Method for forming a non-woven recyclable fabric
11248323 · 2022-02-15
Assignee
Inventors
- Richard Francis Ferrell (Sarasota, FL, US)
- James Michael Posa (Greer, SC, US)
- Joseph D. Wahlquist (Georgetown, TX, US)
Cpc classification
Y02P70/10
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
D01D5/088
TEXTILES; PAPER
Y02P70/62
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
B29C48/2886
PERFORMING OPERATIONS; TRANSPORTING
D04H3/10
TEXTILES; PAPER
B29K2067/00
PERFORMING OPERATIONS; TRANSPORTING
C08J2367/00
CHEMISTRY; METALLURGY
Y02W30/62
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
B29C48/275
PERFORMING OPERATIONS; TRANSPORTING
D01F11/08
TEXTILES; PAPER
B29C65/56
PERFORMING OPERATIONS; TRANSPORTING
D04H3/12
TEXTILES; PAPER
D04H1/49
TEXTILES; PAPER
B29C65/48
PERFORMING OPERATIONS; TRANSPORTING
D04H3/16
TEXTILES; PAPER
Y02P20/143
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
D06P1/004
TEXTILES; PAPER
D04H3/14
TEXTILES; PAPER
B29K2105/251
PERFORMING OPERATIONS; TRANSPORTING
D10B2331/04
TEXTILES; PAPER
International classification
D04H3/12
TEXTILES; PAPER
D04H3/14
TEXTILES; PAPER
D04H1/49
TEXTILES; PAPER
B29C48/285
PERFORMING OPERATIONS; TRANSPORTING
B29C48/275
PERFORMING OPERATIONS; TRANSPORTING
D01D5/088
TEXTILES; PAPER
D04H1/4382
TEXTILES; PAPER
D04H1/541
TEXTILES; PAPER
D02J13/00
TEXTILES; PAPER
D04H1/54
TEXTILES; PAPER
D04H1/56
TEXTILES; PAPER
D04H5/02
TEXTILES; PAPER
D04H5/06
TEXTILES; PAPER
D04H3/16
TEXTILES; PAPER
Abstract
A nonwoven recyclable fabric and associated methods are provided. The fabric is formed from 100% polyester, and may also include surface coatings such as hydrophilic coatings to promote heat transfer as well moisture vapor transmission rates and/or a silicone coating to promote fabric smoothness and reduce abrasiveness of the fabric.
Claims
1. A method for forming a nonwoven recyclable fabric, the method comprising: procuring a plurality of used fiber products, wherein each of the plurality of fiber products is formed of one hundred percent polyester fibers; forming said one hundred percent polyester fibers into recycled polyester flake or pellets; melt extruding the polyester flakes or pellets into recycled polyester fibers via a melt extrusion process; forming a fiber web from said recycled polyester fibers; bonding and mechanically treating said fiber web to produce said nonwoven recyclable fabric, said nonwoven recyclable fabric having a density of no less than 0.15 g/cm.sup.3, a thermal resistance value of less than about 0.025 K-m.sup.2/W per ASTM F1868-14, and an abrasion resistance of greater than or equal to 750 cycles under the Wyzenbeek abrasion test method per ASTM D4157.
2. The method of claim 1 where said fiber web used to produce said nonwoven recyclable fabric is comprised of a blend comprising a ratio of about 1:99 to about 35:65 of said recyclable polyester fibers to virgin polyester fibers, and where at least five per cent of the virgin polyester fibers contain a polyester component that has a melting point at least 50 degrees Celsius below the melting point of said recyclable polyester fibers.
3. The method of claim 2 where at least a portion of said virgin polyester fibers are bicomponent polyester fibers comprising a sheath polyester and a core polyester, the sheath polyester having a melting point at least about 50 degrees Celsius below that of said recyclable polyester fibers.
4. The method of claim 1 further comprising a step of carding said fiber web.
5. The method of claim 4 wherein the step of bonding includes hydroentangling, thermal bonding or adhesive bonding of the recyclable nonwoven fabric.
6. The method of claim 5 where said thermal bonding is at least one of thermal point bonding, thermal calender bonding, through air bonding, ultrasonic bonding.
7. The method of claim 1 wherein the step of forming said fiber web includes forming the fiber web via spunbonding or meltblowing.
8. The method of claim 1, further comprising introducing a hydrophilic coating to said recyclable nonwoven fabric.
9. The method of claim 1, wherein the plurality of fiber products are nonwoven fabric products formed from polyester fiber.
10. The method of claim 1 wherein the step of procuring a plurality of used fiber products includes procuring nonwoven recyclable hospitality or bedding linen as the plurality of used fiber products.
11. The method of claim 10, wherein the procuring hospitality or bedding linen includes procuring bed sheets or a pillow cases.
