Fibers are recently being considered as a new agent for improving the performance of existing building materials. However, until now, only simple methods have been applied for fiber use, such as scattering a small fiber amount inside the material or using fibers as a sheet covering for the material. Application of woven or textile fibers inside the material is believed to result in higher performance of a building material. However, because basic research on composite material performance is still underway and the theoretical manufacturing skills and techniques for fiber application have not been implemented, fibers have not yet been practically used in building materials. The purpose of this study is to evaluate the properties of the flexural strength of composite materials using textile fibers to obtain fundamental data for the production of high-performance building materials. The flexural strength of the textile-reinforced specimens increases by 55% as compared with that of the reference specimens, and it increases proportionally with an increase in the maximum tensile load of the textile. The flexural strength of the panel is estimated to increase on the basis of the tensile load of the textile. However, an increase in the thickness of the specimen containing the textile decreases the rate of increase in flexural strength.

This study investigates the effects of wet and hot press treatments on the structure and mechanical properties of natural silk non-woven fabric under two post-treatment conditions: (a) hot press without wet treatment and (b) hot press with wet treatment. With respect to the fabric structure, a hot press without wet treatment does not alter the arrangement of silk filaments, while a hot press with wet treatment causes wrinkles in the fabric, and further bending of the silk filaments as the temperature is increased. With respect to the fabric mechanical properties, there is no improvement observed in the first condition, while the tensile strength of the fabric remarkably increases in the second condition when the hot press temperature is increased up to $200^{\circ}C$, indicating the crucial swelling of sericin by wet treatment to bind silk filaments. However, at a hot press temperature reaching $230^{\circ}C$, tensile strength decreases due to the molecular degradation of sericin. Moreover, hot press significantly decreases the porosity of the natural silk non-woven fabric with the wet treatment further accelerating the effect.

With the rapid growth of the Internet of things in the recent years, smart textile technologies have correspondingly attracted significant research attention in the industry. One important elementary technology being considered for smart textiles is a touch sensor input device to enable direct communication between users and other electronic devices. This study investigated the effect of the structural difference in conducting fibers on the sensing property of capacitive textile touch sensors. Conducting fibers made of stainless steel spun yarns and filaments used for electrodes presented different changes in electrical resistance with the application of tensile and compressive forces. It is believed that the different structures between spun yarns and filaments induced difference in the electric contact among their constituent fibers with the application of an external force. Moreover, the random deformation of staple fibers resulted in the unstable change of capacitance and large hysteresis, while a stable performance and low hysteresis was observed for textile sensors with filaments.

The ceramide-contained 3D textile structure was designed for itch relief in atopic dermatitis. We confirmed the ability of the prepared 3D fabric to control humidity in the human skin surface, according to composition and density of moisture controlling textile structure, to mitigate atopic dermatitis. With respect to itch relief functionality, the ceramide-contained 3D fabric is chemically treated using insoluble polyphenols, and the protein enzyme is inactivated by an aggregation experiment between polyphenols and bovine serum albumin, which is considered as a standard protein. From the evaluation of the anti-oxidation factor of cotton- and nylon-treated tannin and gallotannin, we concluded that the ceramide-contained 3D fabric is suitable to apply as skin care clothing.

Graphene oxide can be prepared from graphene by introducing hydrophilic functional groups to facilitate dispersion in water. This process has attracted significant attention for production of fillers for polymer composite materials. Alginate is a natural polymer that can be used as a composite fiber matrix that is industrially applicable and is currently being studied for the development of novel materials. Graphene oxide/alginate composite fibers were prepared with various graphene oxide contents by wet spinning in a calcium chloride coagulation solution. To improve thermal and electrical properties, the graphene oxide/alginate fibers were reduced using hydrogen iodide and acetic acid. After low temperature carbonization over a graphite nickel catalyst, the yield of the carbonized alginate precursor increased from 20.3% to 36.1% upon addition of graphene oxide. After reduction and carbonization, XRD analysis showed the presence of a $2{\theta}=26.4^{\circ}$ peak arising from the (002) plane of the graphite structure. In addition, electrical conductivity increased from 225 to 13575 S/m, indicating that the composite fibers successfully incorporated graphite.

The behavioral characteristics of sliver linear density under roller drafting operation were investigated in this study. A theoretical model describing the dynamic behavior of the staples flowing in a single direction was applied. While the model parameters remained constant, the process parameters including draw ratio and roller distance were varied. Simulations of the dynamic behavior of the drawn sliver linear density showed that it was dependent on the process conditions, and the effects varied depending on the staple length distribution. For uniform length staples, the linear density of the drawn sliver showed periodic changes at a steady state when the drawing roller distance was long. For the short drawing zone, the drawn sliver exhibited a constant steady state linear density. Increasing the draw ratio caused the linear density to change periodically which resulted in an increase in the CV% of the drawn sliver linear density. For length distributed staples, the linear density was sensitive to the draw ratio. At a low draw ratio, for example, DR=4, the drawing zone length did not affect the sliver linear density, and a constant linear density was observed. However, at high draw ratios, for example, DR=12, the drawing zone length affected the linear density behavior of the drawn sliver, showing periodic changes in the steady state. Thus, high draw ratios and long drawing zones caused a drastic increase in the CV% of the quasi-steady state linear density. In general, the two passes of sliver in a drawing operation with low draw ratio resulted in improved properties, that is, a more even linear density of the drawn sliver than that obtained using single drawing pass with a high level draw ratio, which drastically increased the linear density.

