MXPA98010729A

MXPA98010729A - The manufacture of products for roof structured with fibrous meshes conditioned with hume

Info

Publication number: MXPA98010729A
Application number: MXPA/A/1998/010729A
Authority: MX
Inventors: W Michelsen Theodore; James Lemonier Byron; Francis Olson Brian; Allen Lundholm Gary
Original assignee: Johns Manville International Inc
Priority date: 1997-12-18
Filing date: 1998-12-15
Publication date: 2000-07-01

Abstract

The present invention relates to a method for the manufacture of impermeable felts, covering folders, base folders and similar structured roofing products of fibrous meshes which includes: the provision of a roofing mesh in a manufacturing process, wetting of the mesh to roof by applying vapor or a liquid mist to one or both of the main surfaces of the roofing net during the manufacturing process to increase the moisture content of the roofing net and to reduce the amount of hot bitumen accepted by the roofing net during a coating operation, and the application of a hot bitumen coating to one or both of the main surfaces of the roofing net during the manufacturing process after the moisture content of the roofing net has been increased through the wetting step.

Description

THE MANUFACTURE OF PRODUCTS FOR ROOF STRUCTURED WITH FIBROUS MESHES CONDITIONED WITH HUMIDITY BACKGROUND OF THE INVENTION The present invention relates to a method of manufacturing waterproof felt, cover folder, base folder and similar structured roofing products and, in particular, to a manufacturing method such as structured roofing products in which the fibrous roofing mesh is wetted, preferably with steam (water vapor) before the application of a bituminous layer (such as with asphalt or with a layer of vegetable tar) to reduce the amount of bituminous coating required to make the products for structured roofing. The products for structured roofing, such as waterproof felts, coverings and base folders, are manufactured by coating the roofing mesh with a hot bitumen, such as asphalt or tar, to impregnate or saturate the roofing mesh. with the hot bitumen. After a roofing net has been covered with hot bitumen, the coated roofing grid is cooled to cool the warm bitumen; one or both of the main surfaces of the coated roofing mesh is normally covered with a release agent, such as a liquid release agent or a sand coating, to prevent the bitumen of the coated roofing mesh from adhering to the equipment rolls. and to prevent the adjacent convolutions of the coated roofing mesh from sticking to each other when it is wound; and the finished product, the waterproof felt, the cover folder or the base folder are typically rolled in one piece for storage and embarkation. Waterproof felts, cover folders and base folders are typically used to form structured roof membranes over roof decks in which the layers of these structured roofing products and hot asphalt or bitumen are applied to form the membrane of the structured roof. The hot asphalt or bitumen is applied to the roof covering by spreading it with a squeegee and the layers of structured roof products work to stabilize the asphalt or bitumen spread with a squeegee and prevent the asphalt or bitumen, which are also excellent barrier against water, crack and drip. The roofing mesh used in the manufacture of reinforced roof products, such as waterproof felts, cover binders and base folders, is typically manufactured with randomly oriented glass fibers, which are placed through a dry or wet process . Preferably, the roofing grid is made with randomly oriented glass fibers that have been placed through a wet process to form the mesh. Fiberglass roofing meshes, manufactured through a wet process such as the Fourdrinier process, are preferred because these wet process meshes have an extremely consistent fiber distribution and density with uniform fine perforations that are sufficiently large to provide adequate ventilation during roof application, but small enough to properly stabilize the bitumen of the structured roof membrane. Fiberglass roofing meshes, made through the dry process, have a porous appearance, of sheers with many relatively large openings irregularly dimensioned, which do not allow the correct stabilization of the bitumen of the membrane of the structured roof. In this way, although fiberglass roofing meshes made through a dry process can be used in the method of the present invention to form the products for structured roofing, roofing meshes made through a wet process they are preferred. COMPENDIUM OF THE INVENTION The present invention is directed to a method of manufacturing products for structured roofing, such as waterproof felts, cover binders and base folders, of fibrous meshes which reduce the amount of bitumen, such as asphalt or tar, required to form the products for structured roofing without adversely affecting the performance of the products for structured roofing in any way that may be appreciable. The method of the present invention for manufacturing structured roof products includes: the provision of a fibrous roofing mesh (preferably a fiberglass roofing mesh) in a manufacturing process; by wetting the roofing net during the manufacturing process to increase the water content of the roofing net and reduce the amount of hot bitumen required to cover the roofing net; and by applying a hot bituminous layer to one or both surfaces of the subsequent roofing net as the moisture content of the roofing net increases. Preferably, the moisture content of the roofing net is increased by a small amount during the manufacturing process through the application of steam (water vapor) to one or both of the main surfaces of the roofing net. The steam can be applied to the mesh for roofing in the open or inside a humidification chamber.

