Non-blocking microfilm jacket

Abstract

A multi-channel transparent jacket for accommodating strips of microfilm to create a microfiche, the jacket having non-blocking characteristics, thereby minimizing the tendency of one jacket in a stack thereof to stick to an adjacent jacket. The jacket is constituted by front and rear panels formed of flexible polyethylene terephthalate film joined together by a parallel array of ribs to define the channels. The exposed surfaces of the panels have a friction-reducing layer thereon constituted by a multiplicity of discrete silicon dioxide nodules bonded to the film, the nodule shape approximating a surface segment of a sphere. The peaks of the segments form microscopic contact points which are bonded by molecular attraction to an abutting panel when the jacket is juxtaposed against a like jacket in frictional relationship thereto. The nodules have a relatively large average diameter whereby the population density thereof in a unit area of the layer produces multiple contact points resulting in a coefficient of friction whose value imparts non-blocking characteristics to the jacket to a degree permitting tangential displacement thereof with a like jacket sticking thereto.