PREFABRICATED ASPHALT-BASED WATERPROOF ROOFING MEMBRANE

Abstract

A prefabricated modified bitumen waterproofing membrane includes a middle layer formed of a non-woven polyester and/or fiberglass reinforcement fabric, an upper layer and a bottom layer of bitumen asphalt modified with SBS (Styrene-Butadiene-Styrene), APP (Atactic Polypropylene) or TPO (Thermoplastic Polyolefin) polymers, aluminum flakes on a top surface of the upper layer, and polyolefin film covering the bottom layer. In a preferred embodiment, the aluminum flakes having a size ranging between 0.508 mm to 2.032 mm in length, 0.508 mm to 1.016 mm in width and 0.02 mm to 0.03 mm in thickness. The top surface, with aluminum flakes applied thereto, has a Solar Reflective Index (SRI) equal to or greater than 73, a reflectance of at least 0.72 and a thermal emittance of at least 0.18.

Claims

1. A high solar reflectance prefabricated modified bitumen waterproofing membrane comprising: a middle layer comprising a non-woven polyester and/or fiberglass reinforcement fabric; an upper layer on the reinforcement fabric comprising bitumen asphalt modified with SBS (Styrene-Butadiene-Styrene), APP (Atactic Polypropylene) or TPO (Thermoplastic Polyolefin) polymers; aluminum flakes on the top surface of the upper layer, and the aluminum flakes having a size ranging between 0.508 mm to 2.032 mm in length, 0.508 mm to 1.016 mm in width and 0.02 mm to 0.03 mm in thickness; a bottom layer on the reinforcement fabric comprising bitumen asphalt modified with SBS (Styrene-Butadiene-Styrene), APP (Atactic Polypropylene) or TPO (Thermoplastic Polyolefin) polymers; and polyolefin film covering the bottom layer.

2. A high solar reflectance prefabricated modified bitumen waterproofing membrane as recited in claim 1 wherein the upper layer having the aluminum flakes on the top surface thereof has a Solar Reflective Index (SRI) of at least 73.

3. A high solar reflectance prefabricated modified bitumen waterproofing membrane as recited in claim 2 wherein the upper layer having the aluminum flakes on the top surface thereof has a reflectance of at least 0.720.

4. A high solar reflectance prefabricated modified bitumen waterproofing membrane as recited in claim 3 wherein the upper layer having the aluminum flakes on the top surface thereof has a thermal emittance of at least 0.18.

5. A high solar reflectance prefabricated modified bitumen waterproofing membrane comprising: a middle layer comprising a non-woven polyester and/or fiberglass reinforcement fabric; an upper layer on the reinforcement fabric comprising bitumen asphalt modified with SBS (Styrene-Butadiene-Styrene), APP (Atactic Polypropylene) or TPO (Thermoplastic Polyolefin) polymers; aluminum flakes on the top surface of the upper layer, and the aluminum flakes having a size ranging between 0.508 mm to 2.032 mm in length, 0.508 mm to 1.016 mm in width and 0.02 mm to 0.03 mm in thickness; and a bottom layer on the reinforcement fabric comprising bitumen asphalt modified with SBS (Styrene-Butadiene-Styrene), APP (Atactic Polypropylene) or TPO (Thermoplastic Polyolefin) polymers.

6. A high solar reflectance prefabricated modified bitumen waterproofing membrane as recited in claim 5 wherein the upper layer having the aluminum flakes on the top surface thereof has a Solar Reflective Index (SRI) of at least 73.

7. A high solar reflectance prefabricated modified bitumen waterproofing membrane as recited in claim 6 wherein the upper layer having the aluminum flakes on the top surface thereof has a reflectance of at least 0.720.

8. A high solar reflectance prefabricated modified bitumen waterproofing membrane as recited in claim 7 wherein the upper layer having the aluminum flakes on the top surface thereof has a thermal emittance of at least 0.18.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] FIG. 1 shows a schematic diagram of the manufacturing process of the prefabricated modified bitumen waterproofing membrane of the invention. Initially in the process, a central reinforcement, which may be fiberglass, polyester fiber or a mixture of both, is placed on a support base that allows the roll to rotate and the reinforcement begins to integrate to the next steps of the process. The reinforcement is driven by a roller system which is directed at a controlled speed to a tank containing the modified asphalt mixture where it is immersed in this mixture and the reinforcement is saturated entirely and to the corresponding thickness desired, the now called roofing membrane passes through a several rollers that are calibrated to remove the excess asphalt mixture and fix the desired thickness. The continuous production line reaches the stage where, through a hopper, the aluminum flake finish is spread on top of the modified bitumen asphalt and a polyethylene film is placed on the bottom. The prefabricated modified bitumen waterproofing membrane is then passed by several cooling rollers, whose function is to ensure the adhesion of the aluminum flake on the asphalt and to adhere to the bottom film of polyethylene. Finally, the prefabricated modified bitumen waterproofing membrane reaches the final stage of the process where it is cut at the desired length and rolled, placing 3 fastening tapes and is placed on pallets for handling and storage as a finished product.

