Device for dispensing volatile material

A device for dispensing volatile material from a reservoir which has a dispensing portion from which the vapor of the volatile material can diffuse into the surrounding atmosphere. The reservoir is retained on a rigid sheet which has a suspending aperture with a slot. There is a removable impermeable layer for sealing the dispensing portion and a detachable portion of the rigid sheet extends over the dispensing portion of the reservoir. In another embodiment, there are two such devices detachably attached by a joint to each other at an edge.

This present invention relates to a device for dispensing volatile 
material. 
BACKGROUND ART 
It is desirable to provide an improved device for dispensing volatile 
materials, e.g., insecticides, which uses simple packaging and which 
minimizes the risk of contact with volatile material. 
DISCLOSURE OF INVENTION 
According to the present invention, a device for dispensing volatile 
material comprises: 
a) a reservoir containing volatile material, said reservoir having a 
dispensing portion from which vapour of the volatile material can diffuse 
into the surrounding atmosphere; 
b) a removable impermeable layer for sealing said dispensing portion; 
c) a substantially flat and rigid sheet; said sheet having 
i) means for retaining the reservoir on the sheet in use; 
ii) an opening by which it may be suspended in use; 
iii) preferably, a detachable portion extending over the dispensing portion 
and the impermeable layer such that removal of the detachable portion from 
the sheet enables the impermeable layer to be removed from the dispensing 
portion. 
The reservoir may be a moulding of thermoplastic polymer of the type used 
in conventional blister packs. The volatile material will generally be 
present in the reservoir in a carrier in which it is dissolved or 
dispersed. The carrier may be a liquid in which the volatile material is 
dispersed or dissolved, and may be a relatively viscous liquid. 
Alternatively, the carrier may, for example, be a solid gel, or a card 
impregnated with the volatile material. The preferred carrier will depend 
on the nature of the volatile material. The volatile material may be an 
insecticide, e.g., a permethrin insecticide, or a perfume, or may be a 
combination of an insecticide and a perfume. The device of the present 
invention may be particularly useful where the volatile material in the 
reservoir is a material, such as an insecticide, which it is desirable to 
avoid coming into contact with the skin. 
Where a liquid is used in the reservoir then the dispensing portion of the 
reservoir may be a sheet of material which allows volatile material to 
pass through but retains the liquid. 
As indicated above, the carrier in the reservoir may be a solid in which 
the volatile material is dispersed and from which it diffuses with time 
and in such a case the dispensing portion may simply be an exposed face of 
the solid. 
Layers which are impermeable to volatile materials and which are suitable 
for sealing the reservoir are well-known to those skilled in the art. Such 
layers usually contain metal, e.g., aluminum, which may be combined with a 
polymer layer. 
Reservoirs or chambers containing volatile material, namely, perfume, 
together with a dispensing portion which is a polymer wall attached to the 
reservoir, and a removable impermeable layer are described in 
international patent application WO 84/02654. WO 84/02654 discloses a 
reservoir made of conventional polymers such as polyamide, polyester, 
polyethylene, or polypropylene. A permeable layer may be made from a 
polymer sold by the firm of E I du Pont de Nemours under the trade name 
"Surlyn". An impermeable layer may be aluminum sheet. A layer of paper is 
disclosed as being provided between the permeable layer and the 
impermeable layer. 
As an alternative, the reservoir may be formed from an acrylonitrile 
copolymer sold under the trade name "Barex". A thin layer of polyethylene 
may be glued to the acrylonitrile copolymer to enable further layers to be 
heat sealed to the reservoir to close it. The reservoir may be closed by a 
laminate of ethylene/ethyl acrylate copolymer membrane, paper, low density 
polyethylene or "Surlyn" polymer, aluminum foil, and polyester. The low 
density polyethylene enables the aluminum foil to adhere to the paper. The 
aluminum foil, strengthened by the polyester, provided an impermeable 
layer. When using ethylene/ethylacrylate copolymer it is desirable to use 
non-polar volatile materials as the volatile material. 
