Patent Publication Number: US-2021170717-A1

Title: Multi-layer needled nonwoven article and methods of manufacture thereof

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. provisional application Ser. No. 62/946,121 filed Dec. 10, 2019, which is hereby incorporated by reference. 
    
    
     FIELD 
     The present disclosure relates to a multi-layer needled non-woven article, and more particularly a multi-layer needled non-woven acoustic article, such as a dilour carpet for the interior trim flooring of a motor vehicle. 
     SUMMARY 
     The present disclosure provides a multi-layer needled non-woven article, and more particularly a multi-layer needled non-woven acoustic article, which may be used to improve acoustic behavior in a motor vehicle. The present disclosure provides an alternative approach to needle a multi-layer non-woven automotive trim article together. The process involves needling through a fibrous substrate to a fibrous cover to mechanically connect the fibrous substrate and the fibrous cover together, while perforating a film disposed between the fibrous substrate and the fibrous cover. The fiber deposited in the perforations, and a torturous path created through the film layer, act to improve the sound absorption and insertion loss of the non-woven article. 
     In at least one embodiment, a method of forming a multi-layer needled non-woven article is provided, which comprises forming a web of a fiber base layer, an intermediate film and a fiber top layer, wherein the intermediate film is disposed between the fiber base layer and the fiber top layer; needle punching the web with a plurality of needles; and wherein, during needle punching, fibers of the fiber base layer are carried by the needles, extended through perforations in the intermediate film formed by the needles and entangled with fibers of the fiber top layer. 
     In at least one embodiment, the method comprises at least partially closing the perforations in the intermediate film formed by the needles as the needles withdraw therefrom. 
     In at least one embodiment, the method comprises inhibiting at least a portion of the fibers of the fiber base layer extending through the perforations in the intermediate film from returning to the fiber base layer by the at least partial closing of the perforations in the intermediate film formed by the needles. 
     In at least one embodiment, the intermediate film has opposite sides; one side of the opposite sides of the intermediate film is in contact with the fiber base layer; and another side of the opposite sides of the intermediate film is in contact with the fiber top layer. 
     In at least one embodiment, the fiber base layer has an area weight in a range of 120 grams/square meter to 2,000 grams/square meter; the fiber base layer has a denier in a range of 0.5 denier to 40 denier; and the fiber base layer has fiber lengths in a range of 10 mm to 100 mm. 
     In at least one embodiment, the fibers of the fiber base layer are formed of thermoplastic. 
     In at least one embodiment, the fibers of the fiber base layer comprise staple fibers and binder fibers. 
     In at least one embodiment, the fiber base layer is a felt layer. 
     In at least one embodiment, the intermediate film has an area weight in a range of 10 grams/square meter to 900 grams/square meter; and the intermediate film has a thickness in a range of 0.0125 mm to 1 mm. 
     In at least one embodiment, the intermediate film is formed of thermoplastic. 
     In at least one embodiment, the intermediate film is a multi-layer film. 
     In at least one embodiment, the intermediate film has a middle layer, two tie layers and two outer layers; and the middle layer is disposed between the two tie layers, and the two tie layers are each disposed between the middle layer and one of the two outer layers, respectively. 
     In at least one embodiment, the intermediate film is a five-layer film having a polyamide middle layer, two tie layers and two polyethylene outer layers; and the polyamide middle layer is disposed between the two tie layers, and the two tie layers are each disposed between the polyamide middle layer and one of the two polyethylene outer layers, respectively. 
     In at least one embodiment, the fiber top layer has an area weight in a range of 120 grams/square meter to 1,200 grams/square meter; the fiber top layer has a denier in a range of 0.5 denier to 40 denier; and the fiber top layer has fiber lengths in a range of 10 mm to 100 mm. 
     In at least one embodiment, the fibers of the fiber top layer are formed of thermoplastic. 
     In at least one embodiment, the fibers of the fiber top layer comprise staple fibers and binder fibers. 
