Limp, Elongate Element with Glass Staple Fibres

Abstract

A rope for reinforcing joints in fibre-reinforced composite structures is described. The rope comprises chopped reinforcement fibres and retaining means for retaining the chopped fibres in a rope-shape. Further, composite structures utilising such ropes as filler elements are described as well as an apparatus for manufacturing such ropes.

1 . A rope for reinforcing joints in fibre-reinforced composite structures characterised in that the rope comprises
 chopped reinforcement fibres in form of glass fibres, which predominantly have a random orientation, and which have an average length between 0.5 cm and 5 cm, and   retaining means for retaining the chopped fibres in a rope-shape.   
     
     
         2 . A rope according to  claim 1 , wherein said predominantly randomly oriented chopped reinforcement fibres are entangled. 
     
     
         3 . A rope according to  claim 1 , wherein the retaining means is an open-structured tube, such as a mesh tube, and wherein the chopped fibres are retained in the tube. 
     
     
         4 . A rope according to  claim 1 , wherein the retaining means is a tackifier. 
     
     
         5 . A rope according to  claim 1 , wherein the average length of the chopped fibres is between 1 cm and 4 cm, advantageously around 2.5 cm. 
     
     
         6 . A rope according to  claim 1 , wherein the rope has a diameter of at least 5 mm. 
     
     
         7 . A use of a rope according to  claim 1  as a filling material in a composite structure or to prevent the formation of resin pools in a resin transfer moulding process for manufacturing a composite structure. 
     
     
         8 . A composite structure, such as a wind turbine blade, made of a fibre-reinforcement material embedded in a polymer matrix and comprising a rope according to  claim 1 , the rope being embedded in the polymer matrix, e.g. with the rope being arranged at or in a joint of the composite structure. 
     
     
         9 . A method of manufacturing a rope comprising chopped reinforcement fibres, the method comprising the steps of:
 a) providing chopped reinforcement fibres, in form of glass fibres, which predominantly have a random orientation, and which have an average length between 0.5 cm and 5 cm,   b) providing retaining means for retaining the chopped reinforcement fibres, and   c) shaping the chopped reinforcement fibres and retaining means to a rope.   
     
     
         10 . A method according to  claim 9 , wherein step a) comprises chopping a fibre reinforcement material into chopped reinforcement fibres. 
     
     
         11 . A method according to  claim 9 , wherein steps b) and/or c) comprises the step of feeding the chopped reinforcement material into a mesh tube. 
     
     
         12 . An apparatus for manufacturing a rope comprising chopped reinforcement fibres, wherein the apparatus comprises:
 a chopping device for chopping reinforcement fibres in form of glass fibres into chopped reinforcement fibres, which have an average length between 0.5 cm and 5 cm,   a rope forming device for providing retaining means for retaining the chopped reinforcement fibres and shaping the chopped reinforcement fibres to a rope-shape, and   a filling device for feeding the chopped reinforcement fibres to the rope forming device, wherein the filling device is adapted to receive said chopped reinforcement fibres from the chopping device, and the filling device further being connected to the rope forming machine so as to feed said chopped reinforcement fibres to said rope forming machine, and wherein the apparatus further comprises means for randomly orienting the chopped reinforcement fibres.   
     
     
         13 . An apparatus according to  claim 12 , wherein the rope forming device comprises a braiding device for braiding one or more wrap wires around the chopped reinforcement fibres. 
     
     
         14 . An apparatus according to  claim 12 , wherein the feeding device comprises a screw compactor for compacting the chopped reinforcement fibres. 
     
     
         15 . An apparatus according to  claim 12 , wherein the filling device further comprises a variable oriented, e.g. rotatable, nozzle for randomising the orientation of chopped reinforcement fibres fed to the rope shaping device.