Patent · US Expired

Method of radiation treatment for fluoropolymer materials

US6340718B1 · kind B1 · utility

8Cited by
24References
13Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJul 24, 2000
Grant dateJan 22, 2002
Priority date
Expiry dateJul 24, 2020

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10S522/911
  • WIPO fieldOther special machines
  • WIPO sectorMechanical engineering

Abstract

A source of radiation (10,12), particularly a pulsed accelerated electron beam, directs a beam of radiation through an irradiation chamber (14, 50). The irradiation chamber is depleted of oxygen and oxygen containing gases, such as being drawn to a vacuum of 10−1 or greater Torr by a vacuum pump (20, 52). Particulate fluoropolymer material is entrained (36) in substantially oxygen free gas and conveyed through the irradiation chamber. The accelerated electrons break chemical bonds in the fluoropolymer particles and electrostatically charge the particles. Magnetic fields (42, 60) of different polarity rotate the charged particles such that they are irradiated from different sides. The irradiated fluoropolymer particles are cooled (24) and separated (26) from the entraining gas. The entraining gas is recirculated through pneumatic line (34) for a continuous cycle. In an alternate batch processing embodiment, the fluoropolymer material is placed in the shallow container (50) which is sealed and evacuated. The container is conveyed through the pulsed electron beam.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.