next , an embodiment of the invention will be described with reference to the attached drawings . fig1 through 11 are drawings of liner tubes , illustrating steps of the method for connecting ends of them in order of the sequence . in fig1 the reference numerals 1 and 11 designate two liner tubes to be connected end to end . these liner tubes can be ones cut from finished tubular liner bags or freshly made liner tubes . in either case they are in principle made in the following manner . rectangular sheets 2 , 12 of resin absorbent material are made from a nonwoven fabric obtained by bonding or punch - pressing a mass of fiber such as of polyester , nylon , acrylic resin , polypropylene , carbon , and glass , or a mixture of some of these . the resin absorbent sheet is then cut to rectangular shape and rolled up such that the long sides of the rectangular sheet meet each other to form a tube ; then , the long sides are sewed together with threads 4 , 14 . the tubular sheets 2 , 12 are passed inside flexible plastic film tubes 3 , 13 , respectively . these film tubes 3 , 13 are made of a highly airtight material such as polyurethane , polyvinylchloride , polyethylene , eva , and nylon , and have diameters substantially greater than the outer diameter of the rolled resin absorbent sheet tubes 2 , 12 ; hence it is relatively easy to pass the sheet tubes 2 , 12 inside the film tubes 3 , 13 , and as of the insertion the film tubes 3 , 13 envelop the sheet tubes 2 , 12 only loosely . incidentally , it is also practiced that the plastic film tube consists of a lamination of more than one films of different materials selected from those described above . now , after preparing such liner tubes 1 , 11 , the loose film tubes 3 , 13 are turned over at the ends of the liner tubes 1 , 11 to be connected , and pulled away from said ends until the sheet tubes 2 , 12 are exposed over a predetermined length each , as shown in fig2 . thereafter , that portions of the threads 4 , 14 which are now exposed are cut and removed , and that portions of the sheets 2 , 12 which are thus undone are unrolled and flattened as wide as possible , as shown in fig3 . these flattened portions of the sheets 2 , 12 are cut along one - dot chain lines c , c &# 39 ;, respectively , which are drawn obliquely such that they are slanted from the front edge line by an angle substantially greater than 0 degree and substantially smaller than 90 degrees , as shown in fig3 . as the result , the cut ends of the sheets 2 , 12 become parallel with each other when the liner tubes 1 , 11 are placed in a manner such that their seams are collinear and the cut ends are opposed to each other , as shown in fig4 . now , these cut ends are brought together , and a thin tape 5 of a nonwoven fabric with one side coated with an adhesive layer is pasted on the inner side of the sheets 2 , 12 along the line at which the cut ends of the sheets 2 , 12 meet , as shown in fig5 so as to tentatively connect the resin absorbent sheets 2 , 12 together . when the two liner tubes 1 , 11 thus become one tentatively , one of them , 1 in this embodiment , is raised at the free end ( fig6 ) and turned over to lie on the other liner tube , 11 in this case , so that the tentatively integral tube is folded at the line at which the cut ends of the sheets 2 , 12 meet , as shown by cross - section in fig7 . then , this bent edge is stitched with a thread 6 , the thread passing through the tape 5 as well as the sheets 2 , 12 . thereafter , the liner tube 1 is picked and turned back to straighten the tentatively integral tube , and , as shown in fig8 the resin absorbent sheets 2 , 12 are now bound together firmly by the thread 6 zigzagging along the oblique meeting line . next , a thin adhesive tape 7 similar as the tape 5 is pasted on the outer side of the sheets 2 , 12 in a manner such that the tape 5 covers the stitch 6 entirely . when the resin absorbent sheets 2 , 12 are thus sewn together , they are rolled up until they become tubular , as shown in fig9 and the tube is closed by re - stitching along the seam so that the stitch 4 , 14 becomes unbroken . next , the overturned plastic films 3 , 13 are unfolded to cover the exposed portions of the resin absorbent sheets 2 , 12 , and at this time since the exposed portions of the sheets 2 , 12 are now shorter than before , the unfolded films 3 , 13 overlap one over the other by some length δl , as shown in fig1 . while the things are maintained as shown in fig1 , the air in the resin absorbent sheets 2 , 12 is drawn by a vacuum pump , not shown , whereupon the loosely enveloping film tubes 3 , 13 are tightly pressed against the outer surface of the tubular resin absorbent sheets 2 , 12 , as shown in fig1 . while the operation of the vacuum pump is thus maintained , the plastic film tubes 3 , 13 are heated whereupon the film tubes shrink and fuses to adhere to the outer surface of the resin absorbent sheets 2 , 12 , and thus the outer surface of the tubular sheets 2 , 12 is coated with the air - tight layer , and the connection of the two liner tubes 1 , 11 is completed . the liner tubes 1 , 11 , which are coupled together through the series of operation as described above , are then ready to be used to line and repair a pipe only after the sheets 2 , 12 are soaked through with a curable liquid resin . in the above embodiment , the two liner tubes 1 , 11 are stitched together along the obliquely cut ends of the sheets 2 , 12 so that the length of the stitching becomes much longer than that in the case of stitching along the cut ends which are cut orthogonally to the seams of the liner tubes , and this will result in a stronger joining strength , and consequently even after the curable liquid resin wetting the tubular sheets 2 , 12 is cured , the jointed ends do not detach from each other and a gap is scarcely formed between the ends . also , now that the sheets 2 , 12 are rolled up , the thin tape 5 pasted on the inner side of the sheets 2 , 12 extends spirally across a region of a length l ( fig1 ), which is a distance between the ends of the tape 5 measured in the direction of the seam 4 , 14 , so that the tape 5 does not form an inwardly protruding ring that would constrict the passage in the pipe 1 , 11 at the joint location . thus , the reduction in the inner diameter of the repaired pipe will not be more than that caused by the liner tubes 1 , 11 . while the invention has been described in its preferred embodiment , it is to be understood that modifications will occur to those skilled in the art without departing from the spirit of the invention . the scope of the invention is therefore to be determined solely by the appended claims .