Wrinkle control method and tool therefor

Abstract

A method for forming a laminate component, the method comprising the steps of: a) providing a tool having a moulding surface; b) arranging a stack of ply layers on the moulding surface of the tool; and c) moulding the stack of ply layers over the moulding surface in a moulding process, wherein the tool has a wrinkle control feature in its moulding surface for managing the development of wrinkle in the ply layers during the moulding process, and wherein the wrinkle control feature cooperates with the stack of ply layers during the moulding process to produce a local surface undulation in a nominal surface of the laminate component nearest the tool to either prevent wrinkling in the ply layers or initiate wrinkling in one or more of the ply layers at a predetermined location. Also, a tool having a wrinkle control feature, and a laminate component so formed.

1 . A method for forming a laminate component, the method comprising the steps of:
 a) providing a tool having a moulding surface;   b) arranging a stack of ply layers on the moulding surface of the tool; and   c) moulding the stack of ply layers over the moulding surface in a moulding process,   wherein the moulding surface is shaped such that the surface of the laminate component nearest the tool when the stack of ply layers are arranged on the moulding surface of the tool substantially conforms to a nominal surface of the laminate component, and   wherein the tool has a wrinkle control feature in its moulding surface for managing the development of wrinkle in the ply layers during the moulding process, and wherein the wrinkle control feature cooperates with the stack of ply layers during the moulding process to produce a local surface undulation in the surface of the laminate component nearest the tool that deviates from the nominal surface of the laminate component to either prevent wrinkling in the ply layers or initiate wrinkling in one or more of the ply layers at a predetermined location.   
     
     
         2 . A method according to  claim 1  wherein the wrinkle control feature comprises a recess extending into the moulding surface of the tool. 
     
     
         3 . A method according to  claim 1  wherein the wrinkle control feature comprises a protrusion extending out from the moulding surface of the tool. 
     
     
         4 . A method according to  claim 1  wherein the wrinkle control feature provides an increased path length over a region of the moulding surface which accommodates excess material in at least one of the ply layers. 
     
     
         5 . A method according to  claim 1  wherein the wrinkle control feature accommodates sufficient excess material in at least one of the ply layers to prevent wrinkling of the ply. 
     
     
         6 . A method according to  claim 1  wherein the wrinkle control feature initiates wrinkling in at least one of the ply layers at a predetermined location adjacent the wrinkle control feature. 
     
     
         7 . A method according to  claim 1  wherein the wrinkle control feature initiates wrinkling in at least one of the ply layers at a predetermined location remote from the wrinkle control feature. 
     
     
         8 . A method according to  claim 1  wherein the wrinkle control feature has a height which varies across its extent. 
     
     
         9 . A method according to  claim 1  wherein the wrinkle control feature has a width which varies across its extent. 
     
     
         10 . A method according to  claim 1  wherein the wrinkle control feature is substantially dart or arrowhead shaped. 
     
     
         11 . A method according to  claim 1  wherein the wrinkle control feature extends to an edge of the moulding surface of the tool. 
     
     
         12 . A method according to  claim 1  comprising a plurality of wrinkle control features. 
     
     
         13 . A method according to  claim 12  wherein at least some of the wrinkle control features are adjacent one another. 
     
     
         14 . A method according to  claim 1  wherein the moulding surface has a complex three-dimensional shape. 
     
     
         15 . A method according to  claim 1  wherein the tool is elongate and has a longitudinal direction, and the shape of the moulding surface varies in the longitudinal direction. 
     
     
         16 . A method according to  claim 1  wherein the tool is a male mould tool. 
     
     
         17 . A method according to  claim 1  performed repeatedly using the same or a similar tool to produce a plurality of substantially identical laminate components. 
     
     
         18 . A method according to  claim 1  wherein the laminate component so formed has a complex three-dimensional shape. 
     
     
         19 . A method according to  claim 1  wherein the laminate component so formed has an L-section or a C-section. 
     
     
         20 . A method according to  claim 1  wherein the laminate component so formed is an aircraft component. 
     
     
         21 . A method according to  claim 20  wherein the aircraft component is a wing spar.