Attached
Sole is a major component of shoes. Shoe soles can be manufactured by using different
typesof materials as wel1 as techniques.
30% of the soles are being manufactured in sheet form and later cut the soles of required
size. The materials such as leather, vulcanized rubber, resin rubber, polyurethane rubber
and ethylene vinyl acetate polymer are used to manufacture soling sheets. The unit soles
are produced from poly vinyl chloride, thermoplastic rubber and polyurethane. I
The two basic moulding techniques used are compression moulding and injection
moulding.
In this project we have concentrated on compression moulded resin rubber soling market,
which continuously expands with a high demand for highly fashionable footwear where
leathercan be directly substituted with high quality resin rubber soles. Resin rubber soles
are as light as leather in weight and can be produced in many different colours and
fashions.
The objective was to develop a compound formulation, which satisfies the internationally
recognizedrequirements for resin rubber shoe soles. We tried to get the best formulation,
which is cost effective to manufacture in Sri Lanka and also to give final product
propertiesrequired in the international market.
We have studied the possibility of using a blend of natural and synthetic rubber in the.
compounds in order to improve most of the properties of the final product in a cost
effectivemanner. The processing techniques were the same as for the existing compound
with minor modifications to make the production more flexible. The product obtained has good properties in compliance to the international footwear
standards, however the formulation needs further modifications to over come certain
processing difficulties. Results show that the replacement of standard raw materials with
cheaper substituents have led to disagreement with one factor or other either in
processing or in properties of the finished product. Therefore, it is necessary to carry out
further studies on raw materials and their effects more closely against the existing
operation system in order to find out the optimum dosage and the best combination of
ingredients.
