Optimization the physical properties of carbon black filled tread compound by replacement with silica
No Thumbnail Available
Date
2015
Journal Title
Journal ISSN
Volume Title
Publisher
Uva Wellassa University of Sri Lanka
Abstract
In tire industry, carbon black (CB) is a widely used filler all over the world (Studebaker, 1965).
Being a product made out of petroleum, there would be scarcity issue with the time, if continue
to use in which it is being used today. It is a high time to look at feasibility of replacing CB with
an alternative such as silica partially/fully as a solution for foreseen scarcity. Compared to CB,
there won’t be scarcity as due to the fact it is made out of quartz (SiO2) which is readily
available in earth crust. In this research, an attempt has been made to study the feasibility to go
for possible replacement with silica while meeting the physical property requirement of a tread
compound.
Methodology
The current study was carried out at Loadstar (Pvt) Ltd, Ekala. This study was conducted as two
separate experiments. In experiment I, optimum CB/Silica combination which gives overall
physical properties was evaluated. Five tread compounds were prepared. Each compound has the
same ingredient except filler amount. Total filler amount was kept constant at 50 phr level.
Carbon black and powder silica was varied in the ranged from 0 to 50 phr level to prepare the
tread compounds with different CB/Silica ratios. Weight of all ingredients in the recipes was in
units of per hundred rubbers. Batch weight was 1100 kg. Compound without silica was treated as
the reference compound. The compounds were named as Si0, Si15, Si25, Si35 and Si50 to
indicate the amount of silica incorporated in the compounds. Silane was added when
incorporation of silica as 1 phr of Silane for 8 phr of silica as the coupling agent. Experiment II
was carried out to find out the effective silica type in order to optimize the physical properties.
Better treatment combination from the experiment I was selected and it has been treated with
three silica types (Powder silica, Hi-sil 243 and New-sil 155). Physical properties such as: tensile
strength, tearing, abrasion resistance, 300 % modulus, elongation at break, hardness and rebound
resilience and cure characteristics were measured in both experiments. Four replicates were used
for each test. Data was analyzed with one way ANOVA using Minitab 16 statistical software and
mean comparison was done using Tukey test.
Results and Discussion
According to the previous studies it shows that the increasing silica loading tends to increase in
the cure time (t90) and scorch time (ts2) of the rubber vulcanizates (Okel and Waddell, 1994).
These properties have increased with increasing silica. At 15 phr level of silica, it tends to reduce
the scorch protection. This can be due to the insufficient coupling of silane with silica during
compounding. Higher processing safety obtained as silica loading high due to formation of
Description
Keywords
Agriculture, Export Agriculture, Mineral Sciences, Materials Sciences, Rubber Technology, Rubber Production