WO2002095111A1

WO2002095111A1 - Vertically lapped material for acoustic applications

Info

Publication number: WO2002095111A1
Application number: PCT/US2002/016065
Authority: WO
Inventors: William C. Attkisson; John K. Fletcher
Original assignee: Lydall, Inc.
Priority date: 2001-05-23
Filing date: 2002-05-23
Publication date: 2002-11-28

Abstract

A vertically lapped material for acoustic applications includes a first layer of material constructed from at least one layer of non-woven textile fibers. The at least one layer of non-woven textile fibers is folded into a plurality of folds to form a pleated structure. A depth of the pleats of the pleated structure determines a thickness of the first layer of material. Furthermore, at least one second layer of material is connected to the at least one first layer of material. A method of assembling a carpet to form a carpet assembly includes the steps of providing the above at least one first layer of material and a heated carpet; inserting the at least one layer in a cold mold adjacent to the heated carpet; and molding the at least one layer with the heated carpet in the cold mold to form the carpet assembly. It is unnecessary for the at least one layer to be preheated or premolded before insertion into the cold mold.

Description

VERTICALLY LAPPED MATERIAL FOR ACOUSTIC APPLICATIONS

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims priority to U.S. Provisional Application No. 60/292,535 filed on May 23, 2001, the entirety of which is hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention:

[0002] The present invention is directed to the use of a vertically lapped material for acoustic applications and acoustic products incorporating a vertically lapped material therein. The present invention is also directed to a method of assembling a molded carpet to a vertically lapped material.

2. Description of Background Art:

[0003] One form of traditional padding is a horizontally lapped material that is usually mechanically bonded by some known processing means. This material is usually referred to as a "shoddy" material and is schematically illustrated in Figure 1 of the present invention. Referring to Figure 1, in order to increase the thickness dimension of shoddy material, it is necessary to stack several finished horizontally laid layers of material 1 onto each other and bond the layers of material together.

[0004] Referring to Figure 2 of the present invention, a rotary method of making a padding material is illustrated. With this construction, the laid fibers are folded over to form a pleated padding material, wherein the location of the folds 2 determine the thickness of the padding material. Examples of a product made by a rotary method are known from U.S. Patents Nos. 4,576,853 and 4,111,733. The above patents are hereby incorporated by reference. The padding material constructed according to the above patents produces a material that would be somewhat between a horizontally lapped material and a vertically lapped material, since the orientation of the laps is not quite vertical.

[0005] The above-mentioned vertically lapped material; however, has more of a true 90° lap when compared with the rotary method of making padding material. A vertically lapped material can be constructed with the use of a machine disclosed in International Publication No. WO 99/61693, and entitled "A DEVICE FOR PERPENDICULAR STRATIFICATION OF PLANARY FIBROUS SHAPES," the entire contents of which are hereby incorporated by reference. A vertically lapped material is illustrated in Figure 3 of the present invention. [0006] Other types of known padding material include conventional non-woven polyester, foam, fiberglass, felt, etc.

SUMMARY OF THE INVENTION [0007] The present invention is directed to the use of a vertically lapped material for acoustic applications and acoustic products incorporating a vertically lapped material therein. The present invention is also directed to a method of assembling a molded carpet to a vertically lapped material.

[0008] According to one aspect of the present invention, a vertically lapped material for acoustic applications, comprises:

[0009] a first layer of material, said first layer of material being constructed from at least one layer of non- woven textile fibers, said at least one layer of non- woven textile fibers being folded into a plurality of folds to form a pleated structure, wherein a depth of the pleats of the pleated structure determines a thickness of said first layer of material; and [0010] at least one second layer of material connected to said at least one first layer of material.

[0011] According to a second aspect of the present invention, a method of assembling a carpet to form a carpet assembly, comprises the steps of:

[0012] providing a first layer of material, said first layer of material being constructed from at least one layer of non-woven textile fibers, said at least one layer of non-woven textile fibers being folded into a plurality of folds to form a pleated structure, wherein a depth of the pleats of the pleated structure determines a thickness of said first layer of material, said at least one layer of non- woven textile fibers including binder fibers therein; [0013] providing a heated carpet;

[0014] inserting said at least one layer in a cold mold adjacent to said heated carpet, said at least one layer not being preheated or premolded before insertion into said cold mold; and [0015] molding said at least one layer with said heated carpet in said cold mold to form the carpet assembly.

