SPRAY FOAM BUILDING INSULATION FOR EXTERIOR APPLICATIONS

Abstract

An open cell polyurethane foam is provided which has a cell size and structure which allows the foam to act as an air and water barrier while still having acceptable water vapour permeability. The foam preferably is produced using water as a blowing agent, and includes a mixture of open cell-promoting, and closed-cell-promoting surfactants so as to provide an open cell foam structure having a cell size of about 1 μm, a density of about 1.05 lb per cubic foot, and wherein the cell structure includes randomly occurring solid walls on some cells. The open cell polyurethane foams of the present invention are suitable for use as insulation on the exterior surfaces of a building.

Claims

1-27. (canceled)

28. A polyurethane foam for use in insulating an exterior surface of a building, wherein said polyurethane foam is prepared by reacting an isocyanate resin, as an A component, with a B Component which B Component comprises a polyol, an optional blowing agent, and at least one surfactant, and has an open cell structure, and wherein said open cell structure comprises cells which are essentially open, but also includes some randomly occurring, solid cell walls, wherein said polyurethane foam has a foam density of between 0.60 and 1.5 lb. per cubic foot, and has a cell size of between 0.03 μm and 1.5 μm, so that said polyurethane foam acts as a water and air barrier, while also being water vapour permeable.

29. The polyurethane foam of claim 28, wherein said foam has a foam density of between 1.00 and 1.15 lb. per cubic foot.

30. The polyurethane foam of claim 28, wherein said polyurethane foam is prepared by reacting a mixture of said A Component with said B Component at a weight ratio of from 0.5 to 5:1.

31. The polyurethane foam of claim 28, wherein said polyurethane foam is prepared by reacting a mixture of said A Component with said B Component at a weight ratio of from 0.9 to 1.1:1.

32. The polyurethane foam of claim 28, wherein said isocyanate resin is a resin selected from MDI, PMDI, TDI , TDA, HMDI, HDI, IPDI and TMXDI.

33. The polyurethane foam of claim 28, wherein said polyurethane foam is prepared by reacting a mixture of PMDI, as said A Component with said B Component at a weight ratio of about 1:1.

34. The polyurethane foam of claim 28, wherein said polyol is an aliphatic or aromatic polyols, including polyester, polyether, sucrose-based polyols, glycerine-based polyols, or caprolactone-based polyols.

35. The polyurethane foam of claim 34, wherein said polyol is prepared by reacting ethylene oxide (EO), propylene oxide (PO) or butylene oxide (BO) with glycerine, sucrose, 1,1,1-tris[(2-hydroxyethoxy)methyl]ethane, 1,1,1,-tris-[(2-hydroxypropoxy)methyl]propane, triethanolamine, triisopropanolamine, pyrogallol or phloroglucinol, in order to form a chain-extended polyol.

36. The polyurethane foam of claim 28, wherein a blowing agent is used, and wherein said blowing agent is water, or wherein said blowing agent is a blowing agent which releases carbon dioxide.

37. The polyurethane foam of claim 28, wherein said surfactant is a mixture of an open-cell promoting surfactant and a closed-cell promoting surfactant.

38. The polyurethane foam of claim 28, wherein said foam is formed by a combination of surfactants that results in a surfactant interaction which produces both completely open and at least partially open, cell walls.

39. The polyurethane foam of claim 28, wherein the open cell content of the foams is greater than 95%, by number.

40. The polyurethane foam of claim 28, wherein said B Component additionally comprises a flame retardant.

41. The polyurethane foam of claim 28, wherein said open cells have a cell size of between 0.1 μm and 1.0 μm.

42. The polyurethane foam of claim 28, wherein said open cells have a cell size of 0.8±0.3 μm.

43. The polyurethane foam of claim 28, wherein said foam has an R value of between 2 and 6 per inch of thickness.

44. Use of a polyurethane foam, for insulating an exterior surface of a building, wherein said polyurethane foam is a foam as claimed in claim 28.

45. A method for insulating the exterior surface of a building comprising spraying the exterior surface of the building with a mixture of an isocyanate and a polyol in order to produce a polyurethane foam having an open cell structure, wherein said foam is a foam as claimed in claim 28.

46. The method for insulating as claimed in claim 45, wherein said open cell polyurethane foam is used to insulate the exterior surface of a wall of said building, and a closed cell polyurethane foam is used to insulate the interior surface of said wall.

