Method of making an insulation assembly

Abstract: There is described a method for making a mineral fiber insulation assembly (30) including a mineral core having opposed major surfaces, opposed side surfaces, and opposed end surfaces, and a polymer film (45) covering only the opposed major surfaces and opposed side surfaces. A mineral fiber pack (25) is moved along a predetermined path (28) and at least one sheet of polymer film (45) is supplied to the predetermined path to cover the major and side surfaces. The polymer film is attached (42) to at least one of the side surfaces, and a plurality of openings are formed (62) in the polymer film adjacent at least one side surface. The mineral fiber pack and the polymer film cover are then cut (68) perpendicular to the predetermined path to form individual mineral fiber insulation assemblies.

Description: This invention relates to a method of making a mineral fiber insulation assembly. The insulation assembly is used to insulate, for example, floors, ceilings, attics, and walls of buildings. Methods of making mineral fiber insulation assemblies are known in the art. In the manufacturing of mineral fiber insulation assemblies, it is commonly used practice to fiberize the mineral fibers from molten mineral material and distribute the fibers on a collecting conveyer to form a pack. After formation, the pack is often slit longitudinally and positioned on conveyors. After processing, the pack is cut into desired lengths or batts. Often the lengths of material are rolled or otherwise tightly compressed for packaging and transport. In some manufacturing processes, a facing material is added to the pack prior to the cutting step. In the procedure described in EP-A-0395466 a cladding is glued to one face of a continuous band of mineral fiber insulation material and the cladding material is then folded along the side edges of the band and glued down. A cladding layer may also be provided on the other face of the band before the band is cut into separate panels. The cladding is applied to improve the mechanical resistance and aesthetic appearance of the panels. The present invention relates to an improved method of making a mineral fiber insulation assembly which can operate at production speeds. The present invention provides a method of making a mineral fiber insulation assembly having a mineral fiber core and an outer polymer film covering the core having opposed major surfaces and opposed side surfaces, the method comprising the steps of moving a mineral fiber pack along a predetermined path; supplying at least one continuous sheet of polymer film along the predetermined path and covering the opposed major surfaces and the opposed side surfaces with the polymer film to provide a polymer film-covered mineral fiber core; attaching the polymer film to one or both of the side surfaces only of the core; providing a plurality of holes in the polymer film adjacent at least one of the side surfaces of the core; and cutting the mineral fiber core and the polymer film in a direction generally perpendicular to the predetermined path to form individual mineral fiber insulation assemblies. The present invention is described below in greater detail by way of example only with reference to the accompanying drawings in which: Figure 1 is a diagrammatic elevational view showing the method and apparatus for making a mineral fiber insulation assembly, according to the present invention, with portions of the apparatus broken away; Figure 2 is a fragmentary sectional view taken along the line 2-2 of Figure 1 and shown on an enlarged scale; Figure 3 is a fragmentary perspective view taken along the line 3-3 of Figure 1; Figure 4 is a fragmentary sectional view taken along the line 4-4 of Figure 3 and shown on an enlarged scale; Figure 5 is a fragmentary elevational view taken along the line 5-5 of Figure 3; Figure 6 is a diagrammatic view, showing one embodiment of an insulation assembly produced by the method, according to the present invention; Figure 7 is a fragmentary perspective view showing apparatus for forming openings in the polymer film; Figure 8 is a fragmentary elevational view showing another embodiment of method and apparatus, according to the present invention; Figure 9 is an end view taken along the line 9-9 of Figure 8; Figure 10 is a bottom view taken along the line 10-10 of Figure 8; Figure 11 is a view similar to Figure 6 showing another embodiment of an insulation assembly, produced using the method and apparatus shown in Figures 8 through 10; Figure 12 is a fragmentary elevational view showing