Patent attributes
A double walled container has a container bottom that is blow molded after an intermediate portion of a parison in the vertical direction is sandwiched by a split mold from the horizontal direction; at least a portion of the container bottom is sandwiched by the split mold; the container bottom has a bottom projection on the underside of the container bottom made of the outer layer of a rigid outer layer container and the outer layer of a flexible inner layer container; in the bottom projection, an extended portion of the rigid outer layer container and an extended portion of the flexible inner layer container have protrusions and recesses of different heights in the horizontal direction; and the protrusions and recesses are combined so that the extended portions of the rigid outer layer container and the flexible inner layer container do not shift vertically with respect to each other.
