THERMALLY INSULATING BATT AND COMPOSITE

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

[0001] The present invention relates to a thermally insulating batt that can be used in a thermally insulated composite suitable for use in an exterior portion, such as a wall or roof, of residential and commercial buildings.

2. Description of the Related Art

[0002] A batt suitable for thermal insulation preferably contains staple fibers that are strong, small in diameter and pack together in an open or loose manner. Undrawn melt spun staple fibers have large diameters. Drawn melt spun staple fibers have smaller diameters and are strong but are difficult to open or to spread the fibers apart during carding resulting in non-uniformity issues. Melt blown fibers have small diameters but are weak and tend to pack together too tightly resulting in sub-optimum thermal insulation.

[0003] US 5,275,875 describes lightweight structures that have a high degree of thermal insulation, are non-wetting and/or buoyant and have good fire resistance.

[0004] JP 60-259664 A discloses a heat retaining fiber sheet for clothing with heat retaining properties and compression strain recovery of the bulk and little bulkiness reduction after being worn with improved shape stability against washing.

[0005] It would be desirable to have a thermally insulating batt that contains staple fibers that are strong, small in diameter and pack together in an open or loose manner.

SUMMARY OF THE INVENTION

[0006] In a first embodiment, the present invention relates to a thermally insulating batt comprising: (i) 10 to 70% by weight of first staple fibers that comprise staple flash spun plexifilamentary fibers, wherein the staple flash spun plexifilamentary fibers comprise a polyolefin polymer; (ii) 10 to 70% by weight of the total batt of second staple fibers, wherein the staple fibers comprise a polyester polymer, polyolefin polymer, polyamide polymer or viscose rayon; and (iii) 5 to 30% by weight binding agent, wherein the binding agent comprises at least one polymeric component with a melting point below the melting point of the staple flash spun plexifilamentary fiber melting point and the staple fiber melting point.

[0007] In another embodiment, the present invention relates to a thermally insulating composite comprising: (a) a thermally insulating batt comprising: (i) 10 to 70% by weight of first staple fibers that comprise staple flash spun plexifilamentary fibers, wherein the staple flash spun plexifilamentary fibers comprise a polyolefin polymer (ii) 10 to 70% by weight of the total batt of second staple fibers, wherein the staple fibers comprise a polyester polymer, polyolefin polymer, polyamide polymer or viscose rayon and (iii) 5 to 30% by weight binding agent, wherein the binding agent comprises at least one polymeric component with a melting point below the melting point of the staple flash spun plexifilamentary fiber melting point and the staple fiber melting point; and (b) a moisture vapor permeable, substantially liquid impermeable, substantially air impermeable substrate on one surface of the thermally insulating batt. The substrate has a Gurley Porosity between 250 and 5990 sec/100 cubic centimeters /inch² a moisture vapor transmission rate (MVTR) of between 250 and 1870 grams/meter²/24hours and a hydrostatic head of between 200 and 400 centimeters of water.

[0008] In still another embodiment, the present invention relates to an exterior portion of a building comprising the aforementioned thermally insulating batt or thermally insulating composite.

DETAILED DESCRIPTION OF THE INVENTION

Definition of Terms

[0009] The term "batt" as used herein means single or multiple sheets of fibers used in the production of a nonwoven.

[0010] The term "nonwoven" or "web" as used herein means a structure of individual fibers or threads that are positioned in a random manner to form a planar material without an identifiable pattern, as in a knitted fabric.

[0011] The term "plexifilamentary fibers" as used herein means a three-dimensional integral network or web of a multitude of thin, ribbon-like, film-fibril elements of random length and with a mean film thickness of less than about 4 microns and a median fibril width of less than about 25 microns. The average film-fibril cross sectional area if mathematically converted to a circular area would yield an effective diameter between about 1 micron and 25 microns. In plexifilamentary structures, the film-fibril elements intermittently unite and separate at irregular intervals in various places throughout the length, width and thickness of the structure to form a continuous three-dimensional network.

[0012] The term "polymer" as used herein, generally includes but is not limited to, homopolymers, copolymers (such as for example, block, graft, random and alternating copolymers), terpolymers, etc., and blends and modifications thereof. Furthermore, unless otherwise specifically limited, the term "polymer" shall include all possible geometrical configurations of the material. These configurations include, but are not limited to isotactic, syndiotactic, and random symmetries.

[0013] The term "polyolefin" as used herein, is intended to mean any of a series of largely saturated polymeric hydrocarbons composed only of carbon and hydrogen. Typical polyolefins include, but are not limited to, polyethylene, polypropylene, polymethylpentene, and various combinations of the monomers ethylene, propylene, and methylpentene.

[0014] The term "polyethylene" as used herein is intended to encompass not only homopolymers of ethylene, but also copolymers wherein at least 85% of the recurring units are ethylene units such as copolymers of ethylene and alpha-olefins. Preferred polyethylenes include low-density polyethylene, linear low-density polyethylene, and linear high-density polyethylene. A preferred linear high-density polyethylene has an upper limit melting range of about 130°C to 140°C, a density in the range of about 0.941 to 0.980 gram per cubic centimeter, and a melt index (as defined by ASTM D-1238-57T Condition E) of between 0.1 and 100, and preferably less than 4.

