vortices that may have been created by a fan or impeller or by the duct work etc the air flow through the duct 15 is preferably rather slow to permit effective straightening thereof accordingly the duct 15 has a rather large cross section to permit a large volume of air to move slowly therethrough an acceleration arrangement 20 sometimes referred to as a nozzle is connected to the end of the duct 15 and has a reducing cross section to increase the velocity of the air passing therethrough the particulars of the acceleration arrangement 20 will be described in more detail below an airlay duct 40 which has a size corresponding to the outlet of the acceleration arrangement 20 is connected to the end of the nozzle which is arranged to convey the air flow along a path which accepts the fiber to be laid into a web and lay down the fibers the airlay duct 40 is arranged in conjunction with a disperser roll 45 which feeds fibers from a batt 55 into the air stream the fibers are carried down the airlay duct 40 to a screen conveyor belt 50 and deposited thereon to form the web w the air which carries the fiber preferably passes through the foraminous belt 50 and is collected in the collection duct 60 the collection duct 60 carries the air out of the airlay equipment to be vented to the atmosphere.