The substantially flat and rigid sheet may be formed from one or more 
layers of synthetic polymer, e.g., thermoplastic polymer. However, it is 
preferred that the sheet is formed from one or more layers of card, i.e., 
layers formed from wood pulp or similar cellulosic fibre. 
The sheet preferably consists of two layers of card. A front layer is 
preferably provided with at least one window through which an exposed part 
of the reservoir extends. The reservoir is preferably provided with a 
flange extending round the exposed part in order to retain it within the 
window. A rear layer holds the reservoir in place between the front and 
rear layers. Alternatively, and with some advantage in materials and 
manufacturing costs and in simplicity of design, the sheet may consist of 
a single layer of card with the reservoir attached to it by any 
conventional means of attachment. If the single layer sheet construction 
is used, the optional detachable portion of the sheet referred to above is 
unnecessary. Instead, its protective function may be supplied by the use 
of a sealing layer that is sufficiently robust to withstand normal 
handling of the device before activation or by providing a second seal or 
some other protective layer, removably adhered to the back of the sheet 
and sufficiently large to cover the sealing layer and preferably the 
entire dispensing potion of the reservoir. 
Preferably, the detachable portion of the sheet is a perforated portion in 
the sheet, e.g., in the rear layer of card where two layers of card are 
used, which defines a panel lying over the dispensing portion of the 
reservoir. Preferably, the panel is larger than the dispensing portion of 
the reservoir so that manual removal of the panel of the sheet to remove 
the sealing layer does not result in fingers coming into contact with the 
dispensing portion of the reservoir. 
The panel may completely cover the impermeable layer and the removable 
impermeable layer may be provided with a tab by which it may be removed. 
The tab may be pulled to remove the impermeable layer after the panel has 
first been completely removed. The panel and the tab may be so disposed 
that partial removal of the panel exposes a sufficiently large tab to 
allow the remainder of the overlying panel to be removed by pulling on the 
tab to remove the impermeable layer lying under the panel. Alternatively, 
the panel may have an opening through which a tab on the impermeable layer 
projects so that pulling the tab causes the impermeable layer to detach 
from the dispensing portion and the movement of the impermeable layer away 
from the dispensing portion causes the overlying panel to become detached 
from the rest of the sheet. A further alternative is to bond the 
impermeable layer to the panel so that removal of the panel removes the 
impermeable layer. 
In general, it is preferred that removal of one of a) the detachable 
portion of the sheet, and b) the impermeable layer, causes removal of the 
other of a) and b). 
The sheet may be provided with a slot with a semi-circular central portion 
such as is conventional on packages intended to be displayed suspended on 
display units at the point of sale. 
The sheet will normally carry printed matter identifying the product and 
giving instructions for its use and disposal. It is a feature of the 
present invention that the point of sale packaging can be used as the 
active device. As a result, instructions on the package are retained 
throughout the life of the device. 
The suspending means is provided in the sheet itself, avoiding the need to 
fabricate a separate suspending device and to attach it to the reservoir. 
The suspending device is preferably provided by an aperture in the main 
body of the sheet rather than by portions of the sheet extending outwardly 
from the main body. Thus, when the sheet is of generally rectangular 
shape, the suspending device is preferably formed by an aperture within 
the rectangular main body rather than by portions projecting beyond the 
boundaries of the generally rectangular body. This is particularly 
advantageous when the sheet is formed from card. 
The suspending means may be shaped to be hung on a hook or door handle but 
is preferably an aperture in the sheet shaped for suspending the device on 
a rail in a wardrobe. Such rails are generally circular. 
The suspending means may be provided by a slot opening in the side of the 
sheet communicating with a larger aperture in the body of the sheet. The 
slot may be a simple slit having essentially no width, but, preferably, 
the slot is of such a width that it can receive a normal wardrobe rail 
without excessive flexing and may, for example, have a width of 5 to 15 
mm. The larger aperture with which the slot communicates may, for example, 
have a substantially circular cross-section with a diameter in the range 
20 mm to 40 mm. 
