MXPA97004685A - Method for the elaboration of fibers of mineral material with organic material - Google Patents

Abstract

The present invention relates to a method for manufacturing fibers of mineral material (18) with organic material (36) which includes centrifuging the mineral fibers (29) of molten mineral material (18) with a first rotary spinner (10), changing the direction of the mineral fibers (20) to form a veil (26) of mineral fibers (20) moving downwards, establishing a flow of molten organic material (36) moving towards a second rotating spinner (28) placed inside the veil (26), dividing the flow of molten organic material (36) into a plurality of streams, directing, by means of the conduits (44), a single one of the plurality of streams towards the peripheral wall (46) of the second rotary spinner (28), the conduits (44) protect the molten organic material (36) from the heat coming from the first spinning spinner (10), and centrifuge the organic fibers (38) from the molten organic material (3).

Description

METHOD FOR THE ELABORATION OF FIBERS OF MINERAL MATERIAL WITH ORGANIC MATERIAL TECHNICAL FIELD This invention relates to the production of mineral fiber products, and in particular, to mineral fiber products having organic or polymeric material applied to mineral fibers. More particularly, this invention relates to fibers of molten mineral material and molten organic material which are simultaneously centrifuged. BACKGROUND OF THE ART Mineral fibers, such as glass fibers, are useful for insulating structural products. The glass fibers for such products are typically made by feeding the molten glass into a spinner, and spinning the fibers by spinning the spinner to form a cylindrical glass fiber web that moves downward. Applied to the fibers are several organic coatings, particularly binders that link the mineral fibers together to form the insulation or structural products. The glass fiber insulation products are typically bonded together with a phenol / formaldehyde binder to form a spring-like matrix that can be recovered after compression during packaging of the product. Usually the phenol / formaldehyde urea binders have a molecular weight of about 600 in the uncured state, and these binders are usually applied in an aqueous medium by light spraying on the glass fibers after the fibers are formed. One of the problems with the application of the aqueous organic binders of the prior art to the cylindrical mineral fiber webs is that a portion of the binder tends to evaporate before contact between the liquid binder drop and the mineral fiber in the web. The evaporated binder material contains a contaminant in the process air stream and must be cleaned in order to avoid contamination problems. Also, the binder material in the mineral fibers tends to adhere, requiring extensive cleaning of the fiber collection apparatus to prevent the accumulation of binders of the fiberglass insulating material that may drip into the product and cause a defect in the product. A recently developed process is to apply binders of high molecular weight to a first spinner that uses glass fibers to produce a veil of glass fibers that move downwards and to a second spinner, placed inside the veil, which forms polymer fibers and distributes them in contact with the glass fibers in the veil. This process produces a mixed insulation gasket having some polymeric fibers and some glass fibers having a polymeric coating. This process of fiber co-processing is described in U.S. Patent Application Serial No. 08 / 079,413, which is incorporated herein by reference, and which was filed on June 23, 1993, in the name of Bakhshi. and collaborators, such as the inventors, and is assigned to the assignee of the present invention. One of the problems with the fiber co-processing approach for organic or polymeric material intermixed with glass fibers is that the polymeric material is exposed to a hostile environment. It is necessary that the spinner for polymeric material be placed below the glass spinner so that it has the polymeric material intersecting the glass fiber web at a level high enough for effective mixing. The glass spinner is operated at a temperature close to 1093 ° C (2000 ° F), and a considerable amount of heat is radiated to the spinner for polymeric material and to the polymeric material within the spinner. The excessive heat of the polymeric material causes the degradation of the polymer. It is still more annoying the problem of it catching fire. If the polymeric material is exposed to air and at elevated temperatures, a part of the polymeric material will vaporize and the combustion process will start. The burning of the polymeric material is an