Formation and properties of cellular foam fibrous material

A foaming process for converting fibrous material into a cellular foam structure, comprising:

• mixing fibrous material and a solvent-based binding agent to form a mixture;
• saturating the mixture with a pressurized gas to form a pressurized gas-saturated mixture;
• expanding the gas-saturated mixture by reducing the pressure of the pressurized gas to form an expanded mixture with voids in the mixture;
• and
• curing the expanded mixture to set the fibrous material and drive off the solvent to form a stable cellular foam structure having cushioning properties, wherein the solvent comprises water, methanol, acetone, denatured alcohol, D-limonene, toluene, xylene or dimethyl sulfoxide.

A foaming process for converting fibrous material into a cellular foam structure, comprising:

• mixing fibrous material and a solvent-based binding agent to form a mixture;
• saturating the mixture with a pressurized gas to form a pressurized gas-saturated mixture;
• expanding the gas-saturated mixture by reducing the pressure of the pressurized gas to form an expanded mixture with voids in the mixture;
• and
• curing the expanded mixture to set the fibrous material and drive off the solvent to form a stable cellular foam structure having cushioning properties, wherein the binding agent comprises natural rubber, thermal plastic urethane, starch, dextrin, animal glue, casein adhesives or synthetic emulsions.

A batch foaming process for converting fibrous material into a cellular foam structure, comprising:

• mixing fibrous material and a solvent-based binding agent to form a mixture;
• placing the mixture into a mold;
• placing the mold into a pressure vessel, wherein the mold comprises holes that allow the exchange of pressure and solvent between the mixture and the pressure vessel and constrains the expansion of the mixture;
• pressurizing the pressure vessel to saturate the mixture with an inert gas to form a gas-saturated mixture and foam the mixture in the mold;
• releasing the pressure in the pressure vessel to create voids in the foamed fibrous material;
• and
• curing the foamed fibrous material to preserve the foamed structure and cross-linking the fibers of the fibrous material to provide a stable network of fibrous material having cushioning properties.

A continuous foaming process for converting fibrous material into a cellular foam structure, comprising:

• mixing a solvent-based binding agent and fibrous material to form a mixture;
• feeding the mixture into a screw driven extruder;
• saturating the mixture in the extruder with high pressure inert gas;
• extruding the saturated mixture from an exit nozzle of the extruder where the mixture undergoes primary expansion through pressure drop;
• and
• transferring the expanded mixture into a vacuum tunnel under controlled temperature where the mixture undergoes secondary expansion, curing and stabilizing of the cellular structure of the foamed product.