A Study of the Airflow and Fibre Dynamics in the Transport Chamber of a Sifting Air-laying System: Part 2 — Fibre Dynamics

• Published in: International Nonwovens Journal 2000-09, Vol.os-9 (3)
• Main Authors: Pourmohammadi, A., Russell, S.J., Bradean, R., Ingham, D.B., Wen, X.
• Format: Article
• Language: English
• ISSN: 1527-2494; 1558-9250; 1527-2494
• DOI: 10.1177/1558925000OS-900306

In Part 1 of this paper (International Nonwovens Journal, Summer 2000), the airflow characteristics in the transport chamber of a sifting air-laying system of the Kroyer type [US patent 4,144,619] was reported. In Part 2, the fibre dynamics in the transport chamber of the machine are investigated. These are of major practical importance because they influence the process of web formation. High-speed photography was used to observe fibres in flight and their deposition onto the conveyor belt during web formation using fixed machine conditions. It was established that fibres move intensively in three dimensions at the top of the chamber and as they travel towards the landing area their motion becomes more uniform. Fibre landing behaviour was studied by analysing photographic images. Using standard machine settings, it was established that about 38% of fibres landed end-on before falling down flat onto the conveyor belt (Hit-Fall configuration) and about 30% of fibres landed flat (along their full length) but bounced before coming to rest on the conveyor belt (Hit and Bounce configuration). Fibres were deformed when passing through the top grid, causing permanent deformation that was evident in the fibres landing on the conveyor belt.