AATCC Journal of Research

The main concern for the limited practical applications of strain-hardening cementitious composite, especially in China, is the high cost of imported materials, mainly polyvinyl alcohol fibers. This study uses local ingredients to develop strain-hardening cementitious composite reinforced with non-oil-coated Chinese polyvinyl alcohol fiber. The cementitious matrix consisting of cement, fly ash, viscosity-modifying agent, and silica fume was prepared, and the matrix tailoring was performed to achieve improved mechanical performance. The prepared composites were evaluated by rheology, three-point bending, and tensile characterizations. It is found that with the given local ingredients and matrix modification, the toughness index value of 100 (I₄₀) according to the American Society for Testing and Materials can be achieved. Besides, the tensile results showed the improvement of 45% and 60% for first-cracking strength and peak tensile strength values, respectively. The effects of matrix modification are also analyzed statistically using the analysis of variance for the mechanical properties of the cementitious composite. The post hoc statistical analysis using the Tukey–Kramer honestly significant difference illustrated the optimum cementitious mix from the experimental data. The presented results of cost-effective strain-hardening cementitious composite are expected to promote the practical applications of strain-hardening cementitious composite in China.

The impact of stitch density and seam type on tactile properties of seams has been investigated. Lapped seam 1 (LSa-1) using stitch class 605 and superimposed seam (SSa-2) using stitch class 514 (ASTM 6193) were constructed with four different stitch densities, namely, stitches per inch (SPI) 10, SPI 14, SPI 18 and SPI 22, and the tactile properties of seams examined by evaluating the characteristics of seams such as seam compression, seam thickness, seam bending behaviour and surface friction of seams. From the study, the optimized stitch density has been identified as SPI 10 for producing soft seam. Seam class and stitch density play a vital role in determining seam comfort properties.

Cuff design is the most important aspect to work on for the accurate measurement of blood pressure. For the very first time, pressure distribution underneath different parts/components of the fabric cuffs was analysed in detail using an advanced interface pressure sensing system. The pressure distribution at the interface of the selected cuffs and an arm simulator were measured experimentally while simulating blood pressure measurement. Fabrics are the main cuff constructing material and a relationship was found between cuff fabric properties and pressure at the interface of the cuff and the arm simulator. It was also found that the pressure distribution under different parts of the same cuff varied due to the uneven contact of the cuff fabric with the arm simulator. Components attached to cuff fabric which facilitate blood pressure measurement either confine or drive fabric according to their size and placement; they may cause non-uniform interface pressure distribution on the human arm too. It was also examined whether the selected cuffs were applying higher or lower average pressure over the surface of the simulator and the range varied from 8 mmHg to 25 mmHg. This indicates that the subsequent pressure distribution inside the arm tissues and over an artery would also vary further due to the cuffs being of different designs. This study found that cuffs would be unable to transfer the required pressure over the artery to block blood flow as and when needed.

Fibrous textiles readily absorb and desorb ambient odors. However, information on the composition and dynamic analysis of tobacco smoke and hot pot odors on fabrics during desorption is limited. This study used gas chromatography–mass spectrometry to analyze the desorption components of cotton, wool, and polyester fabrics exposed to these two odors, respectively. Then, a dynamic diffusion fabric structure model demonstrated the effect of airflow velocity and fabric porosity on nicotine desorption. Furthermore, we proposed mass diffusion coefficients with different molecular weights. The results showed that cotton fabrics with tobacco smoke released many low molecular weight compounds, while with wool fabrics significantly fewer compounds were detected than for the other two fabrics. Notably, 3-ethenylpyridine, a marker of tobacco smoke, was not detected in wool fabrics. For hot pot odor, cotton fabrics released more hexanal, nonanal, and anethole than wool and polyester, while wool fabrics released many β-pinenes. The numerical results of the dynamic model showed that the air inlet velocity significantly affects the nicotine concentration in the fabric. Meanwhile, the concentration of nicotine in fabrics with lower porosity decreased faster. A lower mass diffusion coefficient will cause odors to remain in the fabric. This study aimed at the composition and the dynamics of odor in fabrics and offers essential information and simple models for reducing unnecessary washing of textiles and odor resistance textile design.

Oil sorption capacity is one of the essential parameters to evaluate the practical performances of oil sorbent products. This study aims to compare the dynamic oil sorption capacity of industrial nonwoven sorbents, which were fabricated through the carding process, spun-bond technology, and composite processes. The oil sorbents were produced by polypropylene fibers or cotton fibers with different surface wettability. The study showed that raw cotton layers exhibited a higher oil sorption capacity than the other three samples: eight-layer thermal-bonded melt-blown polypropylene fiber nonwoven, polypropylene fibers on top and bottom with raw cotton layers in the middle, and polypropylene fiber melt-blown nonwovens. Comparatively, eight-layer thermal-bonded melt-blown polypropylene fiber nonwoven had the lowest oil sorption capacity. Moreover, the hydrophilic property can significantly enhance the water pick-up capacity of sorbents on both dynamic and static systems but reduce the maximum oil sorption ability. Overall, the major factors determining a nonwoven fabric’s oil absorption performance are its fiber type, surface wettability, and hydrophobicity/hydrophilicity. Specifically, raw cotton, polypropylene fibers, or polypropylene fiber/cotton composite oil sorbents with low hydrophobicity and high hydrophobicity will contribute to high oil absorption ability. The advantage of raw cotton over polypropylene fibers is 3–7 times higher in oil absorption capability, environmentally friendliness, and sustainability, attributed to their hydrophobic ingredients, including pectin and waxes. From a structure angle, products with a loose structure and good mechanical properties ensure a balance between service life and oil absorption performance.

Graphical abstract

This research is to analyze the effect of fiber types, the structure of sorbents, and surface wettability on nonwoven oil sorption capabilities. We compared the oil sorption capacity of multiple nonwoven sorbents, which were fabricated through the carding process, spun-bond technology, and composite processes. The oil sorbents were produced by polypropylene fibers or cotton fibers with different surface wettability. Their dynamic and static hydrophilic properties and their associations with oil sorption capabilities were examined.

Nylon fibers were the first synthetic fibers to be produced on an industrial scale, and they are one of the most consumed synthetic fibers due to their visual and usage properties. Reactive dyes have been commercially produced since the mid-20th century, and they are mostly preferred in dyeing cellulosic fibers. The most important property of reactive dyes is their ability to make covalent bonds within the fiber. Mordants are used mainly in the application of natural dyes to hold and retain the dye molecules in the fiber. In this paper, nylon fabrics were dyed with three reactive dyes having different reactive groups (monochlorotiazine, trifluoropyrimidine and monochlorotriazine/vinylsulfone) in the presence of three chemical mordants (iron (II) sulfate, potassium aluminum sulfate and tannic acid) to obtain better exhaustion and coloration properties. Pre-mordanting, meta-mordanting, and post-mordanting processes were used for dyeing. The dyeings were performed at two dyeing concentrations (0.5% and 2% owf), and at three pH levels (pH 2, 4, and 6). The percentage of dyebath exhaustion (%E), the percentage fixation of the dye which exhausted (%F) and the overall percentage fixation (%T) were calculated after pyridine extraction. Wash and light fastness tests were applied on the dyed samples. The results were discussed via %E, %T and CIELAB color differences (ΔE_ab*). The results revealed that mordant usage improved the coloration properties of reactive dyes on nylon fabrics. The %E and %T results changed according to the independent variations of pH level, mordant chemical and mordanting method. The correct pH level and mordanting method gave the best dyeing and fastness results for the dyes under test.