For the restitution behavior between the tennis strings and the ball, the setting unit which can set up the interval length and tension force of the string is produced, and identified the viscoelasticity characteristic of string side and ball by compression, vibration and impact tests experimentally. It was found that the restitution coefficient is increased with the increasing distance of string interval, but reduced with the increasing string tension at the impact velocity of 5.42m/s. The regularity about the viscosity characteristic is not very much obvious. Furthermore, the influences on restitution behavior are discussed by numerical simulation analysis. The simulation results are not only corresponded with the experimental results, but also revealed that string rigidity is great effective on restitution coefficient. The effect of viscoelasticity can be ignored due to its slight influence.

抄録全体を表示

This work has demonstrated coaxial electrospun polymeric sheath fibrillar structure as useful tool for hosting chemical reactions within confined volume and potential templating material for the synthesis of extended one-dimensional structures. In addition, this work has successfully demonstrated the novel production of micron sized epoxy fibers via coaxial electrospinning. Epoxy monomer fluids were polymerized within the polyamide 6/6 (PA 66) sheath structures and upon removal of PA 66, long continuous epoxy fibers were revealed.

抄録全体を表示

Double-stack disk friction units were used to produce good, high-crimp yarn like wool and the results were compared to conventional triple-stack disk friction units. The quality of false-twist textured yarn from disk friction spindles is very strongly influenced by unit operating conditions and untwisting tension. The authors previously proposed a method to derive tension and untwisting tension in the yarn given the twisting tension and yarn path in double-stack disk friction units. In this study our goal was to calculate both yarn path and yarn tension. We were able to compare and confirm that the calculated yarn path and yarn tension closely matches experimental results. In addition, we succeeded in using our model to predict conditions for guide hole to produce false-twist yarn. The validity of our model was proven by the results. We have succeeded for the first time in calculating approximate yarn path and yarn tension for the false-twist process in disk friction spindle units. Our results should be helpful in designing disk friction spindle units.

抄録全体を表示

In order to promote the recycle of fiber products, it is necessary to expand the application of recovered fibers. In the present study, the forming method of spherical fiber assembly using recovered fibers was devised; its compatibility as pillow fillers was evaluated as well. By revealing the relationship between structure and compression property of the obtained spherical fiber assembly, it was found that the compression property can be controlled by changing the mixture ratio of core-sheath conjugate fiber, the density of fiber assembly, and the fiber composition. Consequently, it was shown that by using the spherical fiber assembly as pillow fillers, it was possible to make pillows with controlled sinking ratio and body pressure value, indicating that the spherical fiber assembly had sufficient physical properties required for application to pillow fillers.

抄録全体を表示