In this article we show the history and technology of air jet weaving. Our purpose is to model the air flow of the weft insertion of air jet weaving machines marked P by making a series of laboratory measurements and to create such closed-form shape mathematical functions which make it possible to determine the air speed of weft insertion flow without industrial measurements by knowing the maximum air speed of the initial section.
In air jet weaving machines weft is accelerated and taken through the shed by the flow impedance between the flowing medium (air or water jet) and the weft. Air jet weaving machines belong to the set of intermittent-operation weaving machines.
The energy resulting from air pressure directed from the central air tank to the weaving machine changes into kinetic energy in the nozzle, which accelerates and delivers the weft in the differently formed air channels. The speed of air exiting the nozzle is near or sometimes over the local sonic speed.
The air leaving the nozzle mixes with the still air, it disperses, the speed of the axis of the flow drops quickly as it moves away from the nozzle, therefore in order to reach bigger reed width the air speed must be kept up in the line of the weft course.
Source: Óbuda University
Authors: István Patkó | Lóránt Szabó