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vol-3PRESERVATION OF EGYPTIAN COTTON NETTING TWINES
By
G. A. BOTROS, A. A. AL-S
AYES AND R. A. KOURA
INTRODUCTION
Amongst the several causes of deterioration of natural netting-twines
of which operational fatigue, frictional abrasion, sunlight and fish slime are
examples, rotting by the action of cellulose-consuming micro-organisms
is considered the most responsible. Un-preserved netting-twines after a short
time reach a limit of breaking strength (50% of the initial value) below
which the fishing gear becomes of no practical value. In the face of the
growing competition of non-rooting synthetic fibres, it is of utmost import-.
ance to try to find new ways to inununize the natural fibres-of which cotton
twines are our largest concern – against the attacks of micro-organisms.
Fishermen in various countries and even in different areas of the same
country use different preservation methods, each convinced without being
able to give any reasons that his method is the best.
In this work, an attempt i, nade to evaluate certain standard preservation methods used allover the world, w’th the aim of recommending the
use of those that erperimentation proves 110 be the most suitable to our local
environment.
Technique of work :
The field technique followed for this purpose was suggested by Von
Brandt (1959).
Measurenment of resistance to rotting resulting from treatment with
a certain preservative is carried out under field conditions. First of all our
treated twines are suspended in natural waters for a certain period to
determine the destructive action of the micro-biological organisms on them
in other words, the efficiency of the presrvative as a rot-retarding agent.
This is measured by the loss in the breaking strength suffered by the
material at the end of successive periods within the duration of the experiment. As this loss will depend to a large extent on the rotting activity of
the water in which the material is suspended, this value must be determined
simultaneously.
Thus this test is twofold, namely it includes a test of the rotting activity
of the water and another of the rotting resistance of the preserved netting
material.