47. The method for insulating as claimed in claim 45, wherein said open cell polyurethane foam is used as a water and air barrier, while still being water vapour permeable, or wherein said polyurethane foam is used in place of tape to seal a sheathing material.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0068] Embodiments of this invention will now be described by way of example only in association with the accompanying drawings in which:

[0069] FIG. 1 is a perspective, cutaway drawing of an example of an exterior building wall, insulated according to the prior art; and

[0070] FIG. 2 is a perspective, cutaway drawing of an example of an exterior building wall, insulated according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0071] The novel features which are believed to be characteristic of the present invention, as to its structure, organization, use and method of operation, together with further objectives and advantages thereof, will be better understood from the following drawings in which a presently preferred embodiment of the invention will now be illustrated by way of example only. In the drawings, like reference numerals depict like elements.

[0072] It is expressly understood, however, that the drawings are for the purpose of illustration and description only and are not intended as a definition of the limits of the invention. Also, unless otherwise specifically noted, all of the features described herein may be combined with any of the above aspects, in any combination.

[0073] Referring to FIG. 1 the construction of a typical exterior wall 10 according to the prior art, is shown. Wall 10 includes an exterior layer 12, which could be a layer of vinyl siding, or other suitable material, such as a brick facing. Exterior layer 12 is adjacent to a house wrap lay 14, which is used to cover a structural wall sheathing material 16 selected from plywood, OSB, particle board, or the like. This sheathing material is attached to wooden studs 18.

[0074] The cavity formed between wooden studs 18 is filled with fibreglass batt insulation 20, and a polyethylene film vapour barrier 22 is layered on the inside of fibreglass batt insulation 20.

[0075] Numerous variations on this construction approach are known, but the example shown in FIG. 1 is typical of a large majority of residential houses.

[0076] In FIG. 2, a representation of an exterior wall 30 assembled in accordance with the present invention, is shown. Wall 30 includes an exterior layer 12 which is the same as for FIG. 1. Layer 12 covers an open cell polyurethane foam layer 32, of the present invention, which has been sprayed onto a structural sheathing material 16. Since foam layer 32 is capable of acting as a water and air permeable layer, the need for a house wrap layer 14, is eliminated.

[0077] Structural sheathing material 16 is attached to wooden studs 18, and the cavity between wooden studs 18 is filled with a closed cell polyurethane foam resin 34. Because closed cell polyurethane foam resin 34 acts as a vapour barrier, the need for a separate polyethylene film vapour barrier layer 22, is eliminated.

[0078] During construction, wooden studs 18 are assembled, and covered with sheathing material 16. At this point, the cavity between wooden studs 18 can be rapidly and easily filled with the closed cell polyurethane foam 34. No additional vapour barrier is required.

[0079] The outside of sheathing material 16 is sprayed with an open cell foam material 32 which acts as an insulating layer which is a water and air barrier, but which allows for the passage of any water vapour that might form or collect, on the inside of the wall structure. The exterior layer can then be applied to the exterior of the wall, in a known manner.

[0080] By spraying the open celled foam material on the outside of the building, significant time can be saved when compared to applying house wrap (with taping) and/or when compared to use of a non-structural insulation sheathing material (again with taping).

[0081] When combined with the use of a sprayed-on layer of a closed cell insulating material on the inside of the wall cavity (with the elimination of the handling of fibreglass batts, and the use of a vapour barrier), significant time savings can also be achieved.

[0082] As such, the present invention permits for the rapid completion of at least the exterior wall of a building, and when used in combination with a closed cell polyurethane foam on the interior wall, allows a complete wall structure to be completed in a rapid, and cost effective, fashion.

EXAMPLES

[0083] An open cell polyurethane foam of the present invention was prepared for testing. The foam produced was prepared using a 1:1 by weight mixture of PMDI isocyanate resin, such as Mondur MR Light from Covestro, or Rubinate M from Huntsman, as the Part A component, in combination with Wrapsulate Part B, as the B component, which material is a mixture having 44% (all by weight of the B component) of a blend of sucrose and polyether based polyols, 40% of an 80% blend of tris(1-chloro-2-propyl)phosphate (TCPP) and 20% of a tetrabromophthalate diol flame retardants, 3% of a 60/40 blend of an open-cell-promoting silcone surfactant such as TEGOSTAB B8523, B8580, B84710, B8870, Ortegol 204, Ortegol 500, and Ortegol 501, from Evonik, and closed cell-promoting surfactants like TEGOSTAB B8408, B8453, and B8487 from Evonik. Also present is 5% of blend of an amine-based and tin dilaurate-based catalyst, by weight of the B component. The balance of Component B is 8% added water.