unacceptable side effect of the process. It would be advantageous for a fiber co-processing process that was capable of delivering the polymeric material to the spinner in a form that would minimize the thermal degradation of the polymeric material, and reduce the exposure of the molten polymeric material to the air to prevent combustion. . DESCRIPTION OF THE INVENTION A method and apparatus have now been developed to improve a fiber co-processing process by protecting the melted polymer material in the spinner for polymeric material, from exposing it to a little of the heat from the glass spinner, and of contact with the air to avoid burning. In accordance with this invention, there is now provided a method for manufacturing a mineral fiber product comprising the centrifugation of mineral fibers of molten mineral material with a first spinning spinner, which changes the direction of the mineral fibers to form a veil of mineral fibers that moves downwards, establishing a flow of molten organic material that moves towards a second rotating spinner placed inside the veil, dividing the flow of molten organic material into a plurality of streams, directing, through the conduits, some of the plurality of streams towards the peripheral wall of the second rotating spinner, the conduits protect the molten organic material from the heat coming from the first spinning spinner, and the centrifugation of the organic fibers from the molten organic material. By protecting the molten organic material from heat, the organic material is less subject to thermal degradation, and the molten organic material can be maintained at a relative cooling temperature until the last moment, just before going through the peripheral wall of the material. the spinner. By protecting the organic material from exposure to air, there is a likelihood that you will have less opportunity to catch fire. In a specific embodiment of the invention, the ducts are rotated at the same speed or at the speed of rotation according to the second rotary spinner. In another embodiment of the invention, the conduits have conduit outlets that restrict the flow of molten material through the conduits so that no air enters the conduits, thereby avoiding or reducing the amount of vaporization of the polymeric material. In yet another embodiment of the invention, a generally circular shield is placed on the lower wall of the second spinner, the shield extends radially outwardly from the spinner towards the peripheral wall of the second spinner, the shield and the bottom of the spinner. Spinner wall define an annular cavity having at least one outlet from the cavity positioned at the radially outer edge of the shield, and the flow of the molten organic material through the outlet of the cavity is restricted so that no air enters to the cavity. In accordance with this invention, there is also provided an apparatus for making fibers of mineral material with organic material comprising a first spinner mounted to rotate about an axis to form mineral fibers, means to change the direction of the mineral fibers to form a web of mineral fibers moving downward, a second spinner mounted for rotation and placed within the web, means for establishing a flow of molten organic material moving towards the second spinning spinner, means for dividing the flow of molten organic material into a plurality of streams, conduits for directing any of the plurality of streams towards the peripheral wall of the second rotating spinner, the conduits protect the molten organic material from the heat of the first spinning spinner, and means for rotating the second spinner to centrifuge the organic fibers of the molten organic material and to direct the organic fibers in contact with the mineral fiber web. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic cross-sectional elevation view of the apparatus for co-processing fiberglass fibers with fibers of polymeric material according to the invention. Figure 2 is a schematic cross-sectional elevation view of the spinner for polymeric material of Figure 1, without the polymer melt. Figure 3 is a schematic plan view of the spinner for polymeric material of Figure 1, taken along lines 3-3 of Figure 2, showing the polymer melted in the spinner for polymeric material. Figure 4 is a schematic cross-sectional elevation view of a spinner embodiment for polymeric material containing a circular shield. Figure 5 is a schematic elevational cross-sectional view of a spinner embodiment for polymeric material containing a circular shield and an inner vertical wall. Figure 6 is a schematic cross-sectional elevation view of a spinner embodiment for polymeric material containing the spinner cover.

