66.

Referring again to FIG. 2a, the core 66 is configured to dissipate static charges. In the illustrated embodiment, the core 66 has a circular cross-sectional shape. However, it should be appreciated that in other embodiments, the core 66 can have other cross-sectional shapes, such as for example a hexagonal cross-sectional shape sufficient to dissipate static charges.

The core 66 is generally centered within the sheath 64 with the center of the core 66 positioned at the intersection of perpendicular axis A-A and B-B. As will be discussed in more detail below, in other embodiments, the core 66 can be positioned in non-centered locations within the sheath 64.

In the embodiment illustrated in FIG. 2a, the core 66 has a length LC that is substantially the same as the length LF of the sheath 64 and the core 66 extends continuously along its length LC. In alternate embodiments, the core 66 can extend any desired length LC and can be formed of discontinuous or unequal segments sufficient to dissipate static charges.

The core 66 has a diameter DC. The diameter DC of the core 66 is of sufficient size to dissipate static charges. In the illustrated embodiment, the diameter DC of the core 66 is in a range of from about 10 HT to about 30 HT. However, in other embodiments, the core 66 can have a diameter less than about 10 HT or more than about 30 HT sufficient to dissipate static charges.

Referring again to FIG. 2a, the core 66 is formed from a carbon-based material, such as the non-limiting example of carbon black. However, in other embodiments, the core 66 can be manufactured from other desired materials, including the non-limiting example of metallic-based materials, sufficient to dissipate static charges.

Optionally, the materials forming the core 66 can be encapsulated into polymer-based mixtures such that the materials forming the core 66 are not available for inhalation or respiration.

Optionally, the materials forming the sheath 66 and/or the core 64 can include additional electrically conductive materials configured to assist in the dissipation of the static charges. One non-limiting example of an additional electrically conductive material is titanium dioxide. It has been found that the addition of titanium dioxide to the chemical structure of the materials forming the sheath 66 and/or the core 64 provides superior dissipation of static charges. However, it should be appreciated that in other embodiments materials other than titanium dioxide can be added to assist in the dissipation of the static charges.

Also optionally, the materials forming the conductive fiber 52 can be coated with a lubricant (not shown). The lubricant is configured to prevent damage to the conductive fibers 52 as the mixture of the glass fibers 22 and the conductive fibers 52 moves through the manufacturing process 10 and comes into contact with various apparatus as well as other glass fibers 22. The lubricant can be any desired material, such as for example, a silicone compound.

In certain instances, the lubricant used to coat the glass fibers 22 and the lubricant used to coat the conductive fibers 52 can be the same. In other embodiments, the lubricants can be different provided they have no or low VOCs.

In the embodiment illustrated in FIG. 2a, the conductive fiber 52 has a length LF. In certain embodiments, the length LF is similar in length as the glass fibers 22 comprising the finished loosefill insulation material for the purpose of substantially uniform distribution of the conductive fibers 52 within the glass fibers 22. In the illustrated embodiment, the length LF of the conductive fibers 52 is in a range of from about 0.25 inches to about 1.5 inches. Alternatively, the length LF of the conductive fibers 52 can be less than about 0.25 inches or more than about 1.5 inches, sufficient to achieve substantially uniform distribution of the conductive fibers 52 within the finished loosefill insulation material. In still other embodiments, the length LF of the conductive fibers 52 can be different from the length of the glass fibers 22 provided the conductive fibers 52 achieve substantially uniform distribution within the finished loosefill insulation material.

The use of conductive fibers, mixed with the glass fibers forming the loosefill insulation material, to dissipate static charges provides significant benefits, although all benefits may not be present in all circumstances. First, the use of the conductive fibers eliminates the need to coat the glass fibers with a chemical anti-static material, such as for example amine. Since the applied chemical anti-static materials typically utilize moisture in the air to dissipate the static charges, by using the conductive fibers in lieu of a chemical anti-static material, better static charge dissipation can be realized at low levels of relative humidity. Second, elimination or reduced levels of the chemical anti-static materials also results in less build-up of the chemical anti-static material within the material transport ducts in the manufacturing facilities.

Referring now to FIG. 3, a first graph of the performance of the loosefill insulation material having various anti-static materials is illustrated generally at 80. The graph 80 includes a vertical axis 82 of Inches of Static and a horizontal axis 84 of Form of Anti-Static Material. The resulting static formed in the test samples of the loosefill insulation material is measured in inches. The data for graph 80 was generated using a test method of blowing conditioned loosefill insulation material against a test room wall and recording the upper most height of the conditioned loosefill insulation material clinging to the test room wall. The test was performed at a relative humidity level of 30%±2% and at a temperature of 70° F.±2° F.