     In at least one embodiment, the fiber top layer is flat, or is structured with a random velour, loop pattern or random fiber pattern. 
     In at least one embodiment, a multi-layered needled non-woven article is provided, which comprises a fiber base layer, an intermediate film and a fiber top layer, wherein the intermediate film is disposed between the fiber base layer and the fiber top layer; and wherein needled fibers of the fiber base layer extend through needle-formed perforations in the intermediate film and entangle with fibers of the fiber top layer. 
     In at least one embodiment, the article is a carpet. 
     In at least one embodiment, the article is an automotive article. 
    
    
     
       FIGURES 
       The above-mentioned and other features of this disclosure, and the manner of attaining them, will become more apparent and better understood by reference to the following description of embodiments described herein taken in conjunction with the accompanying drawings, wherein: 
         FIG. 1A  is a side view of a needle punching apparatus and a multi-layer needled non-woven article according to the present disclosure; 
         FIG. 1B  is a close-up side view of the needle punching apparatus and the multi-layer needled non-woven article of  FIG. 1A ; 
         FIG. 1C  is a further close-up side view of the needle punching apparatus and the multi-layer needled non-woven article of  FIG. 1B ; 
         FIG. 2  is a close-up side view of the multi-layer needled non-woven article of  FIG. 1A ; 
         FIG. 3  shows sound inserting loss testing of a 3 layer carpet with film herein versus a 2 layer carpet without film at a thickness of 12 mm. 
         FIG. 4  shows sound insertion loss testing of a 3 layer carpet with film herein versus a 2 layer carpet without film at a thickness of 25 mm. 
         FIG. 5  shows sound absorption testing of a 3 layer carpet with film herein versus a 2 layer carpet without film at a thickness of 12 mm. 
         FIG. 6  shows sound absorption testing of a 3 layer carpet with film herein versus a 2 layer carpet without film at a thickness of 25 mm. 
     
    
    
     DETAILED DESCRIPTION 
     It may be appreciated that the present disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. The invention(s) herein may be capable of other embodiments and of being practiced or being carried out in various ways. Also, it may be appreciated that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting as such may be understood by one of skill in the art. 
     Referring now to  FIG. 1A-1C , there is shown a forming apparatus, particularly in a form of a needle punch apparatus  10  to form a multi-layer needled non-woven article  100  according to the present disclosure. 
     Needle punch apparatus  10  comprises a needle loom  12 . Needle loom  12  comprises a needle board  14  having a needle board plate  16  and a plurality of needles  18  (e.g. non-woven structuring/finishing needles) extending vertically therefrom. The needle board  14  may be disposed on a needle beam  26  which holds the needle board  14  in place. The needle beam  26  is then mounted to a needle loom driver  28 , by which the needle beam  26 , including the needle board  12 , is made movable in in upward vertical direction  22  and downward vertical direction  24  by a needle loom driver  28 . 
     As shown the needles  18  are barbed needles having a plurality of barbs  20  ( FIG. 1C ) disposed along their longitudinal length. Needles  18  may more particularly be non-woven felting needles. The felting needles  18  may have a working gage in a range of 12-46 gage with a length in a range of 2.5 inches to 5 inches. More particularly, the felting needles  18  may have a working gage of 32-40 gage with a length in a range of 3 inches to 3.5 inches. The felting needles  18  may have various barb shapes and spacings depending on product type and application. The felting needles  18  may have point characteristics including: sharp very slightly rounded, slightly rounded, rounded, very rounded, or chisel point. The felting needles  18  may utilize various surface coatings and treatments to aid in product appearance. With regards to cross-sectional shape, the felting needles  18  may have, for example, a triangular cross-section, a four-star cross-section, a conical cross-section, twisted cross-section or a teardrop cross-section. Exemplary felting needles  18  may include needles sold under the trademarks GEBECON, CROSS STAR, TRI STAR, ECOSTAR of Groz-Beckert KG of Germany. Exemplary felting needles  18  are disclosed in U.S. publication and patent nos. 2019/0301066; 2010/0251526, 2010/0251525; 2007/0143975; and U.S. Pat. No. 6,233,787, which are incorporated by reference. 
