Methods of manufacturing formaldehyde-free molded products and related parts

Abstract

The present invention provides a moldable mixture containing large portion of agricultural fibers and small portion of a binding agent and a flow-promoting filler material. The moldable mixture is substantially free of formaldehyde, with low moisture content and high draw ratio. The present invention also provides methods of manufacturing molded products and related parts based on the claimed moldable mixture. Molded products ( 830 ) and related parts such as runner ( 810 ) and plank ( 820 ) with light weight, high density and more complex profile are manufactured by the claimed methods including steps of providing required materials for a moldable mixture, mixing the provided materials to form a moldable mixture, shaking the moldable mixture in preparing for compression molding and compression molding the moldable mixture to form molded products and related parts.

1 . A moldable mixture comprising a binding agent, a flow-promoting filler material and an agricultural fiber, wherein said moldable mixture is in the absence of hardener, impact modifier, co-solvent and de-molding agent, and wherein said binding agent is Diisocyanate-diphenylmethane with an amount not more than 5% by weight to said moldable structure. 
     
     
         2 . (canceled) 
     
     
         3 . The moldable mixture of  claim 1 , wherein the said binding agent is free of formaldehyde. 
     
     
         4 . (canceled) 
     
     
         5 . (canceled) 
     
     
         6 . The moldable mixture of  claim 1 , wherein said flow-promoting filler material is wheat flour which is less than 10% by weight to said moldable mixture. 
     
     
         7 . The moldable mixture of  claim 1 , wherein said binding agent may be a soy-based binding agent with an amount not more than 5% by weight to said moldable mixture. 
     
     
         8 . A method of manufacturing a molded product comprising the steps of:
 a. providing an agricultural fiber, a binding agent and a flow-promoting filler material;   b. mixing said agricultural fiber with said flow-promoting filler material and said binding agent to form a moldable mixture;   c. shaking said moldable mixture in preparation for compression molding; and   d. compression molding said moldable mixture to form molded product,
 wherein said mixing further comprises spraying said binding agent at a pressure between 5 to 8 bar into said agricultural fiber with said flow-promoting filler material, wherein said binding agent is Diisocyanate-diphenylmethane with an amount not more than 5% by weight to said moldable mixture. 
   
     
     
         9 . (canceled) 
     
     
         10 . The method of  claim 8 , wherein said binding agent may be a soy-based binding agent with an amount not more that 5% by weight to said moldable mixture. 
     
     
         11 . (canceled) 
     
     
         12 . (canceled) 
     
     
         13 . The method of  claim 8 , wherein said flow promoting filler material is wheat flour which is less than 10% by weight to said construction molding mixture. 
     
     
         14 . The method of  claim 8 , wherein said mixing takes place in the absence of hardener, impact modifier, co-solvent and de-molding agent and is free of formaldehyde. 
     
     
         15 . The method of  claim 8 , wherein said shaking further comprises discharging and moldable mixture through a discharging screw into a weighing hopper and then is further discharged into a material feeding tray that is divided into at least 35 compartments. 
     
     
         16 . The method of  claim 15 , wherein said discharging is followed by transferring said moldable mixture from said material feeding train into a mold with a simultaneous horizontal and vertical vibrating or shaking motion, in preparation for compression molding. 
     
     
         17 . The method of  claim 8 , wherein said compression molding is performed as a single compression stroke and without any pressure release mechanism throughout the molding process, wherein such total molding time is less than one minute. 
     
     
         18 . The method of  claim 17 , wherein said single compression stroke is performed with a draw ratio from 1 to 10, and without any pressure release mechanism throughout the molding process, wherein such total molding time is less than one minute. 
     
     
         19 . The method of claim of  8 , wherein said compression molding is performed at a temperature from 200 to 230 degree Celsius, wherein pallets are produced as a result thereof. 
     
     
         20 . The method of claim of  8 , wherein said compression molding is performed at a pressure from 0.30 to 0.40 kg/mm 2 , wherein pallets are produced as a result thereof.