Anti static finishing
During spinning, weaving and finishing of yarns and fabric, friction will be created by rubbing .Therefore Hydrophobic fibres tend to develop static charge. As the cellulosic fibres are good conductors, they do not produce static charge whereas the synthetic fibres which are not good conductors, develop static charge.
Due to this, shocks are experienced while
working on the stenter, zero-zero machines etc. and the fabrics get entangled
and soil attraction takes place which is also a problem. Therefore the synthetic
fabrics are given a finish to prevent the static charge generation. This is
known as 'Anti static Finish.
It is a chemical and property giving finish both
durable and non-durable finishes can be produced.
Anti static property can be brought out
By reducing the charge.
By reducing the charge.
By increasing the surface conduction
power,
By making the fiber
hydrophilic
Most of the anti static
finishes are based on the first mechanism i.e. by reducing the charge and
increasing the surface conduction
Silicone emulsions, PE emulsions, PE Glycerol,
Poly Quaternary Salts, Acrylic Polymers can be Ammonium used for this purpose.
In fact the Silicone
emulsion when used, produces anti static property by reducing the friction
between the fibres with added advantages of soil release property,softness
and suppleness etc.
Today Antistat PP' is used on polyester
fabrics in 5- 10 gpl concentration by Pad - Dry Cure method.
Normally it is added in
the finishing bath itself along with other additives. The moisture regain of
the fibre plays an important role in static dissipation. The higher the
moisture regain lower will be the static accumulation.
Fibre moisture regain and its resistance
Fibre moisture regain resistance
Viscose 12 7 ohms
Cotton 8 7
ohms
Nylon 4 12ohms
Acrylic 1 14ohms
Polyester 0.4 16 ohms
there are two methods of application of
anti static agents
1) By incorporating non-durable anti static agents into polymer during manufacture of synthetic fibres.
2) By applying either
non-durable or durable anti static agents. on the filament or yarn or fabrics. These
are applied either by Exhaust method or by Pad - Dry Cure
Method Some of the commercial
antistatic agents for synthetic fibres are Cirrasol PT (ICI), Ceramine R.ANS
(Sar.doz).Antistatic Oil, Antista D,M (Abura chemical products) Antistatic Oil,
Antista D
