Pressing describes the action of pushing or squeezing material to exude liquid.
Pressing can be carried out by hand or by using a press. The two presses
illustrated below are made out of galvanised sheet steel.
The drum press (view image) is suitable for making gari. The cotton bag containing the cassava pulp is placed inside the perforated drum. The second drum is lowered down and screwed in place as tightly as possible. This step is equivalent to placing weighted material on top of the bag of cassava pulp. As the cassava de - waters over a few days, the screws are tightened further to maintain pressure on the pulp. The water runs out of the press through the perforations in the outer drum and is collected in the bucket underneath the stand.
The dimensions of the two drums are:
| Outer perforated drum | External diameter and height of 40 cm. The holes are 1/2cm diameter and spaced 21/2 cm apart from the bottom of the drum to a height of 1 5 cm up the drum |
| Inner non-perforated drum | External diameter of 30 cm and height of 50 cm. |
The drum supports are threaded pieces of mild steel.
The drum support stand is also made of galvanised steel, standing 0.6 m off the floor and with a surrounding lip of 0.1 m. On three sides of the table there are screws which tighten against the side of the perforated drum, to secure it onto the table.
The screw press (view image) is of a very similar design and suitable for use in pressing out the water from root crop pulp to collect the starch. The outer drum dimensions are the same as for the drum press. Instead of the inner drum, there is a metal or wooden plate attached to a centre screw piece. As the screw torque is turned the wooden or metal plate presses against the pulp in the cotton bag and presses out the water. The screw torque is fixed onto the drum by a metal bracket. The support stand is of the same dimensions as that supporting the drum press.