[0015] The term "polypropylene" as used herein is intended to embrace not only homopolymers of propylene but also copolymers where at least 85% of the recurring units are propylene units. Preferred polypropylene polymers include isotactic polypropylene and syndiotactic polypropylene.

Detailed Description

[0016] The present invention is directed to a thermally insulating batt comprising: (i) 10 to 70% by weight of first staple fibers that comprise staple flash spun plexifilamentary fibers, wherein the staple flash spun plexifilamentary fibers comprise a polyolefin polymer, (ii) 10 to 70% by weight of second staple fibers, wherein the staple fibers comprise a polyester polymer, polyolefin polymer, polyamide polymer or viscose rayon and (iii) 5 to 30% by weight binding agent, wherein the binding agent comprises at least one polymeric component with a melting point below the melting point of the staple flash spun plexifilamentary fiber melting point and the staple fiber melting point. Described herein are also staple melt spun fibrillated fibers, which can be included in the first staple fibers. Preferably, the present invention is directed to a thermally insulating batt comprising: (i) 25 to 60% by weight of first staple fibers that comprise staple flash spun plexifilamentary fibers and -if present- staple melt spun fibrillated fibers; (ii) 25 to 60% by weight of second staple fibers; and (iii) 15 to 25% by weight binding agent.

[0017] The staple flash spun plexifilamentary fibers of the thermally insulating batt can be made according to the flash spinning process described in U.S. Patent No. 7,744,989 to Marin et al. The flash spinning process produces a flash spun web of plexifilamentary fibers. The plexifilamentary fibers can be unbonded or lightly bonded. The flash spun web of plexifilamentary fibers can then be cut to a length of at least about 2.5 cm to make the staple flash spun plexifilamentary fibers. The staple flash spun plexifilamentary fibers preferably have a surface area of at most 10 m²/g or a crush value of at least 1 mm/g and more preferably a surface area of at most 5 m²/g or a crush value of at least 1.5 mm/g. The staple flash spun plexifilamentary fibers can be made of polyolefin polymer, preferably polyethylene.

[0018] The staple melt spun fibrillated fibers can be made according to any general process known to those skilled in the art. For example, melt spun fibrillated fibers can be made by melt spinning bicomponent polymer fibers with fiber cross sections such as round pie shape with pie wedges of alternating polymers or islands in the sea with the islands made from one polymer and the sea made from another polymer. The melt spun bicomponent polymer fibers can then be cut to a length of at least about 2.5 cm to make staple melt spun unfibrillated fibers. The staple melt spun unfibrillated fibers are later converted into staple melt spun fibrillated fibers via a carding process. The staple melt spun fibrillated fibers can be made of polyolefin polymer, polyester polymer, polyamide polymer or mixtures thereof.

[0019] The staple fibers can be made according to any general process known to those skilled in the art. The staple fibers preferably are stiff to provide some support and loft to the batt. The staple fibers comprise a polyester polymer, preferably polyethylene terephthalate, polyolefin polymer, polyamide polymer or viscose rayon.

[0020] The binding agent comprises at least one polymeric component with a melting point below the melting point of the staple flash spun plexifilamentary fiber melting point and the staple fiber melting point. The binding agent can take the form of staple binder fibers or small particles. The staple binder fibers can comprise multiple polymeric components with (a) at least one polymeric component with a melting point below the melting point of the staple flash spun plexifilamentary fiber melting point or the staple melt spun fibrillated fiber melting point and the staple fiber melting point and occupying at least a portion of a surface of the staple binder fibers and (b) at least one polymeric component with a melting point above that of the melting point of the at least one polymeric component with a melting point below the melting point of the staple flash spun plexifilamentary fiber melting point or the staple melt spun fibrillated fiber melting point and the staple fiber melting point. A common example of this type of staple binder fiber is a bicomponent fiber wherein a low melting point polymer on at least a portion of the surface of the fiber melts and adheres to another fiber while a high melting point polymer does not melt keeping a portion of the fiber intact.

[0021] The staple flash spun plexifilamentary fibers and -if present- staple melt spun unfibrillated fibers, staple fibers and a binding agent are mixed and fed to a carding machine to form a carded web. The carding process splits the larger diameter staple flash spun plexifilamentary fibers into microfibers or splits the staple melt spun unfibrillated fibers into staple melt spun fibrillated fibers by breaking the fibers apart along the interfacial boundary between the different polymers. The carded web is fed, for example, onto a conveyor belt or apron to a crosslapper, where lapper aprons crosslap the carded web by traversing a carrier means such as an intermediate apron in a reciprocating motion, to produce a thermally insulating batt of fibers that are oriented primarily in the transverse direction. The number of laps used to form the thermally insulating batt depends upon variables such as the
desired weight of the base layer, and the final weight of the thermally insulating batt. The thermally insulating batt is then, optionally, fed into an oven at a temperature that will activate the binding agent to adhere fibers together and impart strength to the batt.

[0022] The staple flash spun plexifilamentary fibers or staple melt spun unfibrillated fibers, staple fibers and a binding agent may optionally be mixed and pre-opened in a card opener (For example a Dell'orco Villani co/1500 machine.) The blend may then be fed through a chute feeder (such as disclosed in U.S. Patent 3,981,047), garnet (with crosslapping), or air-lay equipment to make a thermally insulating batt. The thermally insulating batt may then optionally be fed into an oven at a temperature that will activate the binding agent to adhere fibers together and impart strength to the batt.

