MXPA97004613A - Rotary fiberation of asfa - Google Patents

Abstract

The present invention relates to: A method for producing asphalt fibers includes feeding molten asphalt to a rotary asphalt spinning machine, spinning the asphalt fibers from the asphalt spinning machine, and collecting the asphalt fibers. The molten asphalt is fed to the asphalt spinning machine at a temperature in the range of about 132øC (270øF) to about 260øC (500øF). Also disclosed is a method for integrating asphalt with reinforcing fibers including the steps of establishing a web of downwardly moving reinforcing fibers, such as glass fibers, and centrifuging the asphalt fibers from a rotary asphalt spinning machine placed therein. of the veil of reinforcing fibers to integrate the asphalt with the reinforcing fibers. A method for making a shingle for asphalt roofing involves the steps of assembling together a layer of asphalt fibers with a layer of reinforcing fibers, coating the assembled layers to form an asphalt-coated sheet, applying granules to the asphalt-coated sheet. and cut the asphalt coated sheet in roofing shingles. The invention also includes the asphalt roof shingle made with this process. In addition, the invention includes highway reinforcing products containing the asphalt fibers, and the method of making such product.

Description

ROTATING FIBERATION OF THE ASPHALT TECHNICAL FIELD This invention belongs to the manufacture of asphalt products. More particularly, this invention relates to asphalt products in a fibrous form and to methods for producing fibrous forms of the asphalt. PREVIOUS TECHNIQUE Asphalt products have been produced in various forms, with the main uses of asphalt being paving and roofing products. The common source of the asphalt is the waste or funds of the petroleum refining industry. This asphalt must also be refined or processed by air blowing (oxidation), in order to increase the softening point and increase the rigidity to obtain useful products for roofing and especially asphalt products. Some asphalt products have improved properties due to the addition of natural or synthetic rubbers and other organic additives. While the asphalt itself has many beneficial properties, it lacks the inherent resistance to tension and integrity. Therefore, many asphalt products are reinforced with such materials as glass fibers or organic fibers, such as polymer fibers, and have re-fillings, such as ground limestone. For example, asphalt shingles for roofing are based on an inner band or carrier of a wet process glass fiber mat, and the asphalt itself contains about 65 weight percent of ground limestone infill. Other re-fillings used in asphalt products include carbon black, finely ground tires, ground glass and various inorganic and organic pellets. One of the problems with reinforcing asphalt * is that it is often difficult to integrate this reinforcement material into the asphalt matrix, particularly in a uniform manner. Typically, the integration of asphalt and reinforcement is achieved by fixing this reinforcement material on a mat or band, and applying the asphalt in molten form, as is the case in the manufacture of asphalt shingles for roofing. The manufacture of tiles consists of carrying out a mat of glass fibers in a continuous wet process, in a bath of molten asphalt to cause a coating on both sides of the mat, as well as filling the interstices between the individual glass fibers . This process is limited in that it can only be applied to a relatively uniform coating, similar to a film. It would be advantageous to be able to apply asphalt layers in several products, where the layers are not films, but rather porous mats or other types of non-uniform layers. Likewise, the coating process requires the assembly of the final product in the manufacturing establishment, with a coating of liquid asphalt. It would also be advantageous to be able to assemble products containing asphalt layers at field locations, such as at a road repair site. Another known method of integrating asphalt with reinforcements is to mix this asphalt with loose or particulate reinforcement materials. Such mixing requires significant energy and capital for the equipment, and is not always successful in providing a uniform mix of asphalt and reinforcement. It would be advantageous to be able to intermix uniformly or integrate the asphalt with reinforcing materials, which are in a non-fixed or loose form, rather than being joined in a fixed product, such as a mat. Likewise, it would be advantageous to be able to introduce the asphalt itself into several products in forms other than a liquid. Numerous reinforcement layers have been used to reinforce road systems. Such well-known reinforcing layers include glass fibers in the form of mats, or woven or non-woven, mats impregnated with asphalt, steams of organic materials, such as polyester fibers, mats in the form of an open weave or grid, and layers of glass fibers or other reinforcing fibers. These reinforcement layers are applied to the roads below the asphalt layers of bituminous aggregate, applied in sequence, to reinforce this bituminous aggregate. Such reinforcement layers are typically used in locations where the underlying pavement has broken and the road system is being repaired. The reinforcement layers can also be used all over the road to repave or as an original