Patent Publication Number: US-2017361588-A1

Title: Fiber structure having halogen-free foaming polymer layer

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the priority benefit of Korean Patent Application No. 10-2016-0074292, filed on Jun. 15, 2016 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference. 
     TECHNICAL FIELD 
     The present invention relates to a fiber structure having a halogen-free polymer layer that may include a styrenic block copolymer (SBC). 
     BACKGROUND OF THE INVENTION 
     Fibers form fiber structures as used in various mats, polyester fibers, nylon fibers and mixed fibers thereof, and polymeric materials have been used as backing layer/back coating layers thereof. Particularly, when those materials are used in a vehicle mat application produce, weight reduction as well as environmental problems thereof has been focused, and thus, various types of lightweight products have been developed. 
     The polymeric material used as a backing layer of a foaming mat can have waterproof function of a fiber product and maintain the shape of the fiber product and thus requires properties, such as softness, rapid restoration with respect to deformation, heat resistance and slip resistance. 
     Among polymeric materials which satisfy these property requirements and are used as backing layers of various fiber laminates and coated fibers, soft polyvinyl chloride (PVC) has excellent processability and price competitiveness and has been thus most widely used. 
     However, the PVC material including a plasticizer emits substances harmful to humans, such as hydrogen chloride gas, dioxin, and the like, upon combustion. In addition, the PVC material includes various heavy metals as additives, and thus becomes a target of environmental regulation. Further, the PVC material has a high specific gravity and thus cannot satisfy a lightweight trend. 
     Accordingly, non-woven fabric products having improved weight and compound products using non-foaming styrene butadiene styrene thermosetting rubber have been used as substitutes. Further, compound products of polyethylene, polypropylene, ethylene-vinyl acetate, and the like based on olefin are mentioned, but balance between processability and properties thereof may not be secured and thus use thereof may be limited. 
     Accordingly, development of technology regarding a fiber structure, which minimizes the above described problems, is environmentally friendly, reduces specific gravity, as compared to conventional fiber structures, and is soft to the touch so as to have improved commercial quality, has been required. 
     The foregoing is intended merely to aid in the understanding of the background of the present invention, and is not intended to mean that the present invention falls within the purview of the related art that is already known to those skilled in the art. 
     SUMMARY OF THE INVENTION 
     In preferred aspects, the present invention provides a fiber structure which may prevent environmental problems from conventional use of PVC and may have improved low temperature stability and resistance to deformation. 
     Further, the present invention provides a fiber structure which may use a foaming material, which is different from conventional materials, such as PVC, and the like, and may thus reduce weight and cost. 
     However, technical objects to be achieved by the present invention are not limited to those mentioned above, and other objects may be clearly understood by those skilled in the art from the description given below. 
     In one aspect, the present invention may provide a fiber structure including a fiber layer, an adhesive layer and a polymer layer. 
     In one preferred aspect, the polymer layer may be a foaming polymer layer. 
     The polymer layer may include a styrenic block copolymer (SBC), a halogen-free polymer and an inorganic foaming agent. 
     The polymer layer may further include an oil component and a filler. 
     The “oil component” as used herein refers to a component that may promote a process of during forming the polymer layer. Exemplary oil component may include a saturated fat such as paraffin or paraffin-based oil. The “filler” as used herein refers to a material added to a polymer mixture to improve properties or be used as a binding material between the mixture components. Exemplary filler may include both inorganic and organic materials such as calcium carbonate, talc, silica (silicon oxide) and combinations thereof. 
     The styrenic block copolymer (SBC) may include one or more selected from the group consisting of styrene butadiene styrene (SBS), styrene isoprene styrene (SIS), styrene ethylene butylene styrene (SEBS), styrene ethylene propylene styrene (SEPS), and styrene ethylene ethylene propylene styrene (SEEPS). 
     The styrene butadiene styrene (SBS) may be present in an amount of 0 to about 30% by weight with respect to the total weight of the fiber structure. 
     The styrene isoprene styrene (SIS) may be present in an amount of 0 to about 10% by weight with respect to the total weight of the fiber structure. 
     The styrene ethylene butylene styrene (SEBS) may be present in an amount of about 20 to 50% by weight with respect to the total weight of the fiber structure. 
     The halogen-free polymer may be an olefin-based polymer or a styrene-based polymer. 
     The olefin-based polymer may include one or more selected from the group consisting of high density polyethylene (HDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), polypropylene (PP) and ethylene vinyl acetate (EVA). 
