1. Anti-pilling
Properties and Molecular Weight
2. Anti-pilling
Fibers Status in the World
3. A Technology
Breakthrough by Glysil Chemicals Inc.
4. The Amount of
Glysil®
GS-6 in Polyester
5. Analysis For
Anti-pilling Polyester Fibers
1. Anti-pilling
Properties and Molecular Weight
What is pilling?
Pilling is a defect in fabric when fibers are rubbed or
pulled out of yarns and entangled with intact fibers,
forming soft, fuzzy balls on the fabric surface.
Regular polyester
fibers have intrinsic viscosity IV about 0.66 (Mw
16,500). Good spinning performance requires IV 0.52 (Mw
11,500) or higher. Truly pilling free staple requires
intrinsic viscosity IV 0.39 (Mw 7,500) or lower.
2. Anti-pilling
Fibers Status in the World
In North America and
Europe, anti-pilling staple has been commercially
produced in DMT process more than 30 years and is the
largest volume specialty polyester fiber product. A
hydrolyzable additive temporarily increases IV to 0.52
or higher for spinning. After spinning it hydrolyzes to
IV 0.39 or lower in drawing or dyeing.
Since 1980¨s, most new
polyester plants built were TPA process. The additive of
DMT process hydrolyzes and forms rocks/sands in TPA
process due to water byproduct. A dilemma: the additive
must be able to hydrolyze after spinning, but it must
not hydrolyze in TPA polymerization process where there
is byproduct water.
3. A Technology
Breakthrough by Glysil Chemicals Inc.
Glysil Chemicals
invented a new technology to produce anti-pilling fibers
in TPA process, US, China, and Taiwan patents have been
issued.
Glysil®
GS-6 is similar to the multifunctional
additive used in DMT process for anti-pilling
properties, but it does not form sands or rocks in TPA
process.
Glysil®
GS-6 is a breakthrough for anti-pilling
fibers:
,
Glysil®
GS-6 Increases IV to 0.52 or higher for good
spinning.
,
Does not hydrolyze in TPA polymerization process, no
sand or rock formation.
,
After spinning it hydrolyzes to IV 0.39 or lower in
drawing and dyeing.
,
Stay in the fibers after hydrolyzation, does not go
into the water.
,
No permanent branching or crosslinks which affect
spinning.
,
Ethylene glycol solution, miscible with water.
Glysil produce anti-pilling additive
Glysil® GS-6 in Wuxi, China.
Glysil® GS-6 has been used by
our clients in 100 tons/day CP and direct melt spinning
since 2004.
4.
The Amount of
Glysil®
GS-6 in Polyester
Pilling resistant PET staple type |
Spinning IV
(Normal IV) |
Anti-pilling
IV (after hydrolysis) |
Sb
ppm |
Glysil®GS-6 wt % |
Denier per
filament dpf |
Pilling free |
0.52\0.01 |
0.39\0.01 |
150 |
1.00% |
1.2 to 4.5 |
CD Pilling free |
~0.45 |
0.39\0.01 |
100 |
1.00% |
1.2 to 4.5 |
Pilling resistance |
0.53\0.01 |
0.45\0.01 |
200 |
0.50% |
1.0 to 4.5 |
Note:
(1) The amount of
Glysil®
GS-6
in the table included both the active ingredient and EG
solvent. To obtain active ingredient in polymer,
multiply the number in the table by 60%.
(2) Spinning IV is
analyzed in lab but controlled by tortional oscillation
viscometer (TOV). Anti-pilling IV is analyzed in the
lab but controlled by
Glysil®
GS-6 additive.
(3) Free fall yarn
under spinneret should be sampled every 2-8 hours for IV
analysis. If the difference of the two IV is smaller
than that desired, CP engineers should increase
Glysil®
GS-6 input; if the difference is bigger than that
desired, decrease
Glysil®
GS-6 input.
5. Analysis For
Anti-pilling Polyester Fibers
Polyester molecular
weight is measured by intrinsic viscosity (IV).
Spinning IV (normal IV before hydrolysis) is important
for spinning, which is the same as normal IV analysis
familiar to most PET producers. Anti-pilling IV (IV
after hydrolysis) is important for anti-pilling.
Anti-pilling IV analysis has the same procedures as
normal IV, except that the solvent contains 150 ppm
sulfuric acid H2SO4 (98%). The H2SO4
containing solvent should be prepared in larger volume
(1000 ml or more) for accuracy. The solvent can be
hexafluoroisopropanol (HFIP), phenol/tetrachloroethane
3/2, phenol/tetrachloroethane 1/1, and
phenol/o-dichlorobenzene 1/1.
To test pilling
resistance of knitting fabric, ICI pilling box is
commonly used in Europe and Asia. Atlas Random tumble
pilling tester is often used in North America. For
non-woven and other fabrics, some producers also use
Martindale abrasion and pilling tester or brush pilling
tester.
6.
Comparison Of
Anti-pilling Staple With Cotton, Wool And PET Staple.
|
Anti-pilling Staple |
Cotton |
Wool |
PET
Staple |
Natural feeling |
〔 |
〔 |
〔 |
|
Anti-pilling |
〔 |
〔 |
|
|
Wrinkle free |
〔 |
|
|
〔 |
Machine washable |
〔 |
〔 |
|
〔 |
Breathable |
〔 |
|
|
〔 |
Easy
care |
〔 |
|
|
〔 |
Easy
dye |
〔 |
〔 |
〔 |
|
|