| Interlacing is a simple process with many names. Tangling, entangling, intermingling stands all for one and the same process of interlacing. This page will explain to you the principle on how yarns are interlaced, why yarns are interlaced and why interlacing has become such an important factor in the production of textured yarns. We also will dwell shortly on interlaced POY and FDY. |
Why do we interlace yarns:
To give synthetic filaments a cohesion, which could
earlier only be obtained by twisting.
The interlacing principle:
A continuous yarn, running under a defined tension
through an air jet, can be interlaced if a perpendicular or nearly perpendicular
high pressure air stream is applied to the yarn. The air stream creates
a turbulence, splitting the yarn bundle and then forcing individual filaments
together, which creates a kind of braiding effect on the yarn. Thereby
the cohesion between the filaments is increased by a large magnitude.
Such DTY yarn can now be used without any further twisting in weaving and
knitting.
The schematic below shows the principle of how an air stream will produce an interlaced yarn:
A multifilament yarn is fed through the tangling jet. The perpendicular compressed air stream will split the filament bundle. Due to a very high dynamic force the filaments collapse again into the filament bundle where they now entangle. The entangled yarn is characterized by having tangle knots at very regular intervals. This evenness is for subsequent processes most important. The density of the tangle knot is controlled by air pressure and the yarn tension. The evenness of the knots is a result of the evenness of the yarn tension and the compressed air pressure. The design of the air jet and the angle of the yarn path in and out of the jet is mainly responsible for frequency of the knots and the actual air consumption. The shape of the yarn channel and the size of the orifices of the compressed air channel varies between the manufacturers of interlacing air jets.
The next picture shows where in the machine a tangle jet can be located :
The first row shows the ideal situation, where the
jet is located between a set of feed shafts, allowing the producer to exactly
control the tangle tension of the process.
The middle row demonstrates where a jet can be located
on older equipment. Advantage of this location is easy access and supervision
of the process. But a disadvantage is the fact that the tangle tension is
governing the setting tension.
The last row shows the location of the jet after the
second heater and before the last feed shaft. Disadvantage is inaccessibility
and less control. But this location was favored for a long time as
it would allow first to produce a uniform set yarn before the yarn was tangled.
What type of yarns can be interlaced?
Synthetic filament yarns, regardless if they are POY,
FOY or DTY can be interlaced. As a rule, the lower the denier per filament
and the more filaments the easier it is to achieve a cost effective tangle
result.
POY is interlaced for better package formation and better
texturing results, e.g. less filament breaks.
FDY is interlaced for better package formation and for
better warping and weaving results.
If you want to find out more about DTY set yarn and DTY stretch yarn visit my pages:
I hope that my explanation has helped you to understand the principle of the texturing process. There is much more knowledge out there, but unfortunately very little on the web. I will try to remedy this situation and welcome all suggestions. Please let me have your comments.
Last updated November
16, 2002
Copyright Udo P. Schweizer