12. The method of claim 10, wherein the procuring of the bed sheets includes procuring bed sheets having an embossed region adjacent to an edge of the bed sheets.
13. The method of claim 1, wherein the step of procuring a plurality of used fiber products includes procuring nonwoven recyclable duvet covers or mattress covers as the plurality of used fiber products.
14. The method of claim 10, wherein the step of procuring hospitality or bedding linen includes the step of collecting bedding hospitality or bedding linen having a use indicator, the use indicator indicating the hospitality or bedding linen has been used.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present invention and, together with the description, serve to explain the principles of the invention. In the drawings:
(2)
(3)
(4)
(5)
(6)
(7) While the invention will be described in connection with certain preferred embodiments, there is no intent to limit it to those embodiments. On the contrary, the intent is to cover all alternatives, modifications and equivalents as included within the spirit and scope of the invention as defined by the appended claims.
DETAILED DESCRIPTION OF THE INVENTION
(8) Turning now to the drawings, a recyclable nonwoven fabric, products formed from this fabric, and a method of producing the fabric are described herein. The embodiments described advantageously overcome existing problems in the art by providing a nonwoven recyclable product which is readily recyclable while at the same time achieving desirable softness and coolness characteristics heretofore unachieved by prior nonwoven designs. While the following will describe an application of the fabric in a product such as a sheet or pillow case, it will be readily recognized that the fabric may be utilized in any product where a recyclable fabric is desired.
(9) As will be described in greater detail below, the fabric is formed using only polyester fibers. Advantageously, using this single material type allows for a highly efficient recycling process which purifies, sterilizes, and rextrudes the fibers into a form which may be reused in a nonwoven, textile, or other process.
(10) In particular, the fabric is formed from a blend of high melt monocomponent polyester fibers and bicomponent polyester fibers. The monocomponent fibers are obtained by melting down used fabric according to the teachings herein and extruding the same back into monocomponent fibers. The bicomponent fibers are added to the extruded monocomponent fibers as described below. It will be noted from the following that the bicomponent fibers may be virgin or recycled fibers. The term “virgin” as used herein in the context of fibers means that the fibers are newly manufactured fibers, in contrast to the monocomponent fibers mentioned above which are recovered from existing fabric via a recycling process.
(11) The term “monocomponent” as used herein in the context of fibers means fibers which are formed of a single species of material and are homogeneous in their material properties. Conversely, the term “bicomponent” as used herein in the context of fibers means fibers which are formed with two polyester polymers having different melting points. Indeed, the bicomponent fibers are polyester fibers which have a high melt core and an outer low melt sheath. The core of the bicomponent fiber is made with polyester polymer with a melting point of about 270° C. The outer sheath of the bicomponent fiber is made with polyester polymer that has had its melting point reduced to the range of 130-150° C. by the addition of isophthalic acid, as a non-limiting example.
(12) As such, the bicomponent fibers are formed from one species of polyester which serves as the core material, and another species of polyester which serves as the outer sheath. The phrase “high melt” used herein in the context of fibers means fibers which have a higher melting point in comparison to a low melt fiber. As a non-limiting example, a high melt fiber may exhibit a minimum melting point of about 270° C. Ideally, the melting point is at least high enough to sterilize the melted polyester.
(13) The phrase “low melt” used herein in the context of fibers means a fiber with a melting point which is lower in comparison to a high melt fiber. As a non-limiting example, a low melt fiber may exhibit a melting point of not greater than about 130° C.-150° C. The approximate terms “about” used relative to melting temperature is used to allow for ordinary deviations in a specified melting point of a polyester material known in the art. Put differently, high melt fibers have a first melting point, while low melt fibers have a second melting point, the second melting point being less than the first melting point.
(14) With particular reference to
(15) Carding may be achieved using a contemporary carding arrangement. For non-limiting example, carding may be achieved via a drum carder, cottage carder, or similar devices operable to disentangle and orient the fiber mixture such that the fibers thereof are generally parallel to one another.
(16) Once blended and carded, a fiber web 10 is produced. Fiber web 10 generally possesses a number of monocomponent and bicomponent polyester fibers arranged parallel to one another. Fiber web 10 enters a hydroentangling arrangement 24 where the fibers thereof are hydroentangled with one another using one or more hydroentangling jets 26 and hydroentangling cylinders 28.
(17) The result is a hydroentangled web 12. This hydroentangled web 12 may then receive a topical treatment such as a hydrophilic coating applied via an application head 34. Thereafter, hydroentangled web 12 is dried in a drying oven 38. The dried hydroentangled web 12 is then fed through a roller arrangement 42 which, inter alia, compacts hydroentangled web 12 to a predetermined thickness and density to complete the formation of the fabric 14 described herein. Thereafter, post-processing steps may occur. For example, fabric 14 may be wound onto a roll 44 for later formation into a product, e.g. a product. With the foregoing general process layout in hand, the following described each step and its associated structure in greater detail.