[0023] In one embodiment the thermally insulating batt of the invention has a thermal conductivity/basis weight ratio, at 0.0318 m thickness, of less than 7.5 x 10^-5 (W/m•K)/(g/m²), preferably less than 6.0 x 10^-5 (W/m•K)/(g/m²).

[0024] Between 5 to 50% of the second staple fibers can have a weight of less than 3.0 denier per filament.

[0025] In another embodiment the present invention is directed to a thermally insulating composite comprising: (a) a thermally insulating batt comprising: (i) 10 to 70% by weight of first staple fibers that comprise staple flash spun plexifilamentary fibers, wherein the staple flash spun plexifilamentary fibers comprise a polyolefin polymer, (ii) 10 to 70% by weight of second staple fibers, wherein the staple fibers comprise a polyester polymer, polyolefin polymer, polyamide polymer or viscose rayon, and (iii) 5 to 30% by weight binding agent, wherein the binding agent comprises at least one polymeric component with a melting point below the melting point of the staple flash spun plexifilamentary fiber melting point and the staple fiber melting point; and (b) a moisture vapor permeable, substantially liquid impermeable, substantially air impermeable substrate on one surface of the thermally insulating batt. The substrate has a Gurley Porosity between 250 and 5990 sec/100 cubic centimeters/inch² a moisture vapor transmission rate (MVTR) of between 250 and 1870 grams/meter²/24hours and a hydrostatic head of between 200 and 400 centimeters of water.

[0026] The moisture vapor permeable, substantially liquid impermeable, substantially air impermeable substrate can be a nonwoven comprising flash spun plexifilamentary fibers. Flash spun plexifilamentary fibers can be made for example according to the process described in U.S. Patent No. 3,081,519 to Blades et al. A suitable example is Tyvek® Homewrap™.

[0027] 5 to 50% of the staple fibers can weigh less than 3.0 denier per filament.

[0028] One surface of the thermally insulating batt is adhered to the moisture vapor permeable, substantially liquid impermeable, substantially air impermeable substrate via any method known to one of ordinary skill in the art. For example, the thermally insulating batt and the moisture vapor permeable, substantially liquid impermeable, substantially air impermeable substrate can be adhered together by a spray-on adhesive.

[0029] Another embodiment of the present invention is an exterior portion, such as a wall or roof, of a building comprising the thermally insulating batt or the thermally insulating composite of the invention.

TEST METHODS

[0030] In the non-limiting Examples that follow, the following test methods were employed to determine various reported characteristics and properties. ASTM refers to the American Society of Testing Materials.

[0031] Basis Weight was determined according to ASTM D-3776 and reported in g/m².

[0032] Thickness was obtained from the thermal resistance test and is reported in meters.

[0033] Surface Area of the plexifilamentary fiber was measured by the BET nitrogen absorption method of S. Brunauer, P. H. Emmett and E. Teller, J. Am. Chem. Soc., V. 60 p 309-319 (1938) and is reported as m²/g.

[0034] Crush Value was determined using the following procedure. Three plexifilamentary fiber strands of different sizes were manually pulled from an unbonded plexifilamentary web. The three samples weighed about one, two and three grams. The reported crush values are the averages of the values measured on the three samples. Each sample plexifilamentary strand was formed into a ball shape with minimum application of pressure to avoid crushing and the sample was then weighed in grams. A crush tester comprised of an acrylic sample holder and crusher was used to measure the crush value of each sample. The sample holder comprised a cylindrical section having an inner diameter of 2.22 inches (5.64 cm) and an outer diameter of 2.72 inches (6.91 cm). The center of the cylinder was located at the geometric center of a square base measuring 6.00 inches by 6.00 inches (15.24 cm by 15.24 cm). The crusher comprised a cylindrical plunger rod (diameter = 0.75 inches (1.91 cm)) having a first disk-shaped face (the disk having a thickness of 0.25 inches (0.64 cm) and a diameter of 2.20 inches (5.59 cm)) located at one end of the plunger rod and a second disk on the plunger rod spaced back 1.50 inches (3.81 cm) from the first disk. The second disk also had a thickness of 0.25 inches (0.64 cm) and a diameter of 2.20 inches (5.59 cm). The disks were sized slightly smaller than the inner diameter of the cylindrical sample holder in order to allow air to escape from the sample during crushing. The plexifilamentary samples were placed, one at a time, in the sample holder and a thin piece of paper having a diameter of about 2.2 inches (5.59 cm) was placed on top of the plexifilamentary sample prior to crushing. The plunger rod was then inserted into the cylindrical sample holder such that the first disk-shaped face contacted the piece of paper. The second disk served to maintain the axis of the plunger rod in alignment with the axis of the cylindrical sample holder. Each plexifilamentary strand sample was crushed by placing a 2 lb (0.91 kg) weight on the plunger rod. The crush height (mm) was obtained by measuring the height of the sample from the bottom of the cylindrical sample holder to the bottom of the crusher. The plunger and weight were removed from the sample after approximately 2 minutes, leaving the piece of paper in place to facilitate measurement of the restored height of the sample. Each sample was allowed to recover approximately 2 minutes and the restored height (mm) of the sample was obtained by measuring the height of the paper from the center of each of the four sides of the sample holder and averaging the measurements. The crush value (mm/g) is calculated by subtracting the average crush height from the average restored height and dividing by the average of the weights of the samples. The crush value is a measure of how much the sample recovers its original size after being crushed, with higher values indicating greater recovery of original sample height.

