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.

A blow-molded plastic structure, such as a table top, may include an undercut. For example, the table top may include a frame receiving portion and a frame connecting structure with an undercut may be disposed in the frame receiving portion. A first portion of the frame may contact or engage the frame connecting structure when the frame is connected to the table top. In an exemplary embodiment, a first side of the frame receiving portion may include a first frame connecting portion with an undercut and a second side of the frame receiving portion may include a second frame connecting portion with an undercut. The first frame connecting portion with an undercut may be disposed on an opposing surface from the second frame connecting portion with an undercut.

A method for manufacturing a double-wall container includes a blow molding process of forming an intermediate molded body by blow molding, the intermediate molded body including a projection part that is provided at a boundary portion between an inner wall forming part and an outer wall forming part and projects outward in a radial direction of the outer wall forming part; an inverting process of pushing the inner wall forming part inside the outer wall forming part and inverting the inner wall forming part, thereby forming the intermediate molded body into the double-wall container; and a collapsing process of collapsing the projection part in a depth direction of the intermediate molded body to form a crease at the boundary portion between the inner wall forming part and the outer wall forming part, the collapsing process being performed before the inverting process.

A synthetic resin multilayer bottle includes an outer shell bottle and an inner container. The outer shell bottle is capable of restoring itself to its original shape against external pressure. The shoulder portion has a polygonal pyramidal shape, and the bottom portion has a polygonal pyramidal shape, including ridge lines continuing to the extended lines of the polygonal pyramidal ridge lines of the shoulder portion. The inner container includes a an inner container body having a shape extending along the internal shape of the outer shell bottle. It further includes an air passage formed between the outer mouth portion and the inner mouth portion.

A blow-molded structural panel has a stiffening rib structure in which the height and width of the rib structure varies over its length. For example, the rib structure may have three tall portions separated by two short portions, with a gradual slope in height between the various portions. The rib structure is preferably wider in the short portions than it is in the tall portions. The lower height of the rib structure in some portions enhances the stiffness of the panel, while also using less material because the plastic does not have to be drawn so deeply into the mold in the short portions.

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.

A blow-molded plastic structure, such as a tabletop, may include an undercut. For example, the tabletop may include a frame receiving portion and a frame connecting structure with an undercut may be disposed in the frame receiving portion. A portion of the frame may contact or engage the frame connecting structure, such as the undercut, when the frame is connected to the tabletop. In an exemplary embodiment, a first side of the frame receiving portion may include a first frame connecting portion with an undercut and a second side of the frame receiving portion may include a second frame connecting portion with an undercut. The first frame connecting portion with an undercut may be disposed on an opposing surface from the second frame connecting portion with an undercut.

A cooler with a two-color lid includes a cooler body and a lid designed to cover a cavity of the cooler body. The lid includes an outer section and an inner section. The lid is a blow-molded lid, where a color of the outer section is different from a color of the inner section.

One example of a flexible structure includes an elongate body having a first end and a second end, and the first end is configured to be releasably connected to the second end. As well, one or more living hinges are positioned in the elongate body between the first end and the second end, and the one or more living hinges are configured and arranged to enable the first end and second end to be moved toward each other. Finally, the flexible structure is configured to alternatively assume at least a flat state and an assembled state, and in the assembled state, the first end of the elongate body is connected to the second end of the elongate body.

A tool case with single and double wall sections, the double wall sections extend from one edge or from a corner of part of the case and are defined by a cut line, the cut line changes in height as the double wall sections have contours to conform to the tool to be held. The double wall sections may include supporting portions which are sections where the inner surfaces of the two walls are fused or welded together to create a support which transfers load from the tool between the two walls of the double wall section. In certain aspects, the cut line defines a large internal area of single wall as compared to the overall perimeter of the case or case half.