     The olefin-based polymer may be present in an amount of about 10 to 30% by weight with respect to the total weight of the fiber structure. 
     The styrene-based polymer may include one or more selected from the group consisting of general purpose polystyrene (GPPS), high impact polystyrene (HIPS) and styrene maleic anhydride (SMA). 
     The styrene-based polymer may be present in an amount of 0 to about 10% by weight with respect to the total weight of the fiber structure. 
     The inorganic foaming agent may include one or more selected from the group consisting of sodium bicarbonate (NaHCO 3 ), ammonium carbonate ((NH 4 ) 2 CO 3 ), ammonium bicarbonate (NH 4 HCO 3 ), ammonium nitride (NH 4 NO 2 ), azides and a metal compound. 
     The metals may include magnesium (Mg), zinc (Zn) and aluminum (Al). 
     The inorganic foaming agent may be present in an amount of about 2 to 10% by weight with respect to the total weigh of the fiber structure. 
     The fiber layer, the adhesive layer and the polymer layer may be sequentially formed. 
     Further provided is a vehicle mat that may comprise the fiber structure as described herein. 
     Other aspects of the invention are disclosed infra. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  is an exemplary fiber structure according to an exemplary embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. 
     Unless specifically stated or obvious from context, as used herein, the term “about” is understood as within a range of normal tolerance in the art, for example within 2 standard deviations of the mean. “About” can be understood as within 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.5%, 0.1%, 0.05%, or 0.01% of the stated value. Unless otherwise clear from the context, all numerical values provided herein are modified by the term “about.” 
     It is understood that the term “vehicle” or “vehicular” or other similar term as used herein is inclusive of motor vehicles in general such as passenger automobiles including sports utility vehicles (SUV), buses, trucks, various commercial vehicles, watercraft including a variety of boats and ships, aircraft, and the like, and includes hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles and other alternative fuel vehicles (e.g. fuels derived from resources other than petroleum). As referred to herein, a hybrid vehicle is a vehicle that has two or more sources of power, for example both gasoline-powered and electric-powered vehicles. 
     Hereinafter, the present invention will be described in detail with reference to the accompanying drawings to allow those skilled in the art to easily practice the present invention. The terms or words used in the specification and claims of the present invention are not interpreted to have typical or dictionary limited meanings, and are interpreted to have meanings and concepts conforming to the technical sprit of the present invention based on the principle that the inventors can appropriately define the concepts of the terms to explain the present invention in the best manner. Accordingly, it is to be understood that the detailed description, which will be disclosed along with the accompanying drawings, is intended to describe the exemplary embodiments of the present invention and is not intended to represent all technical ideas of the present invention. Therefore, it should be understood that various equivalents and modifications can exist which can replace the embodiments described at the time of application. 
     In one aspect, a fiber structure may include a fiber layer, an adhesive layer and a polymer layer. The polymer layer may include a styrenic block copolymer (SBC), a halogen-free polymer and an inorganic foaming agent. 
     In preferred aspects, the polymer layer may be a foaming layer. Preferred foaming layer will contain foam including gas in a liquid resin or solid (cured) resin. The foaming layer may not be particularly limited by volumes or internal volumes. 
     In the present invention, in order to solve various problems generated from a composite material of a halogen-free fiber backing layer and problems of a product using a foaming agent, such as poor heat resistance and slip resistance, a styrene butadiene styrene (SBS)-based material may be suitably used. Further, a foaming agent for the SBS-based material may be selected and a fiber backing layer may be manufactured by securing processing conditions through many extrusion tests using a compound as a result product and by changing machinery, such as change of an extruder die. 
     Now, the present invention will be described in more detail. As shown in  FIG. 1 , the fiber structure in accordance with the present invention may include a fiber layer  11 , an adhesive layer  12  and a polymer layer  13 , and polyester fibers, nylon fibers and mixed fibers thereof are used as fibers used in the fiber layer  11 . 
     Preferably, the polymer layer  13  of the fiber structure may include a styrenic block copolymer (SBC), which is a thermoplastic elastomer, a halogen-free material, a foaming agent, other additives, and the like and mixing thereof may be carried out using a super mixer or a ribbon mixer. Further, pellets may be manufactured through water cooling using a twin-screw extruder set to have a temperature of about 160 to 200° C., a screw speed of about 240 to 300 rpm, and a feeding speed of about 600 to 800 rpm into a hopper, a test specimen for measuring properties may be manufactured by an injection molding machine using the pellets, and mechanical properties of the test specimen may be measured, which is described later. 
