A blow-molded unitary structure includes a panel having first and second panel walls and a generally hollow interior between the first and second panel walls. The structure also includes one or more different types of strengthening elements monolithically formed with the panel and across a substantial portion of the panel to enhance the strength of the structure. A strengthening element can be a depression recessing from the second panel wall toward an interior of the panel, a protrusion protruding from the second panel wall toward an exterior of the panel, a rib protruding outwardly toward the exterior of the panel and a trench formed by side walls of adjacent protrusions.

A method for manufacturing a plastic container by internal pressure forming including positioning a tubular preform between the die parts of a molding die having a die cavity; closing the molding die and forming or preforming a container from the preform using internal pressure, wherein a peripheral portion of the preform is pressed out of the die cavity through a die gap; laterally withdrawing the peripheral portion pressed out of the die cavity, as a result of which the container is divided into two container halves; and thermally separating plastic bridges and/or plastic threads which arise during the lateral withdrawal of the peripheral portion. Also disclosed is a molding die suitable for carrying out the method.

A blow-molded unitary structure includes a panel having upper and lower panel surfaces and a ridge extending downward beyond the lower panel surface. The ridge includes a first side surface, a second side surface, and a lower ridge surface joined with the first side and second side surfaces of the ridge. The ridge further includes a plurality of depressions formed at one or more of the first side surface, second side surface and lower ridge surface. The plurality of depressions enhances the strength of the ridge, and the ridge in turn enhances the strength of the structure.

A blow-molded unitary structure includes a panel having first and second panel walls and a generally hollow interior between the first and second panel walls. The structure also includes a plurality of depressions, or at least one ridge, or both the depressions and ridge to enhance the strength of the structure. The plurality of depressions is monolithically formed with the panel, recessing from the second panel wall toward the first panel wall. A depression has a side wall composed of first and second segments. Cross-sectional-wise, the first and second segments have different widths and thus collectively forms a step between the first and second segments. A ridge is also monolithically formed with the panel and includes a section, at which the width of the ridge varies along the height direction of the ridge.

A blow-molded unitary structure includes a panel having first and second panel walls and a generally hollow interior between the first and second panel walls. The structure also includes one or more different types of strengthening elements monolithically formed with the panel and across a substantial portion of the panel to enhance the strength of the structure. A strengthening element can be a depression recessing from the second panel wall toward an interior of the panel, a protrusion protruding from the second panel wall toward an exterior of the panel, a rib protruding outwardly toward the exterior of the panel and a trench formed by side walls of adjacent protrusions.

The present invention is a double-walled container manufacturing method in which when a pair of partial molds is brought towards each other to be assembled to form a split mold, at least a portion of the mating surfaces of the pair of partial molds clamp a parison at two side portions that are at horizontal positions facing each other. The method is able to manufacture the container easily with a molding device that does not differ significantly from the past and, in a double-walled container obtained from a relatively rigid outer container and a flexible inner container the volume of which can change according to the amount of contents filled inside said outer container, an opening for introducing outside air can be formed very easily and reliably at a lower cost than the processing cost of prior art.

A resin-laminated board includes a front-side sheet and a backside sheet layered on each other with a hollow part interposed therebetween. The backside sheet is recessed toward the hollow part to provide a plurality of first recesses and a plurality of second recesses. The front-side sheet and the backside sheet are connected to each other with plural ribs by welding bottoms of the first recesses and the second recesses to the front-side sheet. The resin-laminated board has a thin-plate part having the first recesses with small depth and a thick-plate part having the second recesses with large depth, and the first recesses and the second recesses are arranged at substantially the same pitch.

A blow-molded plastic structure has a hollow interior portion formed during a blow-molding process, and includes first and second outer portions that are spaced apart from each other, with the hollow interior portion disposed there between. The structure includes a pattern of structural stiffening features that are integrally formed in the second outer portion. The pattern of structural stiffening features includes a plurality of tripodal depressions disposed in rows and columns and a plurality of convex regions disposed in rows and columns between the plurality of tripodal depressions. Each convex region has a maximum height between the first and second outer portions. Each of the tripodal depressions extends into the hollow interior portion, includes three indentations disposed adjacent the first outer portion, and includes an island spaced away from the first outer portion. The island has three sides, each of which is disposed adjacent one of the three indentations.

The invention teaches a container lid product for controlling access to a container. The container lid comprises one or more hollow molded hinges with solid compressed area to eliminate any seam in use pivotally connecting the product to the container, a hollow-molded edge disposed adjacent to the one or more hollow-molded hinges, and a single-walled cover portion being connected to the hollow-molded edge. The single-walled cover has a length and a width and comprises a plurality of ribs extending the length of the single-walled cover. The single-walled cover has a peripheral rim with an undercut for stiffening. Each the one or more hollow molded hinges comprises an elongate knuckle. The hollow-molded edges comprises a top layer and a bottom layer.

The invention teaches a container lid product for controlling access to a container. The container lid comprises one or more hollow molded hinges with solid compressed area to eliminate any seam in use pivotally connecting the product to the container, a hollow-molded edge disposed adjacent to the one or more hollow-molded hinges, and a single-walled cover portion being connected to the hollow-molded edge. The single-walled cover has a length and a width and comprises a plurality of ribs extending the length of the single-walled cover. The single-walled cover has a peripheral rim with an undercut for stiffening. Each the one or more hollow molded hinges comprises an elongate knuckle. The hollow-molded edges comprises a top layer and a bottom layer.