Method for forming convex non-extractable formed pieces made of a composite material
AssigneeSociete Nationale Industrielle et Aerospatiale
InventorsSauveur A. Azzara, Herve G. F. Coutant
Life of this patent
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Abstract
In order to form shaped convex non-extractable pieces made of a composite material, a partially polymerized (stage B) preform strip (10) is placed in a forming tool (16) along a cylindrical surface having one rectilinear generator and one convex directrix curve whose shape coincides with the shape of the piece to be embodied. The particular section of the piece is obtained with the aid of an inflatable bladder (22) pressing the preform strip against a forming die (24). In this way, the area contractions are kept to a minimum, which avoids may undulations of the fibers and any falling off of the mechanical characteristics of the pieces which may accordingly arise.
Claims9
A method for forming a non-extractable formed piece made of composite material from a flat preform strip including fibers preimpregnated with resin and orientated along at least two different non-longitudinal directions, the method comprising the steps of:
- placing the preform strip in a forming tool along a cylindrical surface having one rectilinear generator and one convex directrix curve which has the shape of the piece to be formed, said tool including a forming die having a formed surface which has a section complementary to the piece to be formed;
- applying a central portion of the preform strip against the formed surface of the forming die, by means of an inflatable bladder placed on the side of the preform strip with respect to the formed surface opposite said central portion;
- forming an outer portion of the piece by moving a mobile hoop of the forming tool substantially parallel to said rectilinear generator, whereby said outer portion slides along said mobile hoop and is returned against the formed surface;
- and
- solidifying the resin.
Dependencies are inferred from the claim text.