[0084] Wrapsulate Part B is commercially available from Elastochem Specialty Chemicals Inc, of Brantford, Ontario, Canada.

[0085] The two components were heated and mixed together in a heated spray gun, and then sprayed onto a wooden substrate and allowed to foam. Samples of the resultant foam, referred to as Wrapsulate (Trade mark) foam, were cut from the sprayed foam,—both with and without a foam skin, and tested for their suitability for exterior construction applications. In order to assess the density variation of the sprayed foam, samples were obtained from various locations within one of the boards. The foam was taken from boards with the OSB as a substrate. The properties of the specimens used for further testing, are shown in Table 1.

TABLE-US-00001 TABLE 1 List of Specimens Prepared # of Length Width Thickness Spec- Location in Test Type (mm) (mm) (mm) imens Thickness Density  25  25 25 12 Top, core, and bottom from four locations Thermal 300 300 300  6 Six 50 mm Testing thick specimens (no skin) Water Circular 150 Full 6 Three with Vapour/Air (Dia.) Insulation skin, and three Permeability without skin Compressive 150 150 50 5 All from core Strength Flexural 300 100 25 6 All From core Strength Tension 150 150 Full 6 Six with skin Insulation Dimensional 100 100 Full 6 Full insulation Stability Insulation (including skin) 100 100 Full 6 Full Insulation Insulation (without skin) Water 150 150 Full 5 full insulation Absorption Insulation (including skin) 150 150 Full 5 Full Insulation Insulation (without skin) Sorption 150 150 50 5 50 mm thick Isotherm with skin

[0086] The density of the prepared specimens was measured after they were dried at a temperature of 40° C. The mass and dimensions of the specimens were measured. The results of the measurements are shown in Table 2.

TABLE-US-00002 TABLE 2 Dimensions, Masses and Densities of Specimens Thickness Length Width Mass Density (mm) (mm) (mm) (g) (kg/m.sup.3) 511-10-AB 27.43 27.91 27.50 0.398 18.91 511-10-AC 27.71 27.57 27.51 0.363 17.27 511-10-AT 27.62 27.58 27.72 0.457 21.64 511-10-BB 27.68 27.70 27.48 0.400 18.98 511-10-BC 27.25 27.61 27.92 0.356 16.95 511-10-BT 28.12 27.30 27.41 0.371 17.63 511-10-CB 27.67 27.72 27.64 0.394 18.59 511-10-CC 28.05 27.62 27.86 0.357 16.54 511-10-CT 27.83 27.72 27.58 0.368 17.29 511-10-DB 27.54 28.36 27.59 0.408 18.93 511-10-DC 27.39 26.48 27.15 0.330 16.76 511-10-DT 27.82 27.06 27.42 0.384 18.61

[0087] The density was approximately 1 lb per cubic foot (or 16.0185 kg per cubic meter).

Thermal Testing

[0088] The specimens used for this set of thermal conductivity measurements were exposed to 23±1° C. and 50±5% Relative Humidity (RH) for a period of 13 days and then the thermal conductivity was measured.

[0089] Tests were conducted in accordance with the ASTM standard C518 (ASTM International 2010). The specimen was tested in an apparatus with a 300 mm×300 mm cross section. Heat flow was perpendicular to this major surface. The heat flow apparatus used to conduct the reported tests has measurement uncertainties within 2%. Three specimens were tested at a mean temperature of 24.1° C. The results are shown in Table 3. The average thermal conductivity was 0.0354 W m.sup.−1 K.sup.−1. The average R value per inch in imperial units was 4.13.