[0035] Thermal Conductivity was determined according to ASTM C-518. The test sample or specimen is located between two flat plates in a heat flow meter, and the plates are maintained at known, but different, temperatures. As heat flows through the test sample from the hot side to the cold side, a heat flux transducer measures the amount of heat transferred and thermocouples measure the temperatures of each of the two plates (i.e., of the so-called hot and cold plates). Fourier heat flow relation is used to calculate thermal conductivity. The thermal conductivity is reported in W/m•K.

[0036] Thermal Resistance is calculated using measured thermal conductivity and the thickness of the sample. Thermal resistance was reported in units of m²•K/W.

[0037] Thermal Conductivity/Basis Weight ratio was calculated by dividing the thermal conductivity by the basis weight and was reported in units of (W/m•K)/(g/m²).

[0038] Moisture Vapor Transmission Rate (MVTR) was determined by ASTM E398-83 (the "LYSSY" method) and is based on a pressure gradient of 85% relative humidity ("wet space") vs. 15% relative humidity ("dry space"). The LYSSY method measures the moisture diffusion rate for just a few minutes and under a constant humidity delta, which measured value, is then extrapolated over a 24 hour period. MVTR is reported in g/m²/24 hr

[0039] Hydrostatic Head (HH) was determined by ATTCC 127 and is a measure of the resistance of the sheet to penetration by liquid water under a static load. A 17.78 cm x 17.78 cm sample is mounted in a SDL 18 Shirley Hydrostatic Head Tester (manufactured by Shirley Developments Limited, Stockport, England). Water is pumped against one side of a 102.6 cm section of the sample at a rate of 60+/-3 cm/min until three areas of the sample are penetrated by the water. The hydrostatic pressure is measured in inches, converted to SI units and reported in centimeters of water. The test generally follows ASTM D 583 (withdrawn from publication November, 1976).

[0040] Gurley-Hill Porosity was measured in accordance with TAPPI T-460 using a Lorentzen & Wettre Model 121D Densometer. This test measures the time of which 100 cubic centimeters of air is pushed through a one-inch diameter sample under a pressure of approximately 12.4 cm of water. The result is expressed in seconds and is usually referred to as Gurley Seconds.

EXAMPLES

[0041] Hereinafter the present invention will be described in more detail in the following examples and the resultant data presented in the Table.

Example 1

[0042] Example 1 represents a thermally insulating batt of the present invention. The staple flash spun plexifilamentary fibers of the thermally insulating batt were made by using the flash spinning technology as disclosed in U.S. Pat. No. 7,744,989 to Marin et al. Plexifilamentary fibers were flash spun at a temperature of 205°C from a 20 weight percent concentration of high density polyethylene having a melt index of 0.7 g/10 min (measured according to ASTM D-1238 at 190°C and 2.16 kg load) in a spin agent of 60 weight percent normal pentane and 40 weight percent cyclopentane. The plexifilamentary fibers were unbonded. The plexifilamentary fibers were cut to a length of about 2.5 cm to make the staple flash spun plexifilamentary fibers. The staple flash spun plexifilamentary fibers had a surface area of 8 m²/g and a crush value of 1 mm/g.

[0043] Fifty(50)% of the staple flash spun plexifilamentary fibers were then mixed with 35% staple polyester fibers with a cut length of about 3 cm and 15% of a low melting bicomponent sheath/core binder fiber of a polyester copolymer as the sheath and polyethylene terephthalate as the core. The staple mixture was fed to a carding machine. The carding process split the larger diameter plexifilamentary fibers into microfibers and further produces a fibrous structure or carded web. The carded web was fed onto a conveyor belt or apron to a crosslapper, where lapper aprons crosslapped the carded web by traversing a carrier means such as an intermediate apron in a reciprocating motion for 13 laps, to produce a thermally insulating batt of fibers that are oriented primarily in the transverse direction. The resulting thermally insulating batt had a basis weight of 534 g/m², a thickness of 0.0318 m, a thermal conductivity of 0.036 W/m•K, a thermal resistance of 0.883 m²•K/W and a thermal conductivity / basis weight ratio of 6.7 x 10^-5 (W/m•K)/(g/m²).

Example 2

[0044] Example 2 represents a thermally insulating composite of the present invention. The thermally insulating batt from Example 1 was used to prepare the thermally insulating composite. The moisture vapor permeable, substantially liquid impermeable, substantially air impermeable substrate used was Tyvek® Homewrap™ (available from the DuPont Company, Wilmington, DE). The substrate was moisture vapor permeable with a moisture vapor transmission rate of 370 g/m²/24 hr, substantially liquid impermeable with a hydrostatic head of 250 cm, and substantially air impermeable with a Gurley Hill porosity of 1200 s. One surface of the thermally insulating batt was adhered to the Tyvek® Homewrap™ by a spray-on adhesive of 77 Multi-purpose (available from 3M, St. Paul, MN).