(18) Turning now to
(19) As a non-limiting example, the used products may be a plurality of used products, e.g. sheets, pillow cases, etc., formed from fabric 14 and recovered from a high occupancy facility such as a hotel which are gathered or bundled in bulk. These gathered products may initially be scanned to ensure there is no foreign material, e.g. jewelry, litter, fabrics which differ from fabric 14, etc., incorporated therein. This scanning may be done via any contemporary manner, e.g. visual metal detection, x-ray, magnetic or mechanical separation, etc. Thereafter, the used fabric 14 is densified into a pellet like substance during material collection step 50.
(20) Once it is ensured that the gathered products are free of foreign material and the gathered fabric 14 has been densified, the gathered products are then melted at step 52 to form a liquid polyester. As stated above, one hundred percent of the fibers in fabric 14 are polyester, i.e. no other fibers of different materials are present. Further, fabric 14 is predominantly formed of high melt polyester, and thus exhibits a melting point property in the range of a high melt polyester. As a result, the melting process is a high melt process requiring a sufficient temperature to melt used fabric 14 into a liquid state.
(21) This melting step 52 contemplates the use of any known controlled melting means typically employed in the melt extrusion process. After melting, the liquid polyester is then extruded at an extrusion step 54. This extrusion may be accomplished via any contemporary fiber extrusion process, including but not limited to melt spinning This extrusion process is a high temperature process (i.e. a temperature above about 275° C.), and thus provides additional sterilization beyond that provided by the initial melting step 52. It should be noted that the resultant product at this stage is a bulk mass of high melt monocomponent polyester fibers. These monocomponent polyester fibers are then ready for processing at fiber preparation stage 22 discussed above relative to
(22) As stated above, the bicomponent polyester fibers may be virgin or recycled. In the case of recycled bicomponent polyester fibers, a similar process to what is shown in
(23) Thereafter, low melt bicomponent polyester fibers are introduced to the bulk mass of monocomponent polyester fibers at step 22. It is envisioned that this addition will be done as a continuous process where a known quantity of virgin bicomponent polyester fibers are added. The result is a fiber mixture. This fiber mixture may for example comprise about 3%-10% bicomponent polyester fibers, with the balance being the extruded monocomponent polyester fibers.
(24) With momentary reference to
(25) Returning now to
(26) While illustrated as occurring prior to carding step 58, topical treatment step 60 may also occur after carding step 58. Further, any number of topical treatments could be applied beyond the hydrophilics mentioned above. While silicon advantageously promotes smoothness and glide, it has also been found to promote moisture wicking and moisture vapor transmission. The foregoing qualities achieved via silicone coatings thus also promote the “cool” feeling of fabric 14. Nevertheless, it is also contemplated that any other coating could be employed which on the one hand is suitable for human contact and on the other promotes moisture wicking and moisture vapor transmission through fabric 14, and possesses desirable smoothness.
(27) Referring back to
(28) Hydroentangled web 12 may then receive a topical treatment via applicator head 34. Applicator head 34 may apply the same or similar substances as those described above relative to optional topical treatment step 60 shown in
(29) After drying, hydroentangled web 12 enters a roller arrangement 42. Roller arrangement 42 includes compaction rollers for compacting hydroentangled web 12 to a desired thickness and density. These compaction rollers may be embodied by heated calendering rolls which serve to compact hydroentangled web 12. The temperature of such calendering rolls may be such that the same activate outer sheath 64 of bicomponent polyester fibers 62 such that the above described binding properties of melted sheath 64 are achieved simultaneously while compaction occurs.
(30) It should be noted that the above mentioned calendar rollers of roller arrangement 42 have a high degree of smoothness to provide an ironing like effect to hydroentangled web 12 to produce a smooth, drapable fabric 14 which is soft to the touch and suitable for skin contact. Once compaction is complete, fabric 14 is produced. Fabric 14 may then be taken up in bulk on a winding roll 44. Thereafter, subsequent operations may be performed on fabric 14 to form the same into a product as discussed below.
(31) Turning briefly to
(32) As stated above, core material 66 is configured such that it is highly similar or the same as the base monocomponent polyester fibers in terms of fiber diameter, melting point, tensile strength, etc. In effect, the resultant fabric 14 is a grouping of highly similar or identical monocomponent polyester fibers bound to one another via a binder formed via melted sheath 64. Notably, this binding functionality is achieved via the low melt polyester of sheath 64. No solution or emulsion chemical binders are required. Put differently, fabric 14 is free of topical binding chemistry. Such a configuration advantageously avoids the need to remove any chemical by products which may not be suitable in the final product. Further, such a configuration advantageously avoids the need for an additional chemical binding step. Instead, fiber-to-fiber binding is achieved simultaneously during drying and/or compaction as discussed above.
