Method of making an insulation assembly

Abstract: An insulation assembly and method of making is disclosed. A fiber pack is engaged along its side edges to tuck the fibers inwardly and also establish a desired width. The insulation assembly has the longitudinally extending tucks along each of its side edges and each of the side edges has a generally concave cross section.

Description: Insulation assemblies including mineral fibers and, more particularly, fibrous glass insulation assemblies are known in the art. Fibrous insulation assemblies are used for insulating buildings. The insulation assemblies take the form of batts or rolls which are compressed for packaging and transport. Many prior art insulation assemblies are sized along their side edges by slicing or cutting the side edges to the desired shape and width. The present invention is directed to a method for making an insulation assembly which does not involve shaping along its side edges by cutting. In this context, note should be made of US 5,277,955 which describes an insulation assembly which includes a binderless fibrous batt and a polyethylene over layer. Also, FR 2686392 describes a thermally insulating shaped body comprising an envelope which can be evacuated filled with solid microporous thermally insulating material, at least one end face of the envelope being of poorly conducting material. Further, US 5,090,981 describes the manufacture of insulation panels by collecting a veil of fiberized glass including silica powder on a conveyor to form a pack, passing the pack through a pressing station to form a board of desired density, chopping the board into panels, encapsulating the panels and evacuating the encapsulation envelope. The present invention now provides a method of making an insulation assembly having a fibrous body with opposed side edges comprising the steps of: placing a plurality of fibers on a path to form a pack , moving the fibers along the path, and cutting the formed pack to a predetermined length, characterized by engaging the side edges of the pack to tuck the fibers inwardly and to establish the desired pack width. The method of the 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 making of an insulation assembly, according to the present invention; Figure 2 is a plan view of the equipment shown in Figure 1; Figure 3 is a cross-sectional view, taken along the line 3-3 of Figure 2; Figure 4 is a cross-sectional view, taken along the line 4-4 of Figure 2; Figure 5 is a cross-sectional view, taken along the line 5-5 of Figure 2; Figure 6 is a diagrammatic view showing a plastic layer being applied to the formed insulation pack; Figure 7 is a cross-sectional view, shown on an enlarged scale, taken along the line 7-7 of Figure 6; and Figure 8 is a perspective view of an insulation assembly made according to the present invention. An insulation assembly made according to the present invention, is generally indicated by the reference number 10 in Figure 8. Preferably, the insulation assembly is constructed from glass fibers. Other types of mineral fibers may also be utilized. The fibrous glass insulation assembly 10 includes a fibrous glass body 11 having a top surface 12, an opposed bottom surface 13, opposed side edges 14 and 15 and opposed ends 16 and 17. In the embodiment shown in Figure 8, the insulation assembly 10 includes an outer plastic layer 18. The layer 18 covers the top surface 12, the bottom surface 13 and the opposed side edges 14 and 15. In the present embodiment, the ends 16 and 17 remain open. In other embodiments, not shown, the ends are also covered by the plastic layer 18. Preferably, the outer plastic layer 18 is constructed from a polyethylene film having a thickness of 25.4µm (1.0 mil) or less. The outer layer 18 can also be constructed from, for example polybutylene film, metalized film, Kraft paper or from non-woven materials. The outer layer 18 can also be constructed from combinations of materials. Preferably, the glass fiber body 11 is constructed of a low density fibrous glass wool having a density of less than 24 kg/m 3 (1.5 pounds per cubic foot). Referring now to Figure 1, glass fibers are manufactured by using a rotary process. Glass from a glass furnace 22 enters rotary spinners 23 where the glass is attenuated into veils of relatively long glass fibers 24. In other embodiments, the fibers can be other types of mineral fibers made from a process other than a rotary process. Preferably, the glass fibers 24 are of varying lengths. While a normal length range for fibers produced by the rotary process is between 51mm (2 inches) and 254 mm (10 inches), it is not unusual to have lengths of glass fibers over 457 mm (18 inche) long. In fact, lengths as high as 914 mm (36 inches) are not uncommon. The glass fibers 24 are deposited on a generally horizontal path 26 defined by the upper surface of a conveyor 27. The fibers 24 form a glass fiber pack 28 as it moves along the path 26. Referring to Figures 2 and 3, an important feature of the method of the present invention is illustrated. A pair of shaping rollers 30 are positioned adjacent the side edges 31 of the pack 28. The shaping rolls 30 engage the side edges 31 and form a crease or tuck in the opposed side edges 31. In addition to the creasing, the shaping rolls 30 move the side edges 31 inwardly to form the desired width of the pack. In the prior art, width control normally included cutting a pack to a desired width. The pack then passes between a pair of shaping conveyors 34 and 35 to establish the correct height of the pack 28. A knife 37 which is perpendicular to the path 26 cuts the glass fiber pack 28 to a predetermined length to form the glass fiber body 11 of the insulation assembly 10. Referring to Figure 5, the body 11 of the insulation assembly 10 has the longitudinal tucks or creases in its opposed side edges 14 and 15 and the side edges 14 and 15 preferably have a concave cross section. The tucks or creases are positioned in the center of the side edges 14 and 15 and extend longitudinally throughout the length of the glass fiber body 11. When the assembly 10 is complete it is normally compressed for shipping to a distributor or to a job site. When the compressed assembly 10 is unrolled or uncompressed it recovers its thickness. It is not unusual to have a recovery rate of six to one. The uncompressed thickness being six times the compressed thickness. When using the method of the present invention, it has been found that the recovery rate is increased normally five percent or more. This is important because the increased recovery rate means an increased insulation valve. The present method also results in an insulation assembly 10 which when uncompressed has a generally rectangular cross section. In some prior art methods, the insulation assembly had a generally oval cross section when uncompressed as opposed to the desired rectangular cross section. Figure 7 shows another embodiment of the present invention where the fibrous glass body 11 includes the outer plastic layer 18. In this embodiment, the crease or tuck in the side edges carries the outer plastic layer 18 inwardly forming flanges 39, as shown in Figure 7. In making the Figure 7 embodiment, the glass fiber pack 28 is redirected downwardly through a shoe 41. A roll of plastic film 42 dispenses the plastic layer 18 through the shoe to encapsulate the formed glass fiber pack 28. Downstream from the shoe 41 a pair of opposed shaping rolls 44 engage the side edges 31 to form longitudinal creases or tucks. During the creasing of the side edges, the outer plastic layer 18 is tucked inwardly to form the opposed flanges 39, shown in Figure 7. Again, the shaping rolls 44 establish the correct width of the insulation assembly.

Claims: A method of making an insulation assembly (10) having a fibrous body (11) with opposed side edges (14,15) comprising the steps of: placing a plurality of fibers (24) on a path (26) to form a pack (28), moving the fibers along the path, and cutting the formed pack to a predetermined length (11), characterized by engaging the side edges (14,15) of the pack (28) to tuck the fibers inwardly and to establish the desired pack width. A method according to claim 1, wherein the opposed side edges are engaged to form a central longitudinal tuck along each of the side edges. A method according to claim 1 or claim 2, including forming a concave surface on each side edge. A method according to any one of claims 1 to 3, including placing a plastics layer (18) over the pack. A method according to claim 4, including tucking the plastics layer (18) inwardly along each of the opposed side edges.

Inventors: GRANT LARRY J, MONNIN RAYMOND V, SCOTT JAMES W, GRANT, LARRY J., MONNIN, RAYMOND V., SCOTT, JAMES W.
Applicants: OWENS CORNING FIBERGLASS CORP, OWENS CORNING
Application year: 1995
Main classification: D04H1
IPC codes: F16L59, B32B27, D04H1, B32B3