Single-phase solution molding
AssigneeNIKE, Inc.
InventorsJeffrey E. Darland, Ryan Alvin Mace
Life of this patent
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Abstract
Aspects hereof provide methods for molding a single-phase solution comprised of a polymer composition and a gas. The polymer composition and the gas are maintained under pressure during the molding operation to prevent a cellular structure from being formed by the dissolved gas in the polymer composition coming out of solution. The mold cavity in which the single-phase solution is introduced for molding purposes is pressurized to a mold pressure that is sufficient to maintain the single-phase solution as a single-phase solution as the mold cavity is filled. Subsequent to filling the mold cavity with the single-phase solution under pressure, the resulting article may be exposed to a reduction in pressure causing the entrapped gas to form a cellular structure.
Claims17
A method of molding a footwear component using a single-phase solution, the method comprising:
- pressurizing a mold cavity of a footwear component mold above atmospheric pressure to a mold pressure, wherein the mold pressure is at least a pressure to maintain a single-phase solution as a single phase, wherein the single-phase solution is comprised of a polymer composition and a gas;
- injecting the single-phase solution into the mold cavity;
- maintaining at least the mold pressure in the mold cavity during the injecting of the single-phase solution;
- and
- cooling the polymer composition below a glass transition temperature of the polymer composition to form the footwear component,
- wherein the mold comprises a pressure regulator that maintains at least the mold pressure as the single-phase solution is injected into the mold cavity and wherein the mold cavity remains a constant volume,
- wherein the gas is selected from one of carbon dioxide (CO2) and nitrogen (N2).
A method of molding a footwear component using a single-phase polymer and gas solution, the method comprising:
- mixing a polymer composition above a glass transition temperature of the polymer composition with a gas above atmospheric pressure to form a single-phase solution;
- pressurizing a first mold cavity of a mold above atmospheric pressure to a mold pressure, wherein the mold pressure is at least a pressure to maintain the single-phase solution as a homogeneous solution;
- while maintaining the first mold cavity at least at the mold pressure, injecting the single-phase solution into the first mold cavity;
- depressurizing the first mold cavity below the molding pressure;
- and
- cooling the polymer composition below the glass transition temperature to form an article in the first mold cavity,
- wherein the mold comprises a pressure regulator that maintains at least the mold pressure as the single-phase solution is injected into the mold cavity and wherein the mold cavity remains a constant volume.
A method of molding a footwear component using a single-phase solution, the method comprising:
- pressurizing a mold cavity of a footwear component mold above atmospheric pressure to a mold pressure, wherein the mold pressure is at least a pressure to maintain a single-phase solution as a single phase, wherein the single-phase solution is comprised of a polymer composition and a gas;
- injecting the single-phase solution into the mold cavity;
- maintaining at least the mold pressure in the mold cavity during the injecting of the single-phase solution;
- and
- cooling the polymer composition below a glass transition temperature of the polymer composition to form the footwear component,
- wherein the mold comprises a pressure regulator that maintains at least the mold pressure as the single-phase solution is injected into the mold cavity and wherein the mold cavity remains a constant volume,
- wherein the polymer composition is comprised of a polymer selected from one of polyurethane and ethylene-vinyl acetate.
Dependencies are inferred from the claim text.