WO2001094108A2

WO2001094108A2 - Flexible hanger strap composite

Info

Publication number: WO2001094108A2
Application number: PCT/US2001/017708
Authority: WO
Inventors: Matthew G. Weir; M. David Moore, Iii; W. Randolph Hursey; J. Richard Sheppard; Eric J. Knauss; Philbrick Allen
Original assignee: Milliken & Company
Priority date: 2000-06-07
Filing date: 2001-06-01
Publication date: 2001-12-13
Also published as: WO2001094108A3; AU2001266646A1

Abstract

A flexible composite fabric is a triple layer material for hanging ductwork, plumbing, and the like, wherein a layer of scrim material (4) is sandwiched between a layer of non-woven material (6) and a layer of metallized film (8). In a preferred embodiment, a tri-directional polyester scrim fabric is attached to a carded web polyester non-woven fabric using a thin layer of polyvinyl alcohol adhesive (10). On an opposite side of the scrim, an aluminized, 48 gauge polyester film is attached using a thermoplastic resin (12). The aluminized film imparts some additional strength to the composite, and provides a pleasing aesthetic feature, as the composite appears in a shiny, metallic color. The composite material has the visual appearance of aluminum film similar to that of ductwork, while maintaining the feel of a textile. Further, the tensile strength of the material should be strong enough to support the weight of the ductwork, plumbing structures, or the like, but the material should also be easy for a user to tear or break without using a cutting implement, such as scissors or a knife. An alternate embodiment includes a double-layered scrim and metallic film composite.

Description

FLEXIBLE HANGER STRAP COMPOSITE

Background of the Invention

1. Field of the Invention This invention is directed to a flexible composite material used for hanging ductwork, plumbing structures, and the like. Specifically, the present apparatus includes a triple layer composite fabric wherein a layer of scrim material is sandwiched between a layer of non-woven material and a layer of metallized film. The flexible hanger strap composite material is strong, lightweight, and inexpensive to manufacture. The metallized film allows the strap material to blend in with the surrounding metal ductwork structures, providing a pleasing aesthetic quality. The strap material may be fastened to the superstructure of a building by mechanical means such as staples, nails, or the like. In a preferred embodiment, the material is cut into strips and rolled into rolls, similarly to duct tape, for commercial use. In an alternate embodiment, a two layered composite is formed from the scrim structure and the metallic film layer.

2. Description of the Prior Art

All patents mentioned below are incorporated herein by reference in their entirety.

U.S. Patent number 1 ,804,472, issued to Leslie, discloses a metal pipe hanger strip having perforations and slots for engagement with buckles and clasps.

U.S. Patent number 5,964,434, issued to Lynch, Jr., teaches a fireproof cable loop forming strap of substantial width having pockets at each end and one intermediate pocket to receive front and rear spreader bars which project beyond the lateral edges of the strap. The projecting ends of the bars are configured to be received in hook tabs projecting from the face of a hanger plate or yoke. The rear spreader bar inter its with the plate or yoke and is preassembled therewith so it cannot be removed. The fireproof strap may be formed of fireproof cloth and has folded and sewn lateral edges in addition to the pockets. The hanger plate or yoke may be mounted directly to a variety of structures or surfaces. With an angle flange and intermediate fasteners the hanger may be secured to a wide variety of structures for cable support.

U.S. Patent number 4,318,518, issued to Davis, discloses an insulated hanger strap, designed to support ductwork, pipes, and the like. A flexible sheet metal strip is provided with holes through which fasteners may be inserted and be secured to a supporting structure. An elastomeric strip completely covers one side of the sheet metal strip, and has flanges formed on its longitudinal edges which cover the edges of the associated sheet metal strip. Channels are formed in the flanges of the electronic strip to receive the respective metal strip edges, thus maintaining the metal strip and the elastomeric strip in attached relationship.

U.S. Patent number 4,170,675, issued to Greengrass, is directed to a fire- retardant sheet comprising superposed layers including a plastic material with a metal foil on one side and a further plastic sheet or layer laminated thereto with the interposition of a wire mesh. This material is used for building construction insulation.

U.S. Patent number 5,001 , 003, issued to Mahr, discloses a laminated sail cloth including a central layer of spaced intersecting scrim yarns which intersect at acute angles in such a manner to reinforce the fabric along the fill and bias directions of the fabric. The outer layers are described as being either film or cloth.

Scrim reinforced fabrics and films are disclosed for various uses in the following U.S. Patents: Patent Number Inventor

3,573,151 Dawbarn

3,629,047 Davison

3,791 ,911 Yaeger, et al.

5,283,111 Schlecker These patents teach the use of various scrim reinforced fabrics or films for such purposes as disposable garments and bed linens ("047 patent), insulation for livestock containment facilities ('111 patent), tarpaulins, covers for crops, moisture barriers, and canopies ('151 patent). None of the prior art, however, teaches a flexible duct hanging composite material having a scrim layer sandwiched between a non-woven layer and a metallized film layer, which is a strong, lightweight alternative to prior duct hanging devices.

