The velocity was measured at a T shaped channel by means of a laser doppler velocimeter. Fluids used for the investigation were water as a Newtonian fluid and polymer (PAA and HEC) solutions as a viscoelastic fluid.
A circulating secondary flow at the upstream side of a T-shaped corner was ascertained as a flowing upstream for the viscoelastic polymer flow. The velocity distribution of the viscoelastic flow was similar to that of the Newtonian flow at the low flow rate, but as increasing the flow rate and developing the circulating secondary flow, the characteristics of viscoelastic flow appeared at the juncnon. At the higher flow rate the velocity distribution reached a fixed shape, and a periodic oscillation of the local flow rate was observed near the junction.

View full abstract

General characteristics of women operators in machine stitching have been investigated, in order to study a systematic method for effective training in stitching by an electric sewing machine. Women operators were asked to stitch along the straight or curved lines printed on prepared paper under the several conditions.
The results obtained are as follows:
1) The tracking ability of operators along the guidelines is proportional to the amount of their experience. The deviation of stitched lines from the guidelines is nearly directly proportional to the feeding speed as well as the curvature of the guidelines. In addition, the increasing rate of the deviation as a result of the increase of the feeding speed is also proportional to the curvature.
2) The phase lag of stitched lines from the guidelines grows with the feeding speed in stitching along sinusoidal curves.
3) The deviation grows with the increment of the interval of the guide marks and it becomes more remarkable on curves than on straight lines. It, however, decreases with the increment of the feeding speed while stitching along straight lines, if the interval between the guide marks are long enough or if the stitching lines are apart from the guidelines.
4) The deviation slightly increases if operators control the feeding speed.
5) Stitching at the high speed along sharp curve tends to cause irregular stitches and indented stitch lines.
6) The feeding speed is more difficult to control in stitching along curved lines than along straight lines.
7) The actual driven speed of the sewing machine for garment manufacturing tends to be higher than the speed at which operators feel easiest to stitch. The difference between these speeds by the experienced operators is less than that by the beginners.
8) The optimum condition of stitching operation is achieved by both the feeding speed and the rotational speed of a sewing machine. The optimum speed, at which operators have felt easiest to stitch slightly increases with the growth in their experience in sticthing.

View full abstract

The centrifugal method of a fiber reinforced plastic (FRP) pipe has been developed owing to the simple processing in the cylindrical forming, and the technique of mass-production has been established. At the next step, the improvement of the quality has been closed up and the study to enhance the fiber content has been considered to be of importance.
On the centrifugal method, only the centrifugal force is applied on fibers and other mechanical forces are not applied at the lamination process. Therefore, the high fiber content has been seemed to be difficult.[6]-[8]
In this report, an experiment have been made on the effective centrifugal forming for the high fiber content by applying the forming behavior of fibers. As a result, a high fiber content of approximate 55 vol.% was achieved, although it was hitherto only 25 vol.% at its maximum.

View full abstract