another embodiment of method and apparatus according to the present invention; Figure 13 is a view similar to Figure 6 showing an insulation assembly constructed using the method and apparatus of Figure 12; Figure 14 is a fragmentary side elevational view showing still another embodiment of method and apparatus according to the present invention; and Figure 15 is a view similar to Figure 6 showing an insulation assembly constructed using the method and apparatus of Figure 14. Referring to Figure 1, a mineral fiber-forming hood 20 is shown. Mineral fibers 21, such as rock wool fibers or glass fibers, move downwardly onto an initial conveyor 22, to form an initial pack 23. Normally, in an operation which is not illustrated, the initial pack is formed into the dimensions desired by forming rollers and then are slit longitudinally to form, for example, the desired mineral fiber pack 25. If the mineral fiber pack 25 is a fibrous glass pack, the glass fibers preferably have a mean length weighted fiber diameter less than 0.00034 inch (8.64 10 -6 m). The glass fibers preferably have a mean weighted fiber diameter between 0.00010 inch (2.54 10 -6 m) and 0.00024 inch (6.10 10 -6 m). The mineral fiber pack 25, according to the present invention, has an unrestrained or recovered thickness of at least 4 inches (101.6 mm) and preferably between 4 (101.6 mm) and 10 inches (254 mm). A conveyor system 26 includes an upper surface 27 which defines a longitudinally extending predetermined path 28. Referring to Figure 6, the apparatus shown in Figure 1 is utilized to make a mineral fiber insulation assembly 30 having a mineral fiber core 31. The core 31 has opposed major surfaces 32 and 33, opposed side surfaces 34 and 35, and opposed end surfaces 36. Referring to Figure 1, optional pull rolls 38 move the mineral fiber pack 25 along the predetermined path 28 defined by the upper surface 27 of the conveyor system 26. In other embodiments, the movement of the conveyor system 26 is sufficient to move the mineral fiber pack 25. In the present embodiment, adhesive applicators 39 are positioned on opposed sides of the mineral fiber pack 25. Referring to Figure 2, each of the adhesive applicators 39 includes a pair of adhesive heads 40 having discharge nozzles 41 adjacent the side surfaces 34 and 35 ofthe mineral fiber pack 25. Referring to Figures 1 through 3, the nozzles 41 of the applicators 39 apply one or two ribbons or layers 42 of adhesive on the side surface 35 of the mineral fiber pack 25. In other embodiments, the polymer film can be attached by thermal bonding to the mineral fiber pack, such as by heat sealing, rather than by the use of adhesive. A dispenser assembly 44 is positioned above the conveyor system 26 and mounts a roll of polymer film 45. Referring to Figure 3, the polymer film 45 is folded in a centerfold or "C" fold. The centerfold or C-fold of the polymer film 45 includes a first leg 46 which is integrally connected to a second leg 47. Referring to Figures 3, 4, and 5, a metal reversing shoe 49 having an entrance throat 50 is mounted adjacent the predetermined path 28. The metal reversing shoe 49 is stationary, and the moving mineral fiber pack 25 is received by the entrance throat 50 and travels through the reversing shoe 49. As shown in Figure 3, the leg 46 of the C-folded polymer film 45 has a first surface 46A and a second surface 46B. Movement of the mineral fiber pack 25 and the optional pull rolls 38 pull the polymer film 45 from the supply roll, around a turning roll 52, and through the reversing shoe 49. In the present embodiment, very little gap is provided between the opposed side surfaces 34 and 35 and the sides ofthe shoe 49. In other embodiments, a gap of between 0.25 inch (6.4 mm) and 0.75 inch (19.1 mm) is provided. As the polymer film 45 is pulled around the entrance throat 50 of the reversing shoe 49, the continuous sheet of polymer film 45 is inverted. The first and second legs 46 and 47 are inverted whereby, for example, the upper surface 46A of the first leg 46 becomes the lower surface and the lower surface 46B becomes the upper surface after the inverting is completed and the continuous sheet of C-folded polymer film is positioned adjacent the mineral fiber pack 25. In the present embodiment, the continuous sheet of polymer film 45 is fed from the dispenser assembly 44 in a direction generally perpendicular to the predetermined path 28. After passing through the reversing shoe 49, the sheet of polymer film 45 is parallel to the predetermined path 28. Preferably, a guide arm assembly 54 is mounted downstream