RENOVATION OR RESTORATION MATERIAL

Abstract: The invention relates to a material for renovating or repairing objects, comprising a knit of strengthening material which is optionally already coated or impregnated with a curable synthetic resin. The invention is particularly applicable when the object for renovating or repairing is a pipe and in the ready-to-use state the knit likewise has a tubular form. The material can further comprise one or more layers of an elastic foil. A tube shape for instance can hereby be made to fit well more easily by being inflated or filled with a fluid. The invention further relates to a renovating or repair method and a device for manufacturing a tubular renovation and repair material.

Description: RENOVATION OR RESTORATION MATERIAL The present invention relates to a material for renovating or repairing objects. Damaged piping for supplying and draining water, such as water pipes and sewage piping, or for transporting oil and other chemical products are usually repaired by replacing the damaged parts. Because it is often necessary to break up streets in order to replace old pipes, this type of renovation is expensive, time- consuming and moreover causes much disruption. It is therefore known for the repair of damaged piping to arrange a new pipe on a basis of a composite material in the pipe to be renovated or repaired. Such a composite material consists of a woven fabric or web which is wound round a core and subsequently impregnated with a resin, usually polyester resin or epoxy resxn. The whole is then pushed, blown or pulled into the old pipe and the resin is cold-cured or cured by means of hot air, steam, hot water, metal threads or UV light. The drawback to this method is that a core is always required round which to wind the woven fabric or web. This core must have a slightly smaller diameter than the pipe for repairing or renovating and must always be adapted to the dxameter of this pipe . To prevent the woven fabric or web being rolled back, the difference in diameter between the pipe and the core will always have to be relatively considerable. The consequence is that the newly arranged inner pipe will never fit quite perfectly. Because the new pipe does not fit closely onto the original pipe, the part between the two must be filled with grout, resins, mortar, cement and so on. Not only does this require additional operations, but the result is also not optimal. Prom DE-41 03 980 is known a tubular inner coating for pipes. The inner coating consists of a woven fabric or honeycomb structure, the mutually facing edges of which are stitched together. These materials are not very elastic. In order to nevertheless be able to obtain some clearance in the diameter, it is proposed to sew the edges very loosely t o each other. This of course results in a weakening of the structure at the position of the loose stitching. The use of a woven fabric or non-woven i s d escribed in EP-S48.417. While this material is indeed flexible, which is also necessary since it is turned inside out when carried into the pipe for repairing, it does not have sufficient elasticity in practice to enable it, once in the pipe, to expand to an extent such that a perfect connection to the wall can be achieved. WO 95/046 4 6 likewise describes an inner coating for pipes. This coating is constructed by winding a strip of fibre tape in spiral form, optionally in two directions. A lthough some variation in length can occur due to the overlap of the windings, it is not possible to adapt the form of the inner coating fully to the inner shape of the pipe for coating. It is the object of the present invention to improve the above stated methods . This is achieved according to the present invention by means of a material for renovating or repairing objects, comprising a knit of strengthening material which is optionally already coated or impregnated with a curable synthetic resin. Due to the fact that a knit is used, which is anyway elastic, it becomes possible to cause the renovation or repair material to fit perfectly onto the object for renovating or repairing. A knit can be folded well and can easily be laid or arranged in complex shapes. In a particularly advantageous embodiment of the invention the knit is a so-called weft knit ( weft jersey, Figure 1) . In such knits the threads are laid in waves, i.e. one or more threads are supplied to the needles in horizontal direction and are knitted into horizontal rows of stitches running in transverse direction. Such a weft knit is exceptionally elastic and can therefore adapt completely to the shape of an object for repairing or renovatin . T he counterpart of this type of knit is warp tricot (Figure 2) , wherein a large number of parallel (warp) threads are knitted into rows running in length direction. Warp tricot is also frequently used for mutually connecting threads or bundles of strengthening material. The products which result with use of this latter method are not elastic and therefore not suitable for the application according to the invention. The knit according to the invention can in principle be manufactured from any suitable material . Particularly recommended are glass fibre, carbon fibre, aramid fibre, thermoplastic fibre or combinations thereo . The fibre used depends on the application. The material preferably further comprises one or more layers of an elastic foil . Such a foil is preferably airtight and can thereby ensure that the knit can be connected perfectly onto the surface for renovating or repairing by means of air, water or other filling material. Such an elastic foil is for instance manufactured at least partly from polyethylene, polypropylene, polyamide, polyacrylate or combinations thereof. The knit can be used as such or in combination with one or more elastic foils. Further additional strengthening materials can also be used. When for instance a determined thickness is required, the knit can be combined with mats. In addition, membranes, unidirectional threads, cut fibres or combinations thereof can be used. In a particularly advantageous embodiment the material f rther comprises curing