Permeable membranes having high temperature capabilities

Details Permeable membranes having high temperature capabilities Permeable membranes having high temperature capabilities

2000-06-16

2003-10-28

Nolan, Sandra M. (Department: 1772)

Stock material or miscellaneous articles

Hollow or container type article

Polymer or resin containing

C206S484000, C206S484100, C428S353000, C428S354000, C428S317700, C428S474400, C428S476100, C428S476900, C428S480000, C428S483000

Reexamination Certificate

active

06638588

ABSTRACT:

FIELD OF THE INVENTION
The invention pertains generally to the field of permeable membranes and packaging for volatile materials such as insecticides and other organic products. It pertains more particularly to permeable multilayer membranes having high temperature capabilities and also to packages incorporating such membranes, which allow for the controlled release of volatile materials over a period of time. The packages contain the volatile materials and prevent any substantial release of the volatile materials until heat has been applied to the packages.
BACKGROUND OF THE INVENTION
The controlled time release of more volatile substances, such as fragrances and other aromatic products, present a number of packaging problems. Room “air fresheners” or fragrances have usually been packaged in glass bottles or vials. The fragrance is released into the atmosphere by transmission through an absorbent wick, which is capped until the time of use. However, glass bottles are bulky and breakable. It is generally not economical to package fragrances in small quantities inside glass containers, because the cost of the glass container is high.
One proposed alternative method of packaging room fragrances involves placing a breakable glass vial within a plastic container formed of a material that is permeable to the vapors of the volatile fragrance. The user deliberately breaks the glass vial to allow the fragrance liquid to seep into an absorbent pad and the vapors from the liquid slowly diffuse into the atmosphere through the permeable outer container. These containers may be subject to accidental breakage of the glass vial during shipping and handling, as well as to possible puncture of the container by broken glass. The manufacturing costs are increased by the use of the glass vial within the container.
Other fragrance dispensers utilize sealed packages, which are opened by peeling back a covering foil to expose a perforated panel covering an absorbent pad saturated with the fragrance liquid. The costs of such containers make them generally inappropriate for dispensing small amounts of the fragrance. For such containers it is also somewhat difficult to control the release of the fragrance at a fairly constant rate over the life of the product, because the liquid is directly exposed to the atmosphere. Also, the consumer may contact the fragrance liquid itself, because the liquid may seep through the holes in the perforated panel.
DESCRIPTION OF THE ART
Rabussier, et al., U.S. Pat. No. 3,858,807 discloses an apparatus which is adapted for emitting vapors of volatile insecticidal agents or of similar volatile active liquid products such as insect repellants comprising a body made from a single fibrous plate or a stack of fibrous plates capable of absorbing the agent or product. The body is coated on at least one of its larger, principal outer faces with a diffusion layer of polymeric material diffusable by the said agent or product so as to emit vapors of the latter from the outer surface of the layer; the layer adheres on its inner side intimately to the fibers of the adjacent face of the fibrous plate to which it is applied. The apparatus further comprises a frame of metal or synthetic thermoplastic or the like material impervious to the volatile agent or product or to its vapors and sealing the body hermetically on all sides except the face or faces thereof which are coated with a diffusion layer where the frame has a window or windows; the layer is hermetically sealed along its periphery to the frame.
Holzner, U.S. Pat. No. 4,634,614 relates to a peel system for a device for perfuming ambient air. The peel system comprises a delamination of a paper layer to separate a non-permeable lidding from a permeable membrane.
Weyenberg et al., U.S. Pat. No. 4,145,001 discloses a dispenser having a permeable membrane. The fragrance is sandwiched between the inner layers of two heat sealable panels. One of the inner layers is permeable to the fragrance vapors. The outer layers of the panels are impermeable to the fragrance and its vapors. The dispenser is opened by peeling back a panel along a release layer to expose the inner permeable layer.
Martin, U.S. Pat. No. 4,254,910 discloses a packaging system for the controlled release of volatile substances. This packaging system comprises a pair of outer vapor-impermeable barrier layers and a vapor-permeable central layer which is bonded to each of the pair of vapor-impermeable outer layers, with the volatile material being contained between the central vapor-permeable layer and each of the outer vapor-impermeable barrier layers. The central vapor-permeable layer is formed from a pair of vapor-permeable webs which are bonded to one another.
Fischel-Ghodsian, U.S. Pat. No. 5,701,704 discloses a controlled release device useful for the release of vapors or liquids is described. The device is a multilayered laminate consisting of a reservoir layer which incorporates an active compound, such as a perfume or fragrance or insect repellant, an impermeable membrane layer adjacent the reservoir layer and a diffusion rate limiting membrane layer adjacent the reservoir layer.
Paul, U.S. Pat. No. 5,782,409 discloses sealing odor absorbing material and fragrance producing compositions separately in a flexible container, preferably formed from multi-layered sheet material. In the preferred embodiment, the odor absorbing material is retained by at least one microprobes or permeable membrane to prevent unwanted dispersion of the odor absorbing material into the ambient surroundings, while also controlling the rate of transfer of the ambient air into contact with the odor absorbing material.
Huber, U.S. Pat. No. 5,518,790 discloses a container to hold aromatic substances which can be sealed aroma-tight with a composite film consisting of several laminae. The composite film on the top of the container is made up of an aroma-tight outer film having at least two laminae and an aroma-permeable inner film which is detachably bonded to the outer film by means of a bonding agent. The outer film can be applied onto the inner film or membrane film, which consists of at least two permanently bonded laminae, whereby the lamina adhering to the container is made of polyethylene and the third or top lamina is made of a polymer material which has a different density.
Cook, U.S. Pat. No. 4,817,868 discloses a dispenser for broadcasting a scent which is particularly useful in connection with insect pheromones, a quantity of volatile pheromone carrying substance is packaged as a solid or gel in a hollow tube. A carrier can be provided for the tube, having a surface to which the tube is to be affixed with the longitudinal axis of the tube substantially parallel to the surface of the carrier, and the tube being disposed directly on the surface of the carrier. The carrier has at least one air circulation opening aligned perpendicular to the longitudinal axis of the tube and one or more stops preventing relative displacement of the tube and the carrier. Preferably, the carrier is a one piece integrally molded thermoplastic panel, with retaining clasps projecting from a planar body and adapted to bear diametrically inwardly on the tube. The length of the tube and dimensions of the carrier are such that the tube positively remains captive. Users are provided with substantially marginal area on the planar body adjacent the tube for manual manipulation, as needed, for example, to install the scent dispenser in a trap.
Despite the considerable art which is known, problems associated with permeable membranes still exist. One of these problems is the membrane's inability to maintain release product over long periods of time when subjected to temperatures above about 125° F. Therefore, in the field of permeable membrane and packaging for volatile products, especially insecticides, there is a need for a permeable membrane which is able to withstand such temperatures while providing control release of product over long periods of time.
One objective of the present invention is to provide a pe

Affiliated with

Also associated with

Rating

Permeable membranes having high temperature capabilities does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Permeable membranes having high temperature capabilities, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Permeable membranes having high temperature capabilities will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3163130