Yasuo Takasu

Preparation of thermoplastic molding from steamed Japanese beech flour.

Abstract Thermoplastic molding has been prepared from beech wood flour steamed at 180°C or at higher temperatures without any additives. It exhibited a smooth and lustrous surface and had a high density of approximately 1.45 g cm-3. The internal structure of molding revealed that the flour particles were completely surrounded by black resin-like substance which was thermoplasticized by heat and pressure during the molding process. The chemical composition of the steamed flour and physical properties of molding were examined as a function of steaming temperature. Maximum bending strength and Youngs modulus of molding reached 63 MPa and 11 GPa, respectively, at 180°C of steaming, which were much higher than those of a hardboard. The water absorption of the molding was 8% or less and decreased with the steaming temperature.

Development of Low-Density Wooden Molding Mat Using Bicomponent Fibers

We attempted to use wood shavings in their raw curled flake form as a base material in a mat to be used primarily as a heat-insulating/acoustic material in houses. The molding succeeded in producin...

Sound absorption and form retention of newly developed heat-insulating/acoustic material

A wooden mat to be used as heat-insulating/acoustic material was developed using wood shavings in their raw curled flake form as the primary material. This report discusses the influences of fabrication conditions on sound absorption and form retention. The results showed that the form retention was increased with kenaf composition. However, the normal incidence absorption coefficient decreased with increasing kenaf composition and improved with increasing shavings composition. The increase of airflow resistivity was shown as the reason. Moreover, element’s internal loss of solid-borne sound transmission and the influences of various acoustic parameters that the shape of the element brought were considered as the reason. Sound absorption coefficient in a reverberation room was measured under optimum fabrication conditions, and the performance of the mat was found to be approximately equal to that of glass wool.ZusammenfassungEntwickelt wurde eine Holzmatte zur Verwendung als Wärme- und Schalldämmmaterial. Dafür wurden als Hauptmaterial natürlich gekrümmte Hobelspäne verwendet. In dieser Studie wird der Einfluss der Herstellungsbedingungen auf die Schallabsorption und Formbeständigkeit beschrieben. Die Ergebnisse zeigten, dass die Formbeständigkeit mit zunehmendem Anteil an Kenafbast zunahm. Jedoch nahm die Dämmwirkung mit zunehmendem Kenafanteil ab und mit zunehmendem Hobelspananteil zu. Als Grund dafür wurde die Zunahme des Luftstromwiderstandes festgestellt. Außerdem wurde die geringere Körperschallübertragung sowie von der Spanform abhängige Akustikparameter als Grund hierfür angesehen. Es wurde der Schallabsorptionsgrad in einem Hallraum unter optimalen Herstellungsbedingungen gemessen und es wurde gezeigt, dass die Eigenschaften der Matte mit denjenigen von Glaswolle vergleichbar sind.