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Textiles are one of the most frequently collected items at crime scenes. Even so, the mechanisms that create bloodstains on textiles are not well understood. This is likely due to the wide range of textiles and the many surface treatments given to them to enhance their performance. In this study, the final appearance of 50 μl passive drip stains on four in-house knitted apparel textiles (scoured cotton, hydrophobic cotton, hydrophilic polyester and hydrophobic polyester) was investigated. The yarns used to make the knits were 167 dTex polyester filament and 342 dTex cotton staple yarns. They were knitted on the same knitting machine under nominally identical conditions. The area of bloodstains on the scoured cotton knit fabrics was 46 mm2 and 30 mm2 on the hydrophobic cotton. i.e. the stains on the hydrophilic cotton were 50% larger than on the hydrophobic cotton. The bloodstains on hydrophobic polyester were only 15.6 mm2, but were 242 mm2 on hydrophilic polyester, i.e. 15 times larger. The stain areas on the polyester were both smaller (hydrophobic finish) and larger (hydrophilic finish) than on the cotton fabrics. It is shown that these typical chemical treatments play a much more important role on bloodstain areas than fibre type or fabric construction. [ABSTRACT FROM AUTHOR]

Global warming is one of the alarming issues, which is impacting humans globally. It is preferred to adopt a lifestyle that promotes heat dissipation from the human body. One approach to cool a human body is improvement in personal apparel, which can help the human body to cool quickly. The required characteristic for cooling performance can be achieved by employing materials with excellent thermal conductivity. Nanodiamonds (ND) have exceptional thermal conductivity properties and can help overcome the poor thermal conductivity of fabrics. This manuscript presents a study on a one‐sided coated fabric where NDs are applied to the skin side of the fabric to promote heat dissipation toward the atmosphere while the other side of the fabric, exposed to the hot atmosphere, remains uncoated to delay the transfer of out from atmosphere to human body. ND was applied onto cotton fabric through electrospraying polyurethane (PU) and carboxylated ND (NDCOOH). Scanning electron microscope (SEM) and optical microscopy images indicated a homogeneous distribution of the sprayed ND/PU solution over the fabric surface. The samples were chemically analyzed by Fourier transform infrared spectroscopy (FTIR). The thermal resistance was measured by a sweating guarded hot plate (SGHP), which confirmed lower thermal resistance of fabric from the ND‐coated side to atmosphere as compared to control, and thermal resistance from the uncoated to atmosphere was the same for both controlled and treated samples. Similarly, thermal conductivity, radiant heat transfer, and infrared spectroscopy characterizations strengthened the findings of SGHP results. Real‐life simulated experiments were also conducted to verify the performance of developed samples. The electrosprayed samples also showed higher ultraviolet protection than the control sample. Air permeability and moisture absorption of the samples slightly decreased after applying the coating but remained within an acceptable range of comfortability. The developed fabric can promote energy conservation, as it will warm slowly but cool quickly. This allows home or office temperature setpoints for localized cooling to be 2–3°C lower with a projected energy savings between 20% and 30%. [ABSTRACT FROM AUTHOR]

Melt-blown webs from ester and ether thermoplastic polyurethanes and polyether-block-amide (PEBA) elastomers were produced at different die-to-collector distances (DCD) to study the correlation between the polymer type and hardness, melt-blowing process conditions, and web properties. An experimental set up was built to measure the air temperature and velocity profiles below and across the melt-blowing die to correlate the fiber formation process and polymer crystallization behavior to process conditions and web properties. It was shown that air temperature and velocity profiles follow similar trends with increasing distance below the melt-blowing die: both drop rapidly until reaching a plateau region approximately 5-6 cm below the die. Thereafter, they remain relatively constant with further increasing distance. It was found that crystallization onset and peak temperatures of all block copolymers in this study fall within this region of rapid velocity and temperature drop. This suggests that the polymers have already started to crystallize and solidify before reaching the collector, the extent of which depends on the crystallization kinetics of the polymer. The strong influence of the crystallization kinetics on web strength was clearly demonstrated in the PEBA series. In particular, the hardest grade produced the lowest web strength mainly because of its high crystallization rate and crystallization onset temperature. It is concluded that the melt-blown web strength is strongly dependent on the degree of fiber-to-fiber adhesion within the web, which is determined by the amount of fiber solidification that occurs prior to the collector. The crystallization kinetics of the polymer and the distances traveled between the die and collector or the exposure time of the polymer melt to process and ambient air were shown to be critical in the amount of fiber solidification attained. POLYM. ENG. SCI., 49:1340-1349, 2009. [C] 2009 Society of Plastics Engineers, INTRODUCTION Thermoplastic elastomers (TPE) represent a unique class of polymers as they combine the processing characteristics of conventional thermoplastics (plastics) and physical properties of elastomers (rubbers). Thermoplastic polyurethane (TPU) and [...]

