Mobil Oil Corporation

Bruce E Nattinger

David V Dobreski

Jack J Donaldson

Pat C Campbell

James A Greiner

A continuous roll or stack of thermoplastic bags having improved openability is disclosed. The bags feature an area of permanently tacky, pressure-sensitive adhesive, applied to an outer surface of each bag. When a bag is pulled from the roll or stack, the adhesive temporarily adheres one side of the bag to the roll or stack, causing the front and back of the bag to separate slightly, thereby enhancing openability. Also disclosed are thermoplastic bags onto the surface of which an area of adhesive is applied in such a manner that the bags are self-closing when twisted shut in the area of the adhesive.

Roll of thermoplastic bags

Plastic bags are made from linear ethylene homopolymer or linear low density copolymers (LLDPE) blended with up to about 10 weight percent of an aromatic polymer, e.g., polystyrene or poly(para-methylstyrene), to improve the ease of opening the bags by reducing the blocking tendency of the film. Although ease of opening is improved the aromatic polymer does not adversely affect the other physical properties of the bag, such as MD tear strength and stiffness, but improves them.

Plastic bags of blends of linear ethylene polymers and aromatic polymers

There is disclosed a modified method of preparing a blown polyethylene film made from a blend of major proportion of a polyethylene resin, e.g., LLDPE, a minor proportion of a second polymeric resin, e.g., polystyrene, and at least one additive, e.g., a colorant. The additive or additives are mixed with the second polymeric resin and the resulting mixture is then blended with the polyethylene resin, thereby reducing the number of process steps. Also disclosed is a method of monitoring and/or controlling the second polymeric resin content in the film made with known proportions of a colorant and the second polymeric resin by measuring the light transmission of the film.

Growing community of inventors

Fairport, NY, United States of America

Bruce E Nattinger