TABLE-US-00003 TABLE 3 Thermal Conductivity 14 days after specimens were sprayed Thickness SI UNITS Specimen (mm) R (K m.sup.2/W) R/L (K m/W) k (W/m K) 511-1-A 25.46 0.72 28.2 0.0352 511-1-B 25.90 0.73 28.2 0.0355 511-1-C 25.83 0.73 28.2 0.0354 Average 0.73 28.17 0.0354 STDEV 0.00 0.00 0.0002

Aging of Insulation Specimens

[0090] The thermal aging of the insulation were also assessed by subjecting the specimens to an exposure of 60° C. for a period of 90 days. The results of the test are shown below in Table 4. The table shows little change in the thermal resistivity of the specimens subject to 60° C. for 90 days. The total drop in thermal resistance of all the specimens was below 1%.

TABLE-US-00004 TABLE 4 Initial Measurements for Aging Specimen R % Change k ID 511-13 m.sup.2K/W % R R W/m.sup.2K Before exposure A 0.75 0.0351 B 0.75 0.0349 C 0.75 0.0352 Average 0.75 0.0350 Post 60° C./90 day A 0.75 99.7 −0.3 0.0352 B 0.74 99.4 −0.6 0.0351 C 0.75 99.6 −0.4 0.0353 Average 0.75 99.6 −0.4 0.0352

Water Vapour Permeability

[0091] Water vapour permeability testing was conducted following the procedure in the ASTM

[0092] Standard E96/96M (ASTM International 2010). For each test condition, a set of 3 circular specimens, having a 150 mm diameter, were tested. The results of these measurements are shown in Table 5.

TABLE-US-00005 TABLE 5 Water Vapour Permeability Measurements Relative Permeability (kg/m*s*Pa) Humidity (%) No skin With skin 10 3.06 × 10.sup.−11 2.29 × 10.sup.−11 20 3.68 × 10.sup.−11 2.75 × 10.sup.−11 30 4.10 × 10.sup.−11 3.06 × 10.sup.−11 40 4.43 × 10.sup.−11 3.30 × 10.sup.−11 50 4.71 × 10.sup.−11 3.50 × 10.sup.−11 60 4.95 × 10.sup.−11 3.67 × 10.sup.−11 70 5.16 × 10.sup.−11 3.82 × 10.sup.−11 80 5.36 × 10.sup.−11 3.96 × 10.sup.−11 90 5.53 × 10.sup.−11 4.09 × 10.sup.−11 100 5.70 × 10.sup.−11 4.21 × 10.sup.−11

[0093] These results are also plotted in Graph 1.

Comparison of WVP to Other Materials

[0094] A comparison of the Wrapsulate foam to several other materials is shown in Table 6. These results show a correlation between the types of materials, their densities and thus, cell size, of the foam and the resultant water vapour permeability. Generally, as density of the polyurethane foam is increased there is a decline in the water vapour permeability.

TABLE-US-00006 TABLE 6 Comparison of 50% Dry Cup (Mean 25%) WVP values Water Vapour Density Permeability Material (kg/m.sup.3) (ng/m s Pa) Low Density SPF 7.5 87.5 Wrapsulate Foam - no Skin 16.80 37.50 Wrapsulate Foam - with Skin 18.66 26.83 Polyisocyanurate Insulation 26.5 4.425 XPS 28.6 1.22 SPF 39 2.49

Sorption Isotherm

[0095] Six specimens with a size of 150 mm×150 mm×25 mm were used in these measurements. The measurements were done following the procedure described in the ASTM Standard C1498 (ASTM International, 2004). The results of the test are shown in Table 7. The moisture content shown for 100% RH is the capillary saturation of the specimen. This value was obtained by immersing the specimen in water for a period of 4 days.

TABLE-US-00007 TABLE 7 Sorption Isotherm of Wrapsulate Foam Moisture content (kg kg.sup.−1) RH (%) No skin With skin 50.8 0.0086 0.0091 70.7 0.0138 0.0151 90.4 0.0230 0.0239 93.5 0.0249 100 1.293

Water Absorption Coefficient

[0096] Measurements for determination of the water absorption coefficient were conducted in accordance with ISO 15148:2002 (International Organization for Standardization 2002). Specimens, each having dimensions of approximately 50 mm×50 mm×50 mm, were used to determine the water absorption coefficient of the foam insulations. Over the course of the tests, water was maintained at 22±1° C. The results (average) from these measurements are shown in Table 8. The numbers in parentheses give the standard deviations.

