Nonwoven panel and method of construction thereof

(54) Title: METHOD FOR BUILDING MATERIAL (57) Abstract: NON-WOVEN SHEET, UNTECTED VEHICLE PANEL, METHOD TO PROVIDE QUANTITATIVE ACOUSTIC DAMPING PROPERTY IN AN ACOUSTIC PANEL,

STRUCTURAL NON-WOVEN PRODUCT, METHOD FOR MANUFACTURING A RECOVERED CARDBOARD VEHICLE COMPONENT (30) Unionist Priority: 10/01/2007 us 60/884368,

11/01/2007 US 60/884534 (73) Holder (s): federal-mogul powertrain, inc.

(72) Inventor (s): Christopher A. Foy, David Briggs, Eric K. Staud, Harry F. Gladfelter (74) Attorney (s): Momsen, Leonardos & Cia.

(86) International Order: pct US2008050698 of 10/01/2008 (87) International Publication: wo 2008 / 086458de 17/07/2008 “METHOD FOR BUILDING A UNDERVED SHEET MATERIAL, NON-WOVEN VEHICLE PANEL, METHOD FOR PROVIDING PROPERTIES QUANTITATIVE ACOUSTIC DAMPING SYSTEMS IN AN ACOUSTIC PANEL, STRUCTURAL UNTECTED PRODUCT, METHOD FOR MANUFACTURING A RECOVERED CARDBOARD VEHICLE COMPONENT ”

REFERENCE TO RELATED REQUESTS

This order claims the benefit of US Provisional Order Serial No. 60 / 884,368, filed on January 10, 2007, and US Provisional Order Serial No. 60 / 884,534, filed on January 11, 2007, which are incorporated here by reference in its entirety. BACKGROUND OF THE INVENTION

1. Technical Field

This invention relates generally to non-woven panels and methods for their construction and, more particularly, to acoustic, thermal and / or structural panels, constructed at least partially from constituents of residual material, ordinarily not suitable for reprocessing, more particularly, a mix including Asian cardboard.

2. Related Technique

In order to reduce the costs associated with the manufacture of fabrics and non-woven materials and to minimize potentially negative effects on the environment, many consumer products are built using recycled constituents. For example, automobile manufacturers in the United States use recycled materials to build fabrics and non-woven materials, having various uses, including sound-absorbing and / or insulating materials. Some recovered or recycled materials used to build sound-absorbing vehicle panels include inferior fabric, such as, for example, cotton, polyester, nylon or recycled fabric fiber mixes. Lower quality cotton is made from scraps of virgin or recycled fabric, which are combined and sewn together to form a non-woven cloth. Another product made from recycled standard paper or cardboard fibers, used on a limited basis to absorb oils, is Ecco paper. In the process of making Ecco paper, the standard cardboard fibers are completely broken using conventional wet recycling techniques, in which the binder ingredients that make up the recycled cardboard are blasted in a dump stream and the remaining fibers are combined with various additives.

Commercial establishments and consumer product manufacturers, for example, manufacturers of automotive component parts and original equipment, receive numerous shipments from various Asian countries, such as China and Korea, in boxes or containers constructed of low-grade “Asian cardboard”. Asian cardboard has very short and very thin fiber constituents, from previously recycled pine cardboard, as well as bamboo and rice fibers. As such, attempts to recycle Asian cardboard into paper, cardboard or other structural panel products have failed through the paper mill process, with the very thin constituents of Asian cardboard being already connected through the screens or mesh used to transport pulp in the paper / cardboard manufacturing process into an environment, via the resulting waste stream from the recycling process. Therefore, Asian cardboard is typically considered to be scrap and thus is selected from standard cardboard at relatively high labor cost and sent to landfills (during selection, Asian cardboard is readily identifiable from standard cardboard due to its relatively fragile structure and its pale brown or greenish color) or the entire bale is thinned if there is more than 5% Asian cardboard mixed in a recycled cardboard bale, also at a relatively high cost for both the product manufacturer and the environment.

SUMMARY OF THE INVENTION

According to one aspect of the invention, a method is provided for building a post-consumer mixed Asian non-woven sheet material (with at least 5% to 100% Asian cardboard), wherein the constructed sheet material is useful for forming structural and / or acoustic and / or thermal panels. The method includes providing post-consumer mixed Asian cardboard and cutting the cardboard into pieces of a predetermined size. In addition, combining the reduced size cardboard pieces with heat-bonding textile fibers, to form a substantially homogeneous mixture, and then forming a continuous sheet of the mixture, with the continuous sheet having a predetermined thickness, in a dry process of formation of non-woven web. Then heat the web to bond the heat-bondable material with the reduced size pieces of mixed Asian cardboard to form the non-woven sheet.

