Diapositiva 1

Yellowing of TextilesAnti Phenolic Yellowing

(2014-2015)

1Causes of yellowing during storageThe 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)

Yellowing of Textiles

2Storage 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 alkaliYellowing of Textiles3Factors influencing the yellowingVarious factors influence the yellowing of white textile goods in presence of antioxidants : Storage conditionsAtmosphere composition in store, shop and home (NOX beside other pollutants)Humidity and temperatureHeating and ventilationStorage timeIlluminationOzone fadingComposition of hot air, particularly on drying / curing/heat-setting equipment with direct gas heating when nitrogen oxides are produced due to unproper burning conditions.

Yellowing of Textiles4Causes :

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.

Yellowing of Textiles5

Mechanism of Yellowing

Yellowing of Textiles6Precautions lowering the risk of yellowingAs 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).

Yellowing of Textiles7Normally 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.

Yellowing of Textiles

8Counter products : Quench-AYNylon fiber yellowing preventing agentSpecial nature of the applicationsPhenol yellow change very excellent suppressionVanillin (vanillin) and BHT (di-tert-butyl-p-cresol), yellowing caused by the suppression effect is very excellentHigh 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.

Storage Yellowing 9 Quench-APY

Is a high performance composition designed for treating fabrics & garments from yellowing due to Storage conditions

Atmosphere composition in store, shop and home(NOX beside other pollutants)Humidity and temperatureHeating and ventilationStorage timeIlluminationStorage Yellowing 10Quench UWPIs 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 processesProducts prevent reactions of nitrous oxides and phenolic substances coming from packing material etc. during storage.No / less yellowing of stored textileNo / less complaints of retailers or consumers.

Storage Yellowing 11Typical appearance :Yellowing colour marking outer folds or surfaces of ready made folded denim fabricsYellowish colour can be removed by warm rinsing but leaves brightened areas.Often occurring in summer, also without light.

Storage yellowing of denim

12Causes:Unsuitable cationic softenersReaction of indigo with ozone and nitrous oxides

Prevention :Use of softeners avoiding yellowing and minimizing ozone fadingPacking of ready-made denim articles avoiding or minimizing exposure to exhaust.Fumes in stores.

Storage yellowing of denim

13Our 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.

Storage yellowing of denim

14Causes 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]

Thermal yellowing15Yellowing of substances on the fibre :Scouring the fabric prior to heat treatmentPre-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-GRFor PES & PA & CO/ELA 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

Thermal yellowing16Yellowing 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 ]

Thermal yellowing17Overview :

Storage yellowing* typical appearance

Storage yellowing* causesof denim* prevention

Thermal yellowing* counter products

OBA yellowing* Lab comparison results

Yellowing of Textiles Overview18Conclusions : Our products to prevent phenolic yellowing on storage :Quench-APYQuench-AYQuench-LGQuench PAT

Our product to prevent thermal yellowing : Altranol-GRQuench UWP Our product to prevent yellowing due ozone fading(Antiozonate) & Noxious gases like (NO)XAquasorb OZOverview19 OFFICE ADDRESS :403, Antariksh, Makwana Road,Marol Naka, Andheri (E),Mumbai 400 059

Tel.- 91-22-4221 6789 (30 Lines) 91-22-6692 4112Fax -91-22-2836 6434FACTORY ADDRESS :-D- 14 /10, T.T.C. M.I.D.C Industrial area,Turbhe , P. O. K. U. Bazar,Navi Mumbai 400 705Tel.- 91-22-4141 9899 (100 Lines)Fax -91-22-4141 9888Email ID: ketan@lnchem.innayana.lnchem@gmail.com

L. N. CHEMICAL INDUSTRIES20