This document provides information on Altranol-GR, a product used to prevent yellowing of textiles during processing. It discusses various causes of textile yellowing including NOx gases from direct heating, heat exposure, light exposure, microorganisms, and chemical interactions. Altranol-GR contains scavengers that react with NOx gases to prevent fiber damage and yellowing. It can be applied by padding or exhaust and provides antioxidant effects during heat setting and molding to maintain whiteness. The document provides application guidelines and recipes for using Altranol-GR at different stages of textile processing.

1. Altranol-GRAltranol-GR
Protection for your whites
2013-2014

2. The continuously increasing consumption of elastane fibres
over the last few years shows that nobody wants to do without
the advantages imparted to the textiles substrates with high
stretching properties & high elastic force, but today these
fibres are also used for women's & men's outerwear in order
to impart a better & permanent form stability.

3. Textile articles especially whites and pale shades are susceptible to yellowing.
This can happen during or after textile processing at the plant but also during
storage & in shops or even at home.
There are many causes which can be responsible for this phenomenon:
Yellowing
Effects
Gas Fading
Temperature
Storage
Miscellaneous
Light
Packaging

4.  The yellowing effects may be due to substrate itself, or due
to the products used such as oils & softeners. It requires an
analysis to detect the problem.
 Gas Fading: NOx fumes of stenters & NOX fumes during
storage & Ozone exposure
 Temperature: Heat setting, Moulding, Softeners & heat
exposure
 Packaging: Phenolic & amine related yellowing
 Light: Fading of optical brighteners & dyestuffs,
Deterioration of fibres
 Micro-organisms: Attack by fungi & bacteria
 Miscellaneous: Interaction of softener & fluorescent
whitening agent

5. Directly heated stenters
One of the most important causes of textile yellowing of
synthetic fibres is gas fading. The combustion of gas and
fuel introduces NOx into the heated air. This NOx - gas is
able to react with the fibre and with products (oils, waxes
and anti-oxidants) on the fibre.
By applying Altranol-GR on the fabric, a reaction of the
NOx with the active ingredients of Altranol-GR takes place.
The resulting reaction product is easily washed off. The
fibres are not attacked.
At the end the result is a cleaner, whiter fabric.

6. Stenters
In the textile industry we meet two different types of stenters. Stenters
heated by burning gas and oil as well as indirectly oil-heated stenters.
The combustion heated stenters produce more harmful nitrogen oxides
as the air is in direct contact with the flame. In the indirectly heated
stenter type air is not mixed with fuel or gas to heat the textile
materials.
By using Altranol-GR the difference in whiteness between similar lots
heat set on different stenters can be minimized (reproducibility).
As explained before, the NOx produced in the direct heated stenter is
scavenged away by the Altranol-GR product.
The levelness in the width and also in the length of the lot as well as
between similar lots is far better when Altranol-GR is used.

7. Gas fading and storage
Some fibres and applied lubricants, but especially packaging materials, can
contain anti-oxidants, based on steric hindered phenols, like BHT. This anti-
oxidant can react with NOx fumes present in shops and ware houses, due to
air pollution especially through traffic (traffic in or close to ware houses).
Avoiding BHT containing packaging and an acid pH value of the finished
goods can minimize this problem.
Ozone fading
Ozone fading is actually an issue in the garment industry, especially on denim
articles. This causes a yellowing effect which is caused by a certain type of
softeners. Special anti-ozonate softeners can reduce this problem to a
minimum (e.g. Aquasorb-OZ)

8. Exposure of textile materials to heat can cause
yellowing due to oxidation of fibres, fibre and spinning
lubricants, fibre impurities (cotton). Fibre oxidation of
Polyamide fibres results in loss of end-amino groups.
As a consequence a loss of colour-yield will be
observed. If oils are present, the heat transfer can be
irregular from fibre to fibre and oxidation takes place
unevenly. Differences in dye-sites (end-amino groups)
automatically will then show up as barriness.
Another yellowing defect can occur during moulding
of articles made of synthetic fibres, especially for lady’s
lingerie ( e.g. PA/EL bra.) Altranol-GR can be of great
help to maintain whiteness and overcome
inconsistency problems. Especially cationic fatty
amide derived softeners as well as some amino
modified silicones (high nitrogen contents) are
sensitive to oxidation and thus yellowing effects.
Drying and finishing conditions should be well
balanced out with the choice of softeners and the
required end-results.