Example 3

[0045] Example 3 represents a thermally insulating batt of the present invention. The staple melt spun fibrillated fibers (T-502 Fiber Innovation Technology, Johnson City, Tn.) were 6 DPF and 0.006 m long. 50% of the staple melt spun fibrillated fibers were then mixed with 35% staple polyester fibers with a cut length of about 3 cm and 15% of a low melting bicomponent sheath/core binder fiber of a polyester copolymer as the sheath and polyethylene terephthalate as the core. The staple mixture was fed to a carding machine. The carding process split the larger diameter melt spun fibrillated fibers into microfibers and further produced a fibrous structure or carded web. The carded web was fed onto a conveyor belt or apron to a crosslapper, where lapper aprons crosslapped the carded web by traversing a carrier means such as an intermediate apron in a reciprocating motion for 13 laps, to produce a thermally insulating batt of fibers that are oriented primarily in the transverse direction. The resulting thermally insulating batt had a basis weight of 646 g/m², a thickness of 0.0318 m, a thermal conductivity of 0.034 W/m•K, thermal resistance of 0.935 m²•K/W and a thermal conductivity/basis weight ratio of 5.3 x 10^-5 (W/m•K)/(g/m²).

Comparative Example 1

[0046] 85% of the staple polyester fibers with a cut length of about 3 cm were mixed with 15% of a low melting bicomponent sheath/core binder fiber of a polyester copolymer as the sheath and polyethylene terephthalate as the core. The staple mixture was fed to a carding machine. The carded web was fed onto a conveyor belt or apron to a crosslapper, where lapper aprons crosslapped the carded web by traversing a carrier means such as an intermediate apron in a reciprocating motion for 13 laps, to produce a thermally insulating batt of fibers that are oriented primarily in the transverse direction. The resulting thermally insulating batt had a basis weight of 528 g/m², a thickness of 0.0318 m, a thermal conductivity of 0.043 W/m•Ka thermal resistance of 0.739 m²•K/W and a thermal conductivity/basis weight ratio of 8.1 x 10^-5 (W m•K)/(g/m²).

Table

Sample	Plexifilament Fiber	Fibrillated Fiber	Binder Fiber	Staple Fiber	Basis Weight	Thermal Cond.	Thermal Resist.	Thermal Cond. /Basis W eight	Gurley Hill	HH	MVTR
	%	%	%	%	g/m2	W/m•K	m2•K/W	(W/m•K)/(g/m2)	sec	cm	g/m2/24hr
Example 1	50		15	35	534	0.036	0.883	6.7X10-5
Example 2	50		15	35					1200	250	370
Example 3		50	15	35	646	0.034	0.935	5.3X10-5
Comp. Ex 1			15	85	528	0.043	0.739	8.1X10-5

Claims

1. A thermally insulating batt comprising:

(i) 10 to 70% by weight of the total batt of a collection of first staple fibers that comprise staple flash spun plexifilamentary fibers,
wherein the staple flash spun plexifilamentary fibers comprise a polyolefin polymer;

(ii) 10 to 70% by weight of the total batt of a collection of second staple fibers;
wherein the staple fibers comprise a polyester polymer, polyolefin polymer, polyamide polymer or viscose rayon; and

(iii) 5 to 30% by weight of the batt of binding agent,
wherein the binding agent comprises at least one polymeric component with a melting point below the melting point of the staple flash spun plexifilamentary fiber melting point and the staple fiber melting point.

2. The thermally insulating batt of claim 1, wherein the first staple fibers are present at 25 to 60% by weight of the total batt, the second staple fibers are present at 25 to 60% by weight of the total batt, and the binding agent is present at from 15 to 25% by weight of the total batt.

3. The thermally insulating batt of claim 2, wherein the first staple fibers are present at 35 to 60% by weight of the total batt, the second staple fibers are present at 35 to 60% by weight of the total batt.

4. The thermally insulating batt of claim 1, wherein between 5 to 50% of the second staple fibers have a weight of less than 3.0 denier per filament.

5. The thermally insulating batt of claim 1, wherein the staple flash spun plexifilamentary fibers have a surface area of 10 m²/g or less as measured by the BET nitrogen absorption method of S. Brunauer, P. H. Emmett and E. Teller or a crush value of at least 1 mm/g as measured according to the method described herein or both.

6. The thermally insulating batt of claim 5, wherein the surface area is less than 5 m²/g or the crush value is at least 1.5 mm/g or both.

7. The thermally insulating batt of claim 1, wherein the polyolefin polymer of the staple flash spun plexifilamentary fibers is polyethylene.

8. The thermally insulating batt of claim 1, wherein the polyester polymer of the second staple fibers is polyethylene terephthalate.

9. The thermally insulating batt of claim 1, wherein the binding agent is in the form of staple binder fibers.

10. The thermally insulating batt of claim 1, wherein the first staple fibers comprise a thermoplastic polymer and the binding agent is in the form of staple binder fibers that comprise multiple polymeric components with (a) a first polymeric component with a melting point below the melting point of the thermoplastic polymer and that occupies at least a portion of a surface of the staple binder fibers and (b) a second polymeric component with a melting point above that of the first polymeric component and with a melting point below that of the thermoplastic polymer.