construction. Likewise, reinforcing layers can be used for special applications, such as bridge decks. It is well known to use a sticky coating on any road reinforcement product to secure this roadway reinforcement product before applying the pavement layer. One of the problems with road reinforcement products currently available, is the assembly of several layers that make up the reinforcement of the road, which is an expensive and time-consuming process. Likewise, it is difficult to accurately measure the asphalt layers in such products. Furthermore, it is not easy to fully integrate the reinforcement layers of the road reinforcement product with the asphalt, without completely impregnating the reinforcement layer in a bath of molten asphalt. Finally, it would be advantageous to be able to produce reinforcement products with greater strength without having to increase the materials used. EXPOSITION OF THE INVENTION Asphalt has now been developed in the fibrous form and a method for producing asphalt fibers. Asphalt fibers are a new form of this asphalt and they can be used in traditional asphalt applications, such as paving, and special roofing products as well as new products. The asphalt fibers can be formed in a rotary process by centrifugation and can be collected as fibrous asphalt bands. Bands can be incorporated into numerous products, such as a layer of asphalt material. According to this invention, a method for producing asphalt fibers is provided, which comprises supplying the molten asphalt to a rotary asphalt spinning apparatus, centrifuging the asphalt fibers of the spinning apparatus and collecting these asphalt fibers. The asphalt can be modified with one or more organic modifiers from the group consisting of natural rubber, synthetic rubber, elastomers, polymers, resins and other thermoplastic or thermoset materials. Preferably, the modifiers are present in an amount within the range of about 2 to 30 percent (percent by weight of the total organic composition). More preferably, the modifiers are present in an amount within the approximate range of 4 to 12 percent. In a specific embodiment of the invention, the molten asphalt is supplied to an asphalt spinning apparatus at a temperature within the range of 132 to 2600C, as measured at the delivery point, just above the spinning apparatus. In another embodiment of the invention, the asphalt is subjected to an oxidation process, sufficient to give the asphalt a softening point in the range of 82 to 177ac, and preferably within the range of 93 to 132ac, approximately, before the Fiberization process. All softening points use the ring and ball method. In yet another embodiment of the invention, the centrifugation step provides the acceleration to the molten asphalt, sufficient to produce primary asphalt fibers, having a diameter in the approximate range of 635 x 103 μm to 1524 x 103 μm. In a specific embodiment of the invention, the spinning apparatus has a peripheral wall having between 500 and 25,000 holes, through which the asphalt is centrifuged. Preferably, the asphalt spinning apparatus has between 500 and 10,000 holes. In yet another embodiment of the invention, the asphalt is centrifuged by the spinning apparatus to form primary asphalt fibers, and these primary asphalt fibers are then attenuated by an annular gaseous flow, moving downward, from a blower, to form a veil, moving downward, of asphalt fibers.

In accordance with this invention, asphalt fibers having diameters less than 6350 x 103 μm are also supplied. Preferably the diameter of the asphalt fibers is within the approximate range of 635 x 103 μm to 3810 μm, with the asphalt having a softening point within the approximate range of 82 to 177ac and preferably within the approximate range of 93 to 132ac, in an unfilled state. More preferably, the diameter of the asphalt fibers is within the range of 635 x 103 μm to 1524 x 103 μm. The asphalt fibers can be filled with a filler and can be reinforced with reinforcing fibers, such as glass fibers. According to this invention, a mat of asphalt fibers is also supplied, these fibers have diameters in the range of 635 x 103 μm to 1524 x 103 μm, approximately, and the asphalt has a softening point within the range of 82 to 177ac, approximately. The mat can be laminated as a layer to a mat of reinforcing material, such as a mat of wet process glass fibers, to obtain a layered asphalt product. Also considered within this invention is a method for obtaining asphalt shingles for the roof, which include the steps of assembling together a layer of asphalt fibers, with a mat of reinforcing fibers, coating the mats assembled with asphalt to form a Asphalt coated sheet, apply granules to the asphalt coated sheet and cut the asphalt sheets coated in tiles for roofing. The invention also includes roofing asphalt shingles obtained by this process. In accordance with this invention, a method is also provided for integrating the asphalt with reinforcing fibers, which includes the steps of establishing a downwardly moving web of reinforcing fibers of material that can be softened by heat, such as glass fibers, supplying the molten asphalt to a rotating asphalt spinning apparatus, placed within the reinforcing fiber web, centrifuging the asphalt fibers from the asphalt spinning apparatus, in a manner that directs these asphalt fibers in contact with the asphalt. veil to integrate