PURPOSE: To materialize work without forming a gap between a frame and a filter medium and to improve work efficiency by positioning the filter medium in the frame by setting a hot melt material containing a foaming agent between them and bonding them simultaneously when the gap is sealed by the expansion of the foaming agent by heating.
CONSTITUTION: A frame 1 made of a metal (preferably containing a magnetic metal such as iron for electromagnetic induction heating), a plastic (preferably heat resistant plastic), paper, wood, etc., and a filter medium 2 made of a nonwoven fabric, etc., which is slightly smaller than the frame 1 are prepared. A hot melt material 3 containing a foaming agent is set between the inner surface of the frame 1 and the filter medium 2, the filter medium 2 is positioned in the frame 1, and the frame 1 is heated by electromagnetic induction. In this way, the hot melt material 3 is expanded 3-4 times, the gap between the frame 1 and the filter medium 2 is sealed, and they are bonded. The simultaneous sealing and bonding between the frame and the filter medium are made possible by the heat expansion of the hot melt material 3.
KAWAGUCHI YOSHIYASU
SAKON TOSHIKAZU