Objects of the Invention Accordingly, it is an important object of the present invention to provide flexible hanger strap composite fabric that is lightweight and strong enough to support ductwork in a building.

Another important object of the present invention is to provide duct hanging strap material that has enough tensile strength to support ductwork, plumbing, and the like, but which also allows a user to break or tear the material easily by hand, without having to use a knife, scissors, or other cutting tool.

Yet another important object of the present invention is to provide material that has a metallized film, which imparts an aesthetically pleasing color and contrast with the supported ductwork or plumbing. Still another important object of the present invention is to provide a material that may be easily attached to a structure using mechanical means, such as nails, tacks, staples or the like.

Another important object of the present invention is to provide a novel flexible hanger strap composite fabric and structure that is inexpensive to manufacture and that overcomes some of the problems associated with traditional duct hanger structures and materials.

Brief Description of the Drawings These and other features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings where: Figure 1 is a cross-sectional view of the flexible composite material, showing a layer of scrim having a non-woven layer attached to a top side, and having a metallized film attached to a bottom side;

Figure 2 is an exploded perspective view of the three layered composite material in accordance with the present invention; and

Figure 3 is an exploded perspective view of a two layered embodiment of the composite material in accordance with the present invention.

Detailed Description Referring now to FIGS. 1 and 2, the composite fabric 2 of the present invention is a triple layer fabric for hanging ductwork, plumbing, and the like, wherein a layer of scrim material 4 is sandwiched between a layer of non-woven material 6 and a layer of metallized film 8. In a preferred embodiment, a tri- directional polyester scrim fabric 4 is attached to a carded web polyester non- woven fabric 6 using a thin layer of polyvinyl alcohol adhesive 10, although any suitable adhesive may be used. On an opposite side of the scrim 4, an aluminized, 48 gauge polyester film 8 is attached using a thermoplastic resin 12. The aluminized film imparts some additional strength to the composite, and provides a pleasing aesthetic feature, as the composite appears in a shiny, metallic color. In a broader sense, the term "scrim" as used herein means not only laid scrim, which is typically adhesively bound, but also either a woven or knitted structure.

The composite material has the visual appearance of aluminum film similar to that of ductwork, while maintaining the feel of a textile. Further, the tensile strength of the material should be strong enough to support the weight of the ductwork, plumbing structures, or the like, but the material should also be easy for a user to tear or break without using a cutting implement, such as scissors or a knife. In a preferred embodiment, the tensile strength of the composite material is in the range of 60 - 67 pounds at peak load in a warp (longitudinal) direction, and between the range of 60 - 80 pounds at peak load in a fill (transverse) direction. Table 1 shows results of tensile strength tests, performed in accordance with ASTM Strip Tensile Strength Test Method D 5035 on composite material manufactured in accordance with the preferred embodiment of the present invention. The test samples were 2 inches by 6 inches, and the jaws used measured 2 inches long by 3 inches wide.

Table 1

It is known to provide a scrim material having a layer of non-woven webbing adhered to both sides thereof, for hanging ductwork. By way of comparison, the same tensile strength test was run on such a product, which is considered to be the closest prior. The comparative material comprises a tri- directional scrim material sandwiched between two layers of polyester non- woven mats (the same non-woven mat material that is present on the composite tested in Table 1), which is held together with polyvinylchloride (PVC) adhesive. The test samples in this test were also 2 inches by 6 inches, and the jaws of the testing machine again measured 2 inches long by 3 inches wide. The results of this test, also performed in accordance with ASTM Strip Tensile Test Method D 5035, are set forth in Table 2 below.

Table 2

It can be seen from Tables 1 and 2 that the composite material of the present invention (Table 1 ) has a significantly higher tensile strength in the warp direction than the prior art (Table 2), thus providing more strength and support for ductwork, pipes, and the like. Further, the tensile strength of the present composite is still low enough so that a worker may snap or tear a strip of the composite material without using undue force, and without using cutting tools such as scissors or a knife. It should also be noted that the stretch factor in the warp direction, measured as the elongation percentage at the peak load is only slightly higher on the novel composite when compared to the double non-woven material of Table 2. Thus, in the warp direction, the present composite material is substantially stronger, and only slightly more stretchable, than the prior art. The scrim material may be made from fiberglass, nylon, or any other suitable material. Further, the preferred adhesives have been described above, but it is to be understood that any suitable adhesives may be used. The preferred thermoplastic resin is Surlyn 1652-1 lonomer resin, commercially available from DuPont, because it adheres well to metals, and maintains a high level of adhesion at high temperatures. Other alternative adhesive agents include: ethylene methylacrylate, ethylene vinylacetate, acid copolymers of polyethylene, or any other suitable thermoplastic resin adhesives. The non- woven material may be constructed from nylon, aramid, olefin, fiberglass, or any other suitable material.