[0028] FIG. 2 is a perspective view of the waterproofing membrane of the present invention shown pulled from a roll and further illustrating the different layers of the waterproofing membrane of the invention including: layer (b) asphalt modified with SBS, APP or TPO; layer (c) non-woven reinforcing polyester and/or fiberglass; layer (d) polyethylene film; and layer (a) aluminum flake.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Definitions

[0029] In order to facilitate the understanding of the invention, certain terms are defined below.

[0030] The term aluminum flake defines very fine, narrow and very thin powder and/or flake of high purity aluminum, which, through a grinding and separation process, obtains its distribution characteristics through a Gilson SS-15 sieve with a flake size ranging between 0.508 mm to 2.032 mm in length, 0.508 mm to 1.016 mm in width and 0.020 to 0.030 mm in thickness.

[0031] The term prefabricated modified bitumen waterproofing membrane, is defined as a prefabricated asphalt-based waterproof roofing membrane made with modified asphalt with SBS (Styrene-Butadiene-Styrene), APP (Atactic Polypropylene) or TPO (Polyolefin Thermoplastic), and finished in its top layer of aluminum flake that provides it the property of high reflectance to the solar rays.

[0032] A comparison of the heat absorption characteristics of the roofing membrane with the aluminum flake top coating of the present invention to other heat reflective roofing membranes in the related art is shown in Tables 1 and 2 below. As seen in Tables 1 and 2, the prefabricated roofing membrane of the present invention, which has a top coating containing aluminum flakes having a size ranging between 0.508 mm to 2.032 mm in length, 0.508 mm to 1.016 mm in width and 0.02 mm to 0.03 mm in thickness, was compared to other prefabricated roofing membrane products on the market, all of which were installed on two different roofs on buildings in Mexico. Temperature measurements were made at the time intervals indicated in Tables 1 and 2. As seen in Tables 1 and 2, the temperature increase of the prefabricated waterproofing membrane of the present invention was significantly lower from the first temperature measurement to the final temperature measurement compared to the other prefabricated waterproofing membrane products. Thus, the prefabricated waterproofing membrane of the present invention achieves a significant reduction in the warming of the inside temperature of the building structure when compared to the other prefabricated waterproofing membranes on the market.

TABLE-US-00002 TABLE 1 Measurements made on Jul. 15, 2017 on a Mexico City Roof. Gradient Initial (Final Difference temperature (IT) temperature (FT) with Aluminum Products-Measuring of the surface of the surface) Gradient Flakes Top Hours in Celsius Degrees 9:00 hours 9:15 10:00 11:00 12:00 13:00 14:00 15:00 hours (FT IT) Surface 1.- Prefabricated 17.9 18.1 19.2 21.3 25.4 28.3 30.5 34.6 16.7 0 C. waterproofing membrane with an Aluminum Flake finish 2.- Prefabricated 17.9 17.9 21.1 26.0 25.5 31.3 34.8 40.3 22.4 +5.7 C. waterproofing membrane with white granules coated with a high reflective acrylic elastomeric top coat finish 3.- Prefabricated 17.9 22.8 18.7 29.4 26.7 35.5 38.4 43.0 25.1 +8.4 C. waterproofing membrane with an Aluminized granule finish 4.- Prefabricated 17.9 22.7 31.1 36.9 36.5 46.8 50.3 53.8 35.9 +19.2 C. waterproofing membrane with a white granule finish 5.- Prefabricated 17.9 24.8 33.6 45.3 44.2 54.5 60.4 61.9 44.0 +27.3 C. waterproofing membrane with a tan granule finish 6.- Prefabricated 17.9 22.8 32.6 40.3 41.3 52.3 55 61.1 43.2 +26.5 C. waterproofing membrane with a green granule finish

TABLE-US-00003 TABLE 2 Measurements made on Jul. 23, 2017 on a Cancun, Mexico Gradient Initial Final difference Temperature (IT) Temperature (FT) with Aluminum Products-Measuring Hours of the surface of the surface Gradient Flakes Top in Celsius Degrees 9:00 hours 09:15 10:00 11:00 12:00 13:00 14:00 15:00 hours (FT IT) Surface 1.- Prefabricated 23 25.7 26.8 28.5 31.2 32.9 36.4 39 16 0 waterproofing membrane with an Aluminum Flake 2.- Prefabricated 23 24.2 32.1 36.4 38.2 41.3 43.8 45.1 22.1 6.1 waterproofing membrane with white granules coated with a high reflective acrylic elastomeric top coat finish 3.- Prefabricated 23 25.4 32.4 38.5 41.6 44.5 44.9 47.1 24.1 8.1 waterproofing membrane with an Aluminized granule finish 4.- Prefabricated 23 25.7 33.5 45.3 53.8 58.4 59.7 61.3 38.3 22.3 waterproofing membrane with a white granule finish 5.- Prefabricated 23 26.8 35.3 47.9 52.6 61.5 65.2 69.1 46.1 30.1 waterproofing membrane with a tan granule finish 6.- Prefabricated 23 29.5 39.7 49.2 56.4 64.3 66.8 72.4 49.4 33.4 waterproofing membrane with a green granule finish

[0033] To reduce the production of greenhouse gases and global warming, particularly in urban areas where a high percentage of the area of a city is the roofs of different types of buildings, a prefabricated modified bitumen waterproofing membrane of the present invention has been developed, with aluminum flake finish coating, which has a Solar Reflectance Index (SRI) of 78 (Report 160921CU dated Sep. 29, 2016, issued by Comprehensive Sustainable Designs 3e, S.C.) measurements made with emisometer equipment that detects radiant energy and solar reflectometer, using ASTM test methods. See Table 3. This modified bitumen waterproofing roofing membrane reflects the greatest amount possible of solar rays, resulting in a reduction of the amount of electrical energy used in air condition equipment in buildings, homes, shopping centers and industries.

