THIN PLASTIC BOTTLE

PROBLEM TO BE SOLVED: To prevent abnormal deformation from occurring to the circumference of a bottle even though negative pressure is produced at the inside of the bottle and to make the bottle easily reducible for its volume on discard by a method wherein folding-up guides in specified numbers or more separating from one another in the circumferential direction are formed intermittently or continuously almost in parallel with the center axis of the bottle. SOLUTION: Depressed parts 10 are formed intermittently at four places each demarcated in a range slightly smaller than 90 deg. at the circumference of a drum part 1, and a drum part folding-up guide 4 formed in a narrow projected stripe is arranged at a space between each of the depressed parts 10. The folding-up guides 4 are arranged in a plurality of tiers separating from one another in the axial direction, thereby enhancing rigidity for the bottle with section modulus thereof enlarged. A virtual folding-up line 9 for the drum part is formed at each of centerlines of the drum part folding-up guides 4, and the bottle is folded up along the folding-up lines 9 when the bottle is crushed with pressure. Furthermore, shoulder part folding-up guides 5 each in the form of projected stripe are extended in bifurcation from the upper ends of the drum part folding-up guides 4 to the mouth part 3, reaching mountain-shaped auxiliary shoulder part guides 6.