Textile fibres used in production of needle felts have to be subjected to a series of mechanical processes before a web can be presented to the needle loom. The most common technology is the "carding" process, where fibres are parallelised by passing them through- & over cylinders which have and led wires mounted on them. The surface velocity of these "carding" cylinders are carefully calibrated and vary widely on the type, density & thickness of fibres being processed. The nett result is a web which largely consists of fibres in "parallel" alignment, & so it follows logically that the finished needle felt will also contain fibres oriented in a specific direction.

The "air laid" technology, unique to heavy needle felts, has been adopted by us on one of our felting lines. Fibres are fed into a "hopper", moved first by a horizontal conveyor, then selectively "lifted" by a "vertical" spiked conveyor. At the top, another spiked roller further opens the fibres & fees them into a "reserve" box which has electronic controls to accurately control the level of the fibres. A fast revolving wire opener separates each individual fibre, and keeps them in free suspension. A pair of perforated drums with suction attracts the fibres in free suspension onto them, and thus creates a randomly formed air laid web, which is continuously laid onto the inlet conveyor of the needle loom. Variable electronic drives closely control te web weight. The web is characterised by completely random orientate of the textile fibres, as compared to uniformly aligned fibres in the conventional "carding" process. A random web & felt is known to give much higher filtration efficiency.