Wick-based delivery system with wick having sections of varying porosities

• Main Authors: LAKATOS, KARA L, VARANASI, PADMA P
• Format: Patent
• Language: English; French; German
• Published: 30.03.2011
• Subjects: AGRICULTURE; ANIMAL HUSBANDRY; APPARATUS FOR THE DESTRUCTION OF NOXIOUS ANIMALS OR NOXIOUSPLANTS; CATCHING, TRAPPING OR SCARING OF ANIMALS; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS, ORSURGICAL ARTICLES; DISINFECTION, STERILISATION, OR DEODORISATION OF AIR; FISHING; FORESTRY; HUMAN NECESSITIES; HUNTING; HYGIENE; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS, OR SURGICALARTICLES; MEDICAL OR VETERINARY SCIENCE; METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS INGENERAL; TRAPPING

A dispensing device for a vaporizable material is disclosed which has a container (1) for holding a vaporizable liquid, the container including an opening therein; and a porous wick having a first section (3a) comprised of a material with a predetermined pore size and a second section (3b) comprised of a material with a predetermined pore size that is greater than that of the first section, positioned so that a lower region of the wick will be in contact with the liquid to be held by the container and an upper region of the wick is exposed to the ambient air to dispense the vaporizable liquid. The opening in the container is substantially sealed by the wick, and the second section of the wick surrounds the portion of the wick that is exposed to the ambient air. Also disclosed is a method of dispensing a vaporizable material from a container. The method comprises positioning a porous wick in the container with a lower region in contact with the liquid in the container and an upper region extending from the container; activating the release of vaporizable material from the wick (3) to the ambient air; and deactivating the release of vaporizable material from the wick (3) to the ambient air; wherein the wick (3) has a first and a second section (3a, 3b) of different pore sizes, the pore size in the first section (3a) being smaller than the pore size in the second section (3b), such that during deactivation, due to the higher equilibrium rise within the first section of the wick than in the second section, the first section becomes saturated whereas the second section does not, and during activation, due to a lower rate of wicking in the first section than in the second section causes produces an initial "spike" effect in the emission from the wick as initially material is emitting from both first and second sections (3a, 3b) until the first section (3a) becomes depleted.