the asphalt with the reinforcing fibers, and collect the asphalt and integrated reinforcing fibers. Another aspect of this invention is to use the asphalt fibers of the invention as the input product for a carbonization process. The carbon fibers are prepared by controlled pyrolysis of an organic precursor in fibrous form. Commercial products have been based on rayon, polyacrylonitrile and pitch (derived from coal tar, petroleum and other sources). The process involves a number of common stages for all materials. First, the fibers are produced by extrusion or blowing of the melt. The fibers are then stabilized by oxidation at temperatures within 200 to 450ac, usually in the air. The oxidation process gives the fiber enough structure at the molecular level to maintain its configuration during the carbonization process. Finally, the fiber is carbonized at temperatures exceeding 800ac, in an inert atmosphere, such as argon. To improve the properties, the frines are stretched during the carbonization stage to orient the molecules. Heating at higher temperatures (2500 to 3000ac) also increases the modulus and resistance. The resulting carbon fibers have a wide variety of uses. Pitch fibers are obtained from petroleum or coal tar pitch and are highly aromatic, with a large proportion of asphaltenes (around 80 to 90 percent, as measured by heptane precipitation by the ASTM method). 3279-78). The melting point of the pitch is preferably about 260 &C, with a glass transition temperature of about 85ac. Many pitches are not compatible with polymers. In contrast to the pitch fibers, the asphalt used to obtain the asphalt fibers of the present invention contain 0 to 35 percent asphaltenes and typically 15 to 25 percent. The content of the asphaltene is kept low to ensure compatibility with the added polymers. The glass transition temperature of the asphalt is within the approximate range of -15 to -5dC. The melting point of the asphalt is typically within the approximate range of 93 to llßac. A further aspect of the invention is a method for obtaining highway reinforcing products, which includes establishing a downwardly moving web of reinforcing fibers of material that can be softened by heat, supplying the molten asphalt to a Rotating asphalt spinning apparatus, placed inside the veil of reinforcing fibers, centrifuge the asphalt fibers of the asphalt spinning apparatus, thus directing these asphalt fibers in contact with the veil, to integrate this asphalt with the reinforcing fibers, feed a reinforcing mat under the asphalt spinning apparatus and collecting the integrated asphalt and reinforcing fibers on the top of the reinforcing fibers to form a road reinforcement product The invention also includes a road reinforcement product Produced by this method By supplying the asphalt layer in the form of asphalt fibers, the process of obtaining road reinforcement products is less expensive. cough and consume less time. The asphalt layers in such products can be dosed more accurately and the asphalt and reinforcing fibers can be easily integrated. In addition, the use of asphalt fibers in road reinforcement products makes possible products of greater strength, without having to increase the materials used. Also, since it is not necessary to immerse the reinforcing mat in a bath of asphalt, the reinforcement for roads can be obtained without the expense and hazards of the open asphalt bath. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic sectional view, in elevation, of the apparatus for centrifuging asphalt fibers, according to the method of the invention; Figure 2 is a schematic sectional view, in elevation, of the apparatus for co-fibrizing asphalt fibers and glass fibers, according to the method of the invention; Figure 3 is a schematic elevational view of the apparatus for alternately mixing asphalt fiber webs with glass fiber webs; Figure 4 is a perspective view of a mat of asphalt fibers of this invention; Figure 5 is a schematic view, in cross section, in elevation, of a laminated mat containing a mat of asphalt fibers and a reinforcing mat; Figure 6 is a schematic view, in elevation, of a process of obtaining asphalt shingles for roofing, according to the invention; Figure 7 is a schematic plan view of a roofing asphalt shingle of this invention; Figure 8 is a schematic elevation view of a process for obtaining a roadway reinforcement product, according to the invention; and Figure 9 is a schematic sectional view, in elevation, of a road reinforcement product, according to the invention. THE BEST WAY TO CARRY OUT THE INVENTION As used in this specification, all references to percentages are in the weight per hundred. The term "asphalt", as used in this specification, includes materials, sometimes referred to as "bitumen," and the two terms are here synonymously synonymous. The asphalts that may be employed in this invention may be the naturally occurring asphalt or a manufactured asphalt produced by the refining of petroleum, and may include asphalts derived from direct operation, thermal decomposition asphalts, asphalts derived from such processes as the oxidation of asphalt, deasfaltization of propane, steam distillation, chemical modification and the like. In one of its preferred embodiments, the invention is applicable to asphalts for the production of roof tiles. The asphalt may be modified or unmodified.