     In the present invention, the polymer layer  13  may be formed of a halogen-free material based on a styrenic block copolymer (SBC), which may be environmentally friendly and may have reduced weight as compared to a PVC material. The polymer layer  13  may be formed of a compound including an amount of about 20 to 60% by weight of an SBC-based polymer, an amount of about 10 to 30% by weight of a halogen-free polymer, an amount of 0 to about 10% by weight of a styrene-based polymer, an amount of about 10 to 40% by weight of an oil component, an amount of about 5 to 30% by weight of a filler, an amount of about 2 to 10% by weight of an inorganic foaming agent, and other additives. All the % by weight are based on the total weight of the polymer. 
     The polymer layer  13  may further include an oil component and a filler. Further, the SBC compound may include various additives, such as a process oil (secondary oil component), an antioxidant, an antistatic agent, a flame retardant, and the like, if necessary. 
     The styrenic block copolymer (SBC) may include one or more selected from the group consisting of styrene butadiene styrene (SBS), styrene isoprene styrene (SIS), styrene ethylene butylene styrene (SEBS), styrene ethylene propylene styrene (SEPS), and styrene ethylene ethylene propylene styrene (SEEPS). 
     Further, styrene butadiene styrene (SBS) may be present in an amount of 0 to about 30% by weight with respect to the total weight of the fiber structure, styrene isoprene styrene (SIS) may be present in an amount of 0 to about 10% by weight with respect to the total weight of the fiber structure, and styrene ethylene butylene styrene (SEBS) may be present in an amount of 20 to 50% by weight with respect to the total weight of the fiber structure. 
     The halogen-free polymer may be an olefin-based polymer or a styrene-based polymer. Preferably, the halogen-free polymer included in the compound may be an olefin-based polymer or a styrene-based polymer, and the halogen-free polymer and the SBC-based polymer may be independently used to be compounded or two or more kinds of polymers (an olefin-based polymer and a styrene-based polymer) may be used together to be compounded. 
     The olefin-based polymer may include one or more selected from the group consisting of high density polyethylene (HDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), polypropylene (PP) and ethylene vinyl acetate (EVA), however, particular kinds thereof may not be limited thereto. The olefin-based polymer suitably may use one or more kinds thereof. For example, when the SBC-based polymer and only the olefin-based polymer are used to be compounded, the olefin-based polymer may be present in an amount of about 10 to 30% by weight with respect to the weight of the compound. 
     Further, the olefin-based polymer may be present in an amount of about 10 to 30% by weight with respect to the total weight of the fiber compound. 
     Alternatively, instead of the olefin-based polymer, the styrene-based polymer may be solely used. 
     The styrene-based polymer may include one or more selected from the group consisting of general purpose polystyrene (GPPS), high impact polystyrene (HIPS) and styrene maleic anhydride (SMA), however, particular kinds thereof may not be limited. 
     The styrene-based polymer may be present in an amount of 0 to about 10% by weight with respect to the total weight of the fiber structure. 
     In the fiber structure of the present invention, the foaming agent causes weight reduction, less deformation, cost and material reduction, and the like, and an organic or inorganic foaming agent may be used as the foaming agent. An inorganic foaming agent used in the present invention may include one or more selected from the group consisting of sodium bicarbonate (NaHCO 3 ), ammonium carbonate ((NH 4 ) 2 CO 3 ), ammonium bicarbonate (NH 4 HCO 3 ), ammonium nitride (NH 4 NO 2 ), azides and a metal component. 
     Further, the light metals may include magnesium (Mg), zinc (Zn) and aluminum (Al), and the inorganic foaming agent may be present in an amount of about 2 to 10% by weight with respect to the total weight of the fiber structure. 
     The fiber layer  11 , the adhesive layer  12  and the polymer layer  13  may be sequentially formed. 
     A single-screw or twin-screw extruder may be used as an extruder necessary to manufacture the fiber structure of the present invention. For example, a single-screw extruder may be used in a pre-test for evaluating the fiber structure of the present invention, and a new T-die mold for molding a sheet may be manufactured and used to execute a property evaluation test which will be described later. 
     The most important factors influencing nucleation of a foaming sheet product may be temperature and pressure. As a temperature increases and a pressure decreases, foaming may be facilitated. Therefore, as factors on which relations between temperature and pressure have a strong influence during processing, sheet processing may be carried out at an extruder barrel temperature of about 160 to 220° C. and a T-die mold temperature of about 150 to 220° C. Further, in order to execute a simple durability test of a mat, laminating with fiber may be executed to facilitate mass-production. 
     The following Table 1 comparatively shows specific gravities, tensile strengths (TS) and elongations (EI) of conventionally used PVC and SBS materials. 
     