9.  Some remarks were already made, on this
topic, under Nitrous fumes and storage. It
is important to set the right final acid pH-
value for the finished goods, as the
yellowing only appears under neutral to
alkaline conditions. It can easily be checked
if the fabric turns white after exposure to
acid.
 The reason for this yellowing is the
combination of phenolic compounds like
BHT and nitrous gases, coming mainly from
air pollution. It occurs much more in cities
than in the countryside.
 BHT may be present in packaging materials
like plastics, foams, recycled paper and
adhesives (try to sue BHT-free plastic and
avoid paper boxes made of recycled paper)
Packaging

10. Light
The light fastness of Fluorescent Whitening Agents (FWA) is generally rather
low. Articles or parts of them, which are exposed to direct sunlight, will look
yellowish. Light, as an energy source, can also deteriorate fibres. Glass does
not filter out all UV light (only < 320 nm). PA is a very susceptible fibre,
especially the Titanium oxide containing dull versions. This photo oxidation
causes yellowing and strength-loss. The presence of moisture accelerates
this effect.

11. Micro-organisms
Fungi and bacteria can cause yellowish or even brown or black stains.
These species need nutrition to grow, such as residual organic chemicals on
the fabric (e.g. organic acids, leveling agents, surfactants, softeners,
lubricants). Humidity and ambient temperatures will speed up their
growth.
Altranol-GRAltranol-GR

12. Miscellaneous
Cationic softeners can interact with anionic fluorescent whitening
agents, reducing the hue of whiteness. The rate of quenching depends
on the type of softener and the accessibility of the nitrogen-atoms.
The pH also plays an important role. Strong acid conditions should be
avoided.
Acid pH values of the fabric may also lead to shade change of the FWA
to greenish, which may already happen at pH of <5. Select the right
FWA if slightly acid conditions on the fabrics are required (e.g. to
avoid phenolic yellowing)

13. • Untreated fabric can be full of different preparations &
impurities. Especially mineral oil / natural oils, silicone
oils, paraffin waxes, antistats etc. affect the fabric.
Normally these impurities would be removed by washing.
However this is impossible due to curling of textile &
hence forced to set the fabric with all contaminating
substances. This have negative effect on the fabric quality.
The most frequent negative appearances are yellowing,
poorer dyeability caused by the oxidation of the fibre,
reservations which are observed after dyeing & poor
fastness properties.
• Volatile preparations indirectly affect the fixing aggregates
because these preparations precipitate on colder machine
parts & drop back onto the fabric , which too cause a
typical faulty appearance.

14. This special product contains selected scavengers to
avoid yellowing effects due to NOx fumes in direct
heated stenters as well as heat-related oxidation. This
product is efficient on PA, PA/EL, PES and PES/EL.
Pre-fixation of greige goods
EASTANE containing fabrics and especially knitwear
need a presenting to relax the fabric and to obtain form
stability of the goods (changing the micro-structure of
the synthetic fibre and partly fusing the Elastane
fibres). Of course in respect to the weight per m2
, the
length and the width per all settings should be within
the final specifications of the goods. Additionally the
undesirable tendency of curling edges can be
eliminated or at least be minimized.
Heat-setting of Polyester/EL and Polyamide/EL is done
at approx. 185º - 195º C, depending on the type of
Elastane – fibre.

15.  Logistically it is preferred to do the heat-setting operation on greige
goods, but impurities such as fibre and spinning lubricants / oils and
emulsifiers may lead to increased yellowing tendency .
 Some industries tend to pre-scour before setting for this reason. It
solves however the yellowing of oils but not that of the Polyamide
and Elastane.
 Heat-setting wet fabric will moreover cause increased yellowing.
However, the circumstances on the stenter play an even greater
influence.
 Direct or indirect heating. Reliability and consistency of the
temperature.
 Direct heated stenters produce NOx
fumes by oxidation of nitrogen.
These fumes are attacking the oils and the fibres during the setting
operation, thereby causing yellowing.
 Altranol-GR prevents this reaction as it contains special scavengers.