In accordance with another aspect of the invention, a method is provided for providing predetermined quantitative acoustic absorption properties in a non-woven acoustic panel. The method includes comminuting cardboard material into cardboard fragments or “dots”; provide fragments of polymeric material (e.g. recycled polypropylene rags) and form a continuous sheet by mixing the cardboard fragments with the fragments of polymeric material in a non-woven continuous sheet forming process. In addition, the method includes controlling the size of the cardboard fragments being mixed on the web and the weight percentage of the cardboard fragments being mixed on the web. Then heat the continuous sheet and make the polymeric fragment bond with the cardboard fragments.

According to yet another aspect of the invention, a structural nonwoven product is provided. The structural non-woven product includes more heat-bondable textile material and comminuted cardboard material. The cardboard material is bonded with the heat-bondable textile material to form the non-woven structural product.

In accordance with yet another aspect of the invention, a method for manufacturing a vehicle component is provided. The method includes receiving a shipment of goods in cardboard containers and recovering at least part of the cardboard containers. Then, reduce the recovered cardboard containers by grinding or shredding the recovered cardboard containers in a dry fibrous state and combining the reduced recovered cardboard with a binder material. Then, form the combined reduced recovered cardboard and binder material to form the vehicle component.

Therefore, the invention here overcomes the limitations examined above, providing non-woven panels, such as those suitable for use in acoustic, thermal or structural applications and methods for their construction by recycling selected types of cardboard materials and using them in combination with bondable textile materials by heat, to create acoustic, thermal or otherwise non-woven structural panels, which can be used in a variety of applications, such as in automobiles.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects, characteristics and advantages of the present invention will be readily appreciated when considered in connection with the following detailed description of the presently preferred embodiments and the best way, attached claims and accompanying drawings, in which:

Figure 1 is a perspective view of a nonwoven panel, constructed in accordance with a presently preferred aspect of the invention;

Figures 2A and 2B are seen in enlarged cross section of the non-woven panel of Figure 1, showing different percentages by weight of the panel constituents;

Figure 3 is a flow chart of the process, illustrating a method for building a nonwoven material according to an aspect of the invention; and

Figure 4-8 are graphs illustrating sound-absorbing characteristics of a non-woven material, constructed in accordance with the present invention.

DETAILED DESCRIPTION OF METHODS

PRESENTLY PREFERRED

With more detailed reference to the drawings, Figure 1 illustrates a structural member or panel 10, constructed in accordance with an aspect of the invention. The panel can be configured for use in any number of applications, such as for an automotive vehicle component, for example. The panel 10, with the exception of being able to provide a moldable structural member, can be manufactured with noise-damping or attenuating properties, thus functioning as an acoustic panel. Furthermore, the panel 10 can be constructed having fire retardant properties, if intended for use in a high temperature environment, such as near an exhaust system or inside a vehicle engine compartment, for example. Panel 10 is constructed of mixed Asian cardboard, filler fibers and bicomponent fibers, with the processed cardboard materials being bonded in the form of panel 10 by low temperature heat-bondable textile fiber and / or other suitable binder materials. With panel 10 being built at least in part from post-consumer or recycled cardboard materials 12, the environment is benefited, so that the recovered cardboard is avoided being sent to landfills or being incinerated.

The mixed recycled cardboard material 12 can be provided as any mixture of Asian cardboard material (a lower grade of cardboard, commonly produced in Asian countries, eg China and Korea and shipped into the United States, which is typically considered non-recyclable by the various state environmental agencies so far, such as in Connecticut, New Hampshire and Massachusetts) and standard (the one produced from wood, such as pine, which is typical in the US). Because recyclers typically allow only 5% Asian cardboard mixed with “Standard Cardboard”, the focus of this patent is on recycled cardboard with between 5% and 100% Asian cardboard. This “Standard” and “Asian” mix will be referred to below as “mixed Asian cardboard”. As such, a method of recycling cardboard materials for use in manufacturing vehicle components, in accordance with one aspect of the invention, invalidates the need to separate lower grade low-grade cardboard materials, including Asian, higher grade cardboard, such as the one manufactured in the US Therefore, stacks, bundles or mixtures of standard high-grade cardboard material from cardboard containers can be readily recycled in combination with Asian cardboard, without worrying about separating the two types of cardboard materials from each other. The cardboard content, whether mixed or 100% Asian, is preferably between about 25 - 99% by weight of the total weight of the web, depending on the desired characteristics of the panel 10 being constructed. Generally, about 25% of recycled material from a new product is needed in order to be considered a “Recycled” product.