BEST MODE FOR CARRYING OUT THE INVENTION The invention will be described in terms of a function that forms fiberglass, although it will be understood that the invention can be practiced using another mineral material that is softened by heat, such as stone, slag and basalt. As shown in Figure 1, the spinner 10 of glass rotates about the axis of rotation 12 and is driven by the rotation of the spindle 14. The glass spinner can be cast from a nickel / cobalt / chromium alloy as is commonly known in the technique. The peripheral wall of the spinner has various holes 16 for the centrifugation of glass fibers, and preferably has between about 2,000 and about 50,000 holes. A stream of molten glass 18 is supplied to the glass spinner, which is centrifuged through the walls of the spinner in the form of glass fibers 20. The glass fibers are maintained in an attenuated state, softened immediately outside of the glass spinner. the spinner by the heat of the annular burner 22, although in some operations of the fiberglass the external burner is not required. Radially traveling glass fibers are tipped by the annular blower 24 into a web 26 of cylindrical fibers traveling downwards, that is to say in the direction of the axis of the spinner. The process for creating the downward movement of the cylindrical glass fiber web is well known in the art. Placed below the glass spinner is a second rotating spinner that distributes the molten organic material in contact with the veil from a position within the veil. In the embodiment shown in Figure 1, the second spinner is a spinner 28 of polymer, which distributes polymeric material in contact with the web. The spinner for polymeric material can be molded from a nickel / cobalt / chromium alloy as used for the production of glass fibers, or it can be any other suitable spinner such as that of welded stainless steel. The peripheral wall of the spinner for polymeric material has numerous holes for the centrifugation of asphalt fibers, and preferably has between about 500 and about 25,000 holes. A spinner for polymeric material successfully used in a fiberglass / PET fiber co-processing process has approximately 3,500 holes. It will be understood that any organic material capable of being fibrillated can be supplied to the second or spinner for polymeric material. Particularly useful examples of polymers include such high molecular weight polymeric material as polyethylene terephthalate (PET), polypropylene sulfide or polyphenylene sulfide (PPS). Other organic materials suitable for making fibers include nylon, polycarbonate, polystyrene, polyamide, resins, various polyolefins, asphalts and other thermoplastic and thermoset materials. The polymer spinner can be mounted on or attached to the spinner for glass. Preferably the spinner for polymeric material is mounted, through the spinner 30 for polymer, in a form that minimizes physical contact with the spinner for glass to reduce heat transfer by conducting the polymeric material and the polymer. Spinner for polymeric material. For this purpose, the spinner for polymeric material is preferably adapted with a mounting bracket 32 having spacing knots 34 that reduce the conductive thermal transfer of the spinner for glass, as shown in Figure 2. The spindle length is sufficient to allow the introduction of the polymer fibers at a desirable height within the web. If the spinner for polymeric material is too high, the polymeric fibers can be degraded, and can penetrate and flow through the web. The polymeric material is supplied to the spinner for polymeric material in the form of a stream 36 of molten polymeric material. As shown, this current can be fed through the hollow portion of the spindle. The molten polymer can be produced or supplied using an extruder equipment commonly known as those of the polymeric material art, such as PET. The temperature at which the molten polymeric material is supplied depends on the nature of the polymer. Normally polypropylene has a temperature of about 260 ° C (500 ° F) as it emerges from the extruder. The asphalt runs to the cooler at approximately 204 ° C (400 ° F), while the PPS operates hotter at approximately 316 ° C. (600"F). Depending on the viscosity, surface and other parameters of the polymeric material tension, and the rotation speed and the size of the holes in the spinner for polymeric material, the polymeric fibers 38 may be produced from the spinner for polymeric material. the polymeric fibers travel radially outwardly where they meet and intermixed with the mineral fibers. the glass fibers intermingled and polymeric fibers may be collected in any suitable device, such as a conveyor 40, and take the form a mat 42 or mixed product. Since the glass fibers and the spinners glass operate at a temperature reaches 1093 ° C (2000 ° F), the polymer fibers are rapidly pushing a region of high temperature, causing polymer fibers are softened.It has been found that some of the polymer fibers melt, form droplets or other particles that are unite by themselves some of the mineral fibers. Other of the polymer fibers retain the fibrous form, resulting in the presence of polymer fibers in the final mineral fiber product. The reason why some of the polymeric material retains the fibrous form is not known, although other portions of the material form polymer particles that bind to the mineral fibers. It may be that some of the polymer fibers do not soften to the required degree which causes them to lose their fibrous form and transform into a more spherical shape. Alternatively, it may be that, although all the polymeric fibers are softened, only a portion of them come in contact with the mineral fibers although in a softened state. Supplying the polymer