By increasing the moisture content of the roofing net through the application of steam to one or both of the main surfaces of the roofing net, the amount of hot bitumen (hot asphalt or tar) required to cover the roofing net, is reduced. The moisture added to the roofing mesh through the wet process of the present invention is removed when the hot bitumen is applied to the wetted roofing mesh and the structured roofing products made through the method of the present invention are typically around 0.2% water by weight which is a moisture content well below 1.0% water by weight allowed by ASTM 2178. It is also contemplated that the moisture content of the roofing mesh can be increased by applying a mist or water spray to one or both of the main surfaces of the roofing net. However, only a small increase in the moisture content of the roofing mesh is required through the method of the present invention, to reduce the amount of hot bitumen coating required to cover the mesh and that moisture can be removed when applies hot bitumen to the roofing net. It is believed that the application of a mist or spray of water to the roofing net would probably over saturate the roofing net with relatively large drops of water that could not be easily removed through the application of hot bitumen, thus leaving , residual water in the finished product of structured roofing. Thus, the use of liquid water, in the form of fog or dew, to increase the moisture content of the roofing mesh could cause problems: a) due to the formation of voids in the bituminous coating subsequently applied to the mesh for roofing due to water droplets inside or on the roofing net; and / or b) due to the water retention in the finished product of structured roofing (eg waterproof felt) can cause a blister to form on the finished roof made with the product for structured roofing. Correspondingly, although if possible, moistening the roofing mesh through the application of a mist or spray of water is not recommended in the method of the present invention. In addition to reducing the amount of bitumen required to form the waterproof felts, the cost is also reduced, the method of the present invention allows a reduction in the coating roll and the tension of the slag used in the manufacturing process and so both the number of breaks in the mesh during the manufacturing process is reduced. The method has also resulted in less accumulation of bitumen in the equipment for the process, resulting in fewer process suspensions due to roller cleaning. The formation of similar waterproof felts, lining binders, base folders and similar, lighter structured roofing products containing less asphalt or tar, through the process of the present invention allows roofing meshes covered with bitumen in the process of present invention, cool more quickly, in the same speed line as roofing meshes coated with heavier bitumen which covers with higher amounts of bitumen. Thus, a smaller amount of release agent is required to prevent the bitumen covered roofing mesh of the present invention from adhering to the equipment for the process and to prevent the adjacent convolutions of the structured roofing product from being made Through the method of the present invention they adhere to each other in the roll of the finished product. