System and method for manufacturing polymer coated controlled release fertilizers

Abstract

A system and method are provided for manufacturing the polymer-coated fertilizers with a controlled release in a single pass. The system has a feeding mechanism connected to a first chill roll to supply the articles to the first cavities provided on the first roll to store and hold the articles. A first machine produces and applies a first polymer film on the articles held in the first chill roll to coat the articles partially with the first polymer film. The partially coated articles are transferred to a second chill roll placed at a side or on a top of the first chill roll. A second machine produces and applies the second polymer film on the partially coated articles in the second chill roll so that the articles are encapsulated by the first and second polymer films. A collector mechanism receives the encapsulated articles from the second chill roll.

1 .- 20 . (canceled) 
     
     
         21 . A method of manufacturing a polymer coated fertilizer, the method comprising:
 placing a solid substrate in a first cavity;   applying a first coating layer onto a first exposed surface area of the solid substrate, the first coating layer covering a part of the first exposed surface area to create a partially coated solid substrate;   transferring the partially coated solid substrate into a second cavity in such a way that exposes a second exposed surface area of the partially coated substrate;   applying a second coating layer onto the second exposed surface area of the partially coated substrate in such a way that the second coating layer covers the second exposed surface area and forms a sealing layer with the first coating layer to form the polymer coated fertilizer;   wherein the polymer coated fertilizer releases the solid substrate through at least one of the first coating layer and the second coating layer over a period of time when placed in an agriculture media.   
     
     
         22 . The method of  claim 21 , wherein the fertilizer includes at least one of the following: an organic fertilizer, an inorganic fertilizer, a natural fertilizer, a synthetic fertilizer, a micronutrient, an insecticide, a fungicide, a herbicide, a nitrification inhibitor, a bioinoculant, a urease inhibitor, and an aluminum sulfate. 
     
     
         23 . The method of  claim 21 , wherein the solid substrate includes at least one of the following: a tablet, a capsule, a briquette, and a granule. 
     
     
         24 . The method of  claim 21 , wherein the first coating layer includes at least one of the following: a natural polymer, a synthetic polymer, a biodegradable polymer, a non-biodegradable polymer, a processing additive, a polymer stabilizing additive, an inorganic mineral, a biodegradation additive, a oxo-biodegradation additive, a nitrification inhibitor, a urease inhibitor, a hydrogel particle, an organic surfactant, an inorganic surfactant, a pigment, a chemical taggant, a physical taggant, a herbicide, an insecticide and a fungicide. 
     
     
         25 . The method of  claim 21 , wherein the second coating layer includes at least one of the following: a natural polymer, a synthetic polymer, a biodegradable polymer, a non-biodegradable polymer, a polymer processing additive, a polymer stabilizing additive, an inorganic mineral, a biodegradation additive, a oxo-biodegradation additive, a nitrification inhibitor, a urease inhibitor, a hydrogel particle, an organic surfactant, an inorganic surfactant, a pigment, a chemical taggant, a physical taggant, a herbicide, an insecticide and a fungicide. 
     
     
         26 . The method of  claim 21 , wherein at least one of the first coating layer and the second coating layer includes any film extrusion grade polymer of natural or synthetic origin. 
     
     
         27 . The method of  claim 21 , wherein at least one of the first coating layer and the second coating layer has a water vapor transmission rate within the range of 1 g/(m 2 ·day) to 2000 g/(m 2 ·day). 
     
     
         28 . The method of  claim 21 , wherein at least one of the first coating layer and the second coating layer is made up of multiple coating layers. 
     
     
         29 . The method of  claim 21 , wherein the first coating layer and the second coating layer have a same thickness, and the sealing layer has a greater thickness than the same thickness of the first coating layer and the second coating layer. 
     
     
         30 . The method of  claim 21 , wherein the first coating layer, the second coating layer, and the sealing layer each have a different thickness. 
     
     
         31 . The method of  claim 21 , wherein the solid substrate has a diameter within a range of 2 mm to 150 mm. 
     
     
         32 . The method of  claim 21 , wherein the solid substrate is a urea tablet having a weight within a range of 100 mg to 800 mg. 
     
     
         33 . The method of  claim 21 , wherein the sealing layer is formed by laminating an edge of the second coating layer with an edge of the first coating layer, wherein the sealing layer is distinct from the first coating layer and the second coating layer. 
     
     
         34 . The method of  claim 21 , wherein the solid substrate includes any fertilizer for use in agriculture crops production. 
     
     
         35 . The method of  claim 21 , wherein the first coating layer includes any polymer film that can be thermoformed. 
     
     
         36 . The method of  claim 21 , wherein the second coating layer includes any polymer film that can be thermoformed. 
     
     
         37 . The method of  claim 21 , wherein applying the first coating layer onto the first exposed surface area of the solid substrate includes depositing the first coating layer onto the first exposed surface area of the solid substrate under a pulling force. 
     
     
         38 . The method of  claim 21 , wherein the first coating layer is deposited onto the first exposed surface area of the solid substrate includes depositing the first coating layer onto the first exposed surface area of the solid substrate under a first pulling force causing the first coating layer to wrap around the solid substrate before the second coating layer is deposited under a second pulling force so that an edge of the first coating layer is interior to an edge of the second coating layer in the sealing layer. 
     
     
         39 . The method of  claim 38 , wherein the edge of the first coating layer is wholly interior to the edge of the second coating layer in the overlap layer.