As shown in FIG. 3, loosefill insulation materials having various anti-static materials were tested. In a first sample, as indicated by reference character 85, the loosefill insulation material was coated with a conventional chemical anti-static material in an amount of 0.135% and the first sample contained no conductive fibers. This sample resulted in a measured static level of 9.0 inches. In a second sample, as indicated by reference character 86, the loosefill insulation material was coated with a conventional chemical anti-static material in an amount of 0.20% and the sample contained no conductive fibers. This sample resulted in a measured static level of 0.0 inches. In a third sample, as indicated by reference character 87, the loosefill insulation material was coated with a conventional chemical anti-static material in an amount of 0.135% and the sample contained 0.1% conductive fibers. This sample resulted in a measured static level of 0.0 inches. In a fourth sample, as indicated by reference character 88, the loosefill insulation material was coated with a conventional chemical anti-static material in an amount of 0.067% and the sample contained 0.1% conductive fibers. This sample resulted in a measured static level of 0.0 inches. In a fifth sample, as indicated by reference character 89, the loosefill insulation material was not coated with a conventional chemical anti-static material and the sample contained 0.1% conductive fibers. This sample resulted in a measured static level of 0.0 inches. Finally, in a sixth sample, as indicated by reference character 90, the loosefill insulation material was not coated with a conventional chemical anti-static material and the sample contained no conductive fibers. This sample resulted in a measured static level of 30.0 inches. As shown by the graph 80, the addition of the conductive fibers improves the dissipation of static charges at low relative humidity levels when combined with low levels of chemical anti-static material and also without chemical anti-static materials.

Referring now to FIG. 4, a second graph of the performance of the loosefill insulation material having various anti-static materials is illustrated generally at 100. The graph 100 includes a vertical axis 102 of Inches of Static and a horizontal axis 104 of Form of Anti-Static Material. The resulting static formed in the loosefill insulation material is measured in inches. The data for graph 100 was generated using the same test method as discussed above for graph 80. The test was performed at a relative humidity level of 21%.

Referring now to FIG. 4, loosefill insulation materials having various anti-static materials were tested. In a first sample, as indicated by reference character 105, the loosefill insulation material was coated with a conventional chemical anti-static material in an amount of 0.15% and the sample contained no conductive fibers. This sample resulted in a measured static level of 30.0 inches. In a second sample, as indicated by reference character 106, the loosefill insulation material was coated with a conventional chemical anti-static material in an amount of 0.10% and the sample contained 0.10% conductive fibers. This sample resulted in a measured static level of 14.0 inches. In a third sample, as indicated by reference character 107, the loosefill insulation material was not coated with a conventional chemical anti-static material and the sample contained 0.10% conductive fibers. This sample resulted in a measured static level of 22.0 inches. As shown by the graph 100, the addition of the conductive fibers improves the dissipation of static charges at low relative humidity levels when combined with low levels of chemical anti-static material and also without chemical anti-static materials.

Referring now to FIG. 5, a graph depicting the color loss performance of the loosefill insulation material having various anti-static materials is illustrated generally at 120. The graph 120 includes a vertical axis 122 of Percentage of Color Loss and a horizontal axis 124 of Test Duration. The color loss of the loosefill insulation material is measured in percentage. The data for the graph 120 was generated using a test method having the steps of: 1) taking initial color readings of the loosefill insulation material contained within a bag of loosefill insulation material with a hand held Colorimeter, such as for example a Hunter Colorimeter (note: a specific color value is used as this correlates to the degree of “the color” observed on the produce, in some instances as many as ten readings are taken from different locations on the surface of the bag of loosefill insulation material, 2) placing the bag of loosefill insulation material on flat surface under constant fluorescent lighting (note the term “constant”, as used herein, is defined to mean 24 hours per day and 7 days per week), and 3) taking additional color readings over time until the loosefill insulation material appears to no longer have the original observed color.

