Polymers (commonly used plastics are also polymers )
have become indispensable to our daily life. It is
relatively easy to manufacture intricate and attractive
articles from a variety of plastics on mass scale
economically. Polymers are engineered to meet specific
technical requirements. Surface properties of polymers
need to meet different demands. Frequently plastics need
to be bonded to other materials including plastics,
metals, glasses, ceramics etc. Such requirements are
common in electronics and medical appliances. However
polymer surfaces are generally hydrophobic and have poor
wettability. As a result adhesives do not stick
properly. It is important to develop an environmentally
friendly technique of modifying the adhesive properties
Bangalore Plasmatek has recently developed a technique
of improving the wettability of surfaces. More
technically speaking, we can make certain surfaces more
hydrophilic. A water droplet placed on most of the
plastics just rolls off. It does not wet the surface.
Exposing the plastic to the plasma makes the water drop
spread on the surface instead of rolling off. This is
important if you want to stick something to the plastic
or print on it.
The plasma used to treat surfaces is shown in the
The two pictures below show the effect of plasma
treatment on acrylic sheets.
Teflon is a well known hydrophobic material. It repels
water. That is the reason it is used as non stick
coating for cook ware. Plasma treatment can increase the
affinity of Teflon to water as seen in pictures below.
The drop looks flatter on plasma treated surface showing
its increased affinity to Teflon.
The plasma increases the surface energy by altering the
chemical bonds on the surface of polymers.
The picture below shows two electronic connectors which
need to be glued to some chassis. The one on the left is
not plasma treated. Water does not spread on its
surface. It has low wettability and can not be glued to
the chassis. The one on the right is treated with
plasma. The surface energy has increased and water
spreads readily on its surface. Now the connector can be
glued to the chassis easily.
It is found that the plasma
treated surfaces retain their good wetting properties
for several months.
Bangalore Plasmatek can provide custom specific plasma
treatment machines as well as take up job work of plasma
Bangalore plasmatek has developed a new machine
“Plasma cleaning system 102B” for plasma cleaning. The
stainless steel plasma chamber has dimensions 1500 mm x
400 mm x 300 mm with a user friendly loading system and
It is found that plasma cleaning gives highly reliable
bonding of the die cast aluminum casings. The cleaning
is achieved by bombardment of the surfaces by plasma
species like energetic ions, electrons, ultra violet
radiation etc. An exposure time of ten minutes is found
to be sufficient. Cleaning is also accompanied by
increase in the wettability of cleaned surfaces, in
other words, cleaned surfaces are rendered more
hydrophilic. Plasma cleaning is found to be effective
for metals, plastics as well as ceramics. However plasma
cleaning can not remove heavy contamination like stains,
oil, rust etc.