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 modified bitumen asphalt, aluminum flakes on a top surface of the upper layer, and polyolefin film covering the bottom layer. A process for manufacturing the prefabricated modified bitumen waterproofing membrane includes modifying the asphalt with SBS (Styrene-Butadiene-Styrene), APP (Attic Polypropylene) or TPO (Thermoplastic Polyolefin) polymers, saturating the top and bottom sides of the middle layer of reinforcement fabric with the modified asphalt, applying the aluminum flakes to the top surface, and applying a polyethylene film to the bottom surface.

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 modified bitumen asphalt with SBS (Styrene-Butadiene-Styrene), APP (Attic Polypropylene) or TPO (Thermoplastic Polyolefin) polymers; aluminum flakes on the top surface of the upper layer; a bottom layer on the reinforcement fabric comprising modified bitumen asphalt with SBS (Styrene-Butadiene-Styrene), APP (Attic Polypropylene) or TPO (Thermoplastic Polyolefin) polymers; and polyolefin film covering the bottom layer.

2. A manufacturing process for the production of the prefabricated modified bitumen waterproofing membrane of claim 1, the process comprising the steps of: providing a modified asphalt that includes SBS (Styrene-Butadiene-Styrene), APP (Attic Polypropylene) or TPO (Thermoplastic Polyolefin) polymers; pumping the modified asphalt into one or more fabric saturation tanks; maintaining the modified asphalt at a temperature of between 150 degrees C. and 220 degrees C.; providing a roll of central reinforcement fabric; placing the roll of central reinforcement fabric on a support base which allows the roll to rotate while the central reinforcement fabric advances through the steps of the manufacturing process in a continuous production line; driving rotation of the roll of central reinforcement fabric by a guide roller system; rotating the roll of central reinforcement fabric at a controlled rate and directing the central reinforcement fabric pulled from the roll towards the one or more fabric saturation tanks containing the modified asphalt; passing the central reinforcement fabric through the one or more fabric saturation tanks; submerging the central reinforcement fabric in the modified asphalt in the one or more fabric saturation tanks so that the central reinforcement fabric is saturated with the modified asphalt; directing the saturated central reinforcement fabric out from the one or more fabric saturation tanks and through thickness control cylinders to yield a modified bitumen waterproofing membrane having a thickness ranging between 1.4 mm and 5.0 mm; allowing the thickness of the modified bitumen waterproofing membrane to set; spreading aluminum flakes on an upper surface of the modified bitumen waterproofing membrane; applying a polyethylene film to a bottom surface of the modified bitumen waterproofing membrane; passing the modified bitumen waterproofing membrane through presses to ensure adhesion of the aluminum flakes and the polyethylene film to the modified asphalt of the modified bitumen waterproofing membrane; cutting the modified bitumen waterproofing membrane to a desired length; and winding the cut length of modified bitumen waterproofing membrane into a roll and taping the roll to prevent unwinding.

3. The manufacturing process of claim 2 further comprising the step of applying the aluminum flake as an upper finish coating of the modified bitumen waterproofing membrane to provide high solar reflectance having a solar reflectance index (SRI) equal or greater than 85.

4. The manufacturing process of claim 2 wherein the modified asphalt further includes one or more additives to improve performance of the manufactured modified bitumen waterproofing membrane.

5. The manufacturing process of claim 4 wherein the one or more additives includes fungus and vegetation growth chemical inhibitors.

6. The manufacturing process of claim 4 wherein the one or more additives includes a water repellant.

7. The manufacturing process of claim 4 wherein the one or more additives includes fire retardant chemicals.

8. The manufacturing process of claim 2 wherein the central reinforcement fabric includes fiberglass.

9. The manufacturing process of claim 2 wherein the central reinforcement fabric includes a polyester fiber.

10. The manufacturing process of claim 2 wherein the central reinforcement fabric includes a blend of fiberglass and polyester fiber.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] 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.

[0027] 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

[0028] 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.

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

[0033] 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 (2) 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.

[0034] 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.

[0035] 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.

[0036] 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

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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 5 below.

TABLE-US-00006 TABLE 5 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

[0041] 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.