As shown in FIG. 5, two samples were prepared and measured. The first sample of the loosefill insulation material was coated with a chemical anti-static material and also coated with a pigment for coloring. The second sample of the loosefill insulation material included conductive fibers mixed with the loosefill insulation fibers and a pigment for coloring, but did not include a coating of chemical anti-static material. Referring now to the Test Duration period of three weeks, the first sample, shown as reference character 125, indicates a color loss of 69.7%. The second sample, shown as reference character of 126, indicates a color loss of only 6%. Referring now to the Test Duration period of six weeks, the first sample, shown as reference character 127, indicates a color loss of 80.4%. The second sample, shown as reference character of 128, indicates a color loss of only 16.1%. Referring now to the Test Duration period of twelve weeks, the first sample, shown as reference character 129, indicates a color loss of 92.5%. The second sample, shown as reference character of 130, indicates a color loss of only 35.0%.

As shown by the graph 120, the unexpected result of the replacement of the chemical anti-static material with the conductive fibers improves not only the dissipation of static charges, but also improves the color retention of the loosefill insulation material. Without being bound by the theory, it is believed the color retention improvement stems from the elimination of chemical interaction between the chemical anti-static material and the pigment.

While the embodiment of the core 66 shown in FIG. 2a has been described above as having a core diameter DC such that the core 66 fills a passage formed by the inner diameter IDS of the sheath 64, it should be appreciated that the core and the sheath can have other configurations sufficient to dissipate static charges within a body of loosefill insulation material. FIGS. 2b-2e illustrate non-limiting alternate embodiments of the core and sheath configuration.

Referring first to FIG. 2b, a sheath 164 and a core 166 are illustrated. In this embodiment, the sheath 164 and the core 166 are the same as, or similar to, the sheath 64 and the core 66 shown in FIG. 2a and described above. However, it should be appreciated that the sheath 164 and the core 166 can be different from the sheath 64 and the core 66. In this embodiment, the core 166 is positioned in a non-centered location within the sheath 164 sufficient to dissipate static charges within a body of loosefill insulation material. While the core 166 is shown in FIG. 2b to be positioned below the centered intersection of axes A-A and B-B, in alternate embodiments, the core 166 can be positioned in any desired off-center position sufficient to dissipate static charges within a body of loosefill insulation material.

Referring now to FIG. 2c, a sheath 264 and a core 266 are illustrated. In this embodiment, the sheath 264 and the core 266 are the same as, or similar to, the sheath 64 and the core 66 shown in FIG. 2a and described above with the exception that the sheath 264 has an inner diameter IDS that is substantially larger than the diameter DC of the core 266. Accordingly, the core 266 fills only a portion of the inner passage formed by the inner diameter IDS of the sheath 264. In this embodiment, the core 266 is attached to the inner diameter of the sheath 264 in any desired manner sufficient to sufficient to dissipate static charges within a body of loosefill insulation material.

Referring now to FIG. 2d, a sheath 364 and a core 366 are illustrated. In this embodiment, the sheath 364 and the core 366 are the same as, or similar to, the sheath 64 and the core 66 shown in FIG. 2a and described above with the exception that the core 366 has been incorporated into the wall thickness TW of the sheath 364. Accordingly, the sheath 364 has an inner diameter IDS that simply forms an empty inner passage along the length of the sheath 364. In this embodiment, the core has a diameter DC that is equal to or smaller than the wall thickness TW sufficient to dissipate static charges within a body of loosefill insulation material.

Referring now to FIG. 2e, a sheath 464 and a plurality of cores 466 are illustrated. In this embodiment, the sheath 464 and the cores 466 are the same as, or similar to, the sheath 364 and the core 366 shown in FIG. 2d and described above with the exception that multiple cores 466 are incorporated into the wall thickness TW of the sheath 364. Accordingly, the sheath 364 has an inner diameter IDS that simply forms an empty inner passage along the length of the sheath 364. In this embodiment, the core has a diameter DC that is equal to or smaller than the wall thickness TW sufficient to dissipate static charges within a body of loosefill insulation material.

Referring again to the embodiments shown in FIGS. 2a-2e, it should be appreciated that the sheath and the one or more cores forming the conductive fibers can have any desired configuration sufficient to dissipate static charges within a body of loosefill insulation, such as one non-limiting embodiment that incorporates one or more cores having the structure of ribbons infused on an outer exterior of a sheath. It should also be appreciated that the conductive fibers mixed with the loosefill insulation material could be a combination of conductive fibers having different configurations.

In accordance with the provisions of the patent statutes, the principle and mode of operation of the use of conductive fibers to dissipate static charges in unbonded loosefill insulation material have been explained and illustrated in its preferred embodiment. However, it must be understood that the use of conductive fibers to dissipate static charges in unbonded loosefill insulation material may be practiced otherwise than as specifically explained and illustrated without departing from its spirit or scope.