TABLE-US-00004 TABLE 3 Prefabricated waterproofing membrane with aluminum flake finish TEST INITIAL 3-year aged* Reflectance (ASTM C1549) 0.772 0.720 Emittance (ASTM C1371) 0.19 0.19 Solar Reflectance Index (SRI) 78 68 (ASTM E 1980) *Tested in accordance with ASTM D 7897

[0034] Today, prefabricated modified bitumen waterproofing membranes are manufactured with top coatings of different colored mineral granules, as well as smaller size aluminum flakes. These products have a Solar Reflectance Index (SRI) of less than 50, allowing roofs to increase their surface temperature during the day when the sun's rays heat the roofs.

[0035] FIG. 1 shows the process of manufacture of the Prefabricated Waterproofing Membrane of the invention.

[0036] The process starts at the point (1) in FIG. 1, in which the roll of the central reinforcement fabric of the waterproofing membrane, which could be fiberglass from 90 to 120 gr/m.sup.2 or polyester fiber from 170 to 250 gr/m.sup.2, is settled over a support base equipment with a rotating cylindrical shaft, which allows the central fabric of the Prefabricated modified bitumen Waterproofing Membrane to start the manufacturing process unwinding continuously. At point the central reinforcing fabric enters the accumulator which is a set of rollers, that move up and down, so that the reinforcement fabric is always available to allow time to add a new roll of fabric and maintaining a continuous process.

[0037] After passing the accumulator, the central reinforcement fabric, reaches point (3) where it enters a tank containing the bitumen asphalt modified with polymers which has been previously prepared in a reactor where the asphalt, polymers, special fillers and additives are blended to produce the modified bitumen asphalt. Other types of products, such as fungicides to avoid the growth of vegetation, fire retardants or other chemical products, can be added to improve physical-chemical, mechanical or chemical properties of the mixture. The temperature of the modified bitumen asphalt in the tank is between 150 C. to 185 C. in which the reinforcement fabric is saturated, and passes through the thickness rollers.

[0038] At the point (4) the roofing membrane enters a cooling system where the temperature of the modified bitumen asphalt is lowered to between 80 to 90 C. at the end of the cooling system.

[0039] The process continues to point (5) where the roofing roll has an average temperature of between 65-70 C. and passes where the final thickness is set between 1.4 to 5.0 mm.

[0040] At point (6), the aluminum flakes are loaded to a hopper, and through a series of metal trays, the aluminum flakes are spread covering completely the top surface of the Prefabricated Modified Bitumen Waterproofing Membrane at an average of 6 million aluminum flakes per every square meter of product area, to produce the final product. This process is completely different compared to other types of modified waterproofing rolls, where mineral granules or silica sand are applied to the top layer.

[0041] At point (7) of FIG. 1, a polyethylene film is placed in the bottom of the roofing roll. At point (8), the Prefabricated Modified Bitumen Waterproofing Membrane is completely finished and goes through a series of cooling rolls that lower the temperature to between 35-40 C.

[0042] At point (9), the waterproofing membrane is passed to an accumulator that controls the feeding of the membrane to the winder. At point (10), the waterproofing membrane is cut and taped at the desired length, and the finished roofing rolls are placed on the pallet for handling and storage.

[0043] The component layers of the prefabricated modified bitumen waterproofing membrane of the present invention are illustrated in FIG. 2. Specifically, the prefabricated modified bitumen waterproofing membrane is shown pulled from a roll and the component layers being separated for illustration purposes include a top layer comprising aluminum flakes, modified bitumen asphalt with SBS, APP or TPO, as an upper layer on top of a reinforcing fabric formed of a non-woven polyester and/or fiberglass reinforcement fabric that provides the middle layer of the prefabricated modified bitumen waterproofing membrane, a bottom layer of modified bitumen asphalt with SBS, APP or TPO and polyolefin film covering the bottom layer. The amount of the composition for each component is shown in Table 4 below.

TABLE-US-00005 TABLE 4 Composition per m.sup.2 Component Range Modified asphalt (kg.) 3-5 Reinforcement fabric (m.sup.2) 1.0 Aluminum flakes (kg.) 1.0-1.4 Polyethylene film (m.sup.2) 1.0

[0044] While the present invention has been shown in accordance with a preferred and practical embodiment, it is recognized that departures from the instant disclosure are fully contemplated within the spirit and scope of the present invention which is not to be limited except as defined in the following claims.