Abstract: There is provided a vacuum cleaner bag with high fine particle removal efficiency under normal and shock loading conditions, shock loading including a short term challenge with high particle concentrations (e.g., when a vacuum is used to pick up a pile of debris). The bag also exhibits high loading capacity without significant loss in pressure drop. The bag includes an outer support layer, a fibrous filter layer that is charged to create electrets, and an inner diffusion layer that is substantially unbonded to the filter layer, except at necessary bag seams required for assembly of the filter bag.

Abstract: Improved microfibrous filtration laminate comprising a highly permeable layer of a self-supporting nonwoven fabric which provided support for a layer of a randomly intertangled nonwoven mat of electret-containing microfibers of synthetic polymers are disclosed. The filtration laminate, which is particularly useful as disposable filter bags or as a lining material for disposable paper filter bags for vacuum cleaners, is characterized by thickness and handling characteristics approaching that of paper filter material typically use in disposable vacuum clean bags but having improved performance in the areas of an immediate, high particle capture efficiency, minimal flow restriction and long service life.

Abstract: A camera adapted for making a chemically developed printing plate or a more economical dry developed printing plate. The camera has a magazine for supplying selectively one of two types of light sensitive film material, advancing a severed sheet of the selected material to the image plane, and directing that subsequently imaged plate to the associated processing station to produce a developed and ready printing press plate.