     The needle punch apparatus  10  further comprises a stripper plate  30  and a bed plate  36 , which are part of the needle loom  12 . 
     Multi-layer needled non-woven article  100  is a composite formed of a fibrous substrate  110  (structured side of article  100 ), an intermediate film  120  and a fibrous cover  130  (non-structured side of article  100 ). Multi-layer needled non-woven article  100  may more particularly be a multi-layer needled non-woven carpet (e.g. dilour carpet) which also preferably functions to improve sound absorption (absorption of sound energy by the multi-layered needled non-woven herein) and insertion losses (reduction in noise level at a given location due to the multi-layer needled non-woven article herein). Multi-layer needled non-woven article  100  may therefore be particularly utilized in automotive motor vehicle applications such as for interior trim, interior flooring, headliners and trunk/storage space liners. 
     Fibrous substrate  110  provides at least one fiber base (bottom) layer  112 , while intermediate film  120  provides at least one film intermediate layer  122  and fibrous cover  130  provides at least one fiber top (outer décor or face) layer  132 . As shown, non-woven article  100  has three layers,  112 / 122 / 132 . 
     While the fiber base layer  112  is shown overlying the fiber top layer  132  in the needle punch apparatus  10 , it should be understood that the fiber top layer  132  and the fiber base layer  112  are referred to as such with regards to use of the non-woven article  100  and how it may be ordinarily perceived when viewed, for example, in an a motor vehicle, in which case the fiber top layer  132  is the outer décor layer which may be viewed by a vehicle occupant and the fiber base layer  112  underlies the fiber top layer  132 . 
     Fiber base layer  112  may more particularly be a felt layer. The fibers may be formed of any material capable of producing a fiber based felt. The fiber base layer  112 , and more particularly the felt layer, may be a single fiber layer (i.e. all fibers formed of a same composition or a multi-fiber layer (i.e. fibers formed of different compositions). 
     For example, the fibers may be formed of thermoplastic. The thermoplastic may comprise, or be selected from the group consisting of, polyethylene terephthalate (PET), polypropylene (PP), polyamide (PA), polyethylene terephthalate glycol (PETG) and mixtures thereof. The individual fibers may have all have the same composition, being formed of one or more thermoplastic compositions, or the individual fibers may have different thermoplastic compositions, again by being formed of one or more thermoplastic compositions. The fibers are preferably selected and configured to provide the desirable acoustic performance attributes noted herein. Non-limiting examples of such fibers for the base layer may include those identified above as well as recycled fibers, such as recycled thermoplastic fibers, cotton, rayon, nylon, viscose, and/or aramid fibers. 
     The fiber base layer  112 , and more particularly the felt layer, may have an area weight in a range of 120 grams/m 2  to 2,000 grams/m 2  (i.e. square meter), and more particularly in a range of 400 grams/m 2  to 900 grams/m 2 . 
     The fiber base layer  112 , and more particularly the felt layer, may have a denier in a range of 0.5 denier to 40 denier, and more particularly in a range of 3 denier to 15 denier. The base layer  112  may comprise fiber lengths in a range of 10 mm to 100 mm, and more particularly in a range of 38 mm and 75 mm. Exemplary applications may be a mixture of denier size and staple lengths that are blended to achieve a desired level of tortuosity, appearance, stiffness, and formability. Generally, base layer  112  will contain a binder fiber that melts during a heating process and bonds the individual fibers together after cooling. Binder fibers may comprise bicomponent polyester fibers, polypropylene fibers, polyethylene fibers, polyamide fibers, or other melt fibers capable of bonding the base layer fiber matrix together after the heating and cooling process. 
