Insulation materials for a heat and sound insulated structure and methods of forming with a mold that is gas and liquid permeable

A method of forming an insulation package that is configured to limit the transfer of at least one of heat and sound, the method comprising the steps of:

• forming a slurry comprising a liquid and an insulation material in a vessel;
• providing an envelope inside a sealed chamber, wherein the envelope is gas-permeable and permeable to the liquid and defines an envelope interior cavity, and wherein providing the envelope inside the sealed chamber includes providing the envelope within a mold, and further wherein the mold is gas-permeable and permeable to the liquid;
• fluidly coupling the envelope interior cavity with the vessel;
• drawing at least a portion of the slurry from the vessel into the envelope interior cavity by decreasing a pressure within the chamber to less than ambient pressure;
• and
• drawing at least a portion of the liquid from the slurry in the envelope interior cavity through the envelope, and
• wherein at least a portion of the insulation material is retained within the envelope interior cavity to form an insulation material filled envelope.