aids . Electrical resistance wires can for instance be envisaged here, wherein development of heat can occur to cause curing of the resin with which the knit is impregnated. One of the most important applications of the renovation or repair material according to the present invention is the repair of damaged pipes, for instance sewage pipes, but also transport pipes for oil and other chemicals, For said applications the knit is tubular and preferably provided with elastic foil layers. In addi ¬ tion, pulling wires can be included in the knitted tube with which the tube can be pulled into the pipe for repairing. The present invention further relates to a method for renovating or repairing objects, comprising of: a) providing a renovation or repair material comprising a knit of a strengthening material coated or impregnated with a synthetic resin; b) arranging the renovation or repair material at the location of the intended renovation or repair; c) shaping the renovation or repair material at least partly into the form of the object for renovating or repairing; and d) causing the resin to cure. This very general method can be used for any random object for renovating or repairing. Particularly recommended however according to the invention is the renovation or repair of pipes, such as sewage pipes, pressure pipes and the like. A method very suitable for this purpose comprises of : a) providing a renovation or repair material comprising a knit of a strengthening material m the form of a tube, sleeve or tubular lining coated or impregnated with a synthetic resin, on at least the inside of which an air- impermeable foil is situated; b) arranging the tubular renovation or repair material in the pipe for renovating or repairing at the location of the intended renovation or repair; c ) filling the tubular renovation or repair material with a fluid; and d ) causing the resin to cure. Filling of the tubular renovation or repair material can for instance take place by means of air or a liquid, such as water. Renovation is ~ understood to mean improving the condition of an object, for instance strengthening the wall of a sewer pipe. Repair is understood to mean the repair of damage, cracks and the like. A tubular renovation or repair material can already be knitted in tubular form. However, the starting point can instead be a flat knit from which a tubular structure is made by fixing together two edges of the knit by adhesion, stitching, knitting, needle punching and the like. Alternatively, the edges may not be fixed to each other but can be held together by the elastic foil. The ends are then preferably mutually overlapping. The diameter of the final tube can of course be adapted to the desired application. Frequently used diameters lie for instance between 150 and 800 mm. Such a tube is preferably obtained by folding a flat strengthening material and stitching together an overlap of about 100 mm. The elastic foil can optionally be chemically bound to the resin. The resin can be cured in different ways, both cold and ho . In this latter case use can for instance be made of hot air, steam, hot water, electrical current, UV light and the like. If desired, the elastic foil on the inside can be removed after the resin is cured. The invention further relates to a device for manufacturing a tubular renovation or repair material, comprising means for supplying a knit and means for forming a tube from the knit. If the tube is already provided with a resin during the manufacture thereof, the device further comprises means for impregnating or coating the knit with a resin. For special embodiments of the renovation or repair tube the device is further provided with means for introducing a foil tube into the tube. In a preferred embodiment the device comprises a supply unit for a knit, a folding machine for carrying the selvages of the supplied knit towards each other in or d er to form a tube, a stitching machine for mutually connecting the selvages of the knit to form a tube, a supply unit for carrying a foil into the formed tube, a discharge unit for the formed tube with foil and a fur ¬ ther processing device . If the objective is a renovation or repair tube provided with a resin, the further processing device comprises an impregnating device. Means can further be incorporated in the further processing device for arranging a protective sleeve round the tube. Finally, the further processing device can comprise a winding or a folding device . Both devices can also be placed directly after the tube-forming device. The other components of the further processing device are then omitted. A schematic view of a preferred embodiment of a device according to the invention is shown in Figure 3. From an unwinding frame a roll of strengthening material A is unrolled and supplied to a folding and laying device 2 which lays the selvages of the knit partly over each other, whereafter the selvages are stitched to each other by means of a stitching machine 1. Optionally supplied from an unwinding frame B is a foil tube which is carried into the tube of strengthening material formed in the folding and laying device 2. The whole is also already brought into a flat form by the folding and laying device, which flat form is discharged by discharge rollers 3 to a further processing device, which in the shown situation consists of a container 4 with resin for impregnating the strengthening material. The impregnated tube is subsequently calendered in rollers 5, whereafter it is carried through a container 6 having around it a plastic protective sleeve C optionally cut to the desired length. There are then two alternatives for further processing. From container 6 the renovation or repair tube which is pre-formed, impregnated and provided with a protective sleeve can either be carried to a laying-off frame 7 which makes thereof a package on a pallet D, or to a winder 8 which winds the material onto a roll. The embodiment of the manufacturing device shown here is only an example. Depending on the desired end product, devices for arranging and fixing additional protective materials can for instance also be included.

