| abstract |
An improved liquid material dispenser of the type which transmits fluid to be diffused from an enclosed reservoir to an exposed evaporative surface by means of a wick. A wick is provided in the form of a sheet which has a very high evaporative area compared to the volume of liquid which is retained outside the confines of the reservoir at a given time. The critical relation of evaporation area to volume of liquid outside the reservoir is such that the exposed liquid material weight per square centimeter of evaporative surface is less than 10 milligrams per square centimeter. The material to be dispensed, preferably a perfume, comprises at least 50% of materials of no more than moderate volatility as defined herein. Materials having low volatility as defined herein are minimized, and the quantity of low volatility ingredients in said liquid materials is related herein to the holding capacity of the evaporative surface of the wick. The combination of the improved dispenser and improved liquid materials to be diffused maintains the evaporating liquid material at a relatively constant composition, and the liquid material evaporates at a relatively steady rate over the life of the dispenser. |