TABLE-US-00008 TABLE 8 Water Absorption Characteristics of Wrapsulate Foam No skin With skin Square Root Water Absorption Square Root Water Absorption of Time (s.sup.1/2) (kg m.sup.−2) of Time (s.sup.1/2) (kg m.sup.−2) 0.0 0.000 (0.000) 0.0 0.000 (0.000) 24.5 0.026 (0.006) 24.5 0.020 (0.006) 34.6 0.028 (0.004) 34.6 0.022 (0.009) 42.4 0.033 (0.006) 42.4 0.021 (0.003) 60.0 0.038 (0.005) 60.0 0.020 (0.005) 73.5 0.040 (0.005) 73.5 0.024 (0.005) 84.9 0.041 (0.006) 84.9 0.023 (0.005) 103.9 0.045 (0.006) 103.9 0.026 (0.005) 120.0 0.047 (0.004) 120.0 0.024 (0.004) 147.0 0.049 (0.005) 147.0 0.023 (0.003) 169.7 0.049 (0.004) 169.7 0.024 (0.004) 283.8 0.050 (0.006) 283.0 0.023 (0.003)

[0097] The water absorption coefficient is obtained from a linear regression using all the data from the first linear part of the absorption process: The water absorption coefficients for the three foams are found to be extremely low as shown below:

TABLE-US-00009 With skin - 0.00015 kg m−2 s−½ No skin - 0.00006 kg m−2 s−½

Air Permeability

[0098] The measurements and calculations were carried out according to the procedure reported by Kumaran and Bomberg (Kumaran, M. K., and M. T. Bomberg. ““A Test Method to Determine Air Flow Resistane of Exterior Membranes and Sheathings”.” Journal of Thermal Insulation, 1986: 9:224-235.). Three circular test specimens, with the same dimensions as the water vapour permeability specimens were used for the measurements. Measurements were executed at a temperature of 22±1° C.

[0099] The resulting air permeability for Wrapsulate—no skin

(1.02±0.34)×10−5 L(75 Pa)−1.Math.m−1.Math.s−1

(1.62±0.48)×10−10 kg.Math.Pa−1.Math.m−1.Math.s−1

(2.31±0.77)×10−15 m2

[0100] The resulting air permeability for Wrapsulate—with skin:

(8.79±2.82)×10−6 L(75 Pa)−1.Math.m−1.Math.s−1

(1.40±0.45)×10−10 kg.Math.Pa−1.Math.m−1.Math.s−1

(1.99±0.64)×10−15 m2

Dimensional Stability

[0101] The dimensional stability of the foam when subject to thermal and humidity aging was assessed. This was done by following the standard test method of ASTM D2126-09, ‘Standard Test Method for the Response of Rigid Cellular Plastics to Thermal and Humid Aging’. The specimens were tested according to following conditions:

Condition A: −20±3° C. & ambient RH for 28 days

Condition B: 80±2° C. & ambient RH for 28 days

Condition C: 70±2° C. & 97±3% RH for 28 days

[0102] The change in absolute density of each of the specimens is shown In Table 9.

TABLE-US-00010 TABLE 9 Density Changes of Wrapsulate Foam Density before aging, kg/m.sup.3 Density after aging, kg/m.sup.3 70° C., 70° C., −20° C. 80° C. 97% RH −20° C. 80° C. 97% RH with external skin 18.6 18.4 18.3 18.6 18.0 18.2 without skin 17.2 17.6 17.4 17.2 17.3 17.4

Water Absorption—Full Immersion

[0103] In order to assess the water absorption of the foam testing was conducted following ASTM D2842-06 ‘Standard Test Method for Water Absorption of Rigid Cellular Plastics.’ Since the foam does not exhibit rapid water absorption, Procedure B was used.

[0104] The dimensions and mass of the specimens were measured before the water absorption of the specimens. These are shown in Table 10.

TABLE-US-00011 TABLE 10 Initial Measurements of Water Absorption Specimens Specimen Thickness Length Width Mass Density ID (mm) (mm) (mm) (g) (kg/m3) 511-57-A 47.84 152.12 152.44 19.026 17.15 511-57-B 47.80 153.15 152.05 19.930 17.91 511-57-C 51.08 153.13 151.95 19.924 16.76

[0105] The test specimens were then immersed in water for a period of 96 hours. The percent volume water absorption was calculated according to Procedure B in ASTM D2842. The results of the calculations are shown in Table 11. The results show average water absorption of 0.49%.

