Abstract:
String hoppers are a popular food in Sri Lanka and recent trends indicate a significant
increase in the demand for string hoppers from food outlets. Catering for such high
demands using the traditional hand press has become a tedious process and a strong need
exists for mechanized or automated string hopper preparation mechanisms/machines. In
Sri Lanka, string hoppers are prepared using the traditional string hopper presses or with
modern hand operated lever type presses which are tedious and time consuming
processes. However, there are several types of mechanized string hopper machines also
available in Sri Lanka. One such type is a rotary type machine which has a piston connected
to a rack having the capacity to produce around 100 string hoppers at a stretch. The main
disadvantage of this machine is that the cylinder needs to be removed after each batch of
string hoppers for re-filling, which tends to fatigue the operator with prolonged usage. There
are many power operated machines used for the preparation of string hoppers and these
are mainly manufactured in India. These machines mainly employ compressed air for
actuation. The disadvantages of these types of machines are that the string hoppers
produced can be irregular in shape and the need for separate equipment for supply of
compressed air which makes the machines relatively expensive. The re-design of a string
hopper machine was thus carried out, taking into consideration the deficiencies identified
in machines currently used and the affordability to a medium scale string hopper producer.
A string hopper machine which is electrically powered and having a piston-cylinder type
feeding mechanism was proposed and designed, also overcoming the need of bulky
additional equipment such as air compressors. A 5 cm extruding die, a mold rotator and a
cutting mechanism were incorporated in the design to make the spread of string hoppers
more uniform. Also, the machine can be manufactured using locally available materials,
making it more affordable than its counterparts, especially for medium scale string hopper
producers in Sri Lanka.
