UTILISATION OF SELECTED VARIETIES OF COTTON PLANTS GROWN IN NIGERIA FOR PAPERMAKING
UTILISATION OF SELECTED VARIETIES OF COTTON PLANTS GROWN IN NIGERIA FOR PAPERMAKING
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Date
1998-08
Authors
MADUAKO, JOSAPHAT NWABUEZE
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Abstract
The utilisation of cotton plant stalks for papermaking,
as an alternative to the wasteful disposal of the crop residue
by burning, was explored in this study, using four varieties
of American upland cotton plants (Gossypium hirsutum),
namely: SAMCOTs 6, 8, 9 and 10 grown in Nigeria. Wood and
bast fibre characteristics, such as fibre wall thickness,
fibre diameter, fibre length, runkel ratio, thickness index,
flexibility coefficient and slenderness ratio were determined.
The composition of alpha-cellulose, hemi-cellulose, lignin,
ash and moisture were also determined.
The fibre length, runkel ratio and slenderness ratio were
found to be 0.270mm, 0.540 and 12.7, respectively, on the
average, for both wood and bast fibres. Varietal effects on
most of the fibre characteristics were found to be significant
at 95% probability level. SAMCOT 9 was found to be the best
variety in most fibre characteristics, followed by SAMCOTs 10,
8 and 6. The alpha-cellulose content of the stalks averaged
54.0%, which was high enough to be explored for papermaking.
In view of the low runkel ratio and short fibre length of
the stalks, thermo-mechanical pulp (TMP) was prepared from
each variety and blended with at least 40% of waste paper (WP)
whose fibre length averaged 2.00 mm, and it improved the sheet
formation and the strength properties of the hand sheets.
Factorial three-factor papermaking experiments involving two
levels each (2x2x2) of furnish ratio (TMP/WP), pulp freeness
and additive were conducted. Standard hand sheets were
produced and tested for physical and mechanical properties.
For the furnish ratio (TMP/WP) of 60/40, freeness of 35°SR and
additive of 1% rosin and 4% alum, the caliper, basis weight,
burst strength and tear strength of the hand sheets averaged
0.510 mm, 127.8 g/m2, 0.420 kPa and 0.820 kN, respectively.
SAMCOT 8 hand sheets consistently maintained the highest tear
strengths, followed by SAMCOTs 10, 9 and 6.
The basis weight versus caliper relationships for SAMCOTs
6,8,9 and 10 hand sheets were found to be linear, with high
and positive correlations and the coefficients of
determination r2 were 0.958, 0.997, 0.914 and 0.866,
respectively. The paper strength properties correlated
positively with the original fibre characteristics of SAMCOTs
6, 8, 9 and 10 cotton plants and were found to have linear
relationships. The tear strength versus runkel ratio, fibre
length and slenderness ratio relationships had coefficients of
determination r2 of 0.674, 0.927 and 0.812, respectively
Description
A THESIS SUBMITTED TO THE POSTGRADUATE SCHOOL,
AHMADU BELLO UNIVERSITY, ZARIA
IN FULFILLMENT OF THE REQUIREMENTS
FOR THE AWARD OF THE DEGREE OF
DOCTOR OF PHILOSOPHY (Ph.D)
IN AGRICULTURAL ENGINEERING
DEPARTMENT OF AGRICULTURAL ENGINEERING
FACULTY OF ENGINEERING
AHMADU BELLO UNIVERSITY
ZARIA - NIGERIA.
AUGUST, 1998
Keywords
UTILISATION,, SELECTED,, VARIETIES,, COTTON,, PLANTS,, GROWN,, NIGERIAN,, PAPERMAKING.