2. University of Horticultural Sciences, Bagalkot
Kittur Rani Channamma College of Horticulture,Arabhavi
Harvesting & Processing of Rubber
3.
4. Tapping
Harvesting in rubber is known as tapping.
Tapping is the periodical removal of thin slices of
bark to extract rubber latex.
It is the process of controlled wounding with the
shaving of bark removed. The latex vessels are
found in the inner layer of soft bast of the bark.
The latex vessels are concentrated in in the soft
bast arranged in a series of concentric rings of
inter connecting vessels.
Tapping is done by skilled men.
8. While tapping, the cambium should not be
damaged as otherwise callus formation will take
place causing swellings.
The rubber trees attain tappable stage in about
seven years. The best season for tapping is March or
September depending upon girth of the tree.
The latex vessels in the bark flow at an angle of 320
to the right and therefore a cut at higher level from
the left to right has to be carried to facilitate
opening of a large number of latex vessels.
Tapping is done in the early morning, late tapping
will cause reduction in the flow of latex.
9. Tapping Systems & Intensity
Sl.No Tapping Sytems Intensity Remarks
1 s2d2- Half spiral, tapping Recommended for budded
alternate days for 6 months 100 % plants.
and rest for 3 months.
2 s2 d3- Half spiral, tapping at Recommended for clonal plants.
every three day for 6 months 67 %
and rest for 3 months.
3 s2 d1 – Half spiral daily Followed by small growers but it
tapping. 200 % favours brown blast incidence
and causes early deterioration of
trees.
10. In South India, rubber trees shed their leaves
during December- January & immediately again
they put forth the new leaves and flowering.
During this period the trees are given rest since
the yield of the rubber will be poor if tapped.
The yield of the rubber steeply increases year by
year and the peak is reached at 14-18 years after
planting.
11. Then it slowly declines . After 40 years it may
not be economical to maintain the trees.
The latex yield will vary with the clone, age of
trees, fertility of soil, climatic conditions and
skill of the tapper.
12. Types of Tapping
1. Puncture tapping
Puncture tapping or micro tapping is basically an
incision method of tapping. Micro tapping is done with
a small needle on a vertical band of stimulated bark.
The length of the strip is usually limited to 60 cm and
the number of punctures made may be 4 or 5.
14. 2. Slaughter tapping
Intensive tapping prior to felling of the old trees is
called slaughter tapping. It is often done at higher
levels sometimes even on branches with the help of
ladders and not on the usual renewed bark levels.
As the objective of slaughter tapping is to extract
as much as latex as possible from the available
bark, no consideration is given to the
technique, intensity or standard of tapping.
16. Rain guarding
By fixing a polythene rain guard to the trunk of the tree above the
tapping panel, tapping can be carried out during rainy season also
Growth regulators like 2,4 dichloro phenoxy acetic acid and 2,4,5
tri-chloro phenoxy acetic acid are applied through vegetables oils
these are applied in a broad band round the trunk under the
tapping cut of the rubber tree many proprietory products like
stimulex, flow more, ready rub containing the above growth
regulators are available in the market as rubber stimulant
20. Yield of Rubber
• In South India, the annual yield of rubber is
about 375 kg/ha from seedlings where as
budded plantations yield about 900-1000 kg
/ha
21. Processing of Rubber
• The latex that flows out from the rubber trees on
tapping is channeled into a container, generally
coconut shell cups then is transferred to clean
buckets, two to three hours after tapping.
• The latex which gets dried up on tapping panel (tree
lace) and the collection cups shell scrap also form a
part of the crop and are collected by the tapper in
baskets just prior to tapping.
22. • The latex split including over flown on the
ground (earth scrap), when gets dried up, is
also collected once in a month. Normally
10-20 % of the total crop constitute the
tree lace, shell scrap and earth scrap.
23. Rubber can be processed and marketed as
1. Preserved latex concentrates.
2. Dried sheet rubber.
3. Dry crepe rubber
24. Preserved latex concentrates
• The latex is collected in the storage tank, from
there it is brought to a centrifuge machine, rotating
at 1400 rpm. Due to centrifugal action, liquid
portion comes out.
• The upper layer and the concentrated latex, is
collected and brought to bulking tank and mixed
with chemical and packed in drums. 60% rubber is
present in it.
25. • Skim latex is taken to another tank then
sulphuric acid is added which gets coagulated
& it is milled to get skim crepe. It is of poor
quality while the concentrated latex fetches
very higher price.
26. Dried sheet rubber
• Anti-coagulants (solutions of
ammonia, Formalin or sodium sulphite are
added to the cups to prevent the coagulation of
latex before it reaches the factory.
• The latex so collected is then bulcked and then
strained to remove the impurities. It is then
diluted to a standard consistency of 12-15%
rubber.
• Special hydrometers like mrtrolac, latex meter
are employed to measure the percentage of
rubber.
27. • After dilution, the latex is strained through a 60
mesh screen for the second time.
• Then it is poured into the special coagulating
tanks or aluminium pans which is divided into
many compartments by thin aluminium sheets
and acetic acid or formic acid is used for
coagulation.
• Slow coagulation produces a soft rubber which
is easy to work on the rollers.
• The acid is to be added quickly and mixed
thoroughly with the latex. Froth formed is
removed to avoid formation of bubbles on the
surface of rubber sheets.
30. • After coagulatuion, rubber sheets are repeatedly washed
several times with changes of water & passed through
hand or power operated rollers. In the roller excess water
& dissolved impurities are pressed & squeezed out
• The surface of the rollers may be either smooth, or
grooved or zig zag or straight or diamond pattern, its
impression is normally left on the surface of the sheets
when they come out of the press
• These sheets are hung in shade for 2 or 3 hrs, for dripping
in a dust free place
31. • They are taken to smoke houses for thorough drying. Smoking
of rubber sheet is done to dry the sheets properly
• To avoid formation of blisters. In the smoke house, the sheets
are smoked at a low temperature of 48-500 C with fairly high
humidity during the first day subsequently during second to
fourth day the temperature being 680 C with low RH
• They are taken out, graded & packed. Such products are known
as smoked sheets or dry ribbed sheet rubber
32. Various grades of rubber sheets are
• RMA IX, RMA-1, RMA-2, RMA-3, RMA-4,
RMA-5.
• High grade rubber sheets are clear, free
from blisters, translucent & of a golden
brown colour & fetch a better price.
33. Dry crepe rubber
• When coagulum from latex or any form of
field coagulum after necessary preliminary
treatments is passed through a set of creeping
machines to get crinkly, lace like rubber called
crepe rubber after drying.
• Various grades of crepe rubbers are
• EPC Super 1X, EPC 1X, EPC 2X & EPC 3X.