11. The thermally insulating batt of claim 1, wherein the thermally insulating batt has a thermal conductivity/basis weight ratio at 0.0318 meters thickness, of less than 7.5 x 10^-5 (W/m•K)/(g/m²), the thermal conductivity/basis weight ratio calculated by dividing the thermal conductivity as determined according to ASTM C-518 by the basis weight as determined according to ASTM D-3776.

12. A thermally insulating composite comprising:

(a) a thermally insulating batt comprising:

(i) 10 to 70% by weight of the total batt of a collection of first staple fibers that comprise staple flash spun plexifilamentary fibers,
wherein the staple flash spun plexifilamentary fibers comprise a polyolefin polymer;

(ii) 10 to 70% by weight of the total batt of a collection of second staple fibers,
wherein the staple fibers comprise a polyester polymer, polyolefin polymer, polyamide polymer or viscose rayon; and

(iii) 5 to 30% by weight of the batt of binding agent
wherein the binding agent comprises at least one polymeric component with a melting point below the melting point of the staple flash spun plexifilamentary fiber melting point and the staple fiber melting point
and

(b) a substrate adjacent to one surface of the thermally insulating batt wherein the substrate has a Gurley Porosity between 250 and 5990 sec/100 cubic centimeters /inch² as measured in accordance with TAPPI T-460, a moisture vapor transmission rate (MVTR) of between 250 and 1870 grams/meter²/24hours as determined by ASTM E398-83, and a hydrostatic head of between 200 and 400 centimeters of water as determined by ATTCC 127.

13. The thermally insulating composite of claim 12, wherein 5 to 50% of the staple fibers weigh less than 3.0 denier per filament.

14. The thermally insulating composite of claim 12 wherein the thermally insulating batt has a thermal conductivity/basis weight ratio at 0.0318 m thickness, of less than 7.5 x 10^-5 (W/m•K)/(g/m²), the thermal conductivity/basis weight ratio calculated by dividing the thermal conductivity as determined according to ASTM C-518 by the basis weight as determined according to ASTM D-3776, or
wherein the substrate is a nonwoven comprising flash spun plexifilamentary fibers.

15. An exterior portion of a building comprising the thermally insulating batt of claim 1, or
comprising the thermally insulating composite of claim 12.

Ansprüche

1. Wärmedämmende Fasermatte, umfassend:

(i) 10% bis 70 Gew .-% der gesamten Fasermatte eine Kollektion von ersten Stapelfasern, die flash-gesponnene plexifilamentäre Stapelfasern aufweisen,
wobei die flash-gesponnenen plexifilamentären Stapelfasern ein Polyolefin-Polymer aufweisen;

(ii) 10% bis 70 Gew.-% der gesamten Fasermatte eine Kollektion von zweiten Stapelfasern;
wobei die Stapelfasern ein Polyester-Polymer, Polyolefin-Polymer, Polyamid-Polymer oder Viskose-Kunstseide umfassen; und

(iii) 5% bis 30 Gew.-% der Fasermatte Bindemittel,
wobei das Bindemittel mindestens eine polymere Komponente mit einem Schmelzpunkt unterhalb des Schmelzpunkts der flash-gesponnenen plexifilamentären Stapelfaser und des Schmelzpunkts der Stapelfaser aufweist.

2. Wärmedämmende Fasermatte nach Anspruch 1, wobei die ersten Stapelfasern mit 25% bis 60 Gew.-% der gesamten Fasermatte vorliegen, die zweiten Stapelfasern mit 25% bis 60 Gew.-% der gesamten Fasermatte vorliegen und das Bindemittel mit 15% bis 25 Gew.-% der gesamten Fasermatte vorliegt.

3. Wärmedämmende Fasermatte nach Anspruch 2, wobei die ersten Stapelfasern mit 35% bis 60 Gew.-% der gesamten Fasermatte vorliegen, die zweiten Stapelfasern mit 35% bis 60 Gew.-% der gesamten Fasermatte vorliegen.

4. Wärmedämmende Fasermatte nach Anspruch 1, wobei 5% bis 50% der zweiten Stapelfasern ein Gewicht von weniger als 30 Denier pro Filament haben.

5. Wärmedämmende Fasermatte nach Anspruch 1, wobei die flash-gesponnenen plexifilamentären Stapelfasern eine Oberfläche von 10 m²/g oder weniger haben, die mit Hilfe der BET-Methode der Absorption von Stickstoff nach S. Brunauer, P. H. Emmett und E. Teller gemessen wird, oder einen Knitterwert von mindestens 1 mm/g haben, der nach der hierin beschriebenen Methode gemessen wird, oder beides gilt.

6. Wärmedämmende Fasermatte nach Anspruch 5, wobei die Oberfläche kleiner ist als 5 m²/g oder der Knitterwert mindestens 1,5 mm/g beträgt, oder beides gilt.

7. Wärmedämmende Fasermatte nach Anspruch 1, wobei das Polyolefin-Polymer der gesponnenen plexifilamentären Stapelfasern Polyethylen ist.

8. Wärmedämmende Fasermatte nach Anspruch 1, wobei das Polyester-Polymer der zweiten Stapelfasern Polyethylenterephthalat ist.