     Film intermediate layer  122  may be a polymer film formed of any thermoplastic or thermoset composition, or combination thereof, capable of producing a film. 
     The film intermediate layer  112  may be a single layer film, or a multi-layer film. A single layer film may be formed of thermoplastic, inclusive of thermoplastic elastomers (TPE). The thermoplastic may comprise, or be selected from the group consisting of polyethylene terephthalate (PET), polypropylene (PP), polyamide (PA), polyethylene (PE) (inclusive of high density polyethylene (HDPE), linear low density polyethylene (LLDPE) medium density polyethylene (MDPE)) and polyurethane (PU) (such as thermoplastic urethane (TPU)), and mixtures thereof. The thermoplastic may be un-crosslinked or partially cross-linked as known in the art. 
     A multi-layer film may comprise at least two layers. A five-layer film may be formed of PE/tie layer/PA/tie layer/PE, thus having two outer polyethylene (PE) layers joined to an intermediate polyamide (PA) layer view two tie layers, respectively. A nine-layer film may be formed of PE/tie layer/PA/tie layer/PE/tie layer/PA/tie layer/PE. 
     The film intermediate layer  122  may have a thickness in a range of 0.0125 mm to 1 mm, and more particularly in a range of 0.025 mm to 1 mm and even more particularly in a range of 0.025 mm to 0.5 mm. The film intermediate layer  122  may have an area weight of 10 grams/m 2  to 900 grams/m 2 , and more particularly in a range of 40 grams/m 2  to 100 grams/m 2 . The film intermediate layer  122  may comprise between 1 and 9 layers, and be continuous (without being pre-perforated). 
     Fiber top layer  132  may be any structured or non-structured layer. For example, the fiber top layer  132  may be flat (no structuring), or have a random (delour) velour, loop pattern or random fiber pattern. The fibers may preferably be formed of any material capable of providing an automotive grade A textile surface. The fiber top layer  132  may be a single fiber layer (i.e. all fibers formed of a same composition or a multi-fiber layer (i.e. fibers formed of different compositions). The fibers may also be selected such that they do not provide an automotive grade A textile surface, but which are still selected and configured to provide the desirable acoustic performance attributes noted herein. 
     For example, the fibers may be formed of thermoplastic. The thermoplastic may comprise, or be selected from the group consisting of, polyethylene terephthalate (PET), polypropylene (PP), polyamide (PA), polyethylene terephthalate glycol (PETG), co-polyethylene terephthalate (CoPET) and mixtures thereof. The individual fibers may have all have the same composition, being formed of one or more thermoplastic compositions, or the individual fibers may have different thermoplastic compositions, again by being formed of one or more thermoplastic compositions (e.g. bi-component fibers having a core and a sheath formed of two different thermoplastics having different melt temperatures). 
     As noted above, the fibers for the fiber top layer are preferably selected to provide an automotive grade A textile surface, but may more generally be selected from fibers that do not provide a grade A textile surface, but still provide the desirable acoustic performance herein. Non-limiting examples of such fibers may include those identified above which do not necessarily provide an automotive grade A textile surface, and which may include for example recycled fibers, such as recycled thermoplastic fibers, as well as cotton, rayon, nylon, viscose, and/or aramid fibers. 
     The fiber top layer  132  may have an area weight in a range of 120 grams/m 2  to 1,200 grams/m 2 , and more particularly in a range of 300 grams/m 2  to 650 grams/m 2 . 
     The fiber top layer  132  may have a denier in a range of 0.5 denier to 40 denier, and more particularly in a range of 3 denier to 15 denier. The top layer  132  may comprise a blend of fibers including staple fibers and binder fibers. Staple fiber length for the top layer  132  may be in a range of 10 mm to 100 mm. The top layer  132  can be a blend of multiple deniers and staple lengths. Binder fibers including polyethylene (PE), polyethylene terephthalate (PET), polypropylene (PP), polyamide (PA), polyethylene terephthalate glycol (PETG) and other thermoplastic or thermosets can be added to the top layer  132  to bond the staple fibers together after heating and cooling. Percent binder fiber in the top layer  132  may be in a range of 10% to 40%, and more particularly in a range of 15% to 25%. Top layer  132  may comprise various fiber cross sections to include flat, round, oval, trilobal, and any other fiber shape commonly used to produce needled non-woven face materials. 
