Thermoformed container having improved strength to weight ratio in sidewall

A container sidewall made of a thermoplastic material, the container comprising a closed bottom wall at one end, an open top area defined at an opposite end, and a sidewall extending between the bottom wall and the open top to define a height, the sidewall comprising:

• a top portion having a width, a smooth exterior surface and adjacent the open top area of the container;
• a first set of annular ribs having a width and disposed adjacent the top portion, wherein the width of the first set of annular ribs is within the range of from about 5% to about 40% of the height of the sidewall;
• a second set of annular ribs having a width and separate from the first set of annular ribs, wherein the width of the second set of annular ribs is within the range of from about 5% to about 40% of the height of the sidewall, and the number of ribs in the second set of annular ribs is identical to the number of ribs in the first set of annular ribs;
• a middle portion having a width, a smooth exterior surface and disposed between the first set and second set of annular ribs, wherein the width of the middle portion of the sidewall is less than the width of the first set of annular ribs and the width of the second set of annular ribs;
• a bottom portion having a width, a smooth exterior surface and disposed adjacent the closed bottom wall of the container;
• and
• an improved sidewall strength to container weight ratio of at least 5% over a substantially similar container sidewall having only a single set of annular ribs, the strength being determined by the force required to deflect the sidewall approximately one inch.

A cup comprising:

• a closed bottom wall;
• an open top area defined opposite the closed bottom wall;
• a sidewall extending between the bottom wall and the open top area to define a height and forming a truncated, substantially-conical shape, the sidewall comprising:
• a top sidewall portion having a width, a smooth exterior surface and disposed adjacent the open top area of the container;
• a first set of annular ribs having a width and disposed on the sidewall adjacent the top portion;
• a second set of annular ribs having a width and separate from the first set of annular ribs on the sidewall;
• a middle sidewall portion having a width, a smooth exterior surface and disposed between the first set and second set of annular ribs;
• a bottom sidewall portion having a width, a smooth exterior surface and disposed adjacent the closed bottom wall of the container;
• and
• an improved sidewall strength to cup weight ratio of at least 5% over a substantially similar cup sidewall having only a single set of annular ribs, the strength being determined by the force required to deflect the sidewall approximately one inch.