Zeitschrift für Textilwissenschaft und -technik

Reduction in noise pollution in general and particularly in automotive industry has become an important issue that has gained the interest of numerous researchers. The present research is aimed to introduce a new product which could serve as an alternative for other commonly used sound absorbing materials. It is expected that hollow fibers due to their structure can significantly influence noise insulation performance of materials in which these fibers are incorporated. Therefore sound absorbing material compose of blend of natural hollow fibers Milkweed or as it known Estabragh and hollow polyester fibers were used to produce needle-punched nonwoven samples. Eighteen different samples were produced by varying blend ratio, mass per unit area, punching density, and frequency of the incident sound. Noise Absorption Coefficient (NAC) of the samples was evaluated using impedance test method. The evaluation procedures were designed using Taguchi method. Results showed samples solely comprise of Estabragh fibers have attained the ability to absorb noise. It was observed that NAC decreases as the amount of Estabragh in the blend is reduced. Although the results showed an increase in punching density improves NAC of the samples, however statistical analysis dismissed the effectiveness of this parameter on sound absorption characteristics of the samples. It was found that NAC increases in direct relation to increase in mass per unit area (g/m2) of the samples. This was attributed to the increase in tortuosity of the samples and the energy losses due to frictional resistance. Finally it was observed that NAC peaks at frequency of 4000 Hz.

Apparel has an important role in keeping the body comfortable by maintaining the needed equilibrium state between the human body and the environment by getting rid of sweat which is exerted due to the physical activity. This happens through a multitude of mechanisms, one being the capillary action which is also known as wicking. Wicking is defined as “A spontaneous transport of liquid driven into a porous system by capillary forces”. This paper is concerned by studying effect of basic fabric weaves and weft densities of synthetic fabrics (PET) on vertical and horizontal wicking rates and their relation to fabric packing factor. For this aim, 9 samples 100% PET woven samples varying in weave type (plain 1/1-basket 2/2-twill 1/3) and three pick densities were produced, taking into account that the other production parameters were constant.

The experiment showed that wicking rate was influenced by fabric porosity. Vertical wicking rate increases with the increase of the porosity, while horizontal wicking rate decreases with the increase of porosity.

Digital image processing has been utilised widely in manufacturing for accurate automated inspection. Image processing is one such technique that involves computer processing of pictures or images that have been converted to numerical form. This paper presents a critical review of the exhaustive work of digital image processing and analysis and their application to measure twist and its distribution in yarns, weave pattern, yarn colour. Techniques of spatial & frequency domain use to extract twist angle and orientation of fibre on yarn surface respectively. Characteristics of weave extracted by Obliqueness (OB) and Orthogonality (OR) and yarn color design obtained by transmitted and reflected images.