Detonating cords are mainly used in initiation of the cap sensitive
explosives, surface connection of the nonelectronic detonators, and in
special applications like presplitting or smooth blasting. It is a flexible cord
containing a core of highly sensitive PETN (Pentaeryhtrol tetranitrate)
explosive which is covered with textile and waterproof PVC layers. When
initiated it detonates with a speed of around 6300-7000 m/sn. Velocity of
detonation increases with the amount of explosive at the core. Depending
on the field of use detonating cords are classified according to amount of
PETN for each meter (5 gr/m – 80 gr/m). Usually 10 gr/m detonating cords
are used for initiating the cap sensitive explosives.
Detonating cords should not be transported together with the detonators.
If to be used directly for initiating the primer, one end should be inserted
into the primer and the chord should be wrapped and tied around the
primer. Always cut the detonating cord with a sharp knife. Never attempt
to cut the cord with a blow from a hard object such as a spade, axe and
stone. The core of the explosive inside the cord is sensitive to impact and
friction and it may explode when struck between two hard surfaces.Cord should not be cut using tools with metal to metal contact such as
scissors or wire cutters. Open end of the cord should be protected from
water and oil and any connection should be made at least 15 cm away
from the open end. Ensure that they are no loops, kinks and severe bends
in the cord which can cause gaps in the explosive core and lead to misfires.
While connecting a detonator to a cord it should be firmly in contact with
the cord and explosive end of the detonator should be in the direction of
propagation. Cord lines should not be overlapped or crossed over each
other, all connection points should be at wide angles; acute angles may
cause misfires. Ensure every blasthole has two paths of initiation, this prevents cutoffs due to ground movements of flying rocks.
Detonating cords are coiled in spools at different lenghts according to their diameters and put into cardboard boxes.
|Core Load||Tensile Strength||Outer Diameter||Cord Color|
|5 g/m||50 kg||3.6 mm||Beyaz|
|10 g/m||50 kg||4.4 mm||Mavi|
|40 g/m||60 kg||8.0 mm||Mavi|
|80 g/m||60 kg||11.0 mm||Mavi|