Claims: CLAIMS 1. Material for renovating or repairing objects, comprising a knit of strengthening material which is optionally already coated or impregnated with a curable synthetic resin. 2. Renovation or repair material as claimed in claim 1, characterized in that the object for renovating or repairing is a pipe and in the ready-to-use state the knit likewise has a tubular form. 3. Renovation or repair material as claimed in claim 1 or 2, characterized in that the knit is manufactured from glass fibre, carbon fibre, aramid fibre, thermoplastic fibre or combinations thereof. . Renovation or repair material as claimed in claim 1, 2 or 3 , characterized in that the material further comprises one or more layers of an elastic foil. 5. Renovation or repair material as claimed in claim 4, characterized in that the elastic foil is manufactured at least partly from polyethylene, polypropylene, polyamide, polyacrylate or combinations thereof. 6. Renovation or repair material as claimed in claims 1-5, characterized in that the material further comprises one or more additional strengthening materials. 7. Renovation or repair material as claimed in claim 6, characterized in that the additional strengthening material is chosen from cut fibres, mats, membranes, unidirectional threads or combinations thereof . 8. Renovation or repair material as claimed in claims 1-7, characterized in that the material further comprises curing aids. 9. Renovation or repair material as claimed in claim 8 , characterized in that the curing aids are formed by electrical resistance wires for causing heat to develop in the material. 10. Method for renovating or repairing objects, in particular pipes such as sewage pipes, pressure pipes and the like, comprising of: a) providing a renovation or repair material comprising a knit of a strengthening material coated or impregnated with a synthetic resin; b) arranging the renovation or repair material at the location of the intended renovation or repair; c) shaping the renovation or repair material at least partly into the form of the object for renovating or repairing; and d) causing the resin to cure . 11. Method as claimed in claim 10 for renovating or repairing pipes such as sewage pipes, pressure pipes and the like, comprising of: a) providing a renovation or repair material comprising a knit of a strengthening material in the form of a tube, sleeve or tubular lining coated or impregnated with a synthetic resin, on at least the inside of which an air- impermeable foil is situated; b) arranging the tubular renovation or repair material in the pipe for renovating or repairing at the location of the intended renovation or repair; c) filling the tubular renovation or repair material with a fluid; and d) causing the resin to cure. 12. Device for manuf cturing a tubular renovation or repair material as claimed in claims 2-9, comprising means for supplying a knit and means for forming a tube from the knit. 13. Device as claimed in claim 12, further comprising means for impregnating or coating the knit with a resi . 14. Device as claimed in claims 12 and 13, further provided with means for introducing a foil tube into the tube . 15. Device as claimed in claim 14, comprising a supply unit for a knit, a folding machine for carrying the selvages of the supplied knit towards each other in order to form a tube, a stitching machine for mutually connecting the selvages of the knit to form a tube, a supply unit for carrying a foil into the formed tube, a discharge unit for the formed tube with foil and a further processing device. 16. Device as claimed in claim 15, characterized in that the further processing device comprises an impregnating device for applying a resin in or on the knit. 17. Device as claimed in claim 15 or 16, characterized in that the further processing device comprises means for arranging a protective sleeve round the tube. 18. Device as claimed in claim 15, 16 or 17, characterized in that the further processing device (further) comprises a rolling-up device. 19. Device as claimed in claim 15, 16 or 17, characterized in that the further processing device (further) comprises a folding device.

Inventors: CLAEIJS ETIENNE, CLAEIJS, ETIENNE
Applicants: CLAEIJS ETIENNE, SYNCOGLAS SA NV, CLAEIJS, ETIENNE, N.V. SYNCOGLAS S.A.
Application year: 1997
Main classification: F16L55
IPC codes: F16L55