Controlling the Quality of Airlaid Paper
Saukoniemi, Aki (2018)
2018
Konetekniikka
Teknisten tieteiden tiedekunta - Faculty of Engineering Sciences
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Hyväksymispäivämäärä
2018-10-03
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:tty-201808312248
https://urn.fi/URN:NBN:fi:tty-201808312248
Tiivistelmä
Demand for airlaid nonwovens is expected to grow at an annual rate of 5 % or greater until at least 2022. While current production machinery capacity may or may not suffice, there is an increasing market for modifications and upgrades to existing production lines to increase efficiency and to allow higher production rates and increasing the quality, if possible.
In this thesis the suitability of computational fluid dynamics modeling in airlaid production line development is examined. By inspecting the flow fields in the former after geometrical and parametrical changes, we can estimate the effects of those changes on the quality of the airlaid web. Feasibility of the changes can then be assessed without slow and expensive prototyping.
Three different simulations were conducted to investigate the effects of two development ideas: first without modifications to achieve a baseline, second with larger fiber inlet ducts and flow rates to inspect their effects, and third with rotating air deflectors to find the optimal fiber inlet angles. The results were reasonable and provided valuable insight to the effects of aforementioned modifications. The used simulation model can be easily extended to include more relevant physics, such as the suction box and the secondary air uniformer.
In this thesis the suitability of computational fluid dynamics modeling in airlaid production line development is examined. By inspecting the flow fields in the former after geometrical and parametrical changes, we can estimate the effects of those changes on the quality of the airlaid web. Feasibility of the changes can then be assessed without slow and expensive prototyping.
Three different simulations were conducted to investigate the effects of two development ideas: first without modifications to achieve a baseline, second with larger fiber inlet ducts and flow rates to inspect their effects, and third with rotating air deflectors to find the optimal fiber inlet angles. The results were reasonable and provided valuable insight to the effects of aforementioned modifications. The used simulation model can be easily extended to include more relevant physics, such as the suction box and the secondary air uniformer.