adjacent the reversing shoe 49 to hold the components in a correct position. As the sheet of polymer film 45 passes through the shoe 49, it encapsulates or covers the longitudinally extending mineral fiber pack 25. In the present embodiment, the polymer film 45 has overlapping free edges 55 and 56 (see Figure 6). As the assembly passes through the reversing shoe 49 (see Figure 5), the shoe 49 includes inwardly directed lips 57 and 58 which turn and overlap the free edges 55 and 56 of the polymer film 45. In the present embodiment, the layers of adhesive 42 on the side surface 35 of the core 31 attach the polymer film 45 and its leading edges 55 and 56. In other embodiments, the polymer film 45 is also attached to the opposite side edge 34. However, the polymer film 45 is not attached to either the major surface 32 or the major surface 33 of the mineral fiber insulation assembly 30. The polymer film 45 is preferably a polyethylene film. However, other polymer films may also be utilized, such as a polypropylene film. Normally, the polymer film 45 is less than or equal to 1.0 mil (25.4 10 -6 m) in thickness. Preferably, the polymer film 45 is less than or equal to 0.5 mil (12.7 10 -6 m) in thickness. The polymer film is also preferably a moisture-permeable film when used in certain applications. One adhesive which is suitable for use for the layer or layers of adhesive 42 is a pressure-sensitive adhesive, such as HM-2707 distributed by H.B. Fuller Company. The adhesive is normally applied at a rate of 0.2 grams per square foot (0.093 m 2 ). Other types of attaching or fastening means may also be utilized to attach one or both of the side surfaces 34 and 35 to the polymer film 45. One such method is to heat seal the polymer film 45 to the side surfaces 34 and 35. The mineral fiber pack 25 which is now encapsulated or covered by the polymer film 45 continues to move along the predetermined path 28. Referring to Figure 7, a plurality of openings 60 are formed in the polymer film 45 adjacent the side surface 35 of the core 31. In other embodiments, the openings 60 are placed or provided in the polymer film 45 prior to positioning adjacent the mineral fiber pack 25. In the present embodiment, the openings 60 comprise a plurality of vertical slits. However, many different shapes of openings 60 may be utilized. For example, it has been found that a preferable opening is a "C" shaped opening: the open end of the "C" being turned toward the downstream end of the moving mineral fiber pack 25. Other shapes of openings 60 may be, for example, triangular. While in some embodiments gangs of rotating saws may be utilized to form the slit openings 60, in the present embodiment a laser assembly 62 is utilized. The laser assembly 62 is mounted adjacent the conveyor system 26. The laser assembly 62 includes a discharge end 63 positioned adjacent the side surface 35. A motor-driven mirror assembly 64 directs the slitting laser beam through the discharge end 63 where it forms the slit openings 60. The laser assembly 62 also includes a laser stop plate 65, which is positioned in opposition to the discharge end 63, and a fume head 66, positioned over the discharge end 63. After the openings 60 are cut in the polymer film 45, the assembly passes through the optional pull rolls 38 and through a chopper apparatus 68. Referring to Figure 1, the chopper apparatus 68 includes a blade 69. The blade 69 is generally perpendicular to the predetermined path 28 and cuts or chops the mineral fiber pack 25 into individual ones of the mineral fiber assemblies 30. In another embodiment, water jets are utilized to cut the mineral fiber pack 25. Water jets tend to prevent lifting of the polymer film 45 adjacent the cut. The mineral fiber insulation assemblies 30 are then removed from the conveyor system 26 for compression and shipment. Referring to Figures 8 through 11, another embodiment of the method of making a mineral fiber insulation assembly, according to the present invention, is shown. In this embodiment, a C-folded continuous sheet of polymer film 72 is moved downwardly toward a longitudinally extending predetermined path 73 which is defined by the upper surface of a conveyor system 74. A mineral fiber pack 75 is carried along the conveyor system 74. The C-folded continuous sheet of polymer film 72 is removed from a supply apparatus 76. A tuck roll 78 is positioned adjacent the pack 75 on one side of the C-folded polymer film 72, and a pull roll 79 is positioned on the other side. The C-folded sheet of polymer film 72 is inverted as it is positioned over the mineral