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a diagram of a portion of the production line using the method of the present invention to manufacture the products for structured roofing of fibrous meshes conditioned with humidity. Figure 1A is a schematic of a portion of a hot bitumen application station that can be used in the method of the present invention. Figure 2 is a diagram of a form of use of the equipment for application of steam (water vapor) or mist (liquid water) that can be used in the humidifying station of a production line using the method of the present invention. Figure 3, is a perspective view of a structured roofing product made through the process of the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown schematically in Figure 1, a production line 20 for the manufacture of waterproof felts, cover folders, base folders and similar structured roof products 22 according to the method of the present invention typically include: a roofing mesh supply station 28, a station for the application of a separating or releasing agent 30, a cooling station 32, a winding station 34. Preferably, the process for the manufacture of the roofing products structured 22 is a continuous online process. As shown schematically, the fibrous roofing mesh 36 is removed from a supply roll 38 and normally passed through a dry caterpillar 40 which provides a mesh stock for roofing 36 on the production line 20 allowing the production line , of this preferred continuous manufacturing process, continue to ope during the supply roll change without interruptions. The fibrous roofing mesh 36 passes from the dry caterpillar 40 to the humidifying station 26 where moisture, for example steam (water vapor), is applied to one or both sides of the roofing net 36 in order to increase the content of moisture of the mesh for roofing and therefore reducing the amount of bitumen (for example asphalt or tar) applied to the roofing grid in the hot bitumen coating station 28. After the fibrous roofing mesh 36 is Moistened in the humidifying station 26, the roofing mesh is passed through the hot bitumen coating station 28 where the hot bitumen is applied to the roofing mesh to satu or impregnate the roofing net with the bitumen and remove moisture from the roofing net including the added moisture in the wetting station (finished structured roof products made through the process can easily meet the ASTM 2178 standard containing less than 1.0% water by weight and typically less than 0.2% water by weight). Typically, the roofing grid covered with bitumen 36 is passed through the application station of the releasing agent 30 where a releasing agent, for example a liquid releasing agent or a sand-coating agent, is applied to one or both sides of the main surfaces of the roofing net covered with bitumen to prevent the bitumen covered roofing mesh from adhering to the equipment for the process or to other convolutions of the roofing net covered with bitumen when the finished product (the waterproof felt, the coating folder, base folder or similar structured roofing product 22) is wound on cylinders 42 in a winding station 34 for storage and shipping. Typically, the bitumen covered roofing mesh 36 is also passed through the cooling station 32 to cool the bitumen in the roofing net before winding the cold bitumen covered roofing mesh (the structured roofing product 22) into the roof. the product roll for structured roofing 42 in the winding station 34. The application station of the releasing agent 30 is typically located at the upper end of the cooling station 32. The roofing mesh 36 can be a fiber mesh with dry or wet layer made of glass fibers and / or other fibers having the performance characteristics and physical properties required to provide a roofing net with the physical properties and performance characteristics required, such as, but not limited to, resistance to natural elements (climatic conditions), reinforced resistance, fire resistance, porosity, resistance to moisture and the ability to accept hot bitumen such as asphalt or tar. However, preferably, the roofing netting 36, used in the method of the present invention, is a glass fiber roofing net with a wet layer, such as, but not limited to, the roofing net DURA-GLASS IV and DURA-GLASS VI, sold by John Manville International, Inc.

