DETERMINATION AND OPTIMIZATION OF COMPRESSION ZONE LENGTH FOR POLYPROPYLENE FIBER PROCESS

Extrusion process is one of the most flexible and important operation for mass production of plastic product. In extrusion process, screw design is very important as it is largely affects the productivity and quality. The technical knowhow in these mills is based on experience of the employee thus processes are designed by trial and error without applying professional engineering design of the process. In this study focus was applied on analyzing and modeling the compression zone, which is considered to be the most important and complicated zone in the screw. An equation was derived so to determine the length of the compression zone that is suitable to produce polypropylene fibers

Numerical analysis of the electrospinning process for fabrication of composite fibers

An electrospun composite fiber process is a multi-phase and multi-physics process. It was very difficult to study a charged jet in the electrospinning process for the fabrication of composite fibers by experiments. In this study, the liquid-solid two-phase flow in the electrospinning process for fabrication of composite fibers was researched numerically. The results showed the addition of conductive nanoparticles resulted in the increase of the jet flow velocity, and the decrease of the fiber?s diameter. The CFD results corresponded well with the experimental data.

Effect of surfactant - assisted enzymatic treatment on the structure and specific properties of wool fibre

The objective of this study is to perform an enzymatic treatment on wool fibers in the presence of a mild detergent containing surfactants obtained from renewable raw materials, in order to obtain a reduction in the felting of wool fibers. This treatment is designed to replace the classic wool fiber process using chlorine compounds, aggressive to people and the environment. FTIR spectroscopy has demonstrated the effect of enzymes by breaking down bonds from the functional groups characteristic of the keratin protein of wool. Determination of relaxation shrinkage and felting shrinkage allowed the selection of the samples that led to a minimal felting phenomenon.