Degradable composite material, its disposable products and processing method thereof

Abstract

There is disclosed a kind degradable material and its disposable products, and their manufacturing process. The primary raw material used in the process consists of powdered shell or stalk of crops, urea-formaldehyde resin, and melamine resin. The materials are mixed thoroughly and hot pressed in a single step forming of the products. Oven drying or spray coating is not needed in the process. The products have the following characteristics: simple formula, simple process, low price; and the following properties: with natural color, dense; tough and tensile; and easy for coloring. In addition, they are water, heat and freezing resistant, anti-corrosion, non-poisonous, anti-pollution and biodegradable. They are entirely new environmental protection green products.

What we claim is:  
     
         1 . A degradable composite material, which comprises the following components by weight in parts:  
       
         
           
                 
                 
                 
               
                     
                     
                 
                     
                     
                 
                     
                   plant fiber: 
                   60-90 parts 
                 
                     
                   urea-formaldehyde resin 
                   10-35 parts 
                 
                     
                   melamine resin 
                    3-10 parts 
                 
                     
                   food coloring agent 
                    1-10 parts 
                 
                     
                     
                 
                     
                     
                 
             
                
                
               
               
                
                
                
                
                
                
               
            
           
         
         wherein the molecular weight of said urea-formaldehyde resin is 300-600.  
       
     
     
         2 . The degradable composite material according to  claim 1 , wherein the plant fiber is crop hull or stalk.  
     
     
         3 . The degradable composite material according to  claim 1 , wherein the amount of the plant fiber is in the range of 70 to 80 parts by weight.  
     
     
         4 . The degradable composite material according to  claim 1 , wherein the amount of urea-formaldehyde resin is in the range 10 to 20 parts by weight.  
     
     
         5 . The degradable composite material in according to  claim 1 , wherein the molecular weight of the urea-formaldehyde resin is 300-400.  
     
     
         6 . The degradable composite material in according to  claim 1 , wherein the amount of the food coloring agent is in the range of 3 to 5 parts by weight.  
     
     
         7 . The degradable composite material according to  claim 1 , wherein the food coloring agent is selected from the group consisting of titanium white, zinc oxide, iron oxide red, pigment yellow 147, pigment blue 15, and combinations thereof.  
     
     
         8 . The plant fiber composite material according to  claim 7 , wherein the food coloring agent is titanium white.  
     
     
         9 . A plant fiber composite material according to  claim 1 , wherein the urea-formaldehyde is prepared by following steps: 
 (1) adding 80-100 weight portions of urea, 160-240 weight portions of formaldehyde (37%) and 16-24 weight portions of glycerol into a reaction vessel with an agitator and stir them at a 60° C. until the urea is fully solved to form a first mixed solution, cooling the first mixed solution to 20-25° C. and adding 5-10 weight portions of sodium diphenylnaphthalenesulfonate and 2.5-7.5 parts by weight of Resorcin, then stirring above mixture for about 10-60 minutes at a rotate speed of 120 rpm to form a second mixed solution; and    (2) adjusting the pH value of the second mixed solution to 7-8 with a pH value conditioner, then stirring it for 30 minutes at a rotate speed of 180-260 rpm, and stirring it for another 30 minutes at a rotate speed of 300-400 rpm to form a third mixed solution, pouring the third mixed solution into a storage and drying it in the shade for 24 hours to obtain an urea formaldehyde resin base material, warming and drying the urea formaldehyde resin base material for 6 hours at 60° C., so as to obtain the final urea formaldehyde resin.    
     
     
         10 . The plant fiber composite material according to  claim 9 , wherein the pH value conditioner is selected from oxalic acid, acetic acid, phosphoric acid, and combinations thereof.  
     
     
         11 . The plant fiber composite material according to  claim 10 , wherein the pH value conditioner is oxalic acid.  
     
     
         12 . A plant fiber composite material according to  claim 1 , which comprises the following components by weight in parts:  
       
         
           
                 
                 
                 
               
                     
                     
                 
                     
                     
                 
                     
                   crops shell or stalk powder of 60 mesh 
                   80 parts 
                 
                     
                   urea-formaldehyde resin 
                   15 parts 
                 
                     
                   melamine resin 
                    5 parts 
                 
                     
                   food coloring agent 
                    3 parts 
                 
                     
                     
                 
                     
                     
                 
             
                
                
               
               
                
                
                
                
                
                
               
            
           
         
       
     
     
         13 . A manufacturing method of the disposable tableware products using the degradable composite material according to  claim 1 , which comprises the following steps: 
 (1) pulverizing a shell or stalk of plant crops into 60 mesh or over, and then thoroughly mixing the pulverized shell or stalk of crops with urea-formaldehyde resin and melamine resin proportionately to form a mixture of the degradable composite material;    (2) feeding the mixture of the degradable composite material into a concave molding mould positioned in an operating platform of a pushing-upward-type oil hydraulic press in a fixed quantity and position with temperature of the mould maintained at 125-190° C.; and    (3) controlling pressure of the pushing-upward-type oil hydraulic press at between 10-30 Mpa and keeping the press operates at 3 intervals by maintaining at above pressure for 3-30 seconds per each interval, so as to obtain the finished products.    
     
     
         14 . The manufacturing method according to  claim 13 , wherein maintaining the concave mould temperature at 160° C., the convex mould temperature at 170° C., controlling working pressure at 25 Mpa, keeping the press operates at 3 intervals by maintaining at above pressure for 3-30 seconds per each interval.  
     
     
         15 . A method for using a degradable composite material according to  claim 1  for the production of tableware products, comprising: 
 (1) feeding the degradable composite material into a concave molding mould positioned in an operating platform of a pushing-upward-type oil hydraulic press in a fixed quantity and position with temperature of the mould maintained at 125-190° C.; and  
 (3) controlling pressure of the pushing-upward-type oil hydraulic press at between 10-30 Mpa and keeping the press operates at 3 intervals by maintaining at above pressure for 3-30 seconds per each interval, so as to obtain the finished products.  
 
     
     
         16 . Tableware products made from degradable composite material according to  claim 1  and that are nontoxic, degradable ecologically benign, and environmentally beneficial, wherein the tableware products are made from a process comprising: 
 (1) feeding the degradable composite material into a concave molding mould positioned in an operating platform of a pushing-upward-type oil hydraulic press in a fixed quantity and position with temperature of the mould maintained at 125-190° C.; and  
 (3) controlling pressure of the pushing-upward-type oil hydraulic press at between 10-30 Mpa and keeping the press operates at 3 intervals by maintaining at above pressure for 3-30 seconds per each interval, so as to obtain the finished products.