FILTER MATERIAL PRODUCTION PROCESS

摘要

An open-pore polyurethane foam support body (20) is impregnated in a single step with a solution of a thermoplastic adhesive dissolved in a solvent that is also a foam expander, or in two sequential steps first with a foam expanding solution and then, after the foam has expanded, with a solution of a thermoplastic adhesive, to form an adhesive layer (40) on the surfaces (25) within the pores (22) and passages (24) of the foam body. Sorbent particles (30) of activated carbon are introduced into the expanded pores until the expanded foam is packed to the desired density of carbon particle loading. The impregnated and loaded foam is then air dried at room temperature to evaporate the foam expanding solution until the foam body contracts to substantially its original volume. Following air drying, the foam body may be heated in an inert atmosphere at a sufficient temperature and for a sufficient time to remove any solvent that still may be coating the exposed surfaces of the activated carbon particles and also to soften the adhesive layer to further strengthen the resultant bonding of the activated carbon particles to the foam support body. The foam filter material (10) is unique in that at least a portion of the activated carbon particles (30) are mechanically bonded to the foam support body (20) by a mechanical locking resulting from the shrinkage of the expanded foam body about the particles (30), while at least portion of the activated carbon particles (30) are adhesively bonded to the foam support body (20) by the adhesive layer (40). A significant portion of the activated carbon particles (30) are both mechanically and adhesively bonded to the foam support body.