In the manufacturing process, generally the scrim layer and the non- woven fabric layer are adhered together in a first step, using a polyvinyl alcohol adhesive either in a dip and calendering process or a roll coating process. In a second step of a preferred method, the metallized polyester film is extrusion coated to an opposite side of the scrim material, using the thermoplastic resin as an adhesive. Any other method of attaching the metallized polyester film to the scrim material may be used, including hot melt coating, roll coating, spray coating, or any other suitable method. Although aluminum is disclosed as the preferred metal for metallizing the film, any suitable metal is acceptable. The composite material is typically manufactured in sheets, and then slit into strips that may be rolled up for commercial use and sold, similarly to duct tape. In use, a strip of the material is attached to the superstructure of a building on one end by mechanical means, such as staples, nails, tacks, or the like. The material is then positioned beneath a duct or pipe, or other similar structure that needs support. Then, the strip is torn or broken at an appropriate length, and the other end of the strip is attached to another portion of the superstructure. Preferably, the metallized film side of the material is facing outwardly, away from the ductwork or pipe structure, so that the shiny metal color is showing adjacent the supported structure. An optional step in the manufacturing process is to use a mild adhesive or tackifying agent as a coating on one side of the composite material. This tackifier is used only to keep the material in a roll, and to prevent premature unraveling of the roll. The tackifier is not used as an adhesive for attaching the strip to any other surface. The aluminized composite is particularly well suited for receiving such a tackifying agent. In an alternate embodiment (shown in FIG. 3), the scrim 4 is adhered to the metallized film layer 8 using a thermoplastic resin adhesive, without the non- woven layer. This two layered embodiment may be manufactured at less cost than the three layered embodiment, due to the lack of required materials (non- woven material and polyvinyl alcohol or other adhesive) and a one-step manufacturing process (extrusion or other single-step attachment method).

Further, instead of adding a tackifying agent to this double-layered embodiment, the composite material may be heated just prior to or during the rolling process, which causes the thermoplastic resin adhesive to become slightly tacky. This arrangement prevents the necessity of using a separate tackifying agent, and saves time and reduces cost.

Although the present invention has been described in considerable detail with reference to certain preferred versions thereof, other versions are possible. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred versions contained herein.

Claims

ClaimsWhat is claimed is:

1. A flexible, composite fabric for hanging ductwork, plumbing structures and the like from the superstructure of a building, said fabric comprising: a first layer of non-woven fabric; a second layer of scrim material attached to said first layer; and a third layer of metallized film attached to said second layer.

2. The composite fabric set forth in claim 1 , wherein said non-woven fabric comprises polyester.

3. The composite fabric set forth in claim 1 , wherein said scrim material comprises polyester.

4. The composite fabric set forth in claim 1 , wherein said metallized film includes polyester.

5. The composite fabric set forth in claim 1 , wherein said metallized film includes aluminum.

6. The composite fabric set forth in claim 1 , wherein said first layer and said second layer are held together by a polyvinyl alcohol adhesive.

7. The composite fabric set forth in claim 1 , wherein said second and third layer are held together by a thermoplastic resin.

8. The composite fabric set forth in claim 7, wherein said thermoplastic resin is an ionomer resin.

9. The composite fabric set forth in claim 1 , wherein said scrim comprises a tri-directional scrim.

10. A flexible, composite fabric for hanging ductwork, plumbing structures and the like from the superstructure of a building, said fabric comprising: a first layer of scrim material; and a second layer of metallized film attached to said scrim material.

11. The composite fabric set forth in claim 10, wherein said scrim material comprises polyester.

12. The composite fabric set forth in claim 10, wherein said metallized film includes polyester.

13. The composite fabric set forth in claim 10, wherein said metallized film includes aluminum.

14. The composite fabric set forth in claim 10, wherein said first and second layer are held together by a thermoplastic resin.

15. The composite fabric set forth in claim 14, wherein said thermoplastic resin is an ionomer resin.

16. The composite fabric set forth in claim 10, wherein said scrim comprises a tri-directional scrim.

17. A composite textile material for hanging ductwork, pipes and the like from a superstructure such as a building, said composite having at least two layers, including a scrim layer and a metallized film layer, and also having a tensile strength in a warp direction of at least 45 pounds at peak load under ASTM Strip Tensile Test Method D 5035.

18. The composite textile material set forth in claim 17, further including a non-woven layer attached to said scrim layer.

19. The composite textile material set forth in claim 17, wherein said tensile strength in said warp direction is at least 55 pounds at peak load under ASTM Strip Tensile Test Method D 5035.

20. The composite textile material set forth in claim 17, wherein said tensile strength in said warp direction is at least 60 pounds at peak load under ASTM Strip Tensile Test Method D 5035.