fiber pack 75. The polymer film 72 passes through a shoe 91 and has free edges 81 and 82 which are positioned adjacent a lower major surface 84 of the mineral fiber pack 75. The mineral fiber pack 75 and its finished cut core 85 also include an upper opposed major surface 86, opposed side surface 87 and 88, and opposed ends 89. A heat-seal seamer 90 joins the free edges 81 and 82 of the polymer film 72 together (see Figures 8 and 9) prior to exiting of the film 72 from the shoe 91. The inverting shoe 91 inverts the film 72 after leaving the supply apparatus 76 as it is being applied to encapsulate or cover the opposed major surfaces 84 and 86 together with the opposed side surfaces 87 and 88 of the mineral fiber pack 75. Ribbons or layers of adhesive 92 are applied to the opposed side surfaces 87 and 88 prior to application of the polymer film 72. Figures 12 and 13 illustrate another embodiment of the present invention. The method illustrated produces a mineral fiber insulation assembly 93. The assembly 93 includes a core 94, opposed major surfaces 95 and 96, opposed side surfaces 97 and 98, and opposed ends 99. A polymer film assembly 100, consisting of an upper sheet of polymer film 101 and a lower sheet of polymer film 102, covers the major surfaces 95 and 96 and the side surfaces 97 and 98. The free edges of the upper film sheet 101 and lower film sheet 102 overlap and are adhered respectively to the side surfaces 97 and 98 of the mineral fiber core 94 and to each other. Referring to Figure 12, a mineral fiber pack 104 moves along a predetermined path 105 defined by the upper surface of a conveyor system 106. A supply roll 108 feeds a continuous sheet of the lower polymer film 102 toward the mineral fiber pack 104. The lower sheet of polymer film 102 covers a portion of the side surfaces 97 and 98 of the mineral fiber pack 104 and also covers the lower major surface 96. An upper supply roll 109 similarly dispenses the upper continuous sheet of polymer film 101 downwardly and positions it adjacent the mineral fiber pack 104 where it covers the upper major surface 95 an a portion ofthe side surfaces 97 and 98, as shown in Figure 13. The adhering steps to fasten the films 101 and 102 to the mineral fiber pack 104, the opening forming steps, and the chopping step to cut the individual mineral fiber insulation assemblies 93 to length are similar to the steps disclosed above with respect to the Figure 1 embodiment. Referring to Figures 14 and 15, still another embodiment of a method according to the present invention is illustrated. A mineral fiber insulation assembly 111 includes a core 112, opposed upper and lower major surfaces 113 and 114, opposed side surfaces 115 and 116, and end surfaces 117. A polymer film assembly 119 includes an upper continuous sheet of polymer film 120 and a lower continuous sheet of polymer film 121. The upper sheet of polymer film 120 covers the upper major surface 113 and the opposed side surfaces 115 and 116 of the core 112. The upper sheet of polymer film 120 includes horizontal flanges 123 at its free edges. The lower sheet of polymer film 121 covers the lower major surface 114 of the core 112 and includes outwardly extending mating edges 124 which mate with and are attached to the flanges 123 of the upper sheet of polymer film 120. In the final mineral fiber insulation assembly 111, the flanges 123 are attached to the mating edges 124 and comprise a stapling flange which may be utilized, for example, to fasten the insulation assembly 111 to vertical studs in a building. Referring to Figure 14, a mineral fiber pack 126 moves along a longitudinally extending predetermined path 127 which is defined by an upper surface of a conveyor system 128. An upper supply roll 130 dispenses the upper sheet of polymer film 120. The film 120 covers the upper major surface 113 and the opposed side surfaces 115 and 116 of the mineral fiber pack 126. The sheet of polymer film 120 is adhered or otherwise attached to the opposed side edges 115 and 116. A lower supply roll 131 dispenses the continuous lower sheet of polymer film 121. The sheet 121 is flat as it is positioned adjacent the lower major surface 114 and is adhered to that surface. At the same time, as shown in Figure 15, the flanges 123 of the upper sheet of polymer film 120 and the mating edges 124 of the lower sheet of polymer film 121 are adhered or otherwise attached. The remaining steps including forming the openings and cutting the mineral fiber insulation assembly 111 to length are similar to those described above, with respect to the Figure 1 embodiment.

