A modern wire-cut brick-making plant outside Chennai uses Chinese technology to reduce dependence on labour and to increase the quality and quantity of production. Nikhil Raghavan has the details
The dawn of the IT era spawned the coinage ‘click and mortar’ but there is no denying the fact that dwellings of any sort have to depend on traditional ‘brick and mortar’ frames. Bricks are an essential part of buildings even if combined with granite or other stones. In vast, multistoried complexes, tonnes of bricks are used in the walls and other structures.
The old ways
With an exponential growth in the housing industry, despite the occasional slowdown, brick manufacturing goes on full swing almost throughout the year, except maybe during the monsoon when drying becomes a problem. This is where technology is coming into brick manufacture.
When brick-making entrepreneur I. Thomas visited China whose economic growth has been accompanied by a real estate boom, he found that the Chinese had developed technologies to automate and improve the quality of traditional bricks.
Back home, Thomas had inherited a family brick-making unit that largely depended on extensive manpower to produce the traditional hand-made bricks. "There were times, during the peak season of demand, when we would employ as many as 270 people, sometimes entire families."
Over the years, demands for more wages, lesser hours and the use of short-cut methods for mixing, combined with labour shortages, resulted in poor output.
The major resultant problem was bricks of lower consistency, rougher edges, inconsistent sizes, breakages, etc. When the real estate industry showed growth, it became important to keep pace with quality and quantity.
Thomas checked the international markets and zeroed in on Chinese technology, which was easily available to medium-sized industries like his.
In China, Thomas came across Baoshen Machinery IBrick Technology from Xi’an, which designs wire-cut brick-making plants for turnkey implementation. "It was amazing to watch the semi-automated process of brick- making. I decided to import the entire machinery, including a fleet of battery-operated transporters," says Thomas.
The deal included installation and training, for which three Chinese technicians from the company came and stayed with Thomas's team for three months. His compny, Reliance Brick Industries in Sellapattidai Village, Sriperumbudur, stands on many acres of land with an existing kiln and old-fashioned ways of making bricks.
The new technology is not totally automated but uses less manpower. Today, the process from raw material to baked bricks takes 15 days. Thomas is moving into the next level of automation with giant blowers for quicker drying and hotter ovens for faster baking, which will reduce the overall number of days to three. Capacity will move to 70,000 wire-cut bricks a day from about 35,000 handmade bricks a year or so ago.
“The increase in production and reduction in manpower does not necessarily mean a drop in prices. This is because, for the consumer, there are many other advantages (see FAQ box ). For one, says Thomas, the damage in transit is about 1 per cent compared to almost 10 per cent for handmade bricks. Second, due to consistent size, fewer wire-cut bricks are required in construction. Further, less cement is needed for stacking bricks and for plastering, as there are fewer gaps and rough edges to be smoothened out.
The new technology
The soil is prepared in batches to maintain moisture content.
The right mixture is fed into the box-type feeder using a front-end loader.
The material is screened by a magnet to remove iron particles and fed to a primary crusher through a conveyor. The lumps and stones are removed and regulated size of soil is fed to the fine crusher. The fine crusher takes care of the final size of raw material. It's then fed to a double shaft mixer.
The mixer homogenises the material and water, if required, can be added at this stage to increase moisture.
The final mixture is fed into a vacuum extruder, which produces a column of clay on to a roller conveyor and compacts the brick.
A flying cut-off slices the column to size before pushing it to the brick wire-cutter. The final brick is cut with wires to actual size and carted by trolleys or conveyors for storage in shade. After a week, the semi-dried bricks are re-stacked for complete drying.
The dried bricks are loaded in firing chambers for baking and unloaded after due process and are ready for market.
The increase in production, however, does not necessarily translate into reduced prices. What you do get is lower breakage rates and savings in cement.
How many bricks can be made in an eight-hour shift?
Normal bricks: 45,000
Wire-cut bricks: 72,000
What is the manpower needed?
Normal bricks: 90 workers
Wire-cut bricks: 30 workers
What is the difference in height when you stack ten normal and wire-cut bricks?
10 bricks = 21 sq. ft.
10 bricks = 28 sq. ft.
What is the number of breakages per lorry load?
Normal bricks per lorry load of 3,000: 150-200
Wire-cut bricks per lorry load of 3,000 bricks: 20-30
For a normal house of 1,200 sq. ft ground and first floor, what will be the savings on cement?
Normal bricks = 600 bags
Wire-cut bricks = 510 bags