RIGIDITY ENHANCED PRESSED PAPERBOARD CONTAINERS

摘要

A container formed from a unitary paperboard blank having a substantially planar inner region, a sidewall region and a rim region formed about the periphery thereof is disclosed. The sidewall region includes a generally annular region flaring upwardly and outwardly from a periphery of the planar inner region and a first frusto-conical region adjoining the annular region with the frusto-conical region sloping outwardly and upwardly and from the annular region. The rim region includes an outwardly flaring arcuate annula4 r region adjoining an outer periphery of the first frusto-conical region, and a second frusto-conical region extending substantially tangentially from the arcuate annular region. The second frusto-conical region extends outwardly and downwardly at an angle of about 6.degree. to about 12.degree. and preferably about 6.degree.-10.5.degree. relative to the plane defined by the planar inner region. The rim of the container may further include an outwardly and downwardly flaring frustoconical lip adjoining an outer periphery of the second frusto-conical region in order to aid in grasping of the paperboard container by the consumer. Additionally, a plurality of radially extending mutually spaced pleats are also formed in the rim region and are internally bonded with portions of the rim region during formation of the paperboard container by a die press. During the fabrication of the paperboard material for forming the aforementioned container, the paperboard material is impregnated with a sizing adhesive equivalent to at least 6 pounds of starch per 3,000 ft material such that the tensile strength of the board is increased, and such that during the press forming of the paperboard containers between respective dies, the pleats adhere to respective portions of the pleats and rim, thereby maintaining the integrity of the pleats during use of the container by the consumer by resisting the opening of the pleats.