Method for molding capsules
AssigneeWarner-Lambert Company
InventorsIvan Tomka, Fritz Wittwer
Life of this patent
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Abstract
A method of producing capsules of a moldable hydrophilic polymer composition, preferably gelatin, using a combination of an injection molding device with a microprocessor to precisely control the conditions of time, temperature, pressure and water content of the hydrophilic polymer composition, in a cyclic molding process.
Claims16
The method of manufacturing a shaped product from a hydrophilic polymer and water mixture having no phase separation of the water from the hydrophilic polymer-water mixture at a water content of between about 5 and 25% by weight of the hydrophilic polymer and having a certain glass transition temperature range, comprising the steps of:
- (a) mixing the polymer with water in a predetermined amount between about 5 and 25% by weight of the hydrophilic polymer;
- (b) heating the hydrophilic polymer with said water while maintaining said predetermined water content to form a melt;
- (c) further heating the hydrophilic polymer melt and water to a temperature to dissolve the melt in the water and achieve a homogeneous dispersion on a molecular level while maintaining said predetermined water content;
- (d) injecting the dissolved hydrophilic polymer melt into a mold cavity while maintaining said predetermined water content;
- (e) cooling the hydrophilic polymer melt in said mold to form a molded product at a temperature below the glass transition temperature range of the hydrophilic polymer while maintaining said predetermined water content;
- and
- (f) ejecting the molded product of said hydrophilic polymer from said mold.
The method of manufacturing a shaped product from a hydrophilic polymer and water mixture having no phase separation of the water from the hydrophilic polymer-water mixture at a water content of between about 5 and 25% by weight of the hydrophilic polymer and having a certain glass transition temperature range, comprising the steps of:
- (a) heating the hydrophilic polymer with water of a predetermined amount between about 5 and 25% by weight of the hydrophilic polymer to form a melt;
- (b) maintaining said predetermined water content during said heating;
- (c) further heating the hydrophilic polymer melt and water to a temperature to dissolve the melt in the water and achieve a homogeneous dispersion on a molecular level while maintaining said predetermined water content;
- (d) injecting the dissolved hydrophilic polymer melt into a mold cavity while maintaining said predetermined water content;
- (e) cooling the hydrophilic polymer melt in said mold to form a molded product at a temperature below the glass transition temperature range of the hydrophilic polymer while maintaining said predetermined water content;
- and
- (f) ejecting the molded product of said hydrophilic polymer from said mold.
The method of manufacturing a shaped product from a gelatin and water mixture having no phase separation of the water from the gelatin-water mixture at a water content of between about 5 and 25% by weight of the gelatin and having a certain glass transition temperature range comprising the steps of:
- (a) feeding the gelatin with a predetermined amount of water of between about 5 and 25% by weight of the gelatin into the input end of an extruder;
- (b) heating the gelatin while maintaining said predetermined water content to form a melt;
- (c) further heating the gelatin melt and water as it moves toward the exit end of the extruder to a temperature above the glass transition temperature range of the gelatin to dissolve the gelatin melt in the water and achieve a homogeneous dispersion on a molecular level while maintaining said predetermined water content;
- (d) injecting the dissolved gelatin melt directly into the cavity of an injection mold while maintaining said predetermined water content;
- (e) cooling the gelatin melt in said mold to form a molded product at a temperature below the glass transition temperature range of the gelatin while maintaining said predetermined water content;
- and
- (f) ejecting the molded product of said gelatin from said mold.
The method of manufacturing a shaped product from a hydrophilic polymer and water mixture having no phase separation of the water from the hydrophilic polymer-water mixture at a water content of between about 5 and 25% by weight of the hydrophilic polymer and having a certain glass transition temperature range, comprising the steps of:
- (a) mixing the polymer with water in a predetermined amount between about 5 and 25% by weight of the hydrophilic polymer;
- (b) heating the hydrophilic polymer in said water while maintaining the water content between said 5 and 25% to form a melt;
- (c) further heating the hydrophilic polymer melt and water to a temperature to dissolve the melt in the water and achieve a homogeneous dispersion on a molecular level while maintaining the water content between said 5 and 25%;
- (d) injecting the dissolved hydrophilic polymer melt into a mold cavity while maintaining the water content between said 5 and 25%;
- (e) cooling the hydrophilic polymer melt in said mold to form a molded product at a temperature below the glass transition temperature range of the hydrophilic polymer while maintaining the water content between said 5 and 25%;
- and
- (f) ejecting the molded product of said hydrophilic polymer from said mold.
Dependencies are inferred from the claim text.