The disclosure relates to pile fabrics and the formation of pile fabrics.
Pile fabrics (which include tufted carpets, carpet tiles, artificial turf, rugs and mats, for example) generally are formed of pile tufts that are stitched into a backing layer and then bonded to the backing layer by a binder. Currently in the art, binders such as styrene butadiene rubber, vinyl acetate ethylene, natural rubber, hot melt thermoplastics and polyurethane are utilized to create a tuft bind and delamination in the pile fabric. The application of binders can be an expensive method and process for producing pile fabric with tuft bind and delamination. Additionally, the utilization of such binders can reduce the ability to recycle spent or discarded pile fabric, which results in the disposal of the spent pile fabric in landfills. Moreover, these processes may also utilize a lot of energy associated with drying or curing of the binder material.
Therefore, what is needed are improvements for addressing one or more of these perceived shortcomings.
An example method for forming a pile fabric, which has a front and a back, comprises: providing a primary backing material, a layer of thermoplastic material, and a plurality of pile tufts, the primary backing material being configured as a sheet having a front side oriented at the front of the pile fabric and an opposing back side oriented at the back of the pile fabric, the layer of thermoplastic material being disposed at the back side of the primary backing material, each of the plurality of pile tufts extending through the primary backing material and at least partially into the layer of thermoplastic material with back stitch portions of the pile tufts being disposed at the back side of the primary backing material; and heating only the back of the pile fabric to melt the back stitch portions of the pile tufts and the layer of thermoplastic material to form a melt bond disposed at the back side of the primary backing material to secure the pile tufts to the primary backing material.
In some embodiments, heating only the back of the pile fabric comprises exposing the back stitch portions of the pile tufts and the layer of thermoplastic material to an open flame.
In some embodiments, exposing the back stitch portions of the pile tufts and the layer of thermoplastic material to the open flame is performed at a location where the primary backing material is redirected about a roller with the back side of the primary backing material facing outwardly from the roller.
In some embodiments, the melt bond is formed without the primary backing material being tentered.
In some embodiments, the front of the pile fabric is cooled for at least a portion of time during which the back of the pile fabric is heated to form the melt bond.
In some embodiments, the cooling is performed by a first chill roller as the primary backing material, the layer of thermoplastic material and the plurality of pile tufts are conveyed about the first chill roller.
In some embodiments, while molten, the back stitch portions of the pile tufts and the layer of thermoplastic material are pressed against the back side of the primary backing material.
In some embodiments, the pressing is performed with a second chill roller.
In some embodiments, the second chill roller is wetted to reduce a potential for the pile tufts and the layer of thermoplastic material to stick to the second chill roller.
In some embodiments, the melt bond is disposed only at the back side of the primary backing material.
An example pile fabric comprises: a front and a back; a primary backing material configured as a sheet having a front side oriented at the front of the pile fabric and a back side oriented at the back of the pile fabric; a layer of thermoplastic material disposed at the back side of the primary backing material; a plurality of pile tufts, each of the plurality of pile tufts extending through the primary backing material and at least partially into the layer of thermoplastic material with back stitch portions of the pile tufts being disposed at the back side of the primary backing material; and a melt bond, disposed only at the back side of the primary backing material, formed of melted material of the back stitch portions of the pile tufts and melted material of the layer of thermoplastic material.
In some embodiments, the pile fabric is configured as artificial turf.
In some embodiments, the pile fabric is liquid permeable.
In some embodiments, the melt bond defines voids, configured as areas of liquid permeability, at which the back side of the primary backing material lacks the melted material of the layer of thermoplastic material.
In some embodiments, the layer of thermoplastic material is configured as a sheet.
In some embodiments, the pile fabric is a recyclable pile fabric formed only of thermoplastic materials.
In some embodiments, the pile fabric is configured as carpet.
In some embodiments, the melt bond comprises material of the back stitch portions pressed against the primary backing material.
In some embodiments, the melt bond comprises material of a first of the back stitch portions adhered to material of adjacent back stitch portions.
In some embodiments, the pile fabric comprises a secondary backing material, configured as a sheet, adhered to the back side of the primary backing material by the melt bond.
In some embodiments, the primary backing material exhibits transverse shrinkage due to exposure to heat.
In some embodiments, the primary backing material is an olefin-based primary backing material.
An example system for forming a pile fabric, which exhibits a front and a back, comprises: a first roller defining a processing path along which material for forming the pile fabric is conveyed in a processing direction, the first roller extending across a width of the material for forming the pile fabric in a direction transverse to the processing direction; a flame singer having an outlet positioned adjacent to the first roller, the outlet being configured to direct an open flame toward the material for forming the pile fabric to expose the back of the material, which faces outwardly from the first roller to the open flame.
In some embodiments, the first roller is a chill roller.
In some embodiments, the system further comprises a second roller downstream of the first roller, the second roller being configured to press molten material, heated by the open flame, against a back side of a primary backing material of the material for forming the pile fabric.
In some embodiments, the second roller is a chill roller.
A more complete understanding of the disclosure may be had by reference to the following Detailed Description when taken in conjunction with the accompanying drawings, in which like reference numerals indicate corresponding parts throughout the several views.
As will be described in greater detail, pile fabrics, systems for forming pile fabrics and methods for forming pile fabrics preferably avoid the use of binder compositions, thus potentially reducing material and/or energy costs and enabling the recycling of a larger quantity of spent pile fabrics, which reduces the accumulation of pile fabric waste. In some applications, such as those that utilize olefin-based primary backing materials, thermal stability may be improved by heat stabilizing (pre-shrinking) the materials prior to use. In some applications, the omission of binder compositions is facilitated by a melt bond that secures pile tufts to a primary backing material of the pile fabric. The melt bond, which may be disposed only at the back side of the primary backing material, is formed of melted material of the back stitch portions of the pile tufts and melted material of a layer of thermoplastic material. In some applications, only the back of the pile fabric is heated to melt the back stitch portions of the pile tufts and the layer of thermoplastic material to form the melt bond, with melting of the materials of the melt bond preferably being performed by exposure to an open flame.
