マイクロ波照射場における電界強度分布の簡易計測と粉末樹脂の加熱特性 Simple measurement of electric field intensity profiles and heating characteristic of a resin powder by microwave irradiation
粉末樹脂の成形・加工における熱効率向上を目的とし, マイクロ波加熱を用いるうえで重要な任意の形状のキャビティー内の電界強度分布及び多成分粉末樹脂の損失係数の簡易計測法の提案をした.電界強度は, 損失係数既知の水を標準試料とし, その昇温速度から求めた.本計測から, 試作されたキャビティー内の電界強度分布は電子撹拌羽根により均一化傾向が認められた.一方, PVCをベースとした粉末樹脂のマイクロ波吸収は, PVCよりも配合物の損失係数の影響を強く受けていることが認められた.また, 試料の予熱を行うことにより成形時間の短縮を図ることが期待できる結果が得られた.さらに, 多成分系の粉末樹脂の見かけの損失係数には, 重量比による各成分の損失係数の加成則が見受けられなかった.
This paper proposes to use microwave heating in molding processes of resin powder for improving the heat efficiency and reducing the processing time. Simple measurement methods of distributions of electric field intensity in various types of cavities and loss coefficients of resin powder with multicomponents were developed. The electric field intensity can be determined from the rising rate of temperature of water whose loss coefficient is known. This measurement showed a large distribution of electric field intensity in a cavity, but the distribution was improved by the stirring of a fan. The microwave absorption performance of the powder resin of a PVC base is superior to the pure PVC since it is much influenced by the plasticizer contained in the sample than PVC itself. The preheating of the sample enhances the energy absorption and it may allow the processing time to be reduced considerably. The loss coefficients of the samples are measured by the method proposed in this work. The effect of additives on the loss coefficient of the samples consisting of multicomponents is studied as well, and it is implied that the apparent coefficient is not successfully correlated in simple proportion to the weight and the loss coefficient of each component.
化学工学論文集 22(4), 808-814, 1996-07-10
The Society of Chemical Engineers, Japan