To investigate the flow of a viscoelastic liquid, it is necessary to consider a relaxation timeaswell as a viscosity. The flow of polyethylene from a reservoir into a slit at low Reynolds numbers has been visually observed to investigate the flow patterns.
The results of this study are as follows :
When Reynolds numbers R_e are lower than 1, the circulating secondary flows occur according to the condition of the main flow and to the characteristics of melted polymers . The liquid of a longer relaxation time has a smaller critical deformation velocity at which circulating secondary flows occur in the reservoir.And the region of circulating secondary flows spreads as the deformation velocity becomes larger. Although a reservoir wall angle is changed, the pattern of the main flow into a slit hardly changes . In regard to the liquid of a shorter relaxation time, the irregular and unstable flow occurs at the inlet region of a slit before the circulating seconbary flow occurs.

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The techniques of suction method to search for a broken end of fiber bundle are applied in the various process of textile technology. This paper discusses the optimum condition of an air stream by comparing the results calculated by Finite Element Method with those experimentally obtained by the model, which has an axisym metrical canal between bobbin and its proper hood.
A considerably good agreement is obtained between both results. It is concluded that searching ability for yarn ends are more dependent on air flow acceleration-especially on an acceleration variances of an air flowthan air flow speed.

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