Maryam Salehi

Study of fiber packing density of lyocell ring‐spun yarns

The study of yarn structure and related yarn properties has been the subject of much research. However, the study of the fiber packing density, which has practical significance for a number of yarns and their characteristics, has been limited to circular yarns because of the disordered yarn structure. In this paper, the fiber packing density of lyocell ring‐spun yarns is determined with the image analysis method. This method does not have any limitation with regard to the fiber cross‐sectional shape. The effect of yarn count, twist factor, spindle speed, traveler weight and front roller diameter on the fiber packing density in the yarn cross‐section is analyzed. The results of this paper and the data published in other scientific works are in good agreement.

Upgrading Fitness in the Production of Garments

This article uses a series of data mining techniques to analyze body types and introduce a new sizing chart in order to produce garments for males. A principle component analysis and hierarchical and non-hierarchical clustering approaches are used to form a new sizing chart. All variables are grouped into two main components with a principle component analysis. Agglomerative hierarchical clustering is used to determine the number of clusters, and then a k-means algorithm is applied to segment the heterogonous population to actually form the clusters. The resultant innovations in designing garments have improved both non-price and price factors, the fittings of garments on all bodies have effectively improved and fabric waste has decreased, so the main goals which include improvement in quality with more comfort and a lower price have been met.

Optimisation of mechanical milling process for production of AA 7075/(SiC or TiB2) composite powders

Abstract The present work concerns the processing of composite powders based on 7075 aluminium alloy by mechanical milling. A premixed powder (Alumix 431D, Ecka Granules, Germany) was used as the matrix material, and two different ceramic reinforcements (SiC and TiB2) were chosen as reinforcements. The main objective was to evaluate the effect of the content and addition method of the process control agent as well as the content and type of reinforcement on the microstructural and morphological evolutions of the powder particles during milling process and the as milled properties of the processed materials. Results showed that regardless of the starting composition, alloying took place through three stages, in which deformation, cold welding and fracturing of powder particles were the main mechanisms involved respectively. The mechanically milled composite powders showed a fine and homogenous distribution of reinforcement particles. A higher content of reinforcement resulted in a lower crystalline size for the milled powders (∼18 nm for composite powders containing 15 vol.-% ceramic particles).