Claims

1. An unbonded loosefill insulation material comprising:

a multiplicity of discrete, individual tufts formed from a plurality of insulative fibers; and

a plurality of conductive fibers mixed with the insulative fibers;

wherein the conductive fibers are configured to dissipate static electrical charges.

2. The unbonded loosefill insulation material of claim 1, wherein the conductive fibers are mixed with the insulative fibers in a quantity range of from about 0.1 pounds of conductive fibers to 100 pounds of insulative fibers to about 0.5 pounds of conductive fibers to 100 pounds of insulative fibers.

3. The unbonded loosefill insulation material of claim 1, wherein the conductive fibers have an electrically conductive core positioned within a protective sheath.

4. The unbonded loosefill insulation material of claim 1, wherein a material forming the sheath includes an electrically conductive material.

5. The unbonded loosefill insulation material of claim 4, wherein the electrically conductive material in the sheath is titanium dioxide.

6. The unbonded loosefill insulation material of claim 1, wherein the insulative fibers have a length and the conductive fibers have a length, and wherein the length of the insulative fibers and the conductive fibers is the same.

7. The unbonded loosefill insulation material of claim 6, wherein the lengths of the insulative fibers and the conductive fibers are in a range of from about 0.25 inches to about 1.5 inches.

8. The unbonded loosefill insulation material of claim 1, wherein the insulative fibers have a coating of anti-static material.

9. The unbonded loosefill insulation material of claim 3, wherein a material forming the core is encapsulated into polymer-based mixtures such that the material forming the core is not available for inhalation or respiration.

10. The unbonded loosefill insulation material of claim 1, wherein the insulative fibers are coated with a coloring material.

11. A method of manufacturing unbonded loosefill insulation material configured for distribution in a blowing insulation machine, the method comprising the steps of:

forming tufts of fibrous insulation materials; and

mixing conductive fibers with the fibrous insulation materials;

wherein the conductive fibers are configured to dissipate static electrical charges.

12. The method of claim 11, wherein the conductive fibers have an electrically conductive core positioned within a protective sheath.

13. The method of claim 12, wherein a material forming the sheath includes an electrically conductive material.

14. The method of claim 13, wherein the electrically conductive material in the sheath is titanium dioxide.

15. The method of claim 12, wherein a material forming the core is encapsulated into polymer-based mixtures such that the material forming the core is not available for inhalation or respiration.

16. A method of insulating a building cavity using a blowing insulation machine, the method including the steps of:

receiving and conditioning loosefill insulation material from a package of compressed loosefill insulation material, the loosefill insulation material having a mixture of fibrous insulation material and conductive fibers; and

distributing the conditioned loosefill insulation material into the building cavity using the blowing insulation machine;

wherein the conductive fibers are configured to dissipate static electrical charges.

17. The method of claim 16, wherein the conductive fibers have an electrically conductive core positioned within a protective sheath.

18. The method of claim 17, wherein a material forming the sheath includes an electrically conductive material.

19. The method of claim 18, wherein the electrically conductive material in the sheath is titanium dioxide.

20. The method of claim 17, wherein a material forming the core is encapsulated into polymer-based mixtures such that the material forming the core is not available for inhalation or respiration.

21. A method of insulating a building cavity using a blowing insulation machine, the method including the steps of:

using the blowing insulation machine to condition and distribute fibrous loosefill insulation material into the building cavity; and

mixing conductive fibers with the fibrous loosefill insulation material;

wherein the conductive fibers are configured to dissipate static electrical charges.

22. The method of claim 21, wherein the conductive fibers are mixed with the fibrous insulation material during the conditioning of the fibrous insulation materials.

23. The method of claim 21, wherein the conductive fibers are inserted into the flow of the fibrous insulation materials within the distribution hose.

24. The method of claim 21, wherein the fibrous loosefill insulation material is compressed within the package.

25. The method of claim 21, wherein the conductive fibers have an electrically conductive core positioned within a protective sheath.

26. The method of claim 25, wherein a material forming the sheath includes an electrically conductive material.

27. The method of claim 26, wherein the electrically conductive material in the sheath is titanium dioxide.

28. The method of claim 25, wherein a material forming the core is encapsulated into polymer-based mixtures such that the material forming the core is not available for inhalation or respiration.