Preferably, the humidifying station 26 has steam application equipment 44 (steam) which applies steam to at least one of the main surfaces of the roofing net 36 and may have equipment for steam application 46 (steam of water) to apply steam to the second main surface of the roofing net 36. Although not shown, the steam application equipment 44 and / or 46 can be attached to form a humidifying chamber through which the roofing mesh 36 passes on its path to the hot bitumen coating station 28. As best shown in FIG. Figure 2, the steam equipment 44 and / or 46, preferably includes: a steam-emitting tube 48 that extends transversely across the full width of the roofing mesh 36 to apply steam to the full width of the roofing mesh; a conventional regulating valve 50 for regulating the vapor pressure provided in the steam emitter tube 48; a conventional on / off valve 52 for activating or deactivating the steam supply to the steam application equipment 44 and / or 46; a pressure gauge 54 for measuring and displaying the vapor pressure supplied to the steam emitter tube 48; and a steam supply, for example a boiler at about 250 ° F, from a steam line of the head 56. When the roofing net 36 is wetted with steam (steam), the steam emitter tube 48 is preferably a tube of about a half inch with a series of holes with a diameter of 0.125 inches (with spaces approximately one inch apart and extending the full width of waterproof felt 36) to distri the steam in and into the roofing net 36 in order to raise the moisture content of the roofing net 36. The vapor pressure applied to the main surface (s) of the roofing net 36 is varied to regulate the increase in the content of moisture of the mesh to roof and achieve the selected or desired moisture content that reduces the amount of hot bitumen (for example asphalt or tar) accepted by the roofing net 36 at the bet application station Hot menu 38 through the desired or selected quantity. The vapor pressure applied to the roofing net 36 with a given thickness increases to cause a further increase in the moisture content of that roofing net. The vapor pressure applied to the roofing net is also increased at the same time as the thickness of the roofing net 36 is increased to achieve the same percentage by weight of the increase in the moisture content of a roofing netting thicker than that of the roofing net. of a mesh to roof thinner. Although the vapor pressure applied to the main surface (s) of the roofing net 36 may be outside the following limits, it is preferable to apply the steam to the main surface (s) ) of the mesh for roofing 36 at pressures of between about 0.350 kg. per cm2 (5 psig.) and about 2.1 kg. per cm2 (30 psig.). The use of too low steam pressures can cause not enough moisture to be added to properly condition the roofing grid for application of the hot bituminous coating, and the use of too high vapor pressures can damage the roofing grid or increase the content of moisture of the mesh to roof beyond what is required for a correct conditioning for the application of the hot bituminous coating in the roofing net. Although it is not recommended, in case the roofing netting 36 is wetted with liquid water in the form of mist or spray, the mist emitting pipe 48 is preferably a half inch pipe with a series of spaced holes spread across the width of the waterproof felt 36 for distring the mist on or into the roofing mesh 36 to raise the moisture content of the roofing mesh 36. The liquid water pressure applied to the main surface (s) ) of the roofing net 36 is preferably between about 0.350 kg. per cm2 (5 psig.) To around 2.1 kg. per cm2 (30 psig.) and is varied to regulate the increase in the moisture content of the roofing mesh and achieve the selected or desired moisture content that reduces the amount of hot bitumen (eg asphalt or tar) accepted by the roofing net 36 in the hot bitumen application station 28 in the desired or selected quantity. The pressure of the liquid water applied to a roofing net 36 with a given thickness is increased to cause a greater increase in the moisture content of that roofing net. The pressure of the liquid water applied to a roofing net is also increased at the same time as the thickness of the roofing net 36 is increased to achieve the same increase in the percentage by weight in the moisture content of the thicker roofing net. than in the mesh for roofing thinner. As discussed above in the Summary of the Invention, the use of liquid water, in the form of mist or spray to increase the moisture content of the roofing mesh, could over saturate the roofing net with relatively large water droplets. that could not be easily eliminated through the application of hot bitumen and therefore leaving residual water in the finished product of structured roofing. Thus, the use of liquid water, in the form of fog or spray, to increase the moisture content of the roofing mesh can cause problems: a) due to the formation of voids in the subsequent bituminous coating applied to the mesh for roofing, for drops of water in or on the roofing net; and / or b) due to the water retention in the finished product (the waterproof felt) can result in a blister in the finished roof made with the waterproof felt. Correspondingly, although if it is possible to moisten the mesh for roofing through the application of mist or spray of water, this is not recommended in the method of the present invention. At the hot bitumen application station 28, hot bitumen, for example asphalt at temperatures between 420 ° F. and about 450 ° F., is preferably applied to one or both surfaces of the roofing net 36 through conventional bitumen application equipment commonly used in product lines for structured roofing. As shown schematically in Figure 1, hot bitumen is applied on the back of the first main surface of the roofing net 36 where the hot bitumen is absorbed into the roofing net. As shown, a heated coating application roller 60 lifts the hot bitumen from a hot bitumen bath 62 and deposits the hot bitumen on the back of the roofing grid. A support roller 64 assists the coating roller 50 in coating to ensure that the roofing mesh 36 is impregnated with the hot bitumen. For applications where, due to the thickness of the roofing mesh 36, or for other reasons, the hot bitumen is applied on both major surfaces of the waterproof felt, a second set of application rollers 160 and 164 is schematically shown in FIG. Apply hot bitumen to the upper or secondary main surface of the roofing net where the warm bitumen is absorbed into the roofing net. When used, this second set of application rollers 160 and 1640 are located in the middle of the first set of application rollers 60 and 64 and the application station of the release agent 40 of Fig. 1.

