Process for manufacturing different shrinkage microfiber texture yarn

A process for manufacturing different shrinkage micro-fiber texture yarn which uses a blend of micro-fiber yarn having a boil-off shrinkage lower than 10% and a low crimped filament having a boil-off shrinkage higher than 15%. The different shrinkage micro-fiber texture yarn is made by false twisting and drawing the micro-fiber, combining the micro-fiber with the low crimped filament and then intermingling the yarns together by using an air-tangling jet.

FIELD OF THE INVENTION 
This invention relates to a process for producing a different shrinkage 
micro-fiber texture yarn, and in particular the invention is related to a 
different shrinkage micro-fiber texture yarn which is less than 0.5 dpf 
and is also related to a process for making the fabric which has improved 
feel such as softness and stiffness. 
BACKGROUND OF THE INVENTION 
Synthetic fiber has been prepared for commercial use for more than thirty 
years. Because consumer's taste changes rapidly and toward higher quality, 
producers of man-made fiber, have researched ways to provide a fabric with 
a natural appearance and which feels better than the natural fiber. For 
example, the popular peach-skin-like and suede-like fabrics have been 
produced with I dpf polyester fiber. The fabric made of 100% micro-fiber 
material will have excessive softness and inadequate anti-drape and 
fullness. Sometimes high twisted fiber may be added or the fabric 
constituent may be changed to overcome the excessive softness problem; but 
this increases the cost and reduce the fullness of the fabric. The 
objective of the invention is to solve the aforementioned problem by 
studying the different shrinkage production process of micro-fiber texture 
yarn. The invention places emphasis on the false-twist process and uses 
micro-fiber yarn as a low shrinkage yarn. Yarn with boil-off shrinkage 
less then 10% will be combined with a high shrinkage yarn, having boil-off 
shrinkage over 15%. These two yarns then be intermingled together during 
the texturing process. 
After a weaving, dyeing and finishing process, heating the different 
shrinkage filaments causes production of the fabric with anti-drape and 
desired feel characteristic. It is different from that common use of high 
shrinkage yarn and low shrinkage yarn which are combined within a twister 
or air texturing process. The traditional process not only increases the 
cost, but also produces a product having inferior feel. 
SUMMARY OF THE INVENTION 
It is therefore an object of the present invention to provide a process for 
producing a different shrinkage micro-fiber texture yarn. A false-twist 
process is used which employs micro-fiber yarn as a low shrinkage yarn. 
This yarn with boil-off shrinkage less then 10% will be combined with a 
high shrinkage yarn, having boil-off shrinkage over 15%. These two yarns 
are then intermingled together during the texturing process.