material within the spinner to polymeric material is provided causing the polymeric material to flow within conduits, such as pipes 44. As shown in Figures 2 and 3, the pipes extend radially outwardly from the spindle of polymeric material towards the peripheral wall of the spinner for polymeric material 46. During the operation, the polymeric material flows down into the spindle for polymeric material, and radially outwardly through the pipes. The molten polymeric material forms a layer or cream on the peripheral wall of the spinner, and is centrifuged through the holes 48 for polymeric material to form the polymer fibers. The pipes have outlets 50, which can be merely the open ends of the pipes, or they can be a means for restricting or dosing the flow of the polymeric material flowing through the pipes. Preferably the outlet of the pipe and the diameter of the pipe are appropriately sized for the operating conditions which ensure that no air can enter the pipes. By preventing air from reaching the polymeric material within the pipes, the degradation of the polymeric material will be retarded until after the polymeric material leaves the pipes. Optionally, the outlets of the pipe can be adapted with nozzles. The pipes can be any suitable conduit for the supply of the polymeric material. The pipes successfully used in a PET mixing process were 6.35 mm (one quarter of an inch) in internal diameter of the stainless steel tubes. Preferably at least four pipes are found, and more preferably eight pipes, although they can be used more or less. The pipes can be mounted for rotation at the same rotational speed according to the spinner for polymeric material, or at a different speed. Optionally, the pipes can be insulated, with a ceramic material or any other suitable material, to further minimize the effects of radiant heat and hot gases entering the spinner for polymeric material through the upper opening 52 of the spinner As shown in Figure 4, the spinner for polymeric material can be adapted with a similar member to a generally flat plate that covers the molten polymeric material to minimize heat exposure. This member may be any that is suitable to protect the polymeric material, such as the shield 54, which may be made of stainless steel or any other suitable material. The shield can generally have the annular shape, which extends radially outwardly from the spinner 30 for polymeric material towards the peripheral wall of the spinner for polymeric material. The shield and lower wall 56 of the spinner for polymeric material define a generally annular space or cavity 58 on the lower part of the spinner. During the operation, the polymeric material will flow through the openings 60 of the spindle to fill the cavity. The shield can be designed to provide a narrow opening, an outlet 62 of the cavity, at the edge 64 of the radially outer shield. The outlet of the cavity can restrict the flow of the polymeric material towards the peripheral wall of the spinner for polymeric material, in a manner similar to the function of the outlets of the pipe. The outlet of the cavity may be annular in shape, or it may be a series of slots spaced circumferentially around the shield. A main function of the exit of the cavity is to prevent the air from reaching the cavity so that the minimum polymer degradation takes place. Degradation leads to vaporization and possible fire problems. An alternative embodiment of the invention, shown in Figure 5, provides an extension at the end of the shield that additionally blocks exposure of the polymeric material to air and heat from sources external to the spinner for polymeric material. The vertical interior wall 66 can be positioned radially inwardly of the peripheral wall of the spinner for polymeric material to define an annular vertical cavity 68 wherein a body or cream of polymeric material can accumulate without exposure to air. As shown in Figure 6, the protection of the polymeric material can be achieved by placing a locking means, such as a spinner cover 70, on top of the spinner for polymeric material. As shown, the molten polymeric material drips down through the spindle for polymeric material, flows through the openings of the spindle towards the spinner, flows radially outwardly into the lower wall of the spinner for polymeric material and upwards of the peripheral wall, and through the holes that form the polymer fibers. It will be apparent from the foregoing that various modifications to this invention can be made, so that, however, they will be considered to be within the scope of the invention. INDUSTRIAL APPLICABILITY The invention can be useful in the production of mixed fiber and glass fiber fibrous products for use as thermal and structural insulation products.

Claims (15)

1. The method for making fibers of mineral material (18) with organic material (36) comprising: a. centrifuging the mineral fibers (20) of molten mineral material (18) with a first spinning spinner (10); b. changing the direction of the mineral fibers (20) to form a web (26) of mineral fibers (20) that moves downward; c. establishing a flow of molten organic material (36) moving towards a second rotating spinner (28) positioned within the web (26); d. Divide the flow of molten organic material (36) in a plurality of streams; and. directing, by means of the conduits (44), any of the plurality of currents towards the peripheral wall (46) of the second rotary spinner (28), the conduits (44) protect the molten organic material (36) from the heat coming from the first spinning spinner (10); F. centrifuging the organic fibers (38) of molten organic material (36), and, g. direct the organic fibers (38) in contact with the web (26) of mineral fibers (20).

