CPC F01D 5/282 (2013.01) [B29C 70/025 (2013.01); B29C 70/682 (2013.01); F01D 5/147 (2013.01); B29K 2105/0845 (2013.01); B29K 2105/16 (2013.01); B29K 2995/0097 (2013.01); B29L 2031/082 (2013.01); F05D 2220/36 (2013.01); F05D 2300/6012 (2013.01); F05D 2300/603 (2013.01); F05D 2300/612 (2013.01)] | 11 Claims |
1. A preform for a composite blade, obtained by three-dimensional weaving, comprising:
a first longitudinal section, configured to form a blade root, and
a second longitudinal section, extending from the first longitudinal section, configured to form a portion of an airfoil,
wherein the first longitudinal section has a first thickness at its upper end,
wherein the second longitudinal section includes at least one set-back zone, forming a recess in the lateral surface of the preform, having a thickness at least three times less than the first thickness, the total surface of the set-back zone occupying at least 50% of the surface of the second longitudinal section,
wherein the second longitudinal section includes a transition zone, provided between the first longitudinal section and the set-back zone, the transition zone having a thickness decreasing in the direction of the set-back zone, and
wherein the transition zone has a layer exit rate greater than 5 layer exits per 100 mm.
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