In
Layer of thermoplastic material 104 is disposed at back side 110 of primary backing material 102 and may be provided in various configurations depending upon the desired application. By way of example,
The plurality of pile tufts 106 (which are depicted schematically in
Pile tufts may be formed of one or more of various thermoplastic materials, such as polyethylene (PE), polypropylene (PP), polyester, nylon 6 6 and/or nylon 6 as non-limiting examples. Preferably, the pile tufts exhibit a melting temperature that is less than or equal to the melting temperature of primary backing material 102. Additionally, pile tufts may be provided in various configurations depending upon the desired application. By way of example, when the pile fabric is configured as artificial turf, the pile tufts may be configured as lengths of slit tape or monofilament yarn. In contrast, when the pile fabric is configured as carpet, bulk continuous filament and spun yarn can be used. In some applications, it may be preferable to ensure that the pile fabric is a recyclable pile fabric that is formed only of compatible thermoplastic materials. For instance, all of the materials used may be olefin-based materials (e.g., PE and/or PP) or all of the materials used may be polyester materials.
As shown in
Conventionally, manufacturers have tended to incorporate polyester (which has a melting temperature of approximately 500° F.) into their primary backing materials when producing artificial turf or carpet tile so that shrinking does not occur after installation due to exposure to high temperatures. For instance, artificial turf is known to experience exposure to 190° F. after installation. However, polyester (e.g., PET) and olefin-based materials cannot be recycled together due to the significant differences in melting points. By subjecting an olefin-based primary backing material, while under little stress/tension (no tentering), to a temperature that it should not be exposed to after installation provides enhanced thermal stability pile fabrics formed of these lower melting point materials.
System 300 incorporates various rollers along the processing path, such as roller 306 (which may be an idler roller) and roller 308. Roller 308 is positioned to redirect material 301 to draw apart and expose the back stitch portions. Specifically, roller 308 is configured to engage front side 302 so that back side 304 and its associated back stitch portions are exposed at the outermost diameter of roller 308 as the material travels about the roller. A gas-fueled assembly 310 is configured to direct an open flame toward roller 308 and the exposed back stitch portions of material 301. Notably, exposure to the open flame for forming a melt bond preferably is performed without the primary backing material being tentered (i.e., tensioned in the transverse direction along the z-axis).
As shown in greater detail in
Flame singer 312 preferentially exposes only the back stitch portions of the pile tufts and the layer of thermoplastic material to open flame 315 across the width of the material 301 to melt the back stitch portions and the layer of thermoplastic material while the material is conveyed about roller 308. To reduce a temperature of front side 302 in the vicinity of open flame 315, roller 308 is optionally a chill roller (which may exhibit a surface temperature of between approximately 70 degrees F. and approximately 100 degrees F.) that helps prevent damaging the face yarns of the pile fabric. Use of a chill roller may also enable the use of a higher flame temperature (a temperature between approximately 400 degrees F. and approximately 525 degrees F., preferably between approximately 400 degrees F. and approximately 475 degrees F.), which provides for efficient melting and increased conveyance speeds. For instance, a conveyance speed of between approximately 10 ft/min and approximately 15 ft/min may be achieved with a flame temperature at or above approximately 400 degrees F.
After melting of the back stitch portions and the layer of thermoplastic material to form a melt bond, molten material 301 may be pressed (calendared) against the back side of the primary backing material by a pressing assembly 320. In the example of
After pressing, an adequate conveyance time along the processing path is provided to permit cooling of the formed pile fabric 340. Specifically, conveyance time is provided to permit cooling of the melt bond, which preferably is disposed only at the back side of the primary backing material. Pile fabric 340 may then be gathered, such as by spooling onto a roll 350.
As shown in greater detail in
In contrast to system 300, however, system 400 further includes a supply 430 of secondary backing material 431. Secondary backing material 431 enters the processing path along which material 401 travels in a vicinity of (i.e., at or downstream of) open flame 415, which is used to melt the back stitch portions and layer of thermoplastic material of material 401. Entering the processing path at this location positions secondary backing material 431 for adhering to the molten material used to form the melt bond. It should be noted that secondary backing material 431 also is a thermoplastic material and, depending on the application, the side of secondary backing material 431 that will be adhered to the pile fabric may be exposed to the open flame and melted. Roller 432, which directs secondary backing material for entry into the processing path, may be a chill roller depending on the application.
After melting of the back stitch portions and the layer of thermoplastic material to form a melt bond, molten material 401 may be pressed (calendared) between the back side of the primary backing material and a side of secondary backing material 431, which may or may not be molten on the side being pressed into the back stitch, by a pressing assembly 420. In the example of
After pressing, an adequate conveyance time along the processing path is provided to permit cooling of the formed pile fabric 440. Thereafter, pile fabric 440 may be gathered, such as by spooling onto a roll 450.
Although preferred embodiments have been illustrated in the accompanying Drawings and described in the foregoing Detailed Description, it should be understood the disclosure is not limited to the embodiments disclosed but is capable of rearrangement, modification, and substitution of parts and elements without departing from the spirit of the invention.
This utility patent application claims the benefit of and priority to U.S. Provisional Patent Application 62/991,897, filed on 19 Mar. 2020, which is incorporated by reference herein in its entirety.
Number | Date | Country | |
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62991897 | Mar 2020 | US |