     Additionally, the multi-layer needled non-woven article  100  may have an acoustic impedance in a range of 500 to 3,000 Rayl (pascal second per meter). 
     During operation of the needle punch apparatus  10  the base layer  112 , the intermediate layer  122  and the top layer  132  may all be taken off individual feed rolls and transported in the shown layered disposition on a carrier into the needle loom  12 . Various types of needle looms may be used to produced this type product. Finishing looms, pre-needle looms, random velour looms, and others. The needle loom must simply penetrate the needle through the base layer  112 , perforate the intermediate layer  122 , and entangle fiber into the top layer  132 . Prior to needle punching, the base layer  112 , the intermediate layer  122  and the top layer  132  may be referred to collectively as a web. After needle punching in the needle loom  12 , the resultant needled non-woven article  100  may be taken up on an exit (take up) roll. 
     During needle punching, the needle punched non-woven article  100  is created by mechanically connecting, particularly by interlocking, the fibers of the fiber base layer  112  and the fiber top layer  132  through the film intermediate layer  122 . The mechanical interlocking is achieved with barbed needles  18  repeatedly passing into and out of the three-layer web  112 / 122 / 132 . 
     As shown, the stripper plate  30  is disposed on top of the web  112 / 122 / 132 , and the bed plate  36  is disposed beneath the web  112 / 122 / 132 . As shown, corresponding through-holes  32  and  38  ( FIG. 1B ) are disposed in the stripper plate  30  and the bed plate  36 , respectively, through which the needles  18  extend in and out with reciprocating motion. 
     Referring to  FIG. 2 , the needles  18  engage and carry bundles of fibers  114  (dashed lines) from the base layer  112  on the downward stroke in the downward direction  24  which then become entangled with the fibers  134  (solid lines) of the top layer  132 . The entangled fibers  114 ,  134  may extend into the bed plate holes  38  when the needles  18  are in there most downward position. On the upward stroke in the upward direction  22 , the stripper plate  30  then strips the fibers  114 ,  134  from the needles  18  so the web  112 / 122 / 132  can advance through the needle loom  12 . 
     More particularly, as the needle loom beam  26  moves in the downward direction  24 , the barbs  20  of the needles  18  (1) pick up and carry fibers  114  from the base layer  112 , (2) perforate the film intermediate layer  122  forming perforations  124  in the intermediate layer  122 , and (3) then carry and push the fibers  114  through the perforations  124  in the intermediate layer  122  to a depth of penetration into the top layer  132 , in which case the drawn fibers  114  are reoriented from a substantially horizontal orientation/position to a substantially vertical orientation/position transverse to the horizontal orientation as they extend through the perforations  124 . 
     It may be appreciated that, use of the film intermediate layer  122  may increase the strength of the mechanical connection between the base layer  112  and the top layer  132  resulting from the needle punching. It may be understood that, when the needles  18  travel out of the top layer  132 , at least some of the fibers  114  of the base layer  112  may exit the top layer  132  and travel back to the base layer  112 , rather than becoming entangled with the fibers  134  of the top layer. However, without being bound to a particular theory, when the fibers  114  of the base layer  112  extend through the perforations  124  of the intermediate layer  122  and into the top layer  132  while being carried by the needles  18 , the longitudinal length of the fibers  114  may be orientated with the longitudinal length of the needles  18 . Then, as the needles  18  travel out of the top layer  132  in the reverse direction, the perforations  124  occupied by the needles  18  may at least partially close (due to the resilience and elastic memory of the polymer material forming the film intermediate layer  122 ), thus trapping and inhibiting a larger portion of the fibers  114  from exiting the top layer  132  back to the base layer  114 . 
