Method for making a reservoir

1. A process for making a reservoir comprising the steps of:

(a) positioning a pliable hollow extrudate into a mold with a serpentine cavity at a first temperature, said extrudate having a profile in cross-section,

(i) said serpentine cavity having at least one cavity dimension which is larger than a corresponding dimension of said extrudate profile, said serpentine cavity having at least two essentially parallel expanded middle sections and at least a pair of oppositely necked regions, each necked region interconnected by generally U-shaped bends;

(ii) said extrudate having a first and second opening, each opening positioned at an end of said extrudate;

(b) inserting one end of a hollow first polymeric profile at a second temperature, said second temperature being less than said first temperature, into said first opening of said extrudate, said end of said first profile being dimensionally smaller than said first opening of said extrudate;

(c) inserting one end of a hollow second polymeric profile at a third temperature, said third temperature being less than said first temperature, into said second opening of said extrudate, said end of said second profile being dimensionally smaller than said second opening of said extrudate;

(d) sealing one non-inserted end in combination with affixing at least one source of pressurized gas to said other non-inserted end of either said first or second profile;

(e) closing said mold and pressurizing said hollow extrudate by the application of pressure through said other non-inserted end having at least one source of pressurized gas affixed thereto so that said hollow extrudate expands to fill said at least one cavity dimension, to form at least one expanded section in said extrudate, and to compressively seal an exterior surface of said two inserted ends of said first and second hollow profiles with an interior surface of said ends of said extrudate using said latent heat within said extrudate at said first temperature and forming a reservoir, wherein said reservoir includes said first and second polymeric profiles;

(f) releasing said pressure; and

(g) removing said reservoir from said mold.

2. The process of claim 1 wherein

said latent heat from said extrudate is sufficient to permit positioning of said hollow extrudate profile into said mold without the application of external heat.

3. The process of claim 1 which further comprises

a step of crosslinking said extrudate.

4. The process of claim 3 wherein

said extrudate and said first and second profiles are polyolefins.

5. The process of claim 4 wherein

said polyolefin is polyethylene.

6. The process of claim 3 wherein

said step of crosslinking is effected by exposure to an electron beam.

7. The process of claim 1 wherein

said hollow extrudate is at least partially crosslinked before insertion of said first and second profiles.

8. A process for making a reservoir comprising the steps of:

(a) positioning a pliable hollow cylindrical extrudate into a mold with a serpentine cavity at a first temperature, said extrudate having a profile in cross-section,

(i) said serpentine cavity having at least one cavity dimension which is larger than a corresponding dimension of said extrudate profile, said serpentine cavity having at least two essentially parallel expanded middle sections and at least a pair of oppositely necked regions, each necked region interconnected by generally U-shaped bends;

(ii) said extrudate having a first and second opening, each opening positioned at an end of said extrudate;

(b) inserting one end of a hollow first cylindrical polymeric profile at a second temperature, said second temperature being less than said first temperature, into said first opening of said extrudate, said end of said first profile being dimensionally smaller than said first opening of said extrudate;

(c) inserting one end of a hollow second cylindrical polymeric profile at a third temperature, said third temperature being less than said first temperature, into said second opening of said extrudate, said end of said second profile being dimensionally smaller than said second opening of said extrudate;

(d) affixing at least one source of pressurized gas to each non-inserted end of said first and second profile;

(e) closing said mold and pressurizing said hollow extrudate by the application of pressure through at least one end so that said hollow extrudate expands to fill said at least one cavity dimension, forming at least one expanded section in said extrudate, and compressively sealing an exterior surface of said two inserted ends of said first and second hollow profiles with an interior surface of said ends of said extrudate using said latent heat within said extrudate at said first temperature, thereby forming a reservoir, wherein said reservoir includes said first and second polymeric profiles;

(f) releasing said pressure; and

(g) removing said reservoir from said mold.

9. The process of claim 8 wherein

said latent heat from said extrudate is sufficient to permit positioning of said hollow extrudate profile into said mold without the application of external heat.

10. The process of claim 8 which further comprises a step of crosslinking said extrudate.

11. The process of claim 10 wherein

said extrudate and said first and second profiles are polyolefins.

12. The process of claim 11 wherein

said polyolefin is polyethylene.

13. The process of claim 10 wherein said step of crosslinking is effected by exposure to an electron beam.

14. The process of claim 8 wherein

said hollow extrudate is at least partially crosslinked before insertion of said first and second profiles.

15. The process of claim 8 which further comprises

the step of adding an insert into at least one of said first and second profiles.

16. A process for making a water reservoir comprising the steps of:

(a) extruding a hollow polymeric profile at an extrusion temperature;

(b) transferring said extrudate into a serpentine mold with a cavity at a temperature where said extrudate is formable,

(i) said serpentine cavity having at least one cavity dimension which is larger than a corresponding dimension of said extrudate profile, said serpentine cavity having at least two essentially parallel expanded middle sections and at least a pair of oppositely necked regions, each necked region interconnected by generally U-shaped bends;

(ii) said extrudate having a first and second opening, each opening positioned at an end of said extrudate;

(c) compressively sealing two hollow polymeric profiles essentially at room temperature in said openings of said extrudate at opposed ends of said extrudate using latent heat of said extrudate;

(d) expanding at least one portion of said extrudate by the application of a means for expanding to said extrudate;

(e) releasing said means for expanding; and

(f) removing said reservoir, including said first and second polymeric profiles, from said mold.

17. The process of claim 16 wherein

said latent heat from said extrudate is sufficient to permit positioning of said hollow extrudate profile into said mold without the application of external heat.

18. The process of claim 17 which further comprises a step of crosslinking said extrudate.

19. The process of claim 18 wherein said extrudate and said first and second profiles are polyolefins.

20. The process of claim 19 wherein

said polyolefin is polyethylene.

21. The process of claim 18 wherein

said step of crosslinking is effected by exposure to an electron beam.

22. The process of claim 16 wherein

said hollow extrudate is at least partially crosslinked before insertion of said first and second profiles.

23. The process of claim 16 which further comprises

the step of adding an insert into at least one of said polymeric profiles.

24. The process of claim 16 wherein

said means for expanding is internal pressure.

25. The process of claim 16 wherein

said means for expanding is external vacuum.

26. The process of claim 16 wherein

said means for expanding is internal pressure and external vacuum.