Asian cardboard is considered to be a low grade non-recyclable cardboard, due to it being constructed of inferior constituent ingredients, such as low quality recycled fibers, bamboo fibers, jute, rice fibers and / or other scrap / waste materials. As such, Asian cardboard is typically considered to be a serious non-recyclable contaminant, either alone or when bundled or otherwise included in recovered post-consumer cardboard loads. Therefore, if Asian cardboard is bundled with standard US cardboard, then the entire bale or cargo is typically considered to be non-recyclable waste (again, typically including an Asian cardboard content above 5%). Asian cardboard can be distinguished from the highest quality US cardboard for its fragility and characteristic color, pale brown, yellow or greenish. Therefore, Asian cardboard is typically separated from US quality cardboard. higher and sent to landfills, burned or otherwise disposed of.

The inability of Asian cardboard to be recycled stems from the lower fiber constituent ingredients used in the construction of Asian cardboard, which are generally very short and thus very weak. Given the relatively fine size of the fibers and other powdered ingredients of Asian cardboard, if Asian cardboard is processed in known wet recycling processes, along with standard cardboard having fibers of an increased length, the ingredients of Asian cardboard are bonded through the screens and transported into the residual stream and / or obstruct and otherwise damage the recycling equipment. Therefore, according to the present invention, the construction of panel 10 is carried out in a dry process, thereby allowing the use of lower Asian cardboard, together with fibers having a length of less than 0.2 mm (referred to as “thin” ”), In its manufacture.

The heat-bondable textile material can be provided, for example, as a low temperature melt polymeric material, such as polyethylene, PET or nylon fibers. It should be recognized that other low-melt polymeric materials could be used, such as thermoplastic bicomponent fibers, whose outer coating, such as polypropylene, for example, melts when heated above its melting point. This melted resin then melts with the mixture of any textile fibers present and the cardboard fibers and with remaining binders from the recycled cardboard materials. As an example, the melting point of the outer part of a low-melt PET fiber can be of production range 110 ° C - 180 ° C, compared to core melting at 250 ° C. Those skilled in the art will recognize that other coatings or fillers and filler fibers can be used in place of low-melt fibers, to obtain the desired result and that the heat-bondable material 14 can be used in combination with or replaced by a binder (for example, less low-melt fiber can be used if a binder is used to tighten the feel of the fabric). An SBR with a Tg of +41 is an example of a binder that can be used. In addition, heat-bonding textile materials can be combined with other organic or inorganic fibers and / or coated with heat resistant or fire retardant (FR) coatings (Ammonium Sulfate, Ammonium Phosphate or Boric Acid, for example) and / or coated with an anti-microbial coating (Polyphase 678, Rocima 200 or UF-15, for example) in at least one of the heat-bondable textile materials or in the recycled cardboard material. This is similar to the cellulose insulation industry, where an RF treatment and a mildeweide are added to the paper during the fibrization process.

According to another aspect of the invention, a method for manufacturing the acoustic and / or thermal panels 10 is provided. The method includes providing the recovered or recycled cardboard materials 12, as examined above, as well as recovering the cardboard materials from containers containing goods shipped to a manufacturer, such as an automotive component manufacturer, for example. Then, comminuting the cardboard materials 12 into the desired pieces and / or dry fibrous state, such as in a mincing, splintering and / or grinding operation. It is contemplated that when mixed Asian cardboard is being used, that the pieces are fibrized using a screen size between 3/32 ”(0.24 cm) and V” (1.27 cm), when using the hammer mill type method. This produces a similar sized fiber and speck of it in the blown insulation industry. Depending on the characteristics sought, such as acoustic damping or structural characteristics, the size of the comminuted pieces or nits can be changed. It was found that by changing the size of the pieces, the acoustic properties of panels 10 change. Using a hammer mill to fibrize the cardboard, the particle size of the cardboard is determined by the size of the canvas used. This screen size is not the actual size of the cardboard particles or nits that are formed. The actual size of the larger pieces is closer to half the size of the canvas. However, much of the cardboard within a certain labeled size is also less than half the size of the canvas and includes particle sizes up to dust size (also called “fine”). Approximately half of the cardboard mass of each labeled size is “large” pieces (meaning half the size of the canvas) and the other half are smaller pieces with a lot of dust. As shown in Figure 4, the test samples containing 50% cardboard, 30% low-melt PET, 20% lower quality material without coating or binder, show the correlations between the particle size of the cardboard versus absorption values of sound. The textile manufacturing process must also be considered as to which particle sizes will work most efficiently and practically. This can change the final air deposition system, depending on which size of nit fiber is determined to be best suited for the application, keeping in mind that the use of most of the “powder” that is produced in the fibrization system is the best environmental option, which can also negatively affect the requirements of “dedusting”. If using a hammer mill, the screen can be oriented in several directions or take different shapes, including circular, vertical or horizontal. If the hammer milled / milled mixture is combined with textile fibers, it is then padded to facilitate mixing with the textile fibers.