2. The method of claim 1, wherein the conduits (44) are rotated at the same speed as the second rotary spinner (28). The method of claim 2, wherein the conduits (44) are isolated. The method of claim 1, wherein the conduits (44) have outlets from the conduit (50), and include the step of restricting the flow of molten organic material (36) through the outlets (50) of the conduit to so that air does not enter the ducts (44). 5. The method for manufacturing fibers of mineral material (18) with organic material (36) comprising: a. centrifuging mineral fibers (20) of molten mineral material (18) with a first spinning spinner (10); (b) changing the direction of the mineral fibers (20) to form a web (26) of mineral fibers (20) that moves downward; (c) establishing a flow of molten organic material (36) moving to a second rotating spinner (28) positioned within the web (26); d. dividing the flow of molten organic material (36) into a plurality of streams; and. directing via conduits (44), any of the plurality of streams towards the peripheral wall (46) of the second rotary spinner (28), the conduits (44) have conduit outlets (50); F. restricting the flow of molten material (36) through the outlets (50) of the conduits so that air does not enter the conduits (44); g. centrifuging the organic fibers (38) of the molten organic material (36); and, h. direct the organic fibers (38) so that they come into contact with the web (26) of mineral fibers (20). The method of claim 5, wherein the conduits (44) are rotated at the same rotational speed as the second rotary spinner (28). The method of claim 5, wherein the conduits (44) function to protect the molten organic material (36) from the heat coming from the first rotary spinner (10). The method of claim 7, wherein the conduits (44) are isolated. 9. The method for making fibers of mineral material (18) with organic material (36) comprising: a. centrifuging mineral fibers (20) of molten mineral material (18) with a first spinning spinner (10); b. changing the direction of the mineral fibers (20) to form a web (26) of mineral fibers (20) moving downward; c. rotating the second spinner (28) positioned within the web (26) and rotatably mounted on a hollow spindle (30), the second spinner (28) has a peripheral wall (46), a bottom wall (56), and a shield (54) generally circular placed on the lower wall (56), the shield (54) extends radially outwardly from the spinner (30) towards the peripheral wall (46) of the second spinner (28), the shield (54) and the lower wall of the spinner (56) define an annular cavity (58) having at least one outlet of the cavity (62) positioned on the edge (64) radially outwardly of the shield (54); d. Establish a flow of molten organic material (36) that moves downward through the spindle (30); and. directing the molten organic material (36) of the spindle (30) towards the cavity (58) and through the outlet (62) of the cavity towards the peripheral wall (46) of the spinner; F. restricting the flow of molten material (36) through the outlet (62) of the cavity so that no air enters the cavity (58);g. centrifuging the organic fibers (38) of the molten organic material (36); and n. direct the organic fibers (38) in contact with the web (26) of mineral fibers (20). The method of claim 9, wherein the shield (54) functions to protect the molten organic material (36) from the heat coming from the first spinning spinner (10). The method of claim 9, wherein the outlet of the cavity is an annular groove. The method of claim 9 wherein the shield (54) has an annular flange (66) extending vertically upwardly to define an annular vertical cavity (68) that protects the molten organic material (36) placed on the wall peripheral (46) of the heat spinner from the first spinning spinner (10). The method of claim 9, wherein the shield (54) is insulated. 14. The method for making fibers of mineral material (18) with an organic material (36) comprising: a. centrifuging mineral fibers (20) of molten mineral material (18) with a first spinning spinner (10); b. changing the direction of the mineral fibers (20) to form a web (26) that moves downward from the mineral fibers (20); c. rotating a second spinner (28) positioned within the web (26) and rotatably mounted on a hollow spindle (30), the second spinner (28) has a peripheral wall (46), a bottom wall (56), and a shield (54) generally circular, oriented generally parallel to the lower wall (56), the shield (54) extends radially outward from the spindle (30) towards the upper part of the peripheral wall (46) of the second spinner (28) , the shield (54) is effective to block hot gases and radiant heat entering the second spinner (28); d. establishing a flow of molten organic material (36) moving downward through the spindle (30); and. directing the molten organic material (36) of the spindle (30) towards the peripheral wall (46) of the spinner; F. centrifuging the organic fibers (38) of the molten organic material (36); and, g. direct the organic fibers (38) so that they come into contact with the web (26) of mineral fibers (20). 15. The method of claim 14, wherein the shield (54) is insulated.