As shown in Figure 2, the apparatus for producing asphalt fibers from a rotary process includes a rotatable mounted asphalt spinning apparatus 10, which is generally comprised of a bottom wall 12 of the spinning apparatus and a peripheral wall 14 of this spinning device. The asphalt spinning apparatus can be molded from a nickel / cobalt / chromium alloy, as used in the production of glass fibers, or it can be any other suitable spinning apparatus, such as one of welded stainless steel. The peripheral wall of the spinning apparatus has numerous holes 16 for the centrifugation of asphalt fibers and preferably between 500 and 25,000 holes, approximately. The molten asphalt falls into the rotating asphalt spinning apparatus as stream 20. Upon reaching the bottom wall of the spinning apparatus, the molten asphalt is driven radially outward and to the peripheral wall, where the centrifugal force centrifuges this asphalt through of the holes, as asphalt streams or asphalt primary fibers 22. After emanating from the asphalt spinning apparatus, the primary asphalt fibers 22 are directed downwardly by the annular blower 24, to form a downwardly moving flow or web 25 of asphalt fibers. Any means can be used to flip the fibers from an outward, generally radial, trajectory to a path directed towards a collection surface. In one embodiment of the invention, the centrifugal attenuation by rotation of the asphalt spinning apparatus is sufficient to produce asphalt fibers of the desired fiber diameter, and no further attenuation is necessary. The centrifugation process provides the acceleration to the molten asphalt, sufficient to produce primary asphalt fibers having a diameter below about 6350 x 103 μm, preferably within the approximate range of 635 x 103 μm to 3810 x 103 μm and more preferably within the range of 635 x 103 μm to 1524 x 103 μm. In another embodiment of the invention, the primary attenuation is used to further attenuate the primary fibers. In this case, the blower is supplied with sufficient air pressure to drive the primary fibers and further attenuate them in the desired final diameter of the asphalt fiber. As shown in Figure 1, the blower attenuates the primary fibers in final fibers 26, which are collected as a band 28 of asphalt fibers on any suitable collection surface, such as the conveyor 30. Next to the formation stage of asphalt fibers, band 28 of asphalt fibers can be transported through any subsequent process step, such as oven 32, to result in the final asphalt product, such as mat 34, which is also shown in Figure 4. Further process steps may also include the lamination of the mat or layer of asphalt fibers with a reinforcing layer, such as a fiberglass mat. The mat of asphalt fibers is porous, has a porosity within the range of about 0.4 x 10 ~ 3m3 / sec up to 23.6 x 10 ~ 3 m / sec, in a sample of 0.645 x 10 ~ 2m2, with a pressure drop of 1.27 cm. of water (0.93 Hg). Preferably the mat of asphalt fibers has a porosity within the approximate range of 1420 to 1890 10 ~ 3 m3 / sec. The mat has a density within the range of 32 kg / m3 to 160 kg / m3 and preferably within the range of 48 to 80 kg / m3, approximately. The mat has a high degree of flexibility and conformability (ability to be molded or configured around sharp corners), when compared to an asphalt film of the same density or thickness. An optional feature of the invention is the use of a heating element, such as an induction heater 35, for heating either the asphalt spinning apparatus or the primary asphalt fibers, or both, to facilitate the attenuation of asphalt fibers, By heating the primary asphalt fibers, the process of further attenuation in the final asphalt fibers is improved. Even without the need for secondary attenuation by the blower, an auxiliary heat source can be used to maintain the temperature of the asphalt spinning apparatus at the level of optimum centrifugation of the asphalt in the fibers. Other heating means for the asphalt spinning apparatus can be employed, such as electric resistance heating. The temperature of the asphalt spinning apparatus should be within the range of 132 to 260ac and preferably within the range of about 165 to 2160C. Example 1 The Venezuelan Lagovan flow was oxidized in a converter at the softening point of 115ac. At this softening point, the asphalt had a viscosity at 177ac of 4,300 cps (4.3 Pa-s) and a penetration of 17 dm at 25ac, as measured by ASTM D-5. The oxidation was sufficiently advanced to be able to form fibers, but not so much as to cause the asphalt to become brittle at room temperature. No padding was added to the asphalt. The asphalt was heated in a hot melt heater before delivering to the asphalt spinning apparatus and delivered to this spinning apparatus at a temperature of 177ac. The asphalt spinning apparatus has a diameter of 381 mm. and it turned at 2300 rpm. The peripheral wall of the spinning apparatus was adapted with 854 holes, each 0.86 