Thesis-1994-Bilgin.pdf (5.57 MB)
Texturing and intermingling processes by using air-jets
thesis
posted on 2013-02-20, 13:51 authored by Sule BilginThe air-jet texturing (AJT) and intermingling (INT) processes
are two applications of air jets used to modify the structure
of synthetic multifilament yarns. The modification is
performed by high-speed jets, which are created by purpose
designed nozzles.
The present work experimentally investigates the interrelation
between properties of the yarn produced and air flow and the
nozzle geometry in order to gain an improved understanding of
the AJT process. Firstly, a number of industrial AJT nozzles
were selected for detailed analysis. undisturbed flows created
by these nozzles are investigated by means of total pressure
measurements and shadowgraphy. The effect of nozzle geometry on the AJT process is
investigated by using a series of systematically designed
nozzles. A number of geometrical parameters of cylindrical
type AJT nozzles are specified for successful texturing, after
assessing performance of the nozzles by stabilising zone
tension and the properties of yarns produced. It is found that
large exit length and slightly diverging main duct are
beneficial for texturing. Also the trumpet shaped exit profile
is found to be necessary for adequate texturing. Low tilt
angle of air inlet hole is recommended.
Effect of wetting on AJT is investigated with special
reference to yarn-to-yarn and yarn-to-metal friction. It is
found that when the supply yarn is treated with water
interfilament friction prior to the nozzle is reduced, but
increased slightly in the texturing area. The former may make
relative movement of filaments easier. The latter is
considered to be one of the ways through which wetting
improves the process, since it assists anchoring the loops in
the yarn.
Subsequently high-speed cine-photograpy is deployed to
visualise the AJT process inside and around exit area of the
nozzle. The nozzle used has rectangular cross-section and one
glass wall, which allows to see inside the main channel. It is
found that for successful texturing loop formation and fixing
the loops are both necessary.
The INT process is investigated by using again several
systematically designed nozzles with reference to correlation
between nip frequency and nozzle geometry. Rectangular nozzles
are found to be performing adequately, depending on their
dimensions. The nozzles with area ratio smaller than unity
perform adequate intermingling. It is also found that small
aspect ratio is benefical in terms of nip frequency.
A better understanding of the INT is achieved by means of SEM,
high speed video and cine-photography and yarn tension
measurements. The yarn is found to be necessary to run
constantly against the incoming flow to reduce missing nips.
History
School
- Mechanical, Electrical and Manufacturing Engineering
Publisher
© S. BilginPublication date
1994Notes
A Doctoral Thesis. Submitted in partial fulfilment of the requirements for the award of Doctor of Philosophy of Loughborough University.EThOS Persistent ID
uk.bl.ethos.566491Language
- en