Pipe joints or couplings – With casing – lining or protector – Lined
Reexamination Certificate
1998-12-16
2001-06-26
Nicholson, Eric K. (Department: 3629)
Pipe joints or couplings
With casing, lining or protector
Lined
C285S021200, C285S197000, C156S292000, C156S273900
Reexamination Certificate
active
06250687
ABSTRACT:
TECHNICAL SECTOR
The invention relates to a process for leakproof connection of branch lines, such as house lines, to main lines, such as rehabilitated sewer pipes, in which one part of the length of a lining hose composed of a sheet of textile, such as a nonwoven fabric, woven fabric, knitted fabric, mesh fabric or laminate, and capable of being saturated with a liquid, curable resin, is introduced into the branch line, before or after saturation with a resin, and its other, collar-shaped expanded end is bonded to the inner side of the main line in a leakproof manner. The invention also relates to a transition piece for bonding a resin-saturated textile lining hose onto a surface made from thermoplastic polymer for this process.
PRIOR ART
When damaged pipelines, in particular sewer pipelines for waste water drainage, are rehabilitated by the procedure known as relining, there is the question, after the main line has been rehabilitated, of the leakproof bonding onto this of the branch lines, in particular house lines, which feed into the main lines. DE 39 29 558 A1, DE 42 07 038 A1 and DE 42 38 982 A1 have disclosed a process according to the precharacterizing clause of claim
1
. However, a precondition of these processes, which are proven per se, was that the inner surface of the rehabilitated sewer pipe is composed of bondable material, such as cured epoxy resin, to which the collar of the lining hose can be bonded. In many modern relining processes, however, the inner surface of the rehabilitated sewer pipe is composed, because of its superior properties, of polyolefins, in particular HDPE, which cannot be bonded to other materials using conventional adhesives.
DE 44 10 592 C1 discloses a hat-shaped connecting sleeve which is also suitable for leakproof connection of house lines to sewer pipes lined with thermoplastic materials, such as HDPE. This connecting sleeve is composed of a short piece of hose made from extensible, woven . . . .
DE 44 10 592 C1 discloses a hat-shaped connecting sleeve which is also suitable for leakproof connection of house lines to sewer pipes lined with thermoplastic materials, such as HDPE. This connecting sleeve is composed of a short piece of hose made from extensible, woven or knitted base material made from glass fibers, which has been saturated with a curing synthetic resin composition, and of a collar composed of thermoplastic polymer. However, these hat-shaped connecting pieces are complicated to produce, since the woven or knitted base material is composed of glass fibers, which are difficult to bond to the thermoplastic material of the collar. Special robots are required for inserting these connecting pieces, and these again imply high cost.
OBJECT
It is therefore an object of the present invention to provide a process for leakproof connection of branch lines, such as house lines, to main lines, such as rehabilitated sewer pipes and which, on the one hand, is based on the proven principle of a lining hose composed of a sheet of textile and, on the other hand, permits a leakproof bond to the rehabilitated main line's inner surface, composed of thermoplastic material.
THE INVENTION
The invention achieves this object by means of a process in accordance with claim
1
, preferably with one or more of the features of the subclaims, and in particular with the aid of a transition piece corresponding to claim
4
, particularly preferably combined with one or more of the features of the other subclaims.
This invention is based on a process corresponding to DE-39 29 558 A1 and DE-42 38 982 A1, i.e., use is made of a lining hose, known per se, which is with [sic] resin-saturated and has a collar-shaped expanded end.
To achieve bonding to the main line's thermoplastic inner surface, a preferably ring-shaped transition piece is used. One side of this ring-shaped transition piece is composed of thermoplastic polymer, preferably HDPE, in particular the same material as that used for the inner surface of the rehabilitated sewer pipe. The other surface of the ring-shaped transition piece is composed of a sheet of textile, in particular a fine-thread nonwoven fabric made from polyester fibers, which is, in particular, heat-laminated to the thermoplastic base material of the transition piece.
Depending on the angle at which the branch line diverts, the ring-shaped transition piece used according to the invention may have the shape of a circular ring or a shape which is rather elliptical.
In a preferred embodiment of the invention, the fusing of the thermoplastic polymer of the transition piece to the thermoplastic inner surface of the rehabilitated sewer pipe takes place by means of an electrical heating spiral known per se. For this purpose, the ring-shaped transition piece has for example on its sides appropriate electrical connections to which a commercially available electric welding apparatus can be connected. The welding rate here must be adjusted in such a way that the heating spiral becomes intimately fused to the thermoplastic inner surface of the rehabilitated sewer pipe, thus giving a leakproof bond. For this procedure use is usually made of robots which can also be used in sewer pipes where human access is impossible.
In a preferred embodiment of the invention, the sheet of textile of the ring-shaped transition piece is saturated with curing resin before the bonding to the resin-saturated lining hose, preferably with the same resin as that used to saturate the lining hose. The curing of the resin in the sheet of textile of the ring-shaped transition piece and/or in the lining hose may be initiated, for example, by exposure to UV light, introduction of heat or incorporation of chemically acting crosslinking agents and/or crosslinking accelerators. The result after the resin has cured is leakproof bonding of one end of the lining hose to the house line and of the other end via the transition piece used according to the invention to the thermoplastic surface of the rehabilitated sewer pipe.
In a preferred embodiment of the invention, the transition piece is composed of an HDPE layer of thickness from 0.5 to 4 mm, to the entire surface of which a nonwoven fabric made from polyester fibers has been laminated by heat lamination. The HDPE layer preferably has a heating spiral bonded to it, which in turn may be encapsulated in HDPE.
REFERENCES:
patent: 4894521 (1990-01-01), Evans
patent: 5104468 (1992-04-01), de Jong
patent: 6089615 (2000-07-01), Jappinen
patent: 4207038A (1993-09-01), None
patent: 4410592C (1995-06-01), None
patent: 565397 (1993-10-01), None
patent: 2223550A (1990-04-01), None
patent: 405248585 (1993-09-01), None
Millen White Zelano & Branigan P.C.
Nicholson Eric K.
Trolining GmbH
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