mm. diameter. There was no external heating of a burner and no secondary attenuation from a blower. The asphalt fibers were collected as a porous mat. Example II The oxidized Lagovan flow of Example I was further modified with 4 percent Kraton 1184. The polymer was incorporated into the asphalt by mixing in a Ross cutter at 204 ° C for about 60 minutes. The resulting modified asphalt has a viscosity at 177ac of 110,000 cps (110 Pa-s), a softening point of 14iac and a penetration of 14 dmm at 25ac. The asphalt was delivered at a temperature of 204 ° C to the asphalt spinning apparatus of Example I, which rotated at 1700 rpm, and the asphalt fibers were centrifuged. These fibers were noticeably longer, stronger and less sticky than the fibers of Example I. Example III A 96 percent mixture of the Lagovan flow (softening point of 40ac and 4 percent of Kraton 1102 was blown by air at 246ac during 3 hours and 50 minutes The resulting asphalt had a softening point of llßac, a penetration of 20 dmm at 25ac, and a viscosity at 177ac of 11,250 cps (11.25 Pa-s) .The asphalt was then processed by heat conditioning to 166ac for 2 hours to raise the viscosity, which results in an asphalt having a softening point of 118 ° c and a viscosity at 177 ° C of 26,900 (26.9 Ps-s). The asphalt was delivered at a temperature of 182 ° C to an asphalt spinning apparatus of Example I, which rotated at 1356 rpm. The resulting asphalt fibers were an open type band. EXAMPLE IV The oxidized Lagovan flow of Example I was modified by mixing it with 10 percent Himont Profax 6301 polypropylene in a cutting mixer. The resulting asphalt had a softening point of 150ac, a penetration of 7 dmm at 25ac and a viscosity at 177ac of 110,000 cps (110 Pa-s). The asphalt was delivered at a temperature of 209ac to the asphalt spinning apparatus of Example I, which rotates at 1229 rpm. The resulting asphalt fibers were drier, less sticky and more prominent than any of the asphalt fiber samples of Examples I to III. Example V The diameter of the asphalt fibers produced in Examples I to IV was measured by first preparing a sample by fixing a thin mat specimen of asphalt fibers of 25.4 x 39.1 mm. on the slide of a microscope with a sliding cover. The microscope is equipped with a 2OOX amplification capability, a video camera and a monitor. The transmitted light was used for all measurements in a bright field mode. A pair of dial gauges was used, capable of measuring 0.1 mm. and a calibration cursor with divisions of at least 10 microns and a total length of at least 100 microns. The calibration cursor was placed in the stage and 100 micras of the video monitor was measured using the quadrant calibrators. From this measurement, a ratio of the actual size of the scale (100 microns) and the measured size of the monitor was calculated. The sample cursor was then placed in the stage and 100 monitor fibers were measured. Only the fibers that are separated from their neighbors (not fused or closely entangled) were measured. The actual diameters of the fibers were calculated, based on the calibration data, and averaged. As used in this specification, the term "having a diameter", within a certain range, means that approximately 95 percent of the asphalt fibers in a random sample have a diameter within the specified range. The results of the measurements of the diameter of the asphalt fibers are shown in Table I. The ability to measure the diameters of the asphalt fibers with the use of the above method was made more difficult by the black color of the asphalt. Because of this, it is difficult to discern which fibers, if any, are double (fused along their axis) or closely entangled in another way. For this reason, the measurements shown in Table I can be diverted to higher values than actually measured. Due to differences in asphalt formulations, some samples have a natural tendency to melt or aggregate more than others. As a comparison, the fiber diameters of a dry, bottle-grade polyethylene terephthalate (PET) sample, obtained by a similar rotary fibrillation process, is included as a control in Table I. The PET material used was the Eastman Kodapet, dried at 230 ° C overnight The PET fibers were obtained by centrifuging the molten PET delivered at 316ac to a spinning apparatus of 318 mm. in diameter, with 2400 holes that have a diameter of 0.406 mm. The spinning apparatus was rotated at 1600 rpm. PET fibers exhibited some function and entanglement. Some of the PET fibers were added, and these fibers exhibited a brittle state (lack of slippage when rubbing one fiber against another). Example VI The asphalt of Example II was improved by the addition of clay filler, to obtain up to 10 percent of the total composition by weight. The fibers were stiffer than the fibers produced in Example II, and also drier and shorter. Preferably, the amount of filling is within the approximate range of 2 to 30 weight percent of the total weight of the asphalt and the filling.

