摘要 |
<p>The present invention provides a generally planar closed envelope device formed from material having vapor barrier properties, which envelope comprises a base layer (1) and a cover layer (4) applied to the base layer (1) and a continuous or discontinuous seal (4) therebetween, characterized in that: a) each of the base (1) and cover (3) layers carries a fluid composition (2) containing a liquid volatile material upon a selected area of the opposed faces thereof; f) the base (1) and cover (3) layers are formed by folding over a single piece of sheet material so as to bring the selected areas of the base (1) and cover (3) layers into opposing register with one another; and g) there is separable and reformable seal (4) between the base (1) and cover (3) layers to retain them in the folded configuration. The invention also provides a method for making such a device.</p> |