Abstract: An improved, plunger-type hand pump for liquids in flexible containers is provided which includes a check valve for preventing outward flow of liquid through the air intake passageway of the pump, as a consequence of simultaneous depression of the pump plunger and incidental deformation of the flexible container walls. The pump includes a skirted head mounted atop the plunger and an upstanding, cooperating, skirt-receiving collar, and an annular vent opening forming a part of the air intake passageway of the pump is presented between the skirt and collar. The check valve preferably comprises a flexible annular washer mounted on the pump head for reciprocation therewith, and the outer periphery of the washer slidingly engages the collar to seal the container opening against outflow of liquid.

Abstract: An inexpensive, easy-to-produce, adhesive-coated polyolefin ribbon or the like is provided which has desirable remoistenability and excellent peel strength characteristics, notwithstanding elimination of the need of physically treating the polyolefin substrate prior to adhesive coating by methods such as chemical etching or other means of surface abrading. A primer layer is applied and bonded directly to the polyolefin ribbon without any preliminary treatment thereof, and a remoistenable adhesive layer containing polyvinyl alcohol is applied over the primer layer and bonded thereto to complete the ribbon. In preferred forms, the primer layer includes respective quantities of ethylene vinyl acetate and chlorinated polyolefin material, and this has been shown to synergistically bond to both the substrate and polyvinyl alcohol remoistenable adhesive applied thereover.