| Air jet textured yarns are a spun look like alternative to the more synthetic hand of false twist textured yarns. This page will explain how ATY is produced and where it is used. We will show you the difference between a parallel and a core effect yarn and will show in some detail what an ATY machines look like. |
Why and where do we need ATY?
ATY can offer an entirely different look and hand
to any fabric. It can be used in a very broad range of fabrics from
simple lightweight scrim all the way to very heavy duty soft luggage
fabrics, from lightweight swim wear to heavy weight parkas.
Several filament yarns can be mixed to construct the ideal ATY for a
certain endues. ATY is a rather expensive yarn if the denier is
low. But higher deniers compare very favorable with competitive
spun yarns.
What is the primary difference between ATY
and DTY?
Although both yarns are made from
POY, ATY is a yarn with zillions of small loops, which give it a
distinct feeling and look whereas DTY is a yarn with preferably no
loops at all. The loops in ATY contribute to the bulk and loft of
a fabric, whereas in DTY the
even crimp in every filament creates the bulk and volume of a fabric.
The ATY texturing principle; parallel ATY
yarn:
One or more ends of filament yarn are
overfed at a constant rate to a special air jet, which blows, depending
on the amount of overfeed between the inlet and outlet feeds, the yarns
into a continuous string of smaller and larger loops. Similar as
in the tangling of yarns the center of the ATY becomes randomly
braided. The individual filaments are compacted by the air
stream, which stabilizes the loops.
Water is added in front of the jet to lubricate the yarn, so that there is less yarn to jet friction inside the jet and the formation of loops becomes more efficient. The water is blown off the yarn at the jet exit and the yarn is basically dry when it is wound onto a package. The picture above represents the most simple way to produce ATY. As POY became widely available the machinery producers were forced to provide suitable production machines by adding a hot pin and a drawing zone to draw the POY. Alternatively hot godets are used to draw the yarn. (See the picture on the bottom, which shows the location of the godets.) In principle the machines functioned like this:
The "ATY" texturing principle, Core Effect:
Core Effect ATY is used widely when high bulk and
volume is required. This is the case for upholstery, furniture
and soft luggage yarn. But also fine denier nylon yarn is
processed as core effect yarn for sports wear.
The core yarn is overfed to the jet with less overfeed than the effect yarn. For example, the core yarn overfeed to the jet could be 8% and the effect yarn overfeed could be 30 %. Jet manufacturers are providing different jets for high and low overfeeds. The final denier also influences the jet design.
Loop size and loop stability matter greatly, especially for finer denier yarns. Smaller loops are more stable and provide a better volume than larger loops. To increase the stability and to shrink the loops into a smaller size ATY can be heat treated in a setting heater.
Specially stabilized ATY can be produced with
an additional drawing zone between the jet and the heater. Here
long loops are stretched to a point where they are not a lose
loop anymore and the rest of the loops are drawn to a smaller
size. This increases the ATY stability and process ability.
This process was once patented by Barmag. As shown in the
lower picture, drawing of polyester yarn can also be done by
using hot draw godets. Hot pins are stationary and the yarn
is drawn by wrapping the pin up to 360 angular degrees. Hot
godets are wrapped several times to allow the yarn to absorb the heat
of the godet. The first godet is normally heated above the glass
transition point of polyester to allow optimum drawing
conditions. The second godet, if heated, is used to anneal the
fiber.
Do you want to know more about ATY?
Check out my ATY process
and fabrics
What are false twisted stretch yarns?
Check out my stretch yarn
page .
What are false twisted set yarns?
Check out my set yarn page
.
What is tangled DTY yarn?
Check out my interlace
page
.
Have you anything on texturing of micro
fibers?
Yes, check out my micro
fiber page .
Do you need help with your ATY production?
Check out this consulting
service.
Interested to buy new or used air texturig machines?
I
can help. Send email to udo@polyspintex.com
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
September 19, 2010
Copyright Udo P.
Schweizer