(33) Turning now to
(34) Further, sheet 80 may also include a use indicator 84. This use indicator 84 may for example be a color changing indicator which changes color upon contact with human skin or other bodily fluids. This color change could occur in response to a detection of a particular pH associated with human skin (typically a pH value of 5.5) for example. Additionally or in the alternative, such indicators could be incorporated as a stylized pattern 86 such as that illustrated. In either case, the indicators would advantageously allow the staff of a high occupancy facility to quickly determine whether or not sheet 80 has been used and is ready to be collected for recycling.
(35) To obtain sheet 80, fabric 14 may be unwound from roll 44, cut to length, embossed with hem region 82. Further, indicator 84 can be emplaced and/or stylized pattern 86 could be added. It is contemplated that this could be achieved at the same facility which employs process 20 described above relative to
(36) Further, it is also contemplated that sheet 80 may be expeditiously folded. This expeditious folding methodology would be highly useful in high occupancy facilities, allowing staff to quickly place sheet 80 on a bed. This folding methodology contemplates a folding process where sheet 80 is fan folded, rolled in a folded state on a mandrel, and then flattened after removing the mandrel. More specifically, sheet 80 may be repeatedly fan folded moving from the bottom most edge of sheet 80 in
(37) To unfold sheet 80, a reverse process is employed. Flattened sheet 80 can be situated at the upper corner of a bed and rolled to the other side of the bed, effectively undoing the roll of sheet 80 formed via mandrel 94. Thereafter, the end of sheet could be pulled from the upper end of the bed to the lower end of the bed, thus covering the bed with sheet 80 in an unfolded configuration.
(38) In addition to sheet 80 as discussed above, it is also contemplated that the fabric of the instant invention may be advantageously employed as a pillow case. Indeed, the same advantages of wicking, drapability, softness, coolness described above are equally achieved by forming fabric 14 into a pillow case. A sheet and pillow case are only two of many examples of the application of fabric 14, and thus should be taken by way of example and not limitation. As discussed above, fabric 14 may be employed in any application where a nonwoven recyclable fabric which has desirable wicking, drapability, softness, and coolness characteristics.
(39) It also conceived that the above described spunlacing process 20 may instead be a woven process. Indeed, recycled fibers may be achieved via the process shown and described relative to
(40) In another advantageous configuration, the recyclable polyester fabric 14 produced according to the teachings herein may comprise a blend of recyclable polyester fibers and other polyester fibers which are blended together at step 22 shown in
(41) While it is contemplated by the invention herein disclosed that the specific ratio of recyclable polyester fibers to other polyester fibers may be any ratio, the Applicants have found a blend of at least about twenty-five percent by weight recyclable polyester fibers with the balance being the other polyester polymer fibers to be ideal. In one possible embodiment, the Applicants have found that a ratio of about 25:75 to about 99:1 of the recyclable polyester fibers to other polyester fibers is particularly advantageous. Each value in the foregoing ratios are in terms of weight versus total weight.
(42) With regard to the recyclable polyester fibers, the same may be obtained via melt extrusion from a blend of a first polyester polymer and a second polyester polymer. The first polyester polymer is obtained from a plurality of polyester fiber products which have been melted down and flaked or pelletized for purposes of melt extrusion (see e.g. step 50 of
(43) With regard to the other polyester fibers, the same may be formed from any polyester homopolymer or copolymer, the bicomponent polyester fibers described above, or biconstituent polyester containing fiber. In the case of bicomponent polyester fibers, the same may have a sheath polyester and a core polyester as introduced above (see e.g.
(44) Alternatively, it is also conceived herein to produce fabric 14 without the introduction of other polyester fibers as described above. As one example, a plurality of polyester fiber products may be procured, and then flaked or pelletized, and then melted.
(45) Similar to the products described above, the applicants have found that the aforementioned fabric is particularly useful when fashioned into a hospitality bedding or linen, a bed sheet or pillow case, a duvet cover or mattress cover, etc.
(46) The Applicants have found that a recyclable polyester fabric utilizing the aforementioned blend of recyclable polyester fibers and other polyester fibers exhibits desirable thermal resistance and abrasion properties. Indeed, the Applicants have found that such a fabric 14 has a thermal resistance value of less than about 0.025 K-m2/W per ASTM F1868-14 as published on Jan. 1, 2019, and an abrasion resistance of greater than or equal to 750 cycles under the Wyzenbeek abrasion test method per ASTM D4157 as published on Jan. 1, 2019. To aid in such favorable properties, it is also contemplated by the invention to mechanically treat fabric 14 via calendering with calender rolls.
(47) As mentioned above, the fiber web 10 produced to form fabric 14 may be carded at stage 22 in
(48) All references, including publications, patent applications, and patents cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.
(49) The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) is to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.
(50) Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.