Porous polytetrafluoroethylene membrane, process for producing t

Details Porous polytetrafluoroethylene membrane, process for producing t Porous polytetrafluoroethylene membrane, process for producing t

1998-08-28

2000-02-29

Spitzer, Robert H.

Gas separation

Two or more separators

Plies or layers of different characteristics or orientation

55524, 55528, 96 13, B01D 4610

Patent

active

060304286

ABSTRACT:
A fine powder of polytetrafluoroethylene is mixed with a liquid lubricant, and the mixture is molded into an unsintered sheet by at least one of an extrusion method and a rolling method. The liquid lubricant is removed from the sheet by at least one of a heating method and an extrusion method. This sheet-form molding is stretched in the machine direction to produce a sheet-form polytetrafluoroethylene molding which, upon analysis with a differential scanning calorimeter, gives a crystal fusion curve having an endothermic peak in the temperature range of 345.+-.5.degree. C. and which has a degree of crystallization of from 0.1 to 0.85 and a specific gravity of 1.4 or lower. The molding is then stretched in the transverse direction to produce a porous polytetrafluoroethylene (PTFE) membrane. The process is effective in producing, with good reproducibility, a useful porous PTFE membrane which has a high collection efficiency and a low pressure loss and is reduced in the leakage of coarse particles.

REFERENCES:
patent: 3953566 (1976-04-01), Gore
patent: 3962153 (1976-06-01), Gore
patent: 3986851 (1976-10-01), Grodek
patent: 4025679 (1977-05-01), Denny
patent: 4187390 (1980-02-01), Gore
patent: 4596837 (1986-06-01), Yamamoto et al.
patent: 4816328 (1989-03-01), Saville et al.
patent: 4877433 (1989-10-01), Oshitari
patent: 4902423 (1990-02-01), Bacino
patent: 4983434 (1991-01-01), Sassa
patent: 5037457 (1991-08-01), Goldsmith et al.
patent: 5041225 (1991-08-01), Norman
patent: 5082472 (1992-01-01), Mallouk et al.
patent: 5096473 (1992-03-01), Sassa et al.
patent: 5154827 (1992-10-01), Ashelin et al.
patent: 5284704 (1994-02-01), Kochesky et al.
patent: 5409515 (1995-04-01), Yamamoto et al.
patent: 5417743 (1995-05-01), Dauber
patent: 5437900 (1995-08-01), Kuzowski
patent: 5462586 (1995-10-01), Sugiyama et al.
patent: 5527569 (1996-06-01), Hobson et al.
patent: 5538545 (1996-07-01), Dauber et al.
patent: 5593482 (1997-01-01), Dauber et al.
patent: 5677031 (1997-10-01), Allan et al.
patent: 5728299 (1998-03-01), Tokudome et al.
patent: 5776343 (1998-07-01), Cullen et al.
patent: 5830261 (1998-11-01), Hamasaki et al.
Abstract of Japan 7-196,831 (Published Aug. 1, 1995).

Affiliated with

Also associated with

Rating

Porous polytetrafluoroethylene membrane, process for producing t does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Porous polytetrafluoroethylene membrane, process for producing t, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Porous polytetrafluoroethylene membrane, process for producing t will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-678817