[0016] Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:

[0018] Figure 1 is a schematic view of a "shoddy" padding material according to the background art;

[0019] Figure 2 is a schematic view of a padding material made by a rotary method of the background art;

[0020] Figure 3 is a schematic view of a vertically lapped material according to the background art;

[0021] Figure 4 is a cross-section of one embodiment of the product according to the present invention;

[0022] Figure 5 is a cross-section of a second embodiment of the product according to the present invention; and

[0023] Figure 6 is a cross-section of a third embodiment of the product according to the present invention.

DESCRIPTION OF PREFERRED EMBODIMENTS [0024] The present invention, according to a first aspect of the present invention is directed to the use of a vertically lapped material for acoustic applications and an acoustic material incorporating a vertically lapped material therein. The vertically lapped material of the present invention is preferably constructed with the use of the machine disclosed in the above-mentioned International Publication No. WO 99/61693. However, the vertically lapped material can also be constructed according to the above-mentioned '853 and '733 Patents which utilize a rotary method of making a padding material, since many of the advantages over horizontally lapped material can be accomplished by padding material made by the rotary method.

[0025] The vertically lapped material of the present invention is a moldable, lightweight, fiber-based composite that offers an economical solution to automotive noise, vibration, and harshness (NVH) opportunities. The end use for the vertically lapped material in an automotive application is primarily for interior trim and some exterior applications, particularly as a recyclable alternative to urethane, fiberglass, or resin-based trim and insulators.

[0026] The vertically lapped material of the present invention is a padding material which includes a blend of natural or synthetic, organic or inorganic fibers, and binder fibers, typically PET with a low melt temperature PET coating to soften at specified temperatures and to act as a bonding agent in the overall blended structure. However, any low temperature melt fiber or any low temperature melt fiber coating can be used. In addition, the vertically lapped material according to the present invention is constructed in such a way that a continuous folding of the material creates a vertically lapped, corrugated or pleated structure. Furthermore, the thickness, density and fiber mixture of the structure can be varied, depending on the application, to obtain a tailored or engineered product for a particular application.

[0027] The vertically lapped material 3 of the present invention has many advantages over the traditional shoddy material as well. For example, it is possible to obtain a thickness equal to traditional shoddy padding with much less weight, and equal or better firmness and resiliency due to the vertically lapped structure. This is a very important advantage, for example, in the carpet industry, since it is not possible to design the feel of the material by only changing the thickness if using a traditional, horizontally lapped shoddy material. Furthermore, the vertically lapped material itself has an inherently better feel than traditional horizontally lapped material.

[0028] Furthermore, it is possible to create padding up to 40 mm with a single structure. As noted above, traditional shoddy must be stacked to achieve this thickness and must include an additional adhesive layer to hold multiple layers of horizontally lapped material together to accomplish a predetermined thickness. Accordingly, there are environmental advantages to the use of a vertically lapped material due to the lack of adhesive. In addition, there is no adhesive to cause unpleasant odors or fog the inside of the windows of a vehicle as is experienced with carpets that include a traditional shoddy material.

[0029] In addition, the vertically lapped material of the present invention can replace traditional padding materials (shoddy, resonated shoddy, polyester, foam) as a lower cost and/or lower weight option. Furthermore, vertical lapping provides a lower density structure, and therefore performs much better as a decoupler in acoustic applications than traditional horizontally lapped materials.

[0030] The vertically lapped material 3 of the present invention can be constructed of virtually any fiborous media. For example, the fibers may be natural or synthetic, organic or inorganic including but not limited to cotton shoddy, raw or finished cotton fibers, polyester, polyolefin, polyamide, polyaramid, acrylic, cellulosic, ramie, or any other fibrous material. [0031] The vertically lapped material 3 of the present invention may be used alone, or may be combined with sound barriers and/or fabric or foil facing materials, depending upon the application for which the vertically lapped material is used. For example, the facing material could be a functional layer used to maximize the sound absorption and/or transmission loss by adjusting the air flow resistance and weight of the facing material. [0032] In addition, two or more layers of the vertically lapped material of the present invention can be stacked one on top of the other, wherein the two or more layers have difference densities. The two or more layers can be attached to each other with or without an adhesive, since the binder fibers in the two or more layers can be used to adhere the two or more layers to each other. In this manner, a multiple density composite is formed from the two or more layers of vertically lapped material.

