US 12,454,086 B2
Method and device for directly preparing foamed polylactic acid (PLA) product from PLA melt
Yanan Song, Ningbo (CN); Lejun Wang, Beijing (CN); Weiwei Huang, Ningbo (CN); Zongqiang Zheng, Ningbo (CN); and Yining Liu, Beijing (CN)
Assigned to JHM Engineering and Technology (Ningbo) Co., Ltd., Ningbo (CN)
Appl. No. 17/421,017
Filed by JHM Engineering and Technology (Ningbo) Co., Ltd., Ningbo (CN)
PCT Filed Jul. 18, 2019, PCT No. PCT/CN2019/096553
§ 371(c)(1), (2) Date Jul. 7, 2021,
PCT Pub. No. WO2020/143208, PCT Pub. Date Jul. 16, 2020.
Claims priority of application No. 201910016587.8 (CN), filed on Jan. 8, 2019.
Prior Publication US 2022/0097274 A1, Mar. 31, 2022
Int. Cl. B29C 48/00 (2019.01); B29C 48/36 (2019.01); B29C 48/385 (2019.01); B29C 48/395 (2019.01); B29C 48/625 (2019.01); B29C 48/92 (2019.01); C08J 9/14 (2006.01); B29C 48/58 (2019.01); B29K 67/00 (2006.01); B29K 105/04 (2006.01)
CPC B29C 48/0012 (2019.02) [B29C 48/0013 (2019.02); B29C 48/022 (2019.02); B29C 48/362 (2019.02); B29C 48/385 (2019.02); B29C 48/397 (2019.02); B29C 48/625 (2019.02); B29C 48/92 (2019.02); C08J 9/144 (2013.01); B29C 48/58 (2019.02); B29K 2067/046 (2013.01); B29K 2105/04 (2013.01); C08J 2201/03 (2013.01); C08J 2367/04 (2013.01)] 7 Claims
OG exemplary drawing
 
1. A method for directly preparing a foamed polylactic acid (PLA) product from a PLA melt, comprising: PLA melt preparation, feeding, and two-stage extrusion, wherein
the PLA melt obtained from the PLA melt preparation has a weight-average molecular weight of 200,000 to 221,000 and a molecular weight distribution of 1.21 to 1.24; and
the two-stage extrusion comprises first-stage extrusion and a second-stage extrusion, wherein
in the first-stage extrusion, a first-stage twin-screw extruder has a length-to-diameter ratio of 40:1, and a temperature distribution of 245° C. to 195° C. in a gradual decrease trend from a main feeding port of the first-stage twin-screw extruder to a die head, and
in the second-stage extrusion, a second-stage single-screw extruder has a length-to-diameter ratio of ≥30:1, and a temperature range of 180° C. to 128° C.