It is preferred to provide packages comprising more than one device, e.g., 
two devices formed in a single sheet, which can be divided into individual 
device portions along at least one preformed line of division, e.g., by 
tearing along perforations provided in the sheet. In such multiple 
packages, the suspending means may be provided in the outer sides of the 
package. However, they may also be provided in the interior of the 
multiple package adjacent to any line of division demarking the contiguous 
sides of adjacent devices such that a suspending means opening from the 
side of a device is only formed when the package is divided into multiple 
devices.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
The package comprises a sheet formed from two layers of card (1,2) (formed 
from wood pulp) forming the front and rear faces of the package. The sheet 
(1,2) has a slot (3) formed in it by which it may be suspended from a 
suitable display unit at the point of sale. A line of perforations (4) 
runs vertically down both layers of card (1,2) to enable the package to be 
torn into two separate halves (5,6). 
The sheet (1,2) has openings (7,8) formed in opposed upper sides. These 
provide suspending means by which the package as a whole or the separate 
portions (5,6) can be suspended on a rail in a wardrobe (clothes storage 
cupboard). 
The front layer (1) has two windows (9,10) provided by apertures in the 
layer. Two reservoirs (11,12) of moulded plastic material extend through 
the windows and are retained under layer (1) by flanges (13) (see FIG. 6) 
extending outwardly from the reservoir under layer (1). 
Each reservoir (11,12) is closed at its rear face by a layer (14) of vapour 
permeable material which prevent the passage of liquid from the reservoirs 
but allow the passage of the volatile material to be released from the 
device. This layer (14) constitutes the dispensing portions of the 
reservoir. The reservoirs are filled with a liquid (18) in which is 
dissolved an active ingredient. When the device is intended for insect 
control, the active ingredient may be a volatile insecticide such as a 
permethrin insecticide. 
The rear layer (2) is provided with perforations defining two removable 
panels (15,16). The panels lie over the corresponding rear faces area of 
reservoirs and the area of each rear panel is greater than that of the 
corresponding front window and of the corresponding dispensing portion. 
Each layer (14) of permeable material on the rear of each reservoir is 
covered by a layer (17) of impermeable material, e.g., aluminized polymer 
film, which has a tab which may be gripped to remove the impermeable layer 
when the portion of the panel covering it has been removed. 
In use, the package can be divided into two portions by tearing along line 
(4) and each half may be activated as required by removing the panel (15) 
or (16) to expose the impermeable layer to enable the layer to be removed. 
By making the panel large in relation to the size of the dispensing 
portion, the risk of fingers coming into contact with the permeable layer 
is reduced. 
Instead of dividing the package before use, it may be used undivided by 
installing on a wardrobe rail using either of openings (7,8) and releasing 
volatile material from both reservoirs after removing the corresponding 
portions of layer (2) where a higher dose rate of insecticide is required 
in a larger wardrobe or releasing volatile material from each reservoir in 
succession to maintain a desired level of insecticide over a prolonged 
period of time. 
It can be seen that the amount of packaging to be discarded when the device 
is first activated is small, and that fingers are kept away from the 
reservoir of volatile material when suspending the device in a wardrobe, 
when removing the impermeable layer to activate the device and on removing 
the exhausted device. The substantially rigid sheet provides a convenient 
means of manipulating the device as a whole. The specific embodiments 
described above have apertures for suspension opening from the sides of 
the sheet which are sized so as to enable the sheet to be hung on a 
conventional wardrobe rail (where there may be no access to a free end of 
the rail) without excessive flexing of the sheet. This enables the use of 
a material for the sheet such as card which is easily damaged by flexing. 
Because the apertures open from the side, the weight of the device is not 
supported by any portion of the card which might have suffered some 
flexing during mounting the device on a rail. 
While preferred forms of the invention have been shown in the drawings and 
have been described above, variations will be apparent to those skilled in 
the art. Consequently, the invention should not be construed as limited to 
the specific forms shown and described. Instead, the invention should be 
understood in terms of the following claims.