Vacuum resin impregnation process

A vacuum impregnation process for producing a resin-fiber composite which comprises:

• forming an assembly comprising a fiber reinforcement layer, a porous parting film, a bleeder layer, a non-porous seal film, and a breather cloth, on the surface of a tool,
• placing a vacuum bag over the assembly and sealing the vacuum bag to the surface of the tool,
• applying a vacuum to the zone beneath said vacuum bag,
• feeding liquid resin from a container to an inlet at one end of said assembly,
• spreading the liquid resin flow at the inlet the entire width of the fiber reinforcement layer transversely from edge to edge thereof,
• passing the spreaded liquid resin flow longitudinally into and through the bleeder layer,
• and then passing the liquid resin from said bleeder layer through said porous parting film and into and through said fiber reinforcement layer to impregnate same,
• providing an extension of said breather cloth at the other end of said assembly and terminating at a vacuum outlet, said bleeder layer being in fluid communication with said breather cloth and said breather cloth extension at said other end of said assembly, and
• passing excess liquid resin through said breather cloth extension,
• the resin gel time being controlled so that the resin gels in the fiber reinforcement layer and in the breather cloth extension before any resin reaches the vacuum outlet.

A vacuum impregnation process for producing a resin-fiber composite which comprises:

• applying a carbon cloth reinforcement layer on the surface of a tool,
• applying a porous parting film over said reinforcement layer,
• placing a fiberglass bleeder layer over said porous parting film,
• applying a mechanical resin flow path means over the bleeder layer,
• applying a non-porous seal film over said mechanical flow path means,
• positioning a breather cloth over said non-porous seal film,
• placing a liquid resin spreader adjacent one end of said carbon cloth reinforcement layer and said fiberglass bleeder layer, for spreading liquid resin flow across the entire width of the carbon cloth reinforcement layer from edge to edge thereof,
• applying a vacuum bag over the entire assembly and sealing said vacuum bag along sealing edges on the tool surface, adjacent said carbon cloth reinforcement layer,
• feeding liquid resin from a container to an inlet in said liquid resin spreader,
• passing the spreaded liquid resin flow longitudinally into and through said mechanical flow path means and said fiberglass bleeder layer,
• passing the liquid resin from said bleeder layer through said porous parting film and into and through said carbon cloth reinforcement layer to impregnate same,
• providing a hole in said non-porous seal film adjacent the other end of said carbon cloth reinforcement layer, to afford liquid resin communication between said bleeder layer and said breather cloth,
• providing an extension of said breather cloth, said extension terminating at a vacuum outlet,
• passing excess liquid resin from said carbon cloth reinforcement layer and from said bleeder layer through said hole in said non-porous separator film, and through the fiberglass extension of said bleeder,
• the resin gel time being controlled so that the resin gels in the carbon cloth reinforcement layer and in the breather cloth extension before any resin reaches the vacuum outlet.

A process for vacuum impregnation of a fiber reinforcement on a supporting block to produce a sandwich panel which comprises:

• providing a supporting block having grooves in the surfaces thereof,
• placing a dry fiber reinforcement layer on said block,
• placing the block covered with said fiber reinforcement layer on a tool,
• positioning a porous separator film over said fiber reinforcement layer,
• applying a bleeder layer over said porous film,
• placing a non-porous seal film over said bleeder layer,
• placing a layer of breather cloth over the entire assembly,
• applying a vacuum bag over the entire assembly,
• providing a source of liquid resin and a resin inlet line to one end of the assembly and communicating with said bleeder layer,
• providing a source of vacuum communicating with said vacuum bag via a vacuum outlet line adjacent the other end of said assembly, the outlet port of said vacuum outlet line communicating with said layer of breather cloth and said bleeder layer, both extending beyond the outer end of said seal film,
• drawing a vacuum to permit passage of the liquid resin through said resin inlet line,
• flowing said resin through a path defined by said bleeder layer,
• flowing said resin from said bleeder layer through and along said fiber reinforcement layer, and
• flowing said liquid resin from said fiber reinforcement layer into said grooves of said supporting block and from said grooves back into said fiber reinforcement layer.

A process for vacuum impregnation of a fiber reinforcement which comprises:

• placing a runner plate on a tool, said runner plate containing a plurality of runner channels in the lower surface thereof, and a plurality of outlet holes in the upper surface and communicating with said runner channels,
• applying a dry fiber reinforcement layer on said runner plate,
• placing a pressure plate on said fiber reinforcement layer, said pressure plate having a plurality of holes therein offset from the outlet holes in the lower runner plate,
• applying a bleeder layer over said pressure plate,
• applying a vacuum bag over the entire assembly,
• providing a source of liquid resin and a resin inlet line in communication with the runner channels in said runner plate,
• providing a source of vacuum communicating with said vacuum bag, and
• drawing a vacuum and permitting passage of the liquid resin through said resin inlet line, said runner channels and the outlet holes in said runner plate, through said fiber reinforcement layer to provide substantially uniform resin impregnation therein, into and through the offset holes in said pressure plate, and into said bleeder layer.

In a process for vacuum impregnation of a fiber reinforcement with a resin to produce a resin-fiber composite, the steps which comprise:

• applying a dry fiber reinforcement layer on a tool,
• positioning a bleeder layer over said fiber reinforcement layer,
• applying a vacuum bag over the entire assembly,
• providing a source of liquid resin and a resin inlet line to the assembly and communicating with said bleeder layer,
• providing a source of vacuum communicating with said vacuum bag,
• drawing a vacuum to permit passage of the liquid resin through said resin inlet line,
• spreading the resin flow from the resin inlet line for the full width of said fiber reinforcement layer transversely from edge to edge thereof, and
• flowing said liquid resin along a flow path through said bleeder layer and into and through the fiber reinforcement layer longitudinally therein from one end thereof to the opposite end of the fiber reinforcement layer to impregnate same uniformly across the length and width of the fiber reinforcement layer.