High-strength, lightweight blow-molded plastic structures

A structure constructed from blow-molded plastic, the structure comprising:

• a first surface;
• a second surface that is spaced apart from the first surface;
• a hollow interior portion that is formed during the blow-molding process;
• a plurality of depressions formed in the second surface and extending towards the first surface, each of the plurality of depressions having generally the same shape, the plurality of depressions comprising:
• a first depression, a second depression, a third depression and a fourth depression positioned in a generally parallelogram shaped configuration, the first depression being disposed proximate the second and fourth depressions, the second depression being disposed proximate the first and third depressions, the third depression being disposed proximate the second and fourth depressions, the fourth depression being disposed proximate the first and third depressions;
• the first and third depressions being positioned at opposing corners of the generally parallelogram shaped configuration, the second and fourth depressions being positioned at opposing corners of the generally parallelogram shaped configuration;
• the first and third depressions being oriented generally perpendicular to each other;
• the second and fourth depressions being oriented generally perpendicular to each other;
• the third depression being orientated at a first angle, the second depression being orientated at angle that is oblique to the first angle, the fourth depression being orientated at angle that is oblique to the first angle.

A structure constructed from blow-molded plastic, the structure comprising:

• a first surface;
• a second surface that is spaced apart from the first surface;
• a hollow interior portion formed during the blow-molding process;
• a plurality of depressions formed in the second surface and extending towards the first surface, each of the plurality of depressions having generally the same shape, the plurality of depressions comprising:
• a first row of depressions, the depressions of the first row alternating between a first orientation and a second orientation, the first and second orientations being generally perpendicular to each other;
• and
• a second row of depressions adjacent the first row of depressions, the depressions of the second row alternating between a third orientation and a fourth orientation, the third and fourth orientations being generally perpendicular to each other,
• the first orientation being at an angle that is oblique to the third and fourth orientations, the second orientation being at an angle that is oblique to the third and fourth orientations, the third orientation being at an angle that is oblique to the first and second orientations, the fourth orientation being at an angle that is oblique to the first and second orientations.