| 摘要 |
A fibrous filter mat of which all or a part of the fibers are coated totally or at least in part with a mixture of at least two dye components which are insoluble in one another, one of said components being fat- and/or oil-soluble and of a color which contrasts with that of the fiber blend and/or of the other component, the other component being fat- and/or oil-insoluble. The mat is especially suited for kitchen exhaust hoods since entrapment of fats and oils causes a color change as the oil-soluble dye dissolves and spreads out. |
