Based on the low cost extruder, Development Alternatives has developed a process for producing hollow bricks. Various experiments have shown that with the soft extrusion technology, a maximum of 14% hollowness can be achieved. The holes are round shaped with three holes equidistant to the length of the bricks. Combined with a waste use of 5-10%, this type of bricks has a capacity to save 25% of soil.
Compressive strength tests of hollow bricks have shown an increase of 3 times compared to normal hand molded bricks using the same soil quality.
The machine is being commercially marketed by TARA Machines and Tech Services Pvt. Ltd., New Delhi under a licensed agreement to manufacture, sell and service the same.