The document discusses various causes of yellowing in textiles during storage and heat processing. It notes that yellowing is often caused by reactions between phenolic antioxidants used in packaging materials and textile finishes with nitrogen oxides in the air. Factors like humidity, temperature, and UV exposure can also influence yellowing. The document recommends several products that can help prevent yellowing, including Quench-APY, Quench-AY, Quench-LG, and Altranol-GR, which protect fibers from oxidative damage and reactions with nitrous oxides.

1. (2014-2015)

2. Causes of yellowing during storage
The intensive yellowing of white or pastel colored
textile good is very often a result of the presence of
phenol-based antioxidants (butylated hydroxyl toluene
derivates).
This chemistry is low in cost and highly effective.
Due to its low vapor pressure it is volatile and can be
transferred to textile goods easily.
Products of this type are commonly used as
stabilizers in Fibre production, Further textile
processing. Packing materials (e.g. polyethylene
wrapping films, packing material in general)

3. • Storage yellowing
• Typical Appearance
• Lemon yellow colour of fabric
• Yellow substance is soluble in alcohol
• Yellow colour often behaves like an indicator :
• Disappearance with acid and reappearance with alkali

4. Factors influencing the yellowing
Various factors influence the yellowing of white
textile goods in presence of antioxidants :
Storage conditions
o Atmosphere composition in store, shop and
home (NOX beside other pollutants)
o Humidity and temperature
o Heating and ventilation
o Storage time
o Illumination
o Ozone fading
Composition of hot air, particularly on drying /
curing/heat-setting equipment with direct gas
heating when nitrogen oxides are produced due to
unproper burning conditions.

5. Causes :
Reaction of nitrous oxides (Nox) in the air with phenolic substances :
Antioxidants e.g. based on butylated hydroxytoluene (BHT) often used in cardboards,
synthetic materials, plastic films or plastic parts.
+ Phenolic substance
+ Nitrous oxides
Yellowing is favoured by pH > 6 ( yellow colour of BHT-Nox reaction products is pH –
dependent )
Yellowing can be favoured by cationic charges on the fabric (affinity of BHT-NOx reaction
products to cationic charges)
Fabric finished with cationic softeners or cationic after treatment : cationic charges, attract
antioxidants.

6. Mechanism of Yellowing

7. Precautions lowering the risk of yellowing
 As long as such antioxidants are used it is virtually very
difficult to prevent such yellowing. To reduce this
yellowing we recommend :
 Warn customers to ensure that fibres and auxiliaries are
free of phenolic antioxidants. Especially packing or
wrapping materials should be free of antioxidants (phenol
free low density polyethylene bags)
 Adjust the final finish with some non volatile organic acid
(shade and optical brightener should be acid stable)
 To avoid the presence of nitrogen oxides (NOX) during
production and storage (no direct gas heat, all
transportation systems such as fork-lift trucks with electric
motors, good ventilation in warehouse to avoid air
pollution).

8. Normally white PA turn yellow even under
slightly acid conditions. This is due to the
cationic character of the free amino end-groups
of PA which interact with the
antioxidant derivate.
Quench APY/Quench-AY / LG are preventing
such yellowing while blocking the free amino
end-groups of the PA.
For the application in general we recommend
to use slight acid conditions. Please check
also whether the optical brightener is acid
stable if non-volatile acids are used.

9. Counter products :
• Quench-AY
 Nylon fiber yellowing preventing agent
 Special nature of the applications
 Phenol yellow change very excellent suppression
 Vanillin (vanillin) and BHT (di-tert-butyl-p-cresol), yellowing caused by
the suppression effect is very excellent
 High affinity for the nylon fiber
• Quench-LG
 Highly effective anti-yellowing agent for polyamide & blends with elastane
during storage.
 Reduces or prevent yellowing during storage.

10. • Quench-APY
Is a high performance composition designed for treating fabrics & garments
fromyellowing due to Storage conditions
 Atmosphere composition in store, shop and home (NOX beside other
pollutants)
 Humidity and temperature
 Heating and ventilation
 Storage time
 Illumination

11. Quench – UWP
 Is highly effective fiber stabilizer for reducing yellowing of polyamide
and PA blends during exposure of any kind of heat.
 It protects all types of polymide fibers and their blends with elastomer
fibers against oxidative damage, thus reducing yellowing due to
thermic and photochemical influence. Avoids yellowing of optical
brightened polyamide and it blends during heat setting or molding
processes.
 Prevents shade changes of pastel dyed polyamide and its blends during
heat setting or molding treatments.
 Applicable on all textile substrates in exhaust or padding processes
 Products prevent reactions of nitrous oxides and phenolic substances
coming from packing material etc. during storage.
 No / less yellowing of stored textile
 No / less complaints of retailers or consumers.

12. Typical appearance :
• Yellowing colour marking outer folds
or surfaces of ready made folded
denim fabrics
• Yellowish colour can be removed by
warm rinsing but leaves brightened
areas.
• Often occurring in summer, also
without light.

13. Causes:
 Unsuitable cationic softeners
 Reaction of indigo with ozone
and nitrous oxides
Prevention :
 Use of softeners avoiding
yellowing and minimizing ozone
fading
 Packing of ready-made denim
articles avoiding or minimizing
exposure to exhaust.
 Fumes in stores.

14. Our recommendation for antiozonate:
Aquasorb-OZ / Powersil-NOZ
 Avoids shade changes due to yellowing of fabrics dyed with
indigo.
 Gives smooth and very soft handle to cotton and yellow fabrics
 Applicable in padding or exhaust process.

15. Causes for yellowing during heat setting or molding :
 Decomposition of lubricants/spin finishes (yellowing of
substances on the fibres)
 Decomposition of cationic softeners (yellowing of substances on
the fibres)
 Reaction of monomers, oligomers or functional groups
(yellowing of fibre itself)
 Especially PA: migration of antioxidants from within the fiber to
the surface. [ yellow reaction products with nitrous oxides,
especially in gas heated stenters]

16.  Yellowing of substances on the fibre :
 Scouring the fabric prior to heat treatment
 Pre-emulsifying of spin finishes and lubricants by padding with
suitable products and washing off during subsequent
dyeing/finishing (especially important in case of micro fibres)
Altranol-GR For PES & PA & CO/EL
A unique product that prevents yellowing of polyester,
polyamide & their blends with elastane during the heat
setting process. Specially designed for the production of
pale shades & optically brightened whites

17.  Yellowing of cationic softeners
 Use of suitable pseudo cationic softeners (quality of raw
materials and reaction control is crucial)
 Yellowing due to reaction within or due to yellow reaction
products.
 Application to fibre stabilizers [ radica / scavenger ]

18. Overview :
1. Storage yellowing * typical appearance
2. Storage yellowing * causes
of denim * prevention
3. Thermal yellowing * counter products
4. OBA yellowing * Lab comparison results

19. Conclusions :
 Our products to prevent phenolic yellowing on storage :
 Quench-APY
 Quench-AY
 Quench-LG
 Quench PAT
 Our product to prevent thermal yellowing :
• Altranol-GR
• Quench UWP
 Our product to prevent yellowing due ozone
fading(Antiozonate) & Noxious gases like (NO)X
• Aquasorb OZ

20. 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 (100 Lines)
Fax -91-22-4141 9888
Email ID: ketan@lnchem.in
nayana.lnchem@gmail.com