16. In a gas chamber combustion fumes (among others NOx)
are brought into contact with fabric and treated at
160ºC.
Moulding of finished fabrics (e.g. women’s brassiers)
PA/EL especially blends are susceptible to yellowing
during moulding to obtain a good fit especially for lady’s
underwear. Oxidation of the Elastane and polyamide
fibres can easily occur. Residual scavenger from the
previous treatment or newly applied Altranol-GR will
avoid this to a large extend.
BLANKOPHOR CLE and BLANKOPHOR CLE Liquid have
the highest moulding resistance of all Fluorescent
Whitening Agents for PA/Elastane.

17. PA/EL knitted fabric was treated with 20 ml/l
Altranol-GR
Pick-up : 60 %
Dried at 120ºC and heat-setted at 195ºC. Part of the
samples were washed with reduction agent at 85ºC,
rinsed and dried.
Contact head was applied on the FIXOTEST according
ISO 105-P01. The treated fabrics, either washed or
unwashed, are showing clearly much less yellowing
after the Fixotest-treatment.
Light fastness
Altranol-GR shows only very little improvement of the
light fastness. To increase the light fastness of the
fibres and the dyestuffs special UV-absorbers are
recommended.
Untreated
Altranol-GR
treated
After
heat
setting
60 secs
at 195ºC
After
heat
setting
60 secs
at 210ºC

18. Influence of amount of product
The amount of scavenger (and thus the amount of product) depends on
the amount of fumes and oxygen in stenter. Good stenters need lower
amounts than critical ones. For moulding articles it is advised to use
some more product as residual scavenger will remain on the fabric
after washing and reduction bleaching. This will help to overcome
yellowing during forming cups etc.
Application:
It can be applied by pad and/or exhaust method.
Pad application
“Altranol-GR” 20-40 ml/l
Exhaust application
“Altranol-GR” 2-4% o.w.f

19. Recipe
The following variation in processing are suggested.
For use on Greige goods:
1. Padding:
20-40ml/l Altranol-GR
0.3-0.5ml/l Sequestering agent
Padding 50-75% pick-up
Drying 100ºC
Heat setting 180-200ºC
For use on Pre scoured goods:
2. Exhaust :
2 -4% Altranol-GR
0.25-0.5ml/l Sequestering agent
Process for about 10-15 mins at 50-60ºC,spin or put through a
mangle & finally dry & heat set.

20. For use during moulding
The conditions during moulding are principally the same as in
heat setting. At temperatures above 200ºC & exposure times
between 20-80 seconds some fibres show a tendency to
yellowing. This problem is aggravated through softeners on the
fabric which cause yellowing under the influence of
temperature. If one optimizes this finish by a combination of
thermostable hydrophilic softeners & an additional wetting
agent with anti-oxidative effects:
Guide Recipe:
10-30g/l Altranol-GR
10-30g/l Powersil-SIQ or Luballen-AH
X g/l Altraplex-GA (To adjust pH to 4.5-5.0)
Subsequent heat setting

21.  Antioxidative effect.
 Prevents yellowing induced by heat
processing specifically for articles
which have to be heat set e.g. because
of curled edges, or for stability reasons.
Maintains the dyeability.
 Very good wetting effect on
hydrophobic untreated fabric.
 Good washing effect.
 Reduces evaporation of spinning
lubricants at the stenter.
 Prevents soiling of the stenter.
 Suitable for articles with a tendency to
yellowing in subsequent heat
treatments (e.g. on a rotary press).
 Preferred application is by padding. An
exhaust application can be used.

22. OFFICE ADDRESS:-
403, “Antariksh”, Makwana Road,
Marol Naka,
Andheri (E), Mumbai – 400 059
Tel.- 91- 22- 4221 6789 (30 Lines)
91- 22- 6692 4112
Fax -91-22- 2836 6434
FACTORY ADDRESS:-
D- 14 /10, T.T.C. M.I.D.C Industrial area,
Turbhe , P.O. K.U.Bazar,
Navi Mumbai – 400 705
Tel.-91- 22- 4141 9899 (30 Lines)
Fax -91- 22- 4141 9888
Email ID – ketan@lnchem.in
lnchem@vsnl.com