     The puncture density, i.e. the number of needle punches on the surface of the web  112 / 122 / 132  per unit area and the penetration depth are factors with regards to the needled article  100  resisting separation of the layers  112 / 122 / 132 , with the greater the number of needles  18  and the greater the depth of penetration (and hence entanglement) increasing retention strength. Puncture density may be in a range of 50 punches/cm 2  to 300 punches/cm 2 , and more particularly in a range of 100 punches/cm 2  to 200 punches/cm 2 . 
     It may also be appreciated that the use of the film intermediate layer  122  may increase the favorable appearance of the top layer  132  of the non-woven article  100  after needle punching. For example, current technologies for needle punching a base layer  112  to a dilour top layer  132  are known to have faced issues with face and pile distortion. However, use of the film intermediate layer  122  does not appear to suffer from the same such distortions. The needled composite dilour material, maintains an acceptable comparable pile height, pile strength, and overall pleasing appearance to the original (prior to being needle processed as disclosed) dilour face layer  132 . 
     It may also be appreciated that the selection of the construction for the fiber base layer  112 , film intermediate layer  122  and fiber top layer  132 , as well as the forming process thereof, have an effect on the acoustic properties of the non-woven article  100 . For example, the construction for the non-woven article  100  and the process of manufacture may be tuned to provide improvements in sound absorption and sound insertion loss. 
       FIG. 3  shows sound insertion loss testing of a 3 layer carpet with film according to the present invention versus a 2 layer carpet without film at a thickness of 12 mm.  FIG. 4  herein now shows insertion loss testing of a 3 layer carpet with film according to the present invention versus a 2 layer carpet without film at a thickness of 25 mm. As can be seen, in both situations, there are higher insertion losses with the 3 layer carpet with film as produced herein. 
       FIG. 5  shows sound absorption testing of a 3 layer carpet with film according to the present invention versus a 2 layer carpet without film at a thickness of 12 mm.  FIG. 6  shows sound absorption testing of a 3 layer carpet according to the present invention versus a 2 layer carpet without film at a thickness of 25 mm. As can be seen, for the 12 mm sample thickness, the 3 layer carpet shows better absorption at the testing frequency of 400 Hz to about 2500 Hz. With regards to the 25 mm sample, the 3 layer carpet shown better absorption at the testing frequency of 400 Hz to about 1000 Hz. It is worth noting that with respect to both  FIGS. 5-6 , 400 Hz to 800 Hz is the tire noise range which absorption has relatively high importance to the vehicle occupants. 
     While a preferred embodiment of the present invention(s) has been described, it should be understood that various changes, adaptations and modifications can be made therein without departing from the spirit of the invention(s) and the scope of the appended claims. The scope of the invention(s) should, therefore, be determined not with reference to the above description, but instead should be determined with reference to the appended claims along with their full scope of equivalents. Furthermore, it should be understood that the appended claims do not necessarily comprise the broadest scope of the invention(s) which the applicant is entitled to claim, or the only manner(s) in which the invention(s) may be claimed, or that all recited features are necessary. 
     LISTING OF REFERENCE CHARACTERS 
     
         
           10  Needle punch apparatus 
           12  Needle loom 
           14  Needle board 
           16  Needle board plate 
           18  Needles 
           20  Barbs 
           22  Upward vertical direction 
           24  Downward vertical direction 
           26  Needle beam 
           28  Needle loom driver 
           30  Stripper plate 
           32  Stripper plate through holes 
           36  Bed plate 
           38  Bed plate through holes 
           100  Non-woven article 
           110  Fibrous Substrate 
           112  Fiber base layer 
           114  Base layer fibers 
           120  Intermediate film 
           122  Film layer 
           124  Intermediate layer perforation 
           130  Fibrous cover 
           132  Fiber top layer 
           134  Top layer fibers