Table I DISTRIBUTION OF THE DIAMETER OF THE FIBERS The process of fiberizing the asphalt with a rotating spinning apparatus can be used in combination with a rotary glass fiber forming process to integrate the asphalt with glass fibers. As shown in Figure 2, the asphalt spinning apparatus 10 is placed under a conventional glass spinning apparatus of the well-known type to produce glass fibers. This asphalt spinning apparatus is preferably mounted below the bottom wall of the glass spinning apparatus for coaxial rotation with the glass spinning apparatus on the shaft 42. The stream 20 of molten asphalt falls through a hollow bobbin 44, which it supports rotating the glass spinning apparatus. The attenuation of the glass fibers can be facilitated by the annular blower 46 and an annular burner 36, in a manner well known in the glass fiber manufacturing art. The molten glass falls as a stream 50 into the spinning apparatus, is centrifuged as glass fibers 52 and tumbled downward as a flow of fibers and gases, or veil 54. An additive apparatus, such as a binder nozzle 56, it can be placed inside the veil or outside the veil, applying any binder or other coating or the desired particles, or to supply liquids to cool the asphalt fibers. In operation, the asphalt fibers are distributed radially outwardly from the asphalt spinning apparatus, and they are intermixed with the glass fibers in the web and are collected in the conveyor, as a mixed mass 58 of asphalt fibers. and glass fibers. Since the process of forming glass fibers necessarily operates at temperatures above the softening point of the glass, the area surrounding and immediately below the glass spinning apparatus is very hot. It is possible that some of the asphalt fibers will be entrained in the hot gases that flow with the fiber veil, and thus experience temperatures sufficient to soften or melt the asphalt fibers. In such a case, some of the asphalt material may bind itself to some of the glass fibers to form asphalt particles on the fibers. The asphalt may also be in the form of a coating on some of the fibers. Care must be taken not to introduce the asphalt into a region with such hot temperatures to ignite this asphalt. The mass of intermixed asphalt and glass fibers can be transported to any suitable process station, such as furnace 32, before becoming the product of asphalt fibers / fibers. Example VII The asphalt sample of Example IV was co-fibered with the glass fibers, with an apparatus similar to that shown in Figure 2. The resulting mass of intermixed asphalt and glass fibers was collected as an insulation product, the which looks like an insulation of black glass fibers. This asphalt / glass fiber insulation product had 60 to 65 weight percent organic components, although the weight percentage of the organic components may be within the approximate range of 20 to 80 percent of the mixed fiber product. asphalt / glass. Four individual samples were prepared, with the results shown in Table II.

Table II PROPERTIES OF THE ASPHALT / GLASS FIBER LINING As an alternative to coaxial fiberization, explained above and shown in Figure 2, alternate blends of asphalt fiber and fiberglass webs can also be used, as shown in Figure 3. Asphalt fibers can be integrated with the glass fibers by centrifugation of the glass fibers from one or more rotating glass spinners 40, which are supplied with molten glass by any suitable delivery means, such as the crucible 66, to establish one or more veils 54 , that move down, of glass fibers. The glass fiber webs are placed above the collecting surface 30 and the webs of the glass fibers are generally aligned along the length of the collection surface. The asphalt fibers are centrifuged by one or more rotating spinners 10 of the asphalt, to establish one or more veils 25, which move downwards, of the asphalt fibers, also placed above the collection surface. The asphalt material can be supplied in a molten form from a common source, such as an asphalt supply conduit 68. The asphalt fiber webs are aligned along the length of the collection surface, generally colli- laterally with the webs of the glass fibers, in an alternating manner with the webs of the glass fibers. The result is that asphalt fibers and glass fibers are intermixed and collected as asphalt fibers and integrated glass fibers. Subsequently, the integrated asphalt and glass fibers can be further processed into the desired asphalt / glass fiber product. In an alternative embodiment, a single asphalt spinning apparatus is placed between a pair of glass spinners. The mat 34 of the asphalt fibers of the invention, shown in Figure 4, can be incorporated into numerous applications, particularly in the construction industry. Possible uses include glass mat thermoplastics, filtration, sound absorption, packaging, sorbents, adhesives, mat binders, moisture resistant coatings, corrosion resistant coatings, insulation, polymer placement for shingle modification, application of a conformal layer without the need for heating or