Seikei-kakou 

About: Seikei-kakou is an academic journal published by The Japan Society of Polymer Processing. The journal publishes majorly in the area(s): Molding (process) & Engineering. It has an ISSN identifier of 0915-4027. It is also open access. Over the lifetime, 724 publications have been published receiving 1188 citations. The journal is also known as: Journal of JSPP & Seikei kakō.

Polymer Clay Nanocomposites

Abstract: The development of polymer-clay nanocomposite materials, in which nanometer-thick layers ofclay are dispersed in polymers, was first achieved about 15 years ago. Since then, the materialshave gradually become more widely used in applications such as automotive production. The first practicalnylon-clay nanocomposite was synthesized by a monomer intercalation technique; however, the productionprocess has been further developed and a compound technique is currently widely used. A polyolefinnanocomposite has been produced by the compound method and is now in practical use at small volumelevels. In this review, which focuses on nylon- and polyolefin-nanocomposites, detailed explanationsof production methods and material properties are described. This article contains mainly the authors’work, but aims to provide the reader with a comprehensive review that covers the works of otherlaboratories too. Lastly, the challenges and directions for future studies are included.

Measurement of Filament Temperature and Analysis of Orientation-induced Crystallization Behavior in High-Speed Melt Spinning Process

Abstract: The measurement of the filament temperature along a spinline in a high speed melt spinning process provides information on the cooling behavior and crystallization behavior of running filament. The filament temperature was analyzed through simultaneous measurements of infrared radiation intensity and the diameter of the filament. The determined empirical formula for the evaluation of the cooling of the running filament predicts a slower cooling rate than that obtained from the Kase and Matsuo equation. The diameter profile for a poly (ethylene terephthalate) spinline at a take-up velocity of 6km/min showed a so-called neck-like deformation at 140-150cm down from the spinneret, and the temperature profile showed a maximum just after the end of the deformation. This temperature increment reflects the heat of crystallization induced by molecular orientation. The rate of crystallization in the spinline, which is estimated from the temperature and diameter profiles, at a temperature of ca. 160°C and birefringence of 0.108 is 105 times greater than that of the isotropic state. It is suggested that crystallization proceeds rapidly just after the end of the neck-like deformation in a high speed spinning process.

Dispersion of Carbon-Nanotubes in a Polymer Matrix by a Twin-Screw Extruder II

Abstract: Recently, carbon-nanotubes (CNT) have become a main focus in the polymer nanocomposites field. In a previous study, polymer composites with good CNT dispersion were obtained using a twin-screw extruder. There was a close correlation among the following three parameters: the total shear strain [γ·t] responsible for the dispersion in the extruder, the area ratio of agglomerate CNT in the composite and the conductivity of the polymer composite. [Ar] indicates the degree of dispersion and is obtained through microscopic observations. Lower [Ar] corresponds to better dispersion, while higher values correspond to poor dispersion. In the high [Ar] region, the composite conductivity increases with a decrease in [Ar], while in the low [Ar] region, the conductivity decreases with a decrease in [Ar]. This indicates that an optimum value of [Ar] exists to obtain the best (highest) conductivity (minimum value of resistivity).This report will describe attempts to obtain better dispersion than those in the previous study by modifying the screw profile with a high shear rate segment. Volume resistivity dependence on [Ar] obtained in this study was in good agreement with previous resistivity results.Uniform dispersibility was proposed as a new parameter. We investigated the relationship between CNT length and uniform dispersibility in the matrix and the behavior of the resistivity curve.We can conclude that a CNT composite shows the best conductivity when it has an optimum balance of CNT length and uniform dispersibility.