As shown, the application roller of the heated coating 160 lifts the hot bitumen from one end of a hot bitumen bath 162 and deposits the hot bitumen on the upper or secondary main surface of the roofing grid 36. A supporting roller 164 aid to the coating application roller 160 to ensure that the roofing mesh 36 is impregnated with the hot bitumen. With the method of the present invention, the moisture content of the roofing net 36 is adjusted until the desired or selected amount of hot bitumen is accepted by the roofing net. Although the amount of hot bitumen accepted by the roofing net 36 is regulated through the humedification of the roofing net 36 to be less than the amount of the roofing net without conditioning (the roofing net before having been conditioned with moisture), the degree of moisture conditioning of the roofing net (the degree of increase in the moisture content of the roofing net) can be changed to vary the amount of hot bitumen accepted by the roofing net. When moisture is applied to only one of the main surfaces of the roofing net 36 in the humidifying station 26, the hot bitumen is preferably applied to the same main surface in the hot bitumen application station 28. After the bitumen hot has been applied to the roofing net 36 in the hot bitumen application station 28, a release agent such as a liquid release agent is usually applied to one or both of the main surfaces of the roofing net 36 covered with bitumen. The release agent is applied through conventional elements, such as application rollers 68 and 70, which extend transversely across the full width of the roofing net covered with bitumen to apply the release agent to all (s) the ( s) surface (s) and prevent the roofing grid covered with bitumen from sticking to the equipment or to itself. Then the roof covering with bitumen is allowed to cool in the cooling station 32 before winding the finished waterproof felt, the cover binder, the base folder or a similar structured roofing product 22 within the roller 42 in the winding station 34 to be stored or shipped. When comparing the weight of the waterproof felts made with the roofing meshes that have not been wetted (roofing meshes without conditioning), the average weight of the waterproof felts 22 made by the method of the present invention can be reduced in weight. weight up to around 15% to around 20% (through a reduction in the amount of bitumen used in waterproof felt) without appreciably affecting the physical properties of waterproof felts. Two examples of waterproof felts are those sold by John Manville International, Inc., manufactured by the method of the present invention.; and GlasPly Premier waterproof felts reduced in average weight between about 15% and 20%, which meet the Type VI requirements of ASTM D 2178 and GlasPly IV waterproof felts that meet the Type IV requirements of ASTM D 2170. Of course, the method of the present invention can be used to reduce the weight of waterproof felts, when compared to waterproof felts made of roofing mats that have not been moistened, in amounts less than 15%, such as , but not limited to amounts of around 5% or 10%, and in amounts exceeding 20%. However, with weight reductions greater than 20%, waterproof felt can not meet the Type IV and VI requirements of ASTM D 2178. In describing this invention, certain types of embodiments have been used to illustrate the invention and the practices of it. However, the invention is not limited to these specific embodiments since other embodiments and modifications within the spirit of the invention could be produced by persons skilled in the art when reading these specifications. Thus, the invention is not intended to be limited to the specific embodiments disclosed, but it will be limited only by the claims attached to this document.