solvent, impact absorbing layers, and surface road repairs. The integrated glass and asphalt fibers can be subjected to a compression or consolidation step, which forms a denser product. Prior to consolidation, the integrated glass and asphalt fibers preferably have a density in the range of 32 kg / m 3 to 240 kg / m 3, while after consolidation, the product of the integrated glass and asphalt fibers preferably has a density within the approximate range of 1041 to 1922 kg / m3. The consolidated product will have uses in several products that include materials that dampen vibrations, molding material, insulation and substrates of slabs for the floor. When the asphalt fiber mat is used in the construction and repair of roadways, the asphalt fiber mat can be laminated with reinforcing mats, such as a mat of glass fibers from a wet process, to form a reinforcing layer . The reinforcement layer is useful in several other construction applications, as well as in road construction. As shown in Figure 5, a laminated mat 70 can be formed by laminating together a mat 34 of asphalt and a reinforcement layer, such as a continuous mat of glass fibers. The laminated mat can be used as an internal layer of membrane that absorbs tensions, in various construction applications, such as on roads. The use of asphalt fiber mat in a tile forming process is shown in Figure 6, where a wet process tile mat 76 and a layer 34 of asphalt fibers are laminated together to form a laminated mat 70. This laminated mat was fed into an asphalt coating 78, and granules are applied to the asphalt sheets coated by the applicator 80 of these granules. The granules are pressed into a sheet, in any suitable manner, such as a granule press 82, and cut into individual tiles 84 by the cutter cylinder 86. An individual tile is shown in Figure 7. After discrete tiles are formed , they can be processed with a device commonly used to handle these tiles, such as a stacker 88 to form stacks 90 of the tiles, and a packer 92 of packages, to form bundles 94 of tiles. The use of a layer of asphalt fibers in the construction of a tile or other roofing product allows the selective placement of a layer having specific properties. For example, if the asphalt fibers in the layer are modified with a polymer to provide high flexibility or elasticity, the use of the layer makes it possible to place high-elastic asphalt in the upper portion of the tile (where this elasticity is needed). ), without requiring that the entire recovery asphalt be modified. This construction will give a better performance of the tiles without much additional cost. Example VIII Asphalt shingles for roofing were manufactured by laminating a layer of asphalt fibers made as in the previous Example II, with a wet process shingle mat. The laminated mat was then coated with asphalt backing to obtain a tile. The Elmendorf tear strength of the resulting tile was 1953 grams. This is approximately 9 percent greater than the typical tear strength for conventional shingles. The process of manufacturing road reinforcement products, shown in Figure 8, includes a spinning apparatus 100 of glass, mounted for coaxial rotation with the first asphalt spinning apparatus 102. The molten glass was supplied to the spinning apparatus and centrifuged from the glass spinning apparatus in the form of glass fibers 106. The molten asphalt 108 supplied to the first asphalt spinning apparatus was centrifuged on asphalt fibers 110 by the first apparatus. asphalt spinner. The asphalt fibers preferably have a diameter in the range of 635-103 μm to 1524-103 μm. This co-fiberization of glass fibers and asphalt fibers mixes the two materials and integrates them together. The glass fibers and the asphalt fibers can be turned down by annular blowers, not shown. The glass spinning apparatus and the first asphalt spinning apparatus are placed above a picking surface, such as the conveyor 112. When desired, a reinforcing mat, such as an open grid 114 of woven glass, can be fed on the conveyor and directed under the flow of integrated asphalt and glass fibers. The reinforcement mat may be of any type suitable for reinforcing woven or non-woven pavement layers of organic or inorganic materials, and preferably in the form of an open weave or grid. The integrated asphalt and glass fibers are collected on the upper part of the glass grid to produce a reinforcement product 116 for roads. Preferably, the integrated asphalt and glass fibers are consolidated by a sanding roller 117. Optionally, a sticky coating material 118 may be applied to the top of the road reinforcing product from any suitable source, such as an applicator 120. of spraying the sticky coating. This sticky coating can be any suitable adhesive for bonding the road reinforcing product to the road, such as an asphalt adhesive. Preferably, the re-coating is tacky at a temperature of 25ac, as measured by the ASTM D-2131 rolling ball test, according to which values above 40mm. They are considered non-sticky. An optional method for applying a