System, valve, and method for liquid resin infusion

A method of infusing liquid resin into a sheet of fibrous material, the method comprising:

• evacuating gaseous contaminants from a sheet of fibrous material, covered by a non-permeable bladder sealed to a tool about the sheet of fibrous material, through a permeable media layer to an outlet;
• flowing liquid resin from an inlet through a permeable media layer interposed between the sheet of fibrous material and the non-permeable bladder;
• infusing the liquid resin into the sheet of fibrous material from the permeable media layer;
• and
• selectively adjusting a permeability of the permeable media layer such that the permeability of the permeable media layer while evacuating the gaseous contaminants is higher than while flowing and infusing the liquid resin.

A valve for adjusting a permeability of a permeable media layer, the valve comprising:

• a gap formed in the permeable media layer;
• a non-permeable bladder directly adjacent the permeable media layer and traversing the gap of the permeable media layer;
• a rigid cap sealed to the non-permeable bladder over the gap, wherein an interior cavity is defined between the rigid cap and the non-permeable bladder;
• a vacuum fluidly coupleable with the rigid cap and selectively operable to reduce a pressure (P1) in the interior cavity to below atmospheric pressure to urge the non-permeable bladder out of the gap of the permeable media layer;
• and
• a vent fluidly coupled with the rigid cap and selectively operable to vent the interior cavity to the atmosphere to urge the non-permeable bladder into the gap of the permeable media layer.