Rapid solidification of molded products

A method of solidifying a molten material, comprising:

• providing a mold including a fluid permeable material, and providing nozzles arranged in voids in the fluid permeable material;
• arranging the molten material in a cavity defined by the mold;
• and
• delivering a cooling fluid to the fluid permeable material via the nozzles such that the cooling fluid permeates through the fluid permeable material, cools the molten material, and solidifies the molten material to a) form a solidified outer skin at a surface of the molten material, b) increase a thickness of the solidified outer skin, or c) both a) and b);
• wherein the cooling fluid is delivered successively through the nozzles such that the molten material is solidified in a desired direction through the cavity;
• and
• wherein the cooling fluid is delivered to the mold at a delivery pressure that is intentionally varied;
• and wherein the delivery pressure is varied as a function of the thickness of the solidified outer skin.

A molding system comprising:

• a mold including a fluid permeable material that defines a mold cavity and is permeable to a cooling fluid, the mold being configured to mold a molten material arranged in the mold cavity;
• and
• a fluid delivery system in fluid communication with the fluid permeable material, and configured to deliver the cooling fluid to the fluid permeable material;
• wherein when the molten material is arranged in the mold cavity, the fluid delivery system includes a controller configured to deliver the cooling fluid to the fluid permeable material at a delivery pressure that is intentionally varied, such that the cooling fluid permeates through the fluid permeable material to cool and solidify the molten material arranged in the mold cavity to a) form a solidified outer skin at a surface of the molten material, b) increase a thickness of the solidified outer skin, or c) both a) and b);
• and wherein the controller is configured to vary the delivery pressure as a function of the thickness of the solidified outer skin.