sticky coating is shown in Figure 8. A second layer of asphalt fibers 126, produced by the second asphalt spinning apparatus 128, can be laid on top of the road reinforcing product. Preferably, the second asphalt spinning apparatus is in general alignment with the first asphalt spinning apparatus along the length of the picking surface. The asphalt stream 130 is supplied to the second asphalt spinning apparatus and is of a composition which creates sticky fibers. This can be achieved in several ways, such as using an asphalt with a high penetration ratio. Preferably, the sticky asphalt fibers have a diameter in the approximate range of 635 x 103 μm to 1524 x 103 μm. When the sticky coating or layer is applied in the form of sticky asphalt fibers, the sticky coating, applied by spraying, is usually not necessary. Preferably, the sticky asphalt fibers are at a temperature of 15 c. As shown in Figure 9, the road reinforcement product 116 has a reinforcing mat or glass grid 114 in its upper layer, since, as the product is applied to the road, it reverses from the orientation shown in FIG. Figure 8. In the middle of the product is the layer 122, which is made of glass fibers 106 and integrated asphalt fibers 110. The bottom layer is the sticky coating 118. Finally, the road reinforcement product may contain a release paper 124, to facilitate the development of the product at the road paving site. It will be apparent from the foregoing that various modifications can be made in this invention. However, they are considered as being within the scope of the invention. INDUSTRIAL APPLICABILITY This invention can be useful in the manufacture of asphalt fiber and glass fiber reinforcing products, and in the manufacture of asphalt shingles for roofing.

Claims (20)

1. CLAIMS 1. A method for producing asphalt fibers, which comprises the steps of: (a) supplying a rotary spinning apparatus, having a bottom wall and a peripheral wall containing holes, a composition of molten asphalt, the sual includes: (i) an asphalt having an asphaltene content of up to 35 weight percent and (ii) from about 2 to 30 weight percent of at least one organic modifier, selected from thermoplastic and thermoset materials; (b) centrifuging the molten asphalt composition from the orifices of the spinning apparatus, to form asphalt fibers having a diameter of about 6.35 to 38.1 μm, and (c) collecting the asphalt fibers.
2. 2. A method, according to claim 1, in which, in the supply step, the molten asphalt composition is at a temperature of about 132 to 260ac.
3. 3. A method, according to claim 1, wherein the modifier is present in the asphalt composition in an amount of 4 to 12 weight percent.
4. 4. A method, according to claim 3, in which, in the supply step, the molten asphalt composition is at a temperature of about 132 to 260BC.
5. 5. A method, according to claim 1, further comprising, prior to the delivery step, oxidizing the asphalt, so that it has a softening point of about 82 to 177ac 6.
6. A method, according to the claim 5, wherein, in the supply step, the molten asphalt composition is at a temperature of 132 to 260ac.
7. A method, according to claim 1, wherein the centrifuging step comprises accelerating, in centrifugal form, the molten asphalt composition through the holes, so that the diameter of the asphalt fibers is between 6.35. at 15.24 μm.
8. A method, according to claim 1, in which the number of holes in the peripheral wall is approximately between 500 and 25,000.
9. 9. A method, according to claim 1, wherein the modifier is selected from the group consisting of natural rubber, synthetic rubber, elastomers, polymers and resins.
10. A method, according to claim 1, further comprising, between the centrifugation stage and the harvest stage, the step of: attenuating the asphalt fibers, which uses an annular gas flow to form a veil , which moves downwards, from asphalt fibers.
11. 11. A method, according to claim 10, wherein the collecting step comprises picking the attenuated asphalt fibers, as a band, on a conveyor.
12. 12. A method, according to claim 11, further comprising the step of heating the band in an oven.
13. 13. A method according to claim 10, further comprising externally heating the spinning apparatus or the asphalt fibers.
14. 14. A method, according to claim 13, wherein the spinning apparatus has a temperature of about 132 to 260ac.
15. 15. A method, according to claim 1, wherein the spinning apparatus has a temperature of about 166 to 216ac.
16. 16. A method, according to claim 1, wherein the asphaltene content is 15 to 25 weight percent.
17. 17. A method, according to claim 1, wherein the asphalt composition further comprises a filler.
18. 18. A method, according to claim 1, wherein the collecting step comprises collecting the asphalt fibers, as a band, on a conveyor.
19. 19. A method, according to claim 18, further comprising the step of heating the band in an oven.
20. 20. A method, according to claim 1, wherein the diameter of the asphalt fibers is from about 6.35 to 15.24 μm.