Method and apparatus for molding composite articles
View Patent ↗A method of molding a composite article includes providing a first floating mold that has a fluid backing, wherein the fluid defining the fluid backing is stored in a fluid chamber positioned beneath the first floating mold, providing a second non-floating mold that does not include a fluid backing, and sealing the first floating mold to the second non-floating mold to define a molding chamber thereinbetween.
1. A method of molding an article having a shape, the method comprising:
providing a support housing defining a fluid chamber;
providing a substantially non-compressible heat-conductive fluid within the fluid chamber;
providing a first mold member, at least a portion of the first mold member supported by the support housing, the first mold member defining an upper molding surface for generally opposing the article to be molded, the first mold member defining a lower surface, wherein at least a portion of the lower surface is configured to be in contact with the fluid located within the fluid chamber such that thermal changes within the fluid in the fluid chamber are communicated from the lower surface to the upper molding surface through the first mold member;
providing a polymeric sheet defining a second mold member, the polymeric sheet defining an upper surface that is to be generally at atmospheric pressure and a lower molding surface for generally opposing the article to be molded, the lower molding surface of the polymeric sheet configured to cooperate with the upper molding surface of the first mold member to form a molding plenum for molding the article, the polymeric sheet vacuum sealed with respect to the first mold member in forming the molding plenum;
drawing down the polymeric sheet with respect to the upper molding surface of the first mold member using vacuum, such that, as vacuum is applied, the polymeric sheet deforms to generally conform to the shape of the article to be molded; and
injecting molding resin into the molding plenum for forming the article, wherein the lower molding surface of the polymeric sheet directly contacts the molding resin in the molding plenum in forming the article.
2. A method according to claim 1 , wherein the polymeric sheet includes nylon.
3. A method according to claim 1 , wherein the polymeric sheet has a thickness between about 5 mils and 25 mils.
4. A method according to claim 3 , wherein the polymeric sheet has a thickness between about 7 mils and 20 mils.
5. A method according to claim 4 , wherein the polymeric sheet has a thickness of about 8 mils.
6. A method according to claim 1 , wherein the molding resin is injected into the molding plenum by an injection port provided through the polymeric sheet.
7. A method according to claim 1 , wherein the substantially non-compressible heat-conductive fluid is water.
8. A method according to claim 1 , further comprising controlling the temperature of the fluid within the fluid chamber through a temperature control system.