Guldemet Basal

Effects of some process parameters on the structure and properties of vortex spun yarn

The effects of a number of process parameters, including the nozzle angle, nozzle pressure, spindle diameter, yarn delivery speed, and distance between the front roller and the spindle, on the structure and properties of vortex spun yarns were investigated. A modified version of the tracer fiber technique (J. Text. Inst.,43, T60-T66, 1952) combined with the Image Analysis Application Version 3.0 (B.A.R.N. Engineering) was utilized to explore yarn structure. The migration behavior of fibers was characterized using the migration parameters introduced by Hearle et al. (Text. Res. J.,35, 329-334,788-795, 1965). The results showed that the short front roller to the spindle distance caused better evenness, low imperfections, and less hairiness. High nozzle angle, high nozzle pressure, low yarn delivery speed and small spindle diameter reduced hairiness as well. High nozzle angle, high nozzle pressure and low speed also led to higher fiber migration. Surprisingly nozzle angle, nozzle pressure or delivery speed did not have any significant effects on yarn tensile properties. This is believed to be caused by the relatively small differences between the levels of these parameters used in the trials. The present study provides a window into the vortex spinning technology, but further research needs to be conducted to establish a “process-structure-property model” for vortex yarns.

Comparison of Properties and Structures of Compact and Conventional Spun Yarns

The properties and structural parameters of compact and conventional ring yarns produced at five different twist levels were compared. A modified version of the tracer fiber technique (J. Textile Inst., 43, T60-T66, 1952) combined with the Image Analysis Application Version 3.0 (B.A.R.N. Engineering) was utilized to explore yarn structure. Results obtained from these analyses showed that the high tenacity values of compact yarns can be attributed to the higher rate and amplitude of fiber migration in these yarns compared to those in conventional ring yarns. Another important finding was the superiority of compact yarns in terms of tensile properties is less noticeable at higher twist levels and in 50/50 polyester/cotton blend.

Micro‐encapsulation of ozonated red pepper seed oil with antimicrobial activity and application to nonwoven fabric

In recent years, functional fabrics possessing antimicrobial activity have drawn significant interest because antibiotic resistance is becoming widespread among pathogenic micro‐organisms. The aim of this study was to produce microcapsules incorporating ozonated red pepper seed oil (ORPSO) with antimicrobial properties and apply them to nonwoven fabrics to prepare functional textiles. Red pepper seed oil (RPSO) was ozonated and micro‐encapsulated via a complex coacervation method using gelatin (GE) and gum arabic (GA) as wall materials. While micro‐encapsulation yield and oil loading decreased with increases in the amount of surfactant, the mean particle size increased. The antimicrobial activity of the oil was tested via the disc diffusion method. The microcapsules were also tested using the agar well method. While RPSO had no effect on the test micro‐organisms, the ORPSO and microcapsules containing ORPSO were found to be active against the test micro‐organisms. The microcapsules were then applied to nonwoven fabric using the padding method to produce a disposable functional textile. The microcapsule‐impregnated functional fabrics provided a 5 log decrease in 1 h. It is therefore possible to functionalize nonwoven fabrics to have antimicrobial activity against antibiotic‐resistant micro‐organisms, using microcapsules containing ORPSO.

A Functional Fabric for Pressure Ulcer Prevention

Pressure ulcers, also known as bed sores, pressure sores and decubitus ulcers, are localized areas of tissue damage that develop due to pressure usually over a bony prominence. They are associated with adverse health outcomes and high treatment costs. This study focused on developing a functional fabric for pressure ulcer prevention. For this purpose, face-to-face velour weaving technique was utilized to produce a spacer fabric from the different combinations of engineered polyester, polypropylene, cotton and viscose fibers. Thermal conductivity, thermal resistance, thermal absorptivity, water vapor permeability, wicking ability, compressibility and fabric hand properties of the resultant 32 fabrics were examined. Based on the results, channeled polyester, cotton and polypropylene were determined as the most promising fiber types for the final product.

Bioactive Sheath/Core nanofibers containing olive leaf extract.

This study aimed at producing silk fibroin (SF)/hyaluronic acid (HA) and olive leaf extract (OLE) nanofibers with sheath/core morphology by coaxial electrospinning method, determining their antimicrobial properties, and examining release profiles of OLE from these coaxial nanofibers. Optimum electrospinning process and solution parameters were determined to obtain uniform and bead‐free coaxial nanofibers. Scanning electron microscopy and transmission electron microscopy (TEM) were used to characterize the morphology of the nanofibers. The antimicrobial activities of nanofibers were tested according to AATCC test method 100. Total phenolic content and total antioxidant activity were tested using in vitro batch release system. The quality and quantity of released components of OLE were determined by high‐performance liquid chromatography. The changes in nanofibers were examined by Fourier‐transform infrared spectroscopy. Uniform and bead‐free nanofibers were produced successfully. TEM images confirmed the coaxial structure. OLE‐loaded nanofibers demonstrated almost perfect antibacterial activities against both of gram‐negative and gram‐positive bacteria. Antifungal activity against C. albicans was rather poor. After a release period of 1 month, it was observed that ∼70–95% of the OLE was released from nanofibers and it was still bioactive. Overall results indicate that the resultant shell/core nanofibers have a great potential to be used as biomaterials. Microsc. Res. Tech. 79:38–49, 2016.