       
         
           
               
               
               
               
               
             
               
                   
                 TABLE 1 
               
               
                   
                   
               
               
                   
                 Division 
                 Specific gravity 
                 TS(kgf/cm 2 ) 
                 EI(%) 
               
               
                   
                   
               
             
            
               
                   
                 PVC 
                 1.4~1.7 
                 20~40 
                 100 or less 
               
               
                   
                 SBS 
                 1.0~1.2 
                 30~50 
                 300 or more 
               
               
                   
                   
               
            
           
         
       
     
     The fiber structure of the present invention may have a lower specific gravity than those of materials which have been mass-produced, i.e., PVC and SBS, as indicated in Table 1 above. In addition, the mechanical properties, i.e., tensile strength, elongation, and the like may be equal to those of the conventional materials. 
     The following Table 2 shows compositions of polymer layers  13  of Test examples of the present invention. 
     
       
         
           
               
               
             
               
                   
                 TABLE 2 
               
             
            
               
                   
                   
               
               
                   
                 Test example (wt %) 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
               
               
               
               
               
            
               
                 Composition 
                 #1 
                 #2 
                 #3 
                 #4 
                 #5 
                 #6 
                 #7 
                 #8 
                 #9 
                 #10 
                 #11 
                 #12 
                 #13 
                 #14 
                 #15 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
               
               
               
               
               
               
            
               
                 SBC 
                 SBS 
                 26 
                   
                 5 
                 13 
                   
                 10 
                 6 
                   
                 5 
                 20 
                   
                 23 
                 7 
                 10 
                   
               
               
                   
                 SIS 
                   
                   
                   
                   
                 5 
                 5 
                   
                 8 
                   
                   
                 5 
                   
                 5 
               
               
                   
                 SEBS 
                   
                 26 
                 31 
                 30 
                 34 
                 25 
                 35 
                 30 
                 48 
                 23 
                 34 
                 20 
                 30 
                 30 
                 37 
               
               
                 Olefin 
                 LDPE 
                 6 
                 6 
                 25 
                 20 
                 10 
                   
                 8 
                 10 
                 10 
                 10 
                 5 
                   
                   
                 20 
                 10 
               
               
                   
                 LLDPE 
                   
                   
                 5 
                   
                   
                   
                   
                   
                 5 
                   
                 5 
                   
                 10 
                 10 
               
               
                   
                 HOMO 
                 10 
                 5 
                   
                   
                 5 
                   
                 5 
                   
                   
                   
                   
                   
                 10 
               
               
                   
                 CO 
                   
                   
                   