TABLE-US-00012 TABLE 11 Calculation of Percent Volume Water Absorption Weight Weight Water Weight of Initial Final Absorption Apparent Dry Submerged Spec. + Spec. + True by Volume - Weight, Jig, W2i Jig, W3i Jig, W3f Volume, Volume Spec. ID V1 (cm.sup.3) W.sub.1 (g) (g) (g) (g) V.sub.2, cm.sup.3 (%) 511-57-A 1109.5 19.03 2089.3 1032.6 1034.9 1075.7 0.21 511-57-B 1113.0 19.93 1564.6 500.7 510.9 1083.8 0.94 511-57-C 1188.5 19.92 1581.1 443.8 447.6 1157.2 0.33

Discussion

[0106] The physical, hygrothermal and mechanical properties presented in the sections above clearly indicate that Wrapsulate foam as an insulation material has many promising characteristics. In particular, the foams of the present invention display a low water absorption capacity, and are able to act as both a water and air barrier, while still providing acceptable water vapour permeability. As such, the open cell foam materials of the present invention are suitable for exterior foam applications.

[0107] For commercial applications, the foams of the present invention preferably have the performance characteristics shown in Table 12.

TABLE-US-00013 TABLE 12 Performance Characteristics Attribute Test Results Density ASTM D1622 1.07 lb/ft.sup.2 17.2 Kg/m.sup.3 Aged Thermal ASTM C518 R 4.3 Resistance (90 Day) 25 mm Thermal Resistance NRC 100% Retention After  Lens 072510.09 Water Vapour ASTM E96 1175 ng/(Pa ) Permeation 25 mm Water Vapour ASTM E96 949 ng/(Pa ) Permeation 50 mm Initial Tensile ASTM 1623 13.6 psi. pass Strength 94 kPa. pass Tensile Strength ASTM 1623 103% Retention After  Lens Water Absorption ASTM 1.6% (% by Volume) UV and Heat Aged  as 2.3% Water Absorption per NRC (% by Volume) 072510.09 Water Penetration ASTM  as 700 Pa Resistance per NRC 072510.09 Flame Spread ULC S-102 Flame <500  Tunnel Smoke <500 VOC Emission CAN/ULC Passed S774- Dimensional Stability ASTM D2126 −20° C. (Volume Change after 28 days) 70° C.  RH 2.3% Fungi Resistance ASTM C1338 No Growth Open Cell Content ASTM D6226  99% Compression Strength ASTM 1621 60 kPa NRC Performance Flexural Strength ASTM C203 16.07 kPa NRC Performance Sorption Isotherm ASTM .02 Kg Kg.sup.−1 (4 day immersion) NRC Performance Water Absorption .00015 Kg m Coefficient NRC Performance (% by Volume) Full Scale Wall Test NRC 5° C. to 40° C. Temperature Limits 072510.09 Adhesion to Substrates NRC Various 072510.09 See Density Variation ASTM D1622 .sup. 1% NRC Performance All Tests Performed On NRC Performance PASS Samples With and Without Skin CCMC 14049-R indicates data missing or illegible when filed

[0108] Thus, it is apparent that there has been provided, in accordance with the present invention, an open cell polyurethane foam, for use in insulation of the exterior surfaces of a building, which fully satisfies the goals, objects, and advantages set forth hereinbefore. Therefore, having described specific preferred embodiments of the present invention, it will be understood that alternatives, modifications and variations thereof may be suggested to those skilled in the art, and that it is intended that the present specification embrace all such alternatives, modifications and variations as fall within the scope of the appended claims.

[0109] Additionally, for clarity and unless otherwise stated, the word “comprise” and variations of the word such as “comprising” and “comprises”, when used in the description and claims of the present specification, is not intended to exclude other additives, components, integers or steps. Further, the invention illustratively disclosed herein suitably may be practised in the absence of any element which is not specifically disclosed herein.

[0110] Moreover, words such as “substantially” or “essentially”, when used with an adjective or adverb is intended to enhance the scope of the particular characteristic; e.g., substantially planar is intended to mean planar, nearly planar and/or exhibiting characteristics associated with a planar element.

[0111] Further, use of the terms “he”, “him”, or “his”, is not intended to be specifically directed to persons of the masculine gender, and could easily be read as “she”, “her”, or “hers”, respectively.

[0112] Also, while this discussion has addressed prior art known to the inventor, it is not an admission that all art discussed is citable against the present application.