9. Wärmedämmende Fasermatte nach Anspruch 1, wobei das Bindemittel die Form von Stapel-Binderfasern hat.

10. Wärmedämmende Fasermatte nach Anspruch 1, wobei die ersten Stapelfasern ein thermoplastisches Polymer umfassen und das Bindemittel in Form von Stapel-Binderfasern vorliegt, die mehrfache polymere Komponenten aufweisen mit (a) einer ersten polymeren Komponente mit einem Schmelzpunkt unterhalb des Schmelzpunkts des thermoplastischen Polymers, und das mindestens einen Teil einer Oberfläche der Stapel-Binderfasern ausmacht, und (b) einer zweiten polymeren Komponente mit einem Schmelzpunkt oberhalb desjenigen der ersten polymeren Komponente und mit einem Schmelzpunkt unterhalb desjenigen des thermoplastischen Polymers.

11. Wärmedämmende Fasermatte nach Anspruch 1, wobei die wärmedämmende Fasermatte ein Verhältnis von Wärmeleitfähigkeit/Flächengewicht bei einer Dicke von 0,0318 m von weniger als 7,5 x 10^-5 (W/m•K)/(g/m²) hat und das Verhältnis von Wärmeleitfähigkeit/Flächengewicht berechnet wird, indem die gemäß ASTM C-518 bestimmte Wärmeleitfähigkeit dividiert wird durch das gemäß ASTM D-3776 bestimmte Flächengewicht.

12. Wärmedämmender Verbundstoff, umfassend:

(a) eine wärmedämmende Fasermatte, umfassend:

(i) 10% bis 70 Gew .-% der gesamten Fasermatte eine Kollektion von ersten Stapelfasern, die flash-gesponnene plexifilamentäre Stapelfasern aufweisen,
wobei die flash-gesponnenen plexifilamentären Stapelfasern ein Polyolefin-Polymer aufweisen;

(ii) 10% bis 70 Gew.-% der gesamten Fasermatte eine Kollektion von zweiten Stapelfasern;
wobei die Stapelfasern ein Polyester-Polymer, Polyolefin-Polymer, Polyamid-Polymer oder Viskose-Kunstseide umfassen; und

(iii) 5% bis 30 Gew.-% der Fasermatte Bindemittel,
wobei das Bindemittel mindestens eine polymere Komponente mit einem Schmelzpunkt unterhalb des Schmelzpunkts der flash-gesponnenen plexifilamentären Stapelfaser und des Schmelzpunkts der Stapelfaser aufweist; und

(b) ein an einer der Oberflächen der wärmedämmenden Fasermatte angrenzendes Substrat, wobei das Substrat eine Porosität nach Gurley zwischen 250 und 5990 s/100 cm³/inch², die nach TAPPI T-40 gemessen wird, eine Wasserdampfdurchlassrate zwischen 250 und 1870 g/m²/24 Stunden, die nach ASTM E398-83 gemessen wird, und einen hydrostatischen Druck zwischen 200 und 400 cm Wasser hat, der nach ATTCC 127 bestimmt wird.

13. Wärmedämmender Verbundstoff nach Anspruch 12, wobei 5% bis 50% der Stapelfasern weniger wiegen als 3,0 Denier pro Filament.

14. Wärmedämmender Verbundstoff nach Anspruch 12, wobei die wärmedämmende Fasermatte ein Verhältnis von Wärmeleitfähigkeit/Flächengewicht bei einer Dicke von 0,0318 m von weniger als 7,5 x 10^-5 (W/m•K)/(g/m²) hat und das Verhältnis von Wärmeleitfähigkeit/Flächengewicht berechnet wird, indem die gemäß ASTM C-518 bestimmte Wärmeleitfähigkeit dividiert wird durch das gemäß ASTM D-3776 bestimmte Flächengewicht, oder
wobei das Substrat ein Faservlies ist, der flash-gesponnene plexifilamentäre Fasern umfasst.

15. Außenteil eines Gebäudes, umfassend die wärmedämmende Fasermatte nach Anspruch 1 oder
umfassend den wärmedämmenden Verbundstoff nach Anspruch 12.

Revendications

1. Panneau semi-rigide thermiquement isolant comprenant :

(i) 10 à 70 % en poids du panneau semi-rigide total constitués par une collection de premières fibres discontinues qui comprennent des fibres discontinues plexifilamentaires à filage éclair ; dans lequel les fibres discontinues plexifilamentaires à filage éclair comprennent un polymère de polyoléfine ;

(ii) 10 à 70 % en poids du panneau semi-rigide total constitués par une collection de secondes fibres discontinues ; dans lequel les fibres discontinues comprennent un polymère de polyester, un polymère de polyoléfine, un polymère de polyamide ou de la rayonne de viscose ; et

(iii) 5 à 30 % en poids du panneau semi-rigide constitués par un agent de liaison ; dans lequel l'agent de liaison comprend au moins un composant polymérique qui présente un point de fusion au-dessous du point de fusion des fibres discontinues plexifilamentaires à filage éclair et du point de fusion des fibres discontinues.

2. Panneau semi-rigide thermiquement isolant selon la revendication 1, dans lequel les premières fibres discontinues sont présentes selon 25 à 60 % en poids du panneau semi-rigide total, les secondes fibres discontinues sont présentes selon 25 à 60 % en poids du panneau semi-rigide total, et l'agent de liaison est présent selon 15 à 25 % en poids du panneau semi-rigide total.