Another aspect of the invention includes changing the percentage of cardboard used in the panel, to adapt to the sound absorption curve of the final panel. Depending on which “filler” fiber is used, the cardboard can increase the sound absorption values ​​or it can actually decrease the sound absorption values ​​of the final panel. As shown in Figures 5 to 8, examples of how the absorption curves differ with different filler fibers when the amount of fibrized mixed cardboard is increased. Jute, recycled carpet, recycled bottom material and recycled white PET fibers were all used for the cargo fibers. In these particular tests, the amount of cardboard used was 25% and 50% of the total weight of the panel. These tests showed that the more fibrous the percentage of Asian cardboard mixed, the higher the sound absorption within the tested frequency range for Jute, recycled carpet and lower recycled material. The recycled white PET fibers showed less sound absorption with the addition of more mixed Asian cardboard. This results in the belief that the more mixed Asian cardboard in the lower performing fibers, the better the absorption values ​​and the more Asian cardboard mixed in the higher performing fibers, the worse the absorption values ​​of the nonwoven. However, this is not a strict and fixed rule, because the size of the nits / dust will also affect the absorption values. These tests used a product ground in a hammer mill sieved at 3/8 ”(0.95 cm). Due to some preliminary tests, there is reason to believe that a high percentage of Asian cardboard mixed with very small nit, together with the fine ones, can produce a panel with superior sound absorption, compared to PET fibers. By changing the percentage of mixed Asian cardboard used in the panel, along with the size of the “nits”, the panel can be constructed to have any absorption curve required by the application, while reducing the residual current.

The fibers and fragments ground by the cardboard hammer mill 12 are then mixed with any desired recycled or virgin textile fibers, which can include the low melt fibers 14 or other binding materials, as mentioned. The proportion of fibers and fragments ground in a hammer mill from cardboard 12 to textile fibers 14 can be varied between about 25 to 99% by weight (% w) of the finished panel 10. The ratio of low melt fibers 14 to recycled cardboard fibers 12 can be varied as best suited to the intended application of panel 10, however low melt fibers 14, if any, are generally provided to be between about 5% to 45% by weight of panel 10.

The mixture is then subjected to a nonwoven continuous sheet forming process, which can be carried out, for example, on a Rando machine. The continuous sheet forming process produces a homogeneously mixed fiber / paper mat or sheet, with the cardboard fibers 12 being randomly oriented. The web is then passed through a heat binding furnace to fuse the low melting fibers or, if desired for the intended application, the web can be fed through a needle loom to be pierced by needle. The heating process can be carried out by passing the web into or through any suitable oven or by feeding it through one or more heated rollers. The resulting web can be passed between cooling rollers after heating, to control its thickness and density. If piercing the web, a thin non-woven fabric that resists tearing, or a layer of grid, can be applied to one or both sides of the web to prevent any fibers or pieces of cardboard from accumulating. on the needles, as the accumulation of cardboard on the needles is undesirable and can cause them to break. The grid layer also serves as a "mesh" to control that dust is released from the web. Reemay fabric is an example of a grid that can be used for this purpose. The protective fabric grid or layer can additionally add resistance to the web and facilitate the web production process. The web can be coated with a binder that still binds to all fibers and paper in position and prevents it from forming dust (SBR, Acrylic or Latex binders are some examples of what can be used). Flame retardant additives can also be added to the coating. When applying the binder, it is preferably dried and cured.

The web can then be rolled up or cut to desired lengths. A cutting press, or a comparable device, can be used to separate the roll / sheets into panels or parts, as dictated by the application of the fiber product.

The resulting non-woven fiber panels 10 can have a thin non-woven fabric or grid layer attached or attached to one side or both sides, or the grid layer can be sandwiched between layers of the non-woven fiber panels 10 The grid layer can be bonded using a suitable heat resistant adhesive, a mixture of low melting fibers within the grid, or it can be fixed via dot connection.

Non-woven panels 10, constructed in accordance with the present invention, are suitable for use in a variety of applications, including acoustic panels and automotive thermal panels. Such applications more specifically include the acoustic panels between the finished interior panel and the steel of the car, including the roof cover, side door panels, the trunk and under the carpet. Thermal applications include, for example, thermal shields with the addition of a reflective layer, such as adjacent exhaust system components or within an engine compartment.

Many modifications and variations of the present invention are possible in light of the above teachings. Therefore, it should be understood that the invention can be practiced in another way than as specifically described.