초록 ▼

One or more PTFE films are heated to greater than 150 degrees centigrade (C) and for a time greater than 20 hours, then the PTFE films are cooled. The PTFE films may be heated to temperatures greater than 200�� C. and less than 250�� C. and most preferably heated to a temperature of about 228�� C. T

One or more PTFE films are heated to greater than 150 degrees centigrade (C) and for a time greater than 20 hours, then the PTFE films are cooled. The PTFE films may be heated to temperatures greater than 200�� C. and less than 250�� C. and most preferably heated to a temperature of about 228�� C. The PTFE films may be kept at a temperature for greater than 50 hours or most preferably kept at a temperature for around 100 hours. The PTFE films may be heat processable PTFE fluoropolymer films and may have a number of heat affected zones. The heat affected zones may be created before or after heat treating. The heat affected zones are generally caused by welding two or more PTFE films together, usually under-pressure. An "optimal" temperature and "optimal" time period are determined at which heat processed polytetrafluoroethylene (PTFE) fluoropolymers should be heat treated.

대표청구항 ▼

What is claimed is: 1. A container adapted to contain a substance, the container comprising a circumscribing wall formed of a polytetrafluoroethylene film material having structural character modified by sustained application thereto of an elevated temperature in a range of between about 130�� and

What is claimed is: 1. A container adapted to contain a substance, the container comprising a circumscribing wall formed of a polytetrafluoroethylene film material having structural character modified by sustained application thereto of an elevated temperature in a range of between about 130�� and 260�� C. sufficient to reduce particle count character of said film material to a particle count of below 10 particles/ml of particles having a diameter of at least 0.2 micron, said circumscribing wall fabricated by welding a first sheet of said polytetrafluoroethylene film material to itself or to a second sheet of said polytetrafluoroethylene film material to define an interior volume adapted to surround said substance. 2. The container of claim 1 wherein the elevated temperature is above a glass transition temperature of the polytetrafluoroethylene film material. 3. The container of claim 1 wherein the application of the elevated temperature is for between about 20 hours and about 100 hours. 4. The container of claim 1 wherein the elevated temperature is about 228�� C. and the application is for about 100 hours. 5. The container of claim 1, wherein the container comprises a spout. 6. The container of claim 5, adapted to fit into an overpack that is more rigid than the container. 7. The container of claim 6, wherein the overpack comprises polyethylene. 8. The container of claim 1, wherein the first sheet is welded to the second sheet with at least one welded joint or seam. 9. The container of claim 1, wherein the polytetrafluoroethylene film material is substantially non-shedding. 10. The container of claim 1 wherein the substance comprises a liquid. 11. The container of claim 1 wherein the substance comprises a powder. 12. The container of claim 1 wherein the substance comprises a semiconductor processing substance. 13. The container of claim 1, containing a semiconductor processing substance. 14. The container of claim 1, containing photoresist. 15. The container of claim 1, wherein the polytetrafluoroethylene film material is substantially contaminant-free. 16. The container of claim 1, wherein said particle count character is reduced a factor greater than 10 by said elevated temperature application. 17. The container of claim 1, containing a substantially contaminant-free substance. 18. The container of claim 1, wherein the welded polytetrafluoroethylene film material forms a four-sided, two-dimensional bag, and the bag comprises a spout. 19. The container of claim 1, wherein said structural character modified by application of elevated temperature effects is sufficient to reduce the particle count character of said film material by a factor greater than 10. 20. A container comprising: a circumscribing wall formed of a polytetrafluoroethylene film material having structural character modified by sustained application thereto of an elevated temperature in a range of between about 130�� and 260�� C. for a sufficient time to reduce said particle count character by a factor greater than 10, said circumscribing wall fabricated by welding a first sheet of said polytetrafluoroethylene film material to itself or to a second sheet of said polytetrafluoroethylene film material to define an interior volume adapted to surround a substance; and a spout affixed to the first sheet of said polytetrafluoroethylene film material. 21. The container of claim 20, containing a substantially contaminant-free substance, wherein said first sheet and said second sheet film has a particle count of below 10 particles/mi of particles having a diameter of 0.2 micron. 22. The container of claim 20, wherein the welded polytetrafluoroethylene film material forms a four-sided, two-dimensional bag.