Method For Making Molded Fiber Bottles

Abstract

A method for forming a molded fiber bottle by pressurizing a flexible plastic bag in a molded pulp bottle preform to press the bag against the inner wall of the molded pulp bottle preform and thereby assist dewatering of the preform and form an internal plastic liner in the molded pulp bottle preform such that the liner provides a barrier function for the bottle and the resulting bottle produced by the method.

1 . A method of producing a pulp molded article having a plastic liner, the method comprising (1) forming a wet pulp layer on a surface of a mold cavity; (2) heating the wet pulp layer, (3) dewatering the wet pulp layer by pressurizing a flexible plastic bag and forcing the bag to press the wet pulp layer against the surface of the mold cavity and form the plastic liner on the pulp layer, wherein the flexible plastic bag is of the same dimension with the inner volume of the molded pulp. 
     
     
         2 . The method of  claim 1  wherein the flexible plastic bag is forced into contact with the pulp layer by maintaining a gauge pressure of at least 50 mm Hg within the flexible plastic bag. 
     
     
         3 . The method of  claim 2  wherein the gauge pressure is in the range of 250 mm Hg to 1550 mm Hg. 
     
     
         4 . The method of  claim 2  wherein the pressure within the flexible plastic bag is created by a pressurized gas at a pressure in the range of 2 MPa to 4 MPa. 
     
     
         5 . The method of  claim 1  wherein the forming step (1) comprises (4) feeding a pulp slurry to a surface of a mold having drainage channels for removing water contained in the pulp slurry; and (5) removing water by suction through the drainage channels to cause pulp of the pulp slurry to deposit on the surface of the mold cavity. 
     
     
         6 . The method of  claim 1  wherein the forming step (1) comprises arranging a wet paperboard on the surface of the mold cavity. 
     
     
         7 . The method of  claim 1  further comprising attaching a finish to the pulp molded article. 
     
     
         8 . The method of  claim 7  wherein the finish is an induction seal tab or a re-closable finish with a cap. 
     
     
         9 . A product made by the method of  claim 1 . 
     
     
         10 . A product made by the method of  claim 2 . 
     
     
         11 . A product made by the method of  claim 3 . 
     
     
         12 . A product made by the method of  claim 4 . 
     
     
         13 . A product made by the method of  claim 5 . 
     
     
         14 . A product made by the method of  claim 6 . 
     
     
         15 . A product made by the method of  claim 7 . 
     
     
         16 . A product made by the method of  claim 8 . 
     
     
         17 . A method of producing a pulp molded article having a plastic liner, the method comprising (1) forming a wet pulp layer on a surface of a mold cavity; (2) heating the wet pulp layer; (3) dewatering the wet pulp layer by pressurizing a flexible plastic bag and forcing the bag to press the wet pulp layer against the surface of the mold cavity and form the plastic liner on the pulp layer, wherein the flexible plastic bag is prepared by a roll-fed-form-seal-press process.