[0033] With the above construction, the resulting composite can be designed for maximum sound absorption, sound transmission loss and vibration isolation. Specifically, the higher density layer of vertically lapped material can be selected to maximize the sound absorption and sound transmission loss, while the lower density material can be selected to maximize the vibration isolation.

[0034] It should also be noted that the above-described multiple density composite may be used alone, or may be combined with sound barriers and/or fabric or foil facing materials, depending upon the application for which the multiple density composite is used. [0035] It has also been determined by the inventors of the present invention that formability is inherent in the vertically lapped material according to the present invention. No additional resins or stiffening layers are needed to produce a molded part. The binder fibers within the vertically lapped material serve to hold the part's shape when thermally molded. In traditional processes, it is necessary to impregnate the horizontally lapped material with phenolic resins and/or attach the padding material to a stiffening layer to hold the padding material in the molded shape.

[0036] In addition, the vertically lapped material 3 of the present invention holds its shape very well when attached to a carpet in a standard carpet molding process (heated carpet, cold mold). In this particular situation, the heat from the heated carpet itself provides sufficient heat to activate the binder fibers within the vertically lapped material. In addition, since the weight of the vertically lapped padding material is approximately half of the weight of traditional shoddy material of the same thickness, the material holds the shape of the carpet, once it is attached thereto in the cold mold.

[0037] In view of the above, there is no need for thermal molding of the padding material prior to inserting the padding material into a cold mold with the heated carpet as in the traditional molded padding construction, which requires a hot mold to activate the molding resins in the padding material. Accordingly, the vertically lapped material 3 of the present invention when used with a carpet in an under carpet installation requires less steps than the traditional molded carpet process, since the necessity of pre-molding the padding material or pre-heating of the padding material is eliminated. In addition, the elimination of the above steps reduces the costs associated with the carpet assembly production, since the tools and labor associated therewith is reduced.

[0038] Several examples of the use of the vertically lapped material 3 of the present invention will now be described with reference to Figures 4-6. It should be noted that these examples have only been provided for explanation, and that many other embodiments of the present invention will be readily appreciated to those having ordinary skill in the art. [0039] Referring to Figure 4, an embodiment of the present invention includes the vertically lapped material 3 and a functional adhesive layer 4 for attaching a caφet, facing, sound barrier layer, etc. In particular, the functional adhesive layer 4 can be a web adhesive, a pressure sensitive adhesive, hot melt glue, etc. With this construction, the vertically lapped material 3 of the present invention can be easily incoφorated into a variety of products that traditionally incoφorate the above-mentioned traditional padding materials. [0040] It should be noted that it is not always necessary to include the adhesive layer 4 on the vertically lapped material 3 in some applications, since binder fibers are present within the vertically lapped material 3. As mentioned above, the vertically lapped material 3 of the present invention is inherently formable and therefore, it is unnecessary to preheat the vertically lapped material when used in under caφet installations. In addition to being inherently formable, the binder fibers can also act as or replace the adhesive layer 4, if the vertically lapped material is used in particular applications that require heating of an adjacent layer of material. In this situation, the binder fibers adjacent the heated adjacent layer melt when brought into contact therewith and adhere to the heated adjacent layer after cooling. [0041] Referring to Figure 5, another embodiment of the present invention includes facestocks such as non- woven webs 5 attached thereto. A material of this type would be used in, for example, interior trim insulators or exterior insulators including, but not limited to the moldable non-woven composites for automotive applications disclosed in U.S. Provisional Application No. 60/258,324 which is hereby incoφorated by reference. [0042] It should be noted that the embodiment illustrated in Figure 5 may include one or more layers of material 5 and may include layers of foil, scrims, and/or sound barrier layers in addition to or in place of the non- woven webs, depending on the application. In addition, viscoelastic damping layers or sound barrier enhancing layers can also be included. [0043] Referring to Figure 6, an embodiment of the present invention is illustrated which includes the vertically lapped material 3 as well as a sound barrier layer 6. This embodiment is constructed in accordance with the disclosure of U.S. Patent No. 6,109,389 entitled "ACOUSTIC INSULATING BARRIER AND METHOD OF MAKING THE BARRIER", the entire contents of which are incoφorated by reference. Specifically, the sound barrier layer 6 is attached to the vertically lapped material 3 by needling the material along with a non-woven first layer 8 of needleable textile fibers. The vertically lapped material 3 of the present invention can therefore be used as the non- woven second layer of needleable textile fibers in the '389 Patent. The construction according to Figure 6, as disclosed in the '389 Patent, avoids the necessity of providing adhesive layers to attach the barrier 6 and caφet 7 to the vertically lapped padding material 3 of the present invention, as in the traditional caφet assembly process.