Herein, the thermal adhesion behavior of polypropylene (PP) mono-component and polyethylene/PP sheath-core non-wovens was investigated. The materials generally showed good mechanical properties and environmental benefits. The proper bonding temperature was determined because thermal bonding among fiber networks results in adversely affects bonding strength and structural integrity. The morphology of the adhesive interface, thermal shrinkage, wrinkle properties, and compressive properties were also characterized and showed that differences in thermal behaviors due to the material and dimensional variation affected bonding strength and air permeability. It is expected that these results, that also include flexibility and durability measurements, will provide guidance for the manufacturing of products containing these materials.

Poly(${\rho}$-phenylene benzobisoxazole) (PBO) and it's nanocomposites with ZnO nanoparicles containing 0.5-2.0 wt% were successfully fabricated in poly(phospheric acid) and $P_2O_5$ via in situ polymerization to investigate the improvement for the UV resistance of PBO fiber. The as-polymerized solutions having 14 wt% of PBO solid content were spun at liquid crystalline state through dry-jet wet spinning to prepare PBO and it's nanocomposite fibers. It was found that the ZnO nanoparticles were dispersed individually in the fibers from SEM observation because of in situ polymerization for a long time up to 33 h. It was concluded that ZnO nanoparticles were significantly effective in enhacing UV resistance of PBO fiber even at low addition amount by exhibiting much lower reduction in tensile strength under the same UV exposure time.

In this study, a 6-line seaming method was used to connect woven geotextiles for soft ground reinforcement and select adhesives were added to the seaming part of the woven geotextile to improve the seam strength. Different reinforcement effects were observed according to the type of adhesive used. The strength retention of the seam strength was excellent when the cyanoacrylate adhesive was used in place of the epoxy adhesive. Since the reduction factor directly affects the tensile and seam strengths of the woven geotextile, it is essential to reinforce the seam using proper adhesives. The reduction factor and long-term performance of the adhesive agent are thought to contribute to the improvement of seam strength in woven geotextiles, and this was supported by the experimental results.

To develop heat insulation fabrics with lightweight, low volume and excellent thermal insulation properties, in this study, a binder-free polypropylene/silica aerogel nonwoven fabric with an area density of ${\sim}79.7g/m^2$ was fabricated via a facile melt-blowing process, and its structure, thermal conductivity and thermal insulation properties were investigated. For comparison, a polyester hollow fiber nonwoven having a similar area density of ${\sim}84.6g/m^2$ was prepared by needle-punching. Additionally, a series of composite nonwoven fabrics was prepared by layering the melt-blown polypropylene/silica aerogel nonwoven and the polyester hollow fiber nonwoven in various combinations, and their thermal insulation properties and thermal conductivity were analyzed. Scanning electron microscopic analyses revealed that 5 wt% silica aerogel added during the melt-blown process was adhered well to polypropylene fiber surfaces of the nonwoven fabric. As a result, the melt-blown polypropylene/silica aerogel nonwoven fabric exhibited a low thermal conductivity of $43mW/m{\cdot}K$ and relatively high level of thermal insulation performance, although its thickness (~1.5 mm) was lower than that (~2.2 mm) of needle-punched polyester hollow fiber nonwoven with a similar area density. The thermal conductivity was lowered and thermal insulation performance was improved, as the melt-blown polypropylene/silica aerogel nonwoven fabric was layered. It was also found that increasing the number of melt-blown polypropylene/silica aerogel nonwoven fabric layers in the composite nonwoven fabrics layered in various combinations decreased the thermal conductivity and improved the thermal insulating properties.

Carbon fiber/polyamide 6 (CF/PA6) composites were prepared via film melt impregnation and their crystallization and mechanical properties were studied. The non-isothermal crystallization behavior and mechanical properties of polyamide 6 and CF/PA6 were investigated at different cooling rates. The crystallization time of CF/PA6 decreased depending on the cooling rate compared to that of polyamide 6. The carbon fibers likely acted as nucleating agents in the polyamide 6 matrix. The flexural strength of the composites increased when manufactured at lower cooling rates due to the effects of increased crystallinity as the crystallization continued for a long time. In addition, as the cooling rate increased, the impact resistance increased.