Recycle methods for water based powder injection molding compounds

Abstract

A process for adjusting the level of water or water soluble additives in aqueous-based powder injection molding compounds for the purpose of recycling scrap material, controlling shrinkage or rehydrating dry feedstock. Depending on the objective, the process may require material granulation equipment, equipment for the addition or removal of water and mixing equipment. The molding compounds may be comprised of either recycled scrap material before being heat-treated or dry, virgin feedstock material.

1 . A process for adjusting the processing characteristics and product properties of a water-based injection molding compound, comprising: 
 a) providing a metal or ceramic powder-based molding compound that is at least one of green material or dry virgin feedstock material;    b) exposing the molding compound to water; and    c) measuring at least one of water content or additive content in the molding compound to produce an optimum balance of injection molding process characteristics and product properties.    
