Powel Automation Limited - Raw materials used for manufacturing roof tiles

Concrete roof tiles are produced by machine, using the principle of extrusion. The basic manufacturing technique is very simple and it is only as production output increases or special effects are required that the process becomes more sophisticated.

Aluminium moulds (pallets - see the image to the right) which form the underneath profile of each roof tile, are coated with a release agent prior to being fed into the entry end of the extrusion machine.

A mortar mix is delivered from a mixing system into the machine extrusion head. This mix is extruded between the pallets and a roller, which is mounted inside the head.

The roller forms the top surface of the roof tile. A trowelling slipper is mounted behind the roller and this serves to further compact the tile and produce a smooth and level surface finish.

The final operation of the tile machine is to cut the tiles to length using a vertical cutting knife.The freshly extruded tiles, still on their own individual pallets, are loaded into racks and placed in heated chambers for curing.

*Click on the diagram to the left to see a larger version of the manufacturing process

The conditions inside the curing chambers are controlled to provide a temperature of 30 ºC to 35 ºC and a relative humidity of 95% (for 24 hour curing).

Once cured, the tiles are separated from their pallets and taken to a stock holding area for a period of up to 28 days. This extra time allows the tiles to further harden before they are despatched to their final destination.