The influences of applied pressure, temperature, heat treatment time, water content on the properties of molded silk were studied. The strength of molded silk was 15 MPa when the water content of the silk powder was 6.5%, the size of the silk powder was about 150 μm or less, heat treatment time was 10 min and the temperature was between 125-150°C. The moisture regain of the molded silk was about 8%.

View full abstract

United Nations Congress in November, 1991, made a resolution to prohibit drift net fishery. As a back ground of the resolution, it was pointed out in the congress that Japanese fishing boats were mostly responsible for the discarded nets drifting in the ocean. Therefore, it has become an urgent problem to make sure where they are from and how long they have been drifting. This report pays attention to the possibility to identify the fishing nets by using IR absorption spectrum in 1379cm^-1, which corresponds to the peak of symmetric deformation vibration of methyl side chain. Since the experiment has verified that the methyl branching coefficient vary according to the makers, this method is considered to be very effective to identify polyethylene fishing nets.

View full abstract

This is the research report of the results of round robin test to survey the reproducibility of artificial accelerated exposure test apparatus using polycarbonate film as reference material which was carried out in the Research Committee of the Weatherability of Polymer and Colored Materials, Materials Life Society, Japan. As the UV absorbance change of polycarbo nate is very sensitive to the spectral distribution of exposed light, PC is convenient to monitor the presence of UV radiation shorter than 300nm. We could not compare the relation between UV absorbance changes and exposure conditions, because at present the calibration procedures for sensor of exposure conditions are not yet standardized.

View full abstract

The study on round robin tests to survey the reproductivity of artificial accelerated exposure test apparatus using polyethylene film was carried out. The linear relationship between Carbonyl index and Exposure time was recognized in the case of the standard specimen. The kinetics constants of carbonyl group generation depended on the temperature of black panel and oven and the activation energy was 40kJ/mol. This round robin test was achieved by the Research Committee of the Weatherability of Polymer and Colored Materials, Materials Life Society with a fund of Suga Weathering Technology Fundation.

View full abstract