The below listed letters and numerals have the following meaning in the 
drawings: 
A: Micro-fiber yarn cake 
B: High shrinkage yarn cake 
1: First guide 
2: First shaft 
3: Heater 
4: Cooling plate 
5: Friction spindle unit 
6: Second guide 
7: Second shaft 
8: Air jet 
9: Third shaft 
10: Take-up cylinder 
DETAILED DESCRIPTION OF THE INVENTION 
The primary purpose of this invention is to provide a process for producing 
a different shrinkage micro-fiber texture yarn. The process uses 
micro-fiber yarn as a low shrinkage yarn in a false twist process. This 
yarn with boil-off shrinkage less then 10% is combined with a high 
shrinkage yarn with boil-off shrinkage over 15%. These two yarns are then 
intermingled together during the texturing process. 
The low shrinkage (lower than 10%) micro-fiber texture yarn used in this 
invention is conventional melt spun or conjugate spun yarn, which can be 
treated through a texturing process or dye-finish process to make the 
weight of per filament below 0.5 denier (gram per 9000 meter). A texture 
yarn lower than 0.5 dpf after drawn can be obtained with a conventional 
melt spinning device. The conjugate spinning process uses different 
polymer composite together, like polyester/polyamide, 
polyester/co-polyester (easily soluble polymer). After drawing and 
dye-finishing, these two different chemical components may be separated by 
mechanical or chemical separation to produce a micro-fiber texture yarn 
with dpf lower than 0.5 denier. The other yarn used in the invention is 
high shrinkage yarn with or without low torque. The high shrinkage yarns 
used in this invention have a boil-off shrinkage over 15%. For example, 
generally, polyethylene terephthalic is added with the third component 
isophthalic acid 5-35 mole percent or dimethyl 5-sulfoisophthalate sodium 
1-10 mole percent, and the molecule crystallization of the chains are 
restrained during the production process to ensure the yarn have high 
shrinkage characteristic. 
According to the above description, the shrinkage variant between two yarns 
must be over 10%. Namely, if the shrinkage of micro-fiber texture yarn is 
higher than 10% and the high shrinkage yarn is lower than 15%, the fabric 
which is made of the different shrinkage yarn compound can not attain the 
desired characteristics of softness and fullness. On the contrary, if the 
variance of shrinkage is higher than 50%, fabric would be over shrink, 
then softness and fullness also can not be obtained. 
One manufacturing process of the invention is illustrated in FIG. 1. In 
this process a micro-fiber (A) passes through first guide (1), then to 
1.sup.st shaft (2), heater (3), cooling plate (4), friction device (5), 
and 2.sup.nd shaft (7) before being intermingled with high shrinkage yarn 
(B) in the air tangling jet (8). 
Another manufacturing process of the invention is illustrated in FIG. 2 
which uses a micro-fiber (A) in combination with high shrinkage yarn (B). 
Yarns (A) and (B) are unwound individually and then go through the guide 
(1) together, 1.sup.st shaft (2), heater (3), cooling plate (4), friction 
device (5) and 2.sup.nd shaft (7). The yarns are drafted and false-twisted 
between the 1.sup.st and 2.sup.nd shafts and and intermingling takes place 
between 2.sup.nd and 3.sup.rd shaft. Take-up of the product occurs in 
roller (10). 
In the false-twisted texturing process mentioned above, the friction device 
(5) is not only limited to the disc type. Alternatively a belt type, or 
pin type friction device may be used. The air-tangling jet (8) is also a 
commonly used device which produces jets of flowing or mixing air. 
Generally, the air pressure should be above 2.0 kg/cm.sup.2, preferably 
between 3.5-4.0 kg/cm.sup.2. The number of entanglements should be over 
100 entanglement per meter. 
The boil-off shrinkage of this invention is analyzed as follows: 
1. Clapping at the sample yarn head and loading with 0.1 gram per denier on 
the other end of sample yarn, and mark it at 100 centimeters place. 
2. Packing the sample in the gauze then placing it in a water tank for 30 
minutes with its temperature maintained at 100.degree. C. 
3. Taking the sample out of the tank, and then cooling with pure water and 
drying by pressing. 
4. Tailing with 0.1 g/d load, reading the index "/"/ of mark. 
5. Defining the boil-off shrinkage define by the following formula: 
EQU [(100-/)/ /].times.100%] 
EXAMPLE 1 
A different shrinkage of 100.sup.d /60.sup.f micro-fiber texture yarn is 
manufactured by the process shown in FIG. 1. A 115.sup.d /48.sup.f 
polyester/polyarnide micro-fiber as yarn (A), is passed through the first 
guide (1) and 1.sup.st shaft (2) to be heated with heater (3) at the 
temperature about 170.degree. C. (100.degree. C.-200.degree. C.) and 
cooled in (4), and false-twisted in friction spindle unit (5) then passed 
to the 2.sup.nd shaft (7) to be drawn with constant draw ratio of 1.7 
(1.3-4.0). This provides a 6% boil-off shrinkage yarn which is then 
combined with a 45% high shrinkage yarn B of 30.sup.d /12.sup.f, modified 
by isophthalic acid of 15 mole %. Both yarns enter the air jet, with 4.0 
kg/cm.sup.2 air pressure, and by the effect of air intermingling a good 
interlace is obtained between the 2.sup.nd and the 3.sup.rd shaft (9). The 
product is then taken up on the roller (10). The 2.sup.nd shaft is set at 
a speed of about 50 to 400 m/min. By the above manufacturing process, a 
100.sup.d /60.sup.f different shrinkage yarn of micro-fiber is obtained. 
Using the 100.sup.d /60.sup.f different shrinkage micro-fiber texture yarn 
as the warp and a 150d/48f regular draw texture yarn as the weft, the 
woven fabric will be 25% of weight reduced by alkali solution. And then by 
rubbing, dyeing and finishing treatment, the surface of fabric will appear 
to be peach-skin like or moss-like with excellent fullness and soft 
texture. 
EXAMPLE 2 
A 225.sup.d /84.sup.f different shrinkage micro-fiber texture yarn 
manufactured by the process shown in FIG. 2. contains (A) which is a 
210.sup.d /48.sup.f PET/CO-PET conjugate spun yarn, and (B) which is a 
75.sup.d /36.sup.f modified by isophthalic acid (3 mole %), and has about 
25% boil-off shrinkage. The two yarns separately go through guide 1(1) and 
second guide (6) and enter first shaft (2) together. They then go to 
heater (3) to be heated at the temperature about 125.degree. C., then 
cooled by cooling plate (4), then through friction disc. then go to second 
shaft (7) where they are drawn at 400 m/min, 1.3 ratio, and thereby become 
two yarns with different shrinkage. Then by the effect of air 
intermingling in jet (8), a 225.sup.d /84.sup.f different shrinkage yarn 
of micro-fiber is obtained. Jet (8) which is located between the second 
shaft (7) and the third shaft (9) employs an air pressure of 3.6 
kg/cm.sup.2. The product is taken up on roller (10). 
With the 225.sup.d /84.sup.f differential shrinkage micro-fiber texture 
yarn as the weft and a 75.sup.d /36f regular texture yarn as the warp, the 
woven fabric will be 30% weight reduced by alkali solution then through 
rubbing, dyeing and finishing treatment, fabric surface will present a 
leather-like appearance.