Molded fiber manufacturing

Abstract

Molded fiber products using agriculture residues are economical and environmentally beneficial. Molded fiber manufacturing is different from molded pulp. The present invention discloses a method of and an apparatus for the manufacturing of molded fiber shaped body ( 10 ) using low consistency fiber slurry ( 12 ) subject to vacuum-forming and thermo-curing. The use of porous material as mold inserts for both vacuum-forming ( 101 ) and thermo-curing ( 102 ) stations provides improved productivity and enables ease of mold release. The incorporation of self-cleaning techniques further ensures consistent performance of the manufacturing system.

1 . An improved method of manufacturing molded fiber shaped body comprises of using low-consistency plant fiber slurry subject to vacuum-forming to form a wet fiber shaped body and thermo-curing the wet fiber shaped body to produce the final molded fiber shaped body; wherein porous materials are used as mold inserts for both vacuum-forming and thermo-curing;  
     
     
         2 . The improved method of manufacturing molded fiber shaped body as claimed in  claim 1  wherein the vacuum-forming process consists of a pair of matching molds with porous mold inserts to produce a uniform thickness wet fiber shaped body under vacuum means.  
     
     
         3 . The improved method of manufacturing molded fiber shaped body as claimed in  claim 2  wherein the vacuum-forming molds are effectively sealed when closed to achieve highly effective vacuum dewatering of the wet fiber shaped body.  
     
     
         4 . The improved method of manufacturing molded fiber shaped body as claimed in  claim 1  wherein the thermo-curing process consists of a pair of matching molds with porous mold inserts that are heated by heating means.  
     
     
         5 . The improved method of manufacturing molded fiber shaped body as claimed in  claim 4  wherein the thermo-curing molds are effectively sealed when closed to reduce the heating energy required to cure the molded fiber shaped body.  
     
     
         6 . The improved method of manufacturing molded fiber shaped body as claimed in  claim 1  wherein the porous mold inserts in the vacuum-forming molds are cleaned by ultrasonic waves and back-flushing means.  
     
     
         7 . The apparatus for manufacturing molded fiber shaped body comprises of three stations namely fiber slurry preparation station, vacuum-forming station and thermo-curing station.  
     
     
         8 . The apparatus for manufacturing molded fiber shaped body as claimed in  claim 7  wherein the vacuum-forming station comprising of a pair of matching molds arranged in a top and bottom arrangement.  
     
     
         9 . The apparatus for manufacturing molded fiber shaped body as claimed in  claim 8 , the vacuum-forming bottom mold consists of a mold platform with openings for installing porous mold inserts, a fiber slurry container and vacuum chamber for connecting to vacuum means and compressed air means.  
     
     
         10 . The apparatus for manufacturing molded fiber shaped body as claimed in  claim 7  wherein the vacuum-forming top mold consists of mold platform with openings for mold inserts that matched the shaped the bottom mold inserts.  
     
     
         11 . The apparatus for manufacturing molded fiber shaped body as claimed in  claim 10  wherein the vacuum-forming top molds platform consists of vacuum chamber that are connected to vacuum means and compressed air means.  
     
     
         12 . The apparatus for manufacturing molded fiber shaped body as claimed in  claim 11  wherein the vacuum top and bottom molds are able to move vertically and closed with air sealed to prevent ambient air infiltration to the wet fiber shaped body during the vacuum dewatering process.  
     
     
         13 . The apparatus for manufacturing molded fiber shaped body as claimed in  claim 12  wherein ultrasonic transducers are mounted onto the fiber slurry container.  
     
     
         14 . The apparatus for manufacturing molded fiber shaped body as claimed in  claim 7  wherein the thermo-curing molds comprises a pair of matching molds arranged in a top and bottom molds arrangement.  
     
     
         15 . The apparatus for manufacturing molded fiber shaped body as claimed in  claim 14  wherein the thermo-curing top mold consists of non-porous mold base with optimized air passage and heating contact surfaces.  
     
     
         16 . The apparatus for manufacturing molded fiber shaped body as claimed in  claim 15  wherein the thermo-curing bottom mold consists of non-porous mold base with optimized air passage and heating contact surfaces.  
     
     
         17 . The apparatus for manufacturing molded fiber shaped body as claimed in  claim 16  wherein the thermo-curing top and bottom molds is able to move vertically and closed to apply heat and pressure to cure the wet fiber shaped body to produce the molded fiber shaped body.  
     
     
         18 . The apparatus for manufacturing molded fiber shaped body as claimed in  claim 7  wherein the porous mold inserts for the thermo-curing station are preferably made of porous metal.