Claims: A method of making a mineral fiber insulation assembly (30,93,111) having a mineral fiber core (31,85,94,112) and an outer polymer film (45,72,100,119) covering the core having opposed major surfaces (32,33,84,86,95,96,113,114) and opposed side surfaces (34,35,87,88,97,98,115,116), the method comprising the steps of moving a mineral fiber pack (25,75,104,126) along a predetermined path (28,73,105,127); supplying at least one continuous sheet of polymer film (45,72,101,102,120,121) along the predetermined path and covering the opposed major surfaces and the opposed side surfaces with the polymer film to provide a polymer film-covered mineral fiber core; attaching (42,92) the polymer film to one or both of the side surfaces only of the core; providing a plurality of holes in the polymer film adjacent at least one of the side surfaces of the core; and cutting the mineral fiber core and the polymer film in a direction generally perpendicular to the predetermined path to form individual mineral fiber insulation assemblies. A method according to claim 1, wherein the polymer film covering comprises a single sheet of polymer film (45) having opposed edges (55,56) overlapping on one of the side surfaces (35) of the core, and wherein the overlapping opposed edges are attached to one another. A method according to claim 2, wherein the sheet of polymer film (45) is a "C" folded sheet having first and second legs (46,47), and wherein the "C" folded sheet of polymer film is moved in a direction generally perpendicular to the predetermined path (28), the first and second legs of the "C" folded sheet are inverted and the "C" folded sheet is supplied along the predetermined path so that the mineral fiber pack (25) is received between the first and second legs. A method according to claim 1, wherein the polymer film covering comprises a single sheet of polymer (72) having opposed edges (81,82) overlapping on one of the major surfaces (84) of the core, and wherein the overlapping opposed edges are attached to one another. A method according to claim 1, wherein the polymer covering comprises two sheets of polymer film (101,102,120,121), each sheet having opposed edges, and wherein the two sheets of the polymer film are moved along the predetermined path on opposed surfaces of the core. A method according to claim 5, including overlapping the opposed edges of one of the two sheets of polymer film (101) with the opposed edges of the other of the two sheets of polymer film (102) adjacent the opposed side surfaces (97,98) of the mineral fiber core (94) and attaching the overlapped edges to one another. A method according to claim 5, including positioning one sheet of polymer film (121) adjacent the lower major surface (114) of the mineral fiber core (112) with its free edges (124) in the plane of the lower major surface and extending outwardly from the side surfaces of the mineral fiber core, positioning the second sheet of polymer film (120) adjacent the upper major surface (113) of the mineral fiber core and adjacent the opposed side surfaces (115,116) of the mineral fiber core with its free edges overlying the free edges of the first sheet to form side flanges (123) and attaching the overlying free edges of the sheets of polymer film to one another. A method according to any one of claims 1 to 7, wherein the attaching step comprises placing at least one layer of adhesive (42) between the polymer film and the side surface. A method according to any one of claims 1 to 7, wherein the attaching step comprises heat sealing the polymer film to the side surface. A method according to any one of claims 1 to 9, wherein the plurality of holes is formed by cutting a plurality of slits (60) through the polymer film. A method according to claim 10, wherein the slits are cut with a laser beam.

Inventors: HALL JR HERBERT L, SCOTT JAMES W, HALL, JR., HERBERT L., SCOTT, JAMES W.
Applicants: OWENS CORNING FIBERGLASS CORP, OWENS CORNING
Application year: 1995
Main classification: B29C63
IPC codes: B29C63, B32B37, B32B5, B32B38, B32B7, B32B27