Thermal and acoustical insulating shield
Inactive Publication Date: 2006-09-05
LYDALL INC
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Benefits of technology
[0030]As a subsidiary discovery, it was found that the same adhesive used for adhering the protective foil to the tufted lower surface of the fibrous batt insulating material can be used on the edge upper surfaces of the edge portions as, simply, a continuation of that adhesive. This makes the application of the adhesive to the edge upper surfaces very convenient.
[0033]In the present improvement, the protective foil has edge portions which extend beyond edges of the fibrous batt. Those edge portions have a flexible adhesive disposed and adhered substantially over edge upper surfaces of the edge portions. Thus, the shield may be flexed and pressed to configure and permanently attach the tufted upper surface to an object to be shielded and the edge portions may be pressed to permanently attach the edge upper surfaces of the edge portions to an object to be shielded so as to self-seal the edge portions, and hence the shield, to that object.
[0036]Further, there is provided a method for applying that shield to an object to be thermally and acoustically protected. In that method, the adhesive on the tufted upper surface and on the edge upper surfaces is exposed, e.g. by removing a strippable foil therefrom. The fibrous batt is then pressed at the protective foil to configure the shield to contours of the object to be shielded and causing the adhesive on the tufted upper surface to permanently adhere to the contours and pressing the edge portions against the object to permanently seal the edge portions, and hence the shield, to the object and, thus, provide a self-sealing shield.
Problems solved by technology
Such sheet metal shields, however, have low acoustical insulating value, and a large portion of noise produced in an adjacent portion of an exhaust system can be transmitted through the floor pan of the automobile and into the passenger compartment.
Additional noise can be produced by loose shields which vibrate and / or rattle.
Where substantial acoustical shielding is also required, metal shields, as described above, are not satisfactory.
However, such insulation can only be used where there are insignificant forces, both static and dynamic, on the fibrous insulation, since batts of fiberglass, for example, have very little strength in any direction, i.e. in either the X, Y or Z directions.
A very particular problem in regard to such shields has been encountered by the automobile industry and like industries, and that problem has become acute in recent years.
However, with modern designs, the spacing between the exhaust system and the tunnel is now very much reduced, and in many situations, it is now no longer practical to suspend shields between the exhaust and tunnel, and, moreover, the reduced spacing correspondingly reduces any air gap remaining between the shield and the tunnel, such that very little conductive and convective heat insulation or acoustical insulation results.
The problem with such insulation is that the batts, especially of such inorganic fibers, are usually made by air laying fibers onto a moving belt, and, hence, the fibers tend to stratify in non-discrete layers throughout the thickness (Z direction) of the batts.
However, because of the needling technique used in that process, the needle punch density could not be greater than about 260 needle punches per square inch, since, at above about 260 needle punches per square inch, glass fiber damage resulted and with a more than 25% loss of mat strength.
While such an approach certainly improved Z-directional strength, with such low numbers of needle punches, the Z-directional strength of such a composite is still quite low and unacceptable for most modern thermal / acoustical insulating applications where substantial static and dynamic forces are placed on the insulation, e.g. in suspended use with an automobile, as discussed above.
However, shrinking fibers is not only a difficult process, but is substantially uncontrollable, and this approach does not result in uniform products.
Moreover, the tensile strengths, and particularly the Z-direction tensile strengths, are not greatly improved by that process.
While this approach is a very decided advance in the art, it still encounters difficulties when such batts experience high static and dynamic loadings, such as in the case of an automobile with a suspended shield, as described above.
However, the use of a synthetic resin to achieve formability of such a shield is a decided disadvantage, since it is quite expensive to use a binder, and, moreover, the shield must be molded with conventional tools and dies, which themselves are quite expensive.
All of this is expensive and time consuming in assembly of the automobile and does not solve the problem or severely limited space in modern designs, as noted above.
However, with the combination of the protective foil, particularly when that foil is a radiation barrier foil, and the composite batt, high thermal insulation and high acoustical insulation results.
As can be appreciated, this results in a more expensive insulating shield, and in that sense, the arrangement for enclosing the insulating material is not as desired.
Method used
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[0100]A first web of 3 denier, 3 inches staple length polyester fibers was carded onto a moving conveyor belt with the web having a weight of about 2 ounces per square yard. A preformed glass fiber batt (Owens Corning SR-26 range glass) 1 inch thick and 1 lb. / cu. ft. density was unrolled onto the moving conveyor and placed on top of the carded web of polyester fibers. A second web of polyester fibers, which was the same as the first web, was carded onto the moving conveyor and on top to the glass fiber batt, so as to form a sandwich of the glass fiber batt between the two carded polyester fiber webs.
[0101]The sandwich was passed from the conveyor to a conventional double-acting needle loom (Shoou Shyng Model SDP250112-2) fitted with conventional needles (Groz Beckert 15-18-36-3, style F 333). The sandwich was needled in the double-acting loom with needle punches of approximately 800 needle punches per square inch, with needle penetrations such that the barbs of the needles extended ...
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Abstract
A flexible, adhesively attachable, self-sealing, thermal and acoustical insulating shield has a needled, flexible, fibrous batt having an insulating layer of insulating fibers disposed between opposite binding layers of binding fibers. Binding fibers of each binding layer are needledly disposed through the insulating layer and an opposite binding layer to provide tufts of binding fibers protruding from the opposite binding layer so a to form a tufted upper surface and a tufted lower surface of the batt. A flexible adhesive is disposed and adhered substantially over the upper surface and, preferably, over lower surface of the batt such that the tufts on the upper and lower surfaces are secured to the surfaces by the adhesive. A flexible, protective foil is adjacent to, and preferably permanently adhered by the adhesive to, the lower surface of the batt. The protective foil has edge portions which extend beyond edges of the fibrous batt and the edge portions have a flexible adhesive disposed and adhered substantially over upper edge surfaces of the edge portions. The shield may be flexed and pressed to configure and permanently attach the tufted upper surface to an object to be shielded and the edge portions may be pressed to permanently attach the edge upper surfaces of the edge portions to the object so as to self-seal the edge portions to the object.
Description
[0001]This application is a Continuation-In-Part of U.S. patent application Ser. No. 09 / 033,852, filed on Mar. 3, 1998, now U.S. Pat. No. 6,092,622, the entirety of which is hereby incorporated by reference. The present invention relates to an improved thermal and acoustical insulating shield and more particularly to such shield which is adhesively attached to an object to be protected. The present invention, more specifically, is an improvement of the invention disclosed in U.S. patent application Ser. No. 09 / 033,852 <?delete-start id="DEL-S-00001" date="20060905" ?>, filed on Mar. 3, 1998, the disclosure of which is incorporated herein by reference .BACKGROUND OF THE INVENTION[0002]Thermal and acoustical insulating shields, to which the present invention is an improvement, have long been known in the art. Such shields are used in a wide variety of applications, among which are shielding in space crafts, automobiles, home appliances, electronic components, industrial engines...
Claims
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Login to View More IPC IPC(8): E04B2/02B32B5/06B32B5/26E04B1/82G10K11/16
CPCB32B3/02B32B15/14B32B27/12B60R13/0815D04H1/46D04H11/08G10K11/16D04H1/498Y10T442/667
InventorBYRD, TIMOTHY L.HIERS, JOHN J.
OwnerLYDALL INC