                 5 
                   
                 10 
                   
                   
                   
                 5 
                   
                 8 
               
               
                   
                 Random 
                   
                 5 
                   
                   
                   
                   
                   
                 5 
                   
                 5 
                 8 
               
               
                   
                 EVA 
               
               
                 Styrenic 
                 HIPS 
                   
                   
                   
                   
                   
                 5 
                   
                   
                   
                   
                   
                 5 
               
               
                 Oil 
                 Paraffin- 
                 28 
                 28 
                 20 
                 20 
                 30 
                 30 
                 30 
                 25 
                 20 
                 25 
                 30 
                 29 
                 25 
                 10 
                 40 
               
               
                 component 
                 based 
               
               
                 Fillers 
                 Calcium 
                 28 
                 27 
                   
                   
                   
                 10 
                 14 
                   
                   
                   
                   
                 10 
                 10 
               
               
                   
                 carbonate 
               
               
                   
                 Talc 
                   
                   
                 5 
                 10 
                 5 
                   
                   
                 20 
                 5 
                 10 
                 5 
                   
                   
                 5 
                 5 
               
               
                   
                 Silica 
                   
                   
                 5 
                   
                 5 
                   
                   
                   
                 4 
                   
                 5 
                   
                   
                 5 
                 5 
               
               
                 Foaming 
                 Inorganic 
                 2 
                 3 
                 4 
                 2 
                 6 
                 5 
                 2 
                 2 
                 3 
                 2 
                 3 
                 5 
                 3 
                 10 
                 3 
               
               
                 agent 
                 foaming 
               
               
                   
                 agent 
                   
               
               
                 Sum 
                   
                 100 
                 100 
                 100 
                 100 
                 100 
                 100 
                 100 
                 100 
                 100 
                 100 
                 100 
                 100 
                 100 
                 100 
                 100 
               
               
                   
               
            
           
         
       
     
     Further, the following Table 3 shows measured values of mechanical properties of Test examples of the present invention. 
     
       
         
           
               
               
             
               
                   
                 TABLE 3 
               
               
                   
                   
               
             
            
               
                   
                 Test example (Wt %) 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 Composition 
                 #1 
                 #2 
                 #3 
                 #4 
                 #5 
                 #6 
                 #7 
                 #8 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
            
               
                 Mechanical 
                 Specific 
                 0.92 
                 0.90 
                 0.82 
                 0.86 
                 0.79 
                 0.81 
                 0.82 
                 0.85 
               
               
                 properties 
                 gravity 
               
               
                   
                 TS 
                 24 
                 60 
                 50 
                 25 
                 26 
                 23 
                 38 
                 35 
               
               
                   
                 (kgf/cm 2 ) 
               
               
                   
                 EI 
                 230 
                 450 
                 320 
                 200 
                 220 
                 200 
                 380 
                 350 
               
               
                   
                 (%) 
               
               
                   
               
            
           
           
               
               
            
               
                   
                 Test example (Wt %) 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                   
                 Composition 
                 #9 
                 #10 
                 #11 
                 #12 
                 #13 
                 #14 
                 #15 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
            
               
                   
                 Mechanical 
                 Specific 
                 0.75 
                 0.86 
                 0.79 
                 0.81 
                 0.86 
                 0.71 
                 0.83 
               
               
                   
                 properties 
                 gravity 
               
               
                   
                   
                 TS 
                 30 
                 40 
                 32 
                 23 
                 50 
                 22 
                 39 
               
               
                   
                   
                 (kgf/cm 2 ) 
               
               
                   
                   
                 EI 
                 320 
                 400 
                 320 
                 260 
                 300 
                 210 
                 410 
               
               
                   
                   
                 (%) 
               
               
                   
                   
               
            
           
         
       
     
     On the other hand, the following Table 4 shows compositions of polymer layers of Comparative examples. 
     