[0044] It should be noted that, although not required, it is also within the scope of the present invention to include an additional layer or layers 10 on the bottom of the embodiment illustrated in Figure 6 in order to provide a tailored or engineered product for a particular application. For example, a viscoelastic damping material can be provided on the side of the vertically lapped material 3 away from the caφet 7. This viscoelastic damping material, such as a bituminous-based layer can provide vibration dampening or vibration isolation. In addition, the surface of the vertically lapped material can be patterned on the side away from the caφet 7 in order to provide an air space between portions of the vertically lapped material 3 and the body panel on which the embodiment of Figure 6 can be positioned adjacent to. The pattern limits vibration transmission to the material 3 by reducing surface contact with the adjacent body panel. In this particular example, the additional layer of layers 10 would not be present. However, if the additional layer or layers 10 are present, the patterning can be provided on the bottom surface of the additional layer or layers 10 adjacent to the vehicle body panel to accomplish a similar effect.

[0045] In addition to the above, it will be readily apparent to those having ordinary skill in the art to include other materials, in place of, or in addition to the above in order to tailor the sound absoφtion, sound transmission loss, vibration dampening, and vibration isolation (decoupling) for a particular application.

[0046] The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.

Claims

WHAT IS CLAIMED IS:

1. A vertically lapped material for acoustic applications, comprising: a first layer of material, said first layer of material being constructed from at least one layer of non-woven textile fibers, said at least one layer of non-woven textile fibers being folded into a plurality of folds to form a pleated structure, wherein a depth of the pleats of the pleated structure determines a thickness of said first layer of material; and at least one second layer of material connected to said at least one first layer of material.

2. The vertically lapped material for acoustic applications according to claim 1, wherein said at least one layer of non- woven textile fibers includes binder fibers therein.

3. The vertically lapped material for acoustic applications according to claim 1, wherein said at least one second layer of material is a sound barrier layer.

4. The vertically lapped material for acoustic applications according to claim 3, wherein said sound barrier layer is needled to said first layer of material with a non-woven layer of needleable textile fibers.

5. The vertically lapped material for acoustic applications according to claim 1, wherein said at least one second layer of material is a fabric cover stock material.

6. The vertically lapped material for acoustic applications according to claim 1, wherein there are a plurality of said first layers of material and at least two of said plurality of said first layers have a different density.

7. A method of using a vertically lapped material for acoustic applications in a vehicle, comprising the steps of: providing a first layer of material, said first layer of material being constructed from at least one layer of non-woven textile fibers, said at least one layer of non-woven textile fibers being folded into a plurality of folds to form a pleated structure, wherein a depth of the pleats of the pleated structure determines a thickness of said first layer of material; and placing said first layer of material adjacent to a body panel of the vehicle.

8. The method according to claim 7, wherein said at least one layer of non-woven textile fibers includes binder fibers therein.

9. The method according to claim 7, further comprising the step of attaching at least one second layer of material to said first layer of material, wherein said at least one second layer of material is a sound barrier layer.

10. The method according to claim 9, further comprising the step of needling said sound barrier layer to said first layer of material with a non- woven layer of needleable textile fibers.

11. The method according to claim 7, further comprising the step of attaching at least one second layer of material to said first layer of material, wherein said at least one second layer is a non- woven cover stock material.

12. The method according to claim 7, further comprising the step of providing a plurality of said first layers of material, wherein at least two of said plurality of said first layers have a different density.

13. A method of assembling a caφet to form a caφet assembly, comprising the steps of: providing a first layer of material, said first layer of material being constructed from at least one layer of non-woven textile fibers, said at least one layer of non-woven textile fibers being folded into a plurality of folds to form a pleated structure, wherein a depth of the pleats of the pleated structure determines a thickness of said first layer of material, said at least one layer of non- woven textile fibers including binder fibers therein; providing a heated caφet; inserting said at least one layer in a cold mold adjacent to said heated caφet, said at least one layer not being preheated or premolded before insertion into said cold mold; and molding said at least one layer with said heated caφet in said cold mold to form the caφet assembly.