Low permeation pinchoff connection for bridging a barrier...

Details Low permeation pinchoff connection for bridging a barrier... Low permeation pinchoff connection for bridging a barrier...

2002-05-07

2004-04-20

Moy, Joseph Man-Fu (Department: 3727)

Receptacles

Vehicle mountable tank

C220S004140, C220S062220

Reexamination Certificate

active

06722521

ABSTRACT:

BACKGROUND OF THE INVENTION
The present invention relates to a low permeation pinchoff connection and a method of bridging a low permeation barrier layer at a pinchoff end of a fluid tank for reducing permeation of gaseous fluids through the fluid tank.
Fluid tanks are common in several industries. For example, fuel tanks for motorized vehicles have been used for many years. Many of the current fuel tanks installed in motorized vehicles are made of plastic or metal. Plastic storage containers provide a number of advantages over those made of other materials. Some advantages include reduced weight, reduced cost for both materials and construction, and greater flexibility and shape. Along with these advantages, the ability of certain plastic containers to stretch or flex makes them useful in automotive applications. A problem in plastic tanks that manufacturers have experienced is fuel may permeate through the walls of the plastic tank. For example, monolayer polyethylene fuel tanks, while benefiting from the advantages mentioned above, suffer from a relatively high permeability to gasoline with respect to containers formed of other materials.
Several approaches have been taken to improve the permeability characteristics of plastic fuel containers or tanks. One solution to this problem has been a fuel tank formed of a multi-layer wall material that is composed of layers of polyethylene and an ethylene-vinyl alcohol copolymer (EVOH). The EVOH copolymer exhibits good gasoline vapor barrier properties.
Polyethylene-EVOH thermoplastics structures can be formed into a variety of container shapes using twin-sheet thermo-forming and blow molding techniques. Polyethylene-EVOH container walls typically have about five to seven layers. The five layers include polyethylene inner and outer layers and one EVOH layer with an adhesive layer on each side. Regardless of the forming process, there are areas on the fuel tank known as the pinchoff where opposing multilayer structures are “pinched” together, e.g., to rejoin sheets in the case of thermoforming, or to rejoin parisons in the case of blow molding. This forms a continuous container. In a pinchoff region or area where the multilayer structures are brought together, typically two EVOH barrier layers from opposing walls are not able to re-bond to a continuous state. The resultant pinchoff area has a higher permeation rate than other portions of the container.
BRIEF SUMMARY OF THE INVENTION
The present invention provides a low permeation pinchoff connection between first and second formed multilayer walls or sheets of a fluid tank for reducing permeation of gaseous fluids therefrom. The low permeation pinchoff connection seals a barrier layer of the fluid tank to reduce gaseous permeation therefrom. This is accomplished by bridging barrier ends of a low permeation barrier layer on a pinchoff end of a pinchoff region of the fluid tank. More specifically, a barrier bridge is disposed on the pinchoff end to bridge a pinchoff gap within which the barrier ends are separated. This provides continuity between the barrier ends and reduces gaseous permeation therethrough.


REFERENCES:
patent: 2439562 (1948-04-01), Cunningham
patent: 3115987 (1963-12-01), Barnstead
patent: 3426937 (1969-02-01), Boschi et al.
patent: 3606958 (1971-09-01), Coffman
patent: 3779420 (1973-12-01), Knaus
patent: 3811173 (1974-05-01), Baumann
patent: 3912107 (1975-10-01), Baumann
patent: 4513906 (1985-04-01), Chang et al.
patent: 4753368 (1988-06-01), Lescaut
patent: 4962862 (1990-10-01), Farrington et al.
patent: 5129544 (1992-07-01), Jacobson et al.
patent: 5230935 (1993-07-01), Delimoy et al.
patent: 5398839 (1995-03-01), Kleyn
patent: 5443874 (1995-08-01), Tachi et al.
patent: 5547096 (1996-08-01), Kleyn
patent: 5582729 (1996-12-01), Shioda et al.
patent: 5691016 (1997-11-01), Hobbs
patent: 5766713 (1998-06-01), Ravishankar et al.
patent: 6033749 (2000-03-01), Hata et al.
patent: 6044999 (2000-04-01), Kido
patent: 6179145 (2001-01-01), Roth
patent: 6189716 (2001-02-01), Lawrukovich et al.
patent: 6409040 (2002-06-01), Distelhoff et al.
patent: 6491180 (2002-12-01), Distelhoff et al.
patent: 2001/0025666 (2001-10-01), Brown et al.
patent: 2001/0029994 (2001-10-01), Brown et al.
patent: 0 448 329 (1991-03-01), None
patent: 0 930 190 (1999-07-01), None
patent: 0 930 190 (2000-03-01), None
patent: 1 031 725 (2000-08-01), None
patent: 1 031 725 (2001-05-01), None
patent: 1 108 598 (2001-06-01), None
patent: 1 108 599 (2001-06-01), None
patent: 1 285 746 (2003-02-01), None
patent: 1 108 596 (2003-10-01), None
PCT Publication, WO 01/62535, Aug. 30, 2001, WIPO.
PCT Publication, WO 01/42692, Jun. 14, 2001, WIPO.

Affiliated with

Also associated with

Rating

Low permeation pinchoff connection for bridging a barrier... does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Low permeation pinchoff connection for bridging a barrier..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Low permeation pinchoff connection for bridging a barrier... will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3231422