US 12,343,921 B2
Double container and manufacturing method therefor, preform, and container manufacturing method
Yuhi Kurahashi, Yamato (JP); Shinsuke Taruno, Yamato (JP); and Yosuke Muroya, Yamato (JP)
Assigned to KYORAKU CO., LTD., Kyoto (JP)
Appl. No. 18/248,114
Filed by KYORAKU CO., LTD., Kyoto (JP)
PCT Filed Oct. 12, 2021, PCT No. PCT/JP2021/037747
§ 371(c)(1), (2) Date Apr. 6, 2023,
PCT Pub. No. WO2022/080370, PCT Pub. Date Apr. 21, 2022.
Claims priority of application No. 2020-174189 (JP), filed on Oct. 15, 2020; application No. 2020-189809 (JP), filed on Nov. 13, 2020; application No. 2021-011489 (JP), filed on Jan. 27, 2021; and application No. 2021-028500 (JP), filed on Feb. 25, 2021.
Prior Publication US 2023/0364847 A1, Nov. 16, 2023
Int. Cl. B29C 49/22 (2006.01); B29C 49/10 (2006.01); B65D 65/40 (2006.01); B65D 77/06 (2006.01); B65D 83/00 (2006.01); B29K 23/00 (2006.01); B29K 67/00 (2006.01); B29L 31/00 (2006.01); B65D 1/02 (2006.01)
CPC B29C 49/22 (2013.01) [B29C 49/10 (2013.01); B65D 65/40 (2013.01); B65D 77/06 (2013.01); B65D 83/771 (2025.01); B29C 2949/0724 (2022.05); B29C 2949/0725 (2022.05); B29C 2949/3016 (2022.05); B29K 2023/00 (2013.01); B29K 2067/003 (2013.01); B29L 2031/7158 (2013.01); B65D 1/0207 (2013.01); B65D 1/0246 (2013.01); B65D 1/0284 (2013.01); B65D 2565/387 (2013.01)] 11 Claims
OG exemplary drawing
 
1. A method of manufacturing a container, the method comprising a biaxial stretch blow molding step for biaxially stretching a preform by blowing air thereinto with the preform being heated and softened in the biaxial stretch blow molding step, wherein:
the preform has a tubular body part and a bottom part closing a lower end of the body part;
the preform comprises a pinch-off part at the bottom part,
T2/T1 is greater than 1, where T1 represents a thickness of the body part on a center surface in a height direction of the preform, and T2 represents a thickness of the bottom part at a middle point between a center and an end in a longitudinal direction of the pinch-off part when the preform is viewed along a longitudinal direction of the preform from a side of the bottom part, and
at the middle point, when a protrusion amount of the pinch-off part from the bottom part is defined as T3, T3/T2 is 0.4 or less.