       
         
           
               
               
             
               
                   
                 TABLE 4 
               
             
            
               
                   
                   
               
               
                   
                 Comparative example (wt %) 
               
            
           
           
               
               
               
               
               
               
            
               
                 Composition 
                 #1 
                 #2 
                 #3 
                 #4 
                 #5 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
            
               
                 SBC 
                 SBS 
                   
                   
                   
                 22 
                 22 
               
               
                   
                 SIS 
               
               
                   
                 SEBS 
                 9 
                 9 
                 22 
               
               
                 Olefin 
                 LDPE 
               
               
                   
                 LLDPE 
                   
                 12 
               
               
                   
                 HOMO 
               
               
                   
                 CO 
                   
                   
                 15 
                 15 
               
               
                   
                 Random 
                   
                 10 
               
               
                   
                 EVA 
                 22 
                   
                   
                   
                 15 
               
               
                 Styrenic 
                 HIPS 
               
               
                 Process 
                 Paraffin- 
                 24 
                 24 
                 30 
                 30 
                 26 
               
               
                 coil 
                 based 
               
               
                 Filler 
                 Calcium 
                 27 
                 23 
                 20 
                 29 
                 26 
               
               
                   
                 carbonate 
               
               
                   
                 Talc 
                   
                 20 
               
               
                   
                 Silica 
                 15 
                   
                 10 
                   
                 5 
               
               
                 Foaming 
                 Inorganic 
                 3 
                 2 
                 3 
                 4 
                 6 
               
               
                 agent 
                 foaming 
               
               
                   
                 agent 
                   
                   
                   
                   
                   
               
               
                 Sum 
                   
                 100 
                 100 
                 100 
                 100 
                 100 
               
               
                   
               
            
           
         
       
     
     Further, the following Table 5 shows measured values of mechanical properties of Comparative examples. 
     
       
         
           
               
               
             
               
                   
                 TABLE 5 
               
             
            
               
                   
                   
               
               
                   
                 Comparative example (wt %) 
               
            
           
           
               
               
               
               
               
               
            
               
                 Composition 
                 #1 
                 #2 
                 #3 
                 #4 
                 #5 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
            
               
                 Mechanical 
                 Specific 
                 1.03 
                 1.05 
                 1.01 
                 1.05 
                 1.05 
               
               
                 properties 
                 gravity 
               
               
                   
                 TS 
                 36 
                 27 
                 62 
                 48 
                 38 
               
               
                   
                 (kgf/cm 2 ) 
               
               
                   
                 EI (%) 
                 480 
                 360 
                 590 
                 420 
                 360 
               
               
                   
               
            
           
         
       
     
     As exemplarily shown in Tables 2 to 5, it may be understood that the fiber structures in accordance with Test Examples of the present invention may have specific gravities in a range of about 0.71 to 0.92, which are reduced as compared to those of Comparative examples. Further, Test Examples may have tensile strengths of about 22 to 60 kgf/cm 2  and elongations of about 210 to 450%, which are equal to those of Comparative examples, thereby securing sufficient mass-production ability. 
     Further, as results of analysis of environmentally hazardous substances from the fiber structures of Test examples, substances, such as chlorine, lead, cadmium, chrome, mercury, were not detected. 
     Moreover, a fiber structure in accordance with the present invention may be applied to textile products, such as bags, shoes, household mats, and the like in addition to vehicle mats. 
     Accordingly, the fiber structure in accordance with the present invention may provide following advantages. 
     The fiber structure may not contain toxic substances, such as a unreacted vinyl chloride monomer (VCM), dioctyl phthalate (DOP), and the like form the conventional use of PVC, and thus, may decrease a generation amount of harmful gas, such as dioxin, when the fiber structure is burned, and may not include heavy metals and be environmentally friendly, In addition, the fiber structure may have a reduced specific gravity than other materials, such as PVC, and thus may have reduced weight effects of about 30% or greater. Further, the fiber structure may be soft based on the nature of a material and thus may have improved low temperature stability and improved fixing ability when the fiber structure is conventionally applied in a vehicle, and may have improved resistance to deformation according to change of external environmental conditions, such as temperature and humidity. Moreover, the fiber structure may reduce cost due to use of a foaming material, as compared to PVC, when the fiber structure is used for vehicles. 
     Although the various exemplary embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.