US 12,420,290 B2
Method for removing metallic foreign matter from fluororesin and method for producing fluororesin with reduced metallic foreign matter
Masayoshi Miyamoto, Osaka (JP); Hiroyuki Sendan, Osaka (JP); Kouichi Hirota, Osaka (JP); Makoto Kawamorita, Osaka (JP); and Tsunehiko Fuwa, Jiangsu (CN)
Assigned to DAIKIN INDUSTRIES, LTD., Osaka (JP); and DAIKIN FLUOROCHEMICALS (CHINA) CO., LTD., Jiangsu (CN)
Filed by DAIKIN INDUSTRIES, LTD., Osaka (JP); and Daikin Fluorochemicals (China) Co., Ltd., Jiangsu (CN)
Filed on Nov. 13, 2023, as Appl. No. 18/507,699.
Application 18/507,699 is a continuation of application No. PCT/JP2022/020540, filed on May 17, 2022.
Claims priority of application No. 202110549939.3 (CN), filed on May 20, 2021.
Prior Publication US 2024/0075481 A1, Mar. 7, 2024
Int. Cl. B03C 1/32 (2006.01)
CPC B03C 1/32 (2013.01) 6 Claims
OG exemplary drawing
 
1. A method for removing metallic foreign matter from a fluororesin, the method comprising:
applying a magnetic field to a fluororesin containing the metallic foreign matter with a magnet while dropping the fluororesin by gravity to thereby remove metal,
wherein the method provides a screen made of a magnetic material in a flow path of the fluororesin dropped by gravity,
the fluororesin is dropped from a position above the screen in a vertical direction and travels toward the screen by gravity, the metallic foreign matter becomes magnetically attached to the screen, and the fluororesin from which the metallic foreign matter has been removed passes through the screen and is discharged from a position below the screen in the vertical direction, and
when the fluororesin passes through the screen, the screen is not vibrated.