3. Panneau semi-rigide thermiquement isolant selon la revendication 2, dans lequel les premières fibres discontinues sont présentes selon 35 à 60 % en poids du panneau semi-rigide total, les secondes fibres discontinues sont présentes selon 35 à 60 % en poids du panneau semi-rigide total.

4. Panneau semi-rigide thermiquement isolant selon la revendication 1, dans lequel entre 5 et 50 % des secondes fibres discontinues présentent un poids inférieur à 3,0 deniers par filament.

5. Panneau semi-rigide thermiquement isolant selon la revendication 1, dans lequel les fibres discontinues plexifilamentaires à filage éclair présentent une aire de surface de 10 m²/g ou moins telle que mesurée au moyen du procédé par absorption d'azote BET de S. Brunauer, P. H. Emmett et E. Teller ou une valeur d'écrasement d'au moins 1 mm/g telle que mesurée selon le procédé décrit dans le présent document ou présentent les deux.

6. Panneau semi-rigide thermiquement isolant selon la revendication 5, dans lequel l'aire de surface est inférieure à 5 m²/g ou la valeur d'écrasement est d'au moins 1,5 mm/g ou les deux.

7. Panneau semi-rigide thermiquement isolant selon la revendication 1, dans lequel le polymère de polyoléfine des fibres discontinues plexifilamentaires à filage éclair est le polyéthylène.

8. Panneau semi-rigide thermiquement isolant selon la revendication 1, dans lequel le polymère de polyester des secondes fibres discontinues est le téréphtalate de polyéthylène.

9. Panneau semi-rigide thermiquement isolant selon la revendication 1, dans lequel l'agent de liaison est sous la forme de fibres discontinues d'agent de liaison.

10. Panneau semi-rigide thermiquement isolant selon la revendication 1, dans lequel les premières fibres discontinues comprennent un polymère thermoplastique et l'agent de liaison préfigure sous la forme de fibres discontinues d'agent de liaison qui comprennent de multiples composants polymériques déclinés selon (a) un premier composant polymérique qui présente un point de fusion au-dessous du point de fusion du polymère thermoplastique et qui occupe au moins une partie d'une surface des fibres discontinues d'agent de liaison et (b) un second composant polymérique qui présente un point de fusion au-dessus de celui du premier composant polymérique et qui présente un point de fusion au-dessous de celui-ci du polymère thermoplastique.

11. Panneau semi-rigide thermiquement isolant selon la revendication 1, dans lequel le panneau semi-rigide thermiquement isolant présente un rapport conductivité thermique/poids de base pour une épaisseur de 0,0318 mètre inférieur à 7,5 x 10^-5 (W/m•K)/(g/m²), le rapport conductivité thermique/poids de base étant calculé en divisant la conductivité thermique telle que déterminée conformément à ASTM C-518 par le poids de base tel que déterminé conformément à ASTM D-3776.

12. Composite thermiquement isolant comprenant :

(a) un panneau semi-rigide thermiquement isolant comprenant :

(i) 10 à 70 % en poids du panneau semi-rigide total constitués par une collection de premières fibres discontinues qui comprennent des fibres discontinues plexifilamentaires à filage éclair, dans lequel les fibres discontinues plexifilamentaires à filage éclair comprennent un polymère de polyoléfine ;

(ii) 10 à 70 % en poids du panneau semi-rigide total constitués par une collection de secondes fibres discontinues ; dans lequel les fibres discontinues comprennent un polymère de polyester, un polymère de polyoléfine, un polymère de polyamide ou de la rayonne de viscose ; et

(iii) 5 à 30 % en poids du panneau semi-rigide constitués par un agent de liaison ; dans lequel l'agent de liaison comprend au moins un composant polymérique qui présente un point de fusion au-dessous du point de fusion des fibres discontinues plexifilamentaires à filage éclair et du point de fusion des fibres discontinues ; et

(b) un substrat qui est adjacent à une surface du panneau semi-rigide thermiquement isolant, dans lequel le substrat présente une porosité de Gurley entre 250 et 5990 sec/100 centimètres cube/pouce² telle que mesurée conformément à TAPPI T-460, une vitesse de transmission de vapeur d'eau (MVTR) entre 250 et 1870 grammes/mètre²/24 heures telle que déterminée selon ASTM E398-83, et une charge hydrostatique entre 200 et 400 centimètres d'eau telle que déterminée selon ATTCC 127.

13. Composite thermiquement isolant selon la revendication 12, dans lequel 5 à 50 % des fibres discontinues pèsent moins que 3,0 deniers par filament.

14. Composite thermiquement isolant selon la revendication 12, dans lequel :

le panneau semi-rigide thermiquement isolant présente un rapport conductivité thermique/poids de base pour une épaisseur de 0,0318 mètre inférieur à 7,5 x 10^-5 (W/m•K)/(g/m²), le rapport conductivité thermique/poids de base étant calculé en divisant la conductivité thermique telle que déterminée conformément à ASTM C-518 par le poids de base tel que déterminé conformément à ASTM D-3776, ou dans lequel :

le substrat est un non tissé qui comprend des fibres discontinues plexifilamentaires à filage éclair.

15. Partie extérieure d'un bâtiment comprenant :

le panneau semi-rigide thermiquement isolant selon la revendication 1, ou comprenant :

le composite thermiquement isolant selon la revendication 12.