Claims

CLAIMS 1. A method of manufacturing products for structured roofing consisting of: the supply of a fibrous roofing mesh for a manufacturing process; humidification of the roofing net by applying moisture to the first main surface of the roofing net during the manufacturing process to increase the moisture content of the roofing net and reduce the amount of hot bitumen accepted by the roofing net when Cover with hot bitumen during the manufacturing process; and the application of a hot bituminous coating to a main surface of the roofing net during the manufacturing process after the moisture content of the roofing net has been increased upon wetting. 2. The method of manufacturing products for structured roofing according to claim 1, wherein: the roofing net is moistened by applying steam to the first main surface of the roofing net. 3. The method of manufacturing products for structured roofing according to the claim 2, where: steam is applied at a pressure of between 0.350 kg per cm2 (5 psig.) And about 2.1 kg. per cm2 (30 psig.). 4. The method of manufacturing products for structured roofing according to the claim 3, where: the vapor pressure is adjusted to control the amount of moisture content increase. 5. The method of manufacturing products for structured roofing according to claim 1, wherein: the roofing net is wetted through the application of a liquid mist to the first main surface of the roofing net. 6. The method of manufacturing products for structured roofing according to claim 5, wherein: the liquid mist is applied at a pressure of between 0.350 kg. per cm2 (5 psig) and around 2.1 kg. per cm2 (30 psig.). The method of manufacturing structured roofing products according to claim 6, wherein: the liquid mist pressure is adjusted to control the amount of the increase in moisture content. 8. The method of manufacturing products for structured roofing according to any of claims 1, 2 or 5, wherein: the moisture content of the roofing net is increased through the humedification of the roofing net in an amount sufficient to reduce the average weight of the waterproof felt by at least 5%, when compared to a waterproof felt made of roofing mesh that has not been wetted, through a reduction in the amount of bitumen accepted by the roofing mesh . 9. The method of manufacturing structured roof products according to claim 8, wherein: the average weight reduction is at least 10%. 10. The method of manufacturing structured roof products of claim 8 wherein: the roofing grid is a wet mesh layer of randomly oriented glass fibers. 11. The method of manufacturing the products for structured roofing according to any of claims 1, 2 or 5, wherein: the moisture content of the roofing mesh is varied during a production run of the manufacturing process to vary the amount of betumen accepted by the roofing net. 12. The method of manufacturing products for structured roofing according to claim 1, wherein: the hot bitumen is applied to the first main surface of the roofing net. The method of manufacturing products for structured roofing according to claim 1, wherein: moisture is applied to a second main surface of the roofing net during the manufacturing process to increase the moisture content of the roofing net and reduces the amount of asphalt accepted by the roofing net. 14. The method of manufacturing the products for structured roofing according to the claim 13, where: the roofing net is moistened by applying steam to the first and second main surfaces of the roofing net. 15. The method of manufacturing the products for structured roofing according to the claim 14, where: the steam is applied at a pressure of between about 0.350 kg. per cm2 (5 psig.) and around
2. 1 kg. per cm2 (30 psig.). 16. The method of manufacturing products for structured roofing in accordance with the claim 15, where: the vapor pressure is adjusted to control the amount of the increase in moisture content. 17. The method of manufacturing the structured roof products according to claim 13, wherein: the roofing net is wetted by applying a liquid mist to the first and second major surfaces of the roofing net. 18. The method of manufacturing structured roof products of claim 17, wherein: the liquid mist is applied at a pressure of between about 0.350 kg. per cm2 (5 psig.) and about 2.1 kg. per cm2 (30 psig.) 19. The method of manufacturing the structured roof products according to claim 18, wherein: the pressure of the liquid mist is adjusted to control the amount of the increase in moisture content . 20. The method of manufacturing the structured roof products according to any of claims 13, 14 or 17 wherein: the moisture content of the roofing net is increased by wetting the roofing net in an amount sufficient to reduce the Average weight of the waterproof felt produced at least 5%, when compared to a waterproof felt made of roofing mesh that has not been wetted, through a reduction in the amount of the bitumen accepted by the roofing net. 21. The method of manufacturing the products for structured roofing according to claim 20, wherein: the reduction in the average weight is at least 10%. 22. The method of manufacturing the products for structured roofing according to claim 20 wherein: the roofing net is a mesh with wet layer of randomly oriented glass fibers. 2
3. The method of manufacturing the products for structured roofing according to any of claims 13, 14 or 17 wherein: the moisture content of the roofing mesh is varied during the run of production of the manufacturing process to vary the amount of betumen accepted by the mesh for roofing. 2
4. The method of manufacturing structured roof products according to any of claims 1, 2 or 5, wherein: the application of the hot bituminous coating removes moisture from the roofing mesh and the structured roofing product contains less than 1.0 % water by weight.