Method of manufacturing using resin transfer molding

Abstract

A method for molding an article having an upper portion, a lower portion, and an insert located between the upper portion and the lower portion, wherein the article is molded as a single, unitary piece with no seams or discontinuities located between the upper portion and the lower portion, includes providing a first semi-rigid membrane removably mounted to a first rigid housing to define a first fluid tight chamber therein, providing a mold plenum defined at least in part by the first semi-rigid membrane removably mounted to the first rigid housing, filling the first fluid tight chamber with a substantially non-compressible backing fluid to support the first semi-rigid membrane during injection of resin, positioning the insert in the mold plenum, providing fibrous reinforcing material within the mold plenum, the fibrous reinforcing material including portions positioned between the first semi-rigid membrane and the insert, the fibrous reinforcing material portions positioned between the first semi-rigid membrane and the insert being in contact with the insert, injecting resin under pressure into the mold plenum such that the resin envelops the fibrous reinforcing material and the insert, distributing a resulting injection pressure by the backing fluid, and curing the resin by heating the backing fluid to produce the molded article.

1 . (canceled) 
   
   
       2 . A method for molding an article having an upper portion, a lower portion, and an insert located between the upper portion and the lower portion, wherein the article is molded as a single, unitary piece with no seams or discontinuities located between the upper portion and the lower portion, the method comprising:
 providing a first semi-rigid membrane removably mounted to a first rigid housing to define a first fluid tight chamber therein;   providing a mold plenum defined at least in part by the first semi-rigid membrane removably mounted to the first rigid housing;   filling the first fluid tight chamber with a substantially non-compressible backing fluid to support the first semi-rigid membrane during injection of resin;   positioning the insert in the mold plenum;   providing fibrous reinforcing material within the mold plenum, the fibrous reinforcing material including portions positioned between the first semi-rigid membrane and the insert, the fibrous reinforcing material portions positioned between the first semi-rigid membrane and the insert being in contact with the insert;   injecting resin under pressure into the mold plenum such that the resin envelops the fibrous reinforcing material and the insert;   distributing a resulting injection pressure by the backing fluid; and   curing the resin by heating the backing fluid to produce the molded article.   
   
   
       3 . The method of  claim 2 , wherein the molded article is a boat. 
   
   
       4 . The method of  claim 2 , wherein the insert includes a buoyant material. 
   
   
       5 . The method of  claim 4 , wherein the buoyant material includes foam. 
   
   
       6 . The method of  claim 2 , wherein the insert includes an elongated portion including a top surface, a bottom surface, and a side surface, wherein at least one of an upper surface and a lower surface of the article is formed by portions of the resin enveloped fibrous reinforcing material that cover at least one of the top surface and the bottom surface of the insert, respectively, and an elongate support structure of the article is formed by portions of the resin enveloped fibrous reinforcing material that cover the side surface of the insert. 
   
   
       7 . The method of  claim 2 , further comprising providing a finish layer within the mold plenum to form a finished outer coat on an exterior surface of at least the upper portion and the lower portion of the article. 
   
   
       8 . The method of  claim 7 , wherein the finish layer includes gel coat.