Print clarity of a digitally printed product has great impact on the final esthetic appearance and performance of the printed products. Print clarity on various textile substrates is considered as image sharpness in this research. The current standard test method is a subjective test where a printed fabric is evaluated visually by one or more human subjects. To advance digital printing of textiles further, it is critical to create a quantitative evaluation method for testing print clarity (sharpness), as has been done with paper. In this paper, a quantitative evaluation of the print clarity (sharpness) of a digitally printed test pattern on textiles was created. Different colors, directions, and fabrics (substrates) were considered in the design of experiment. Eight similar weight and structure woven polyester samples along with a paper substrate were printed with MS JP7 printers using nano-pigments and printed in two directions. The resulting prints were scanned with an EPSON Expression 11000XL Photo Scanner. Several software packages, including Image-Pro and MatLab, were used to process data to analyze and compare image contrast of the test pattern under different conditions. Improved print clarity in digital printing on polyester woven fabric was explored. The newly developed test method is a quantitative test method that makes optimization of the print quality (sharpness) easier and more accurate. [ABSTRACT FROM AUTHOR]

There are few reports of studies of impact spatter on textiles even though bloodstained textiles are found at many violent scenes. Impact spatter was deposited at 90° impact angle onto three knit fabrics of different yarn sizes and on paper. The resulting stain areas and number of stains were measured using ImageJ and compared with stains on paper using one‐factor ANOVA. The number of stains observed and their areas on the knit fabrics decreased as the yarn size increased. It was also found that blood that deposited on the fabric wicked only in the direction of the fibers at that location within the fabric which led to distorted stain shapes. Fewer observed impact spatter stains were found on cotton jersey knits for fabrics made with larger yarns than on paper. As the yarn size became smaller, the number of stains became the same as on paper. [ABSTRACT FROM AUTHOR]

Indoor fungi growth is an increasing home health problem as our homes are more tightly sealed. One thing that limits durability of the antifungal agents is the scarcity of reactive sites on many surfaces to attach these agents. In order to increase graft yield of photosensitizers to the fabrics, poly(acrylic acid-co-styrene sulfonic acid-co-vinyl benzyl rose bengal or phloxine B) were polymerized and then grafted to electrospun fabrics. In an alternative process, azure A or toluidine blue O were grafted to poly(acrylic acid), which was subsequently grafted to nanofiber-based and microfiber-based fabrics. The fabrics grafted with photosensitizers induced antifungal effects on all seven types of fungi in the order of rose bengal > phloxine B > toluidine blue O > azure A, which follows the quantum yield production of singlet oxygen for these photoactive dyes. Their inhibition rates for inactivating fungal spores decreased in the order of P. cinnamomi, T. viride, A. niger, A. fumigatus, C. globosum, P. funiculosum, and M. grisea, which is associated with lipid composition in membrane and the morphology of fungal spores. The antifungal activity was also correlated with the surface area of fabric types which grafted the photosensitizer covalently on the surface as determined by the bound color strength. [ABSTRACT FROM AUTHOR]

ABSTRACT This study demonstrates that nanostructured fabrics grafted with rose bengal (RB) and phloxine B (PB) have photodynamic antifungal effects on Aspergillus fumigatus. RB and PB were attached to vinyl benzyl chloride, and, subsequently, this was polymerized with acrylic acid and styrene sulfonic acid to produce long, water-soluble polymers to attach to the fabric surface. This gave high grafting yield and photodynamic antifungal activity against A. fumigatus. In RB and PB microdilution tests, there was no visible turbidity at 63 µmol/L. When polymerized RB and PB were incorporated into fabrics, the actions of polymerized RB and PB resulted in less hyphal growth and germination of conidia on A. fumigatus than the free RB and PB dyes. Nanostructured fabrics created by bonding RB- or PB-containing polymers to electrospun nylon mats exhibited higher concentrations of the dyes, equivalent to 86 µmol/L. The microstructured fabrics created by bonding RB- or PB-containing polymers to spunbonded nylon nonwoven fabrics only exhibited the equivalent of 32 µmol/L of the dyes. The nanostructured fabrics had a specific surface area of 28.1 m2/g, whereas the microfabric had 1.5 m2/g. Thus, the nanostructured fabrics increased the surface area 18.7× and the reflectance percent 16.2× when compared with the microstructured fabrics. This resulted in much higher photodynamic antifungal activity against A. fumigatus. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42114. [ABSTRACT FROM AUTHOR]