Relationship between electrospun fibers and spinning conditions are investigated from the view point of jet profiles such as diameter distribution, jet velocity, and the evaporation rate of solvent from the surface of jet in solution electrospinning process by changing (i) the applied voltage and (ii) the relative humidity of ambient air. Profiles of jets near the droplet at the tip of needle are measured as functions of the position along the spinning line by using photographs. The measured profiles of jet can be fitted nicely by the analytic expression of spinning profile for a non-evaporating Newtonian fluid, which enables us to calculate the velocity profile of jets and the evaporation rate of solvent from the jet as a function of the position along the spinning line. Changing the applied voltage, it is found that the jet velocity and the evaporation rate in our measured region are decreased and beaded fibers are increased when increasing the applied voltage, on the other hand the total amount of evaporated solvent from a jet in our measured region is too small to affect the profile of jet and to change the viscosity of solution in the jet. Changing the relative humidity, it is found that profiles of jets are almost the same except for the evaporation rate. The evaporation rate in our measured region is increased by decreasing the relative humidity. In the lower humidity region, less than 60% of humidity, beaded fibers are hardly formed, but in the higher humidity region, more than 60%, beaded fibers are increased with increasing humidity. From the results in two conditions (i) and (ii), it is found that the beaded fibers are easily formed as the evaporation rate of solvent becomes smaller.

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In this study, a quantitative analysis of foam cell distribution at the cross section of products in microcellular injection molding was conducted concerning the relationship between the mold conditions and laminar morphology. The following results were obtained; (1) The morphology consists of a surface layer (Skin layer I) with silver streaks, a layer (Skin layer II) with no cells inside, and a foam layer (Core layers I, II, III) with many cells of different size. (2) The morphology changes depending on the molding conditions and cavity position. (3) The core layer domain decreases from the gate to the distal end. (4) Injection conditions greatly affect the thickness of Skin layer II. (5) Maximum filling pressure in the mold affects mainly the core layer of the foam morphology.

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The surface properties are important to evaluate the quality of injection molded products. The spectrum analysis was introduced to clarify the surface roughness of the injection molded products with emboss. Moreover, the influence of polymer temperature and pressure on the surface properties was investigated by using the injection molding analysis.
The results of a new evaluation method in spectrum analysis proposed in this study were in agreement with the observation results, and showed the validity in the numerical evaluation of the surface state of emboss. Moreover, the polymer surface temperature and pressure obtained from the numerical analysis showed the good agreement with the tendency of evaluation results. From the experimental and numerical results, it was considered that the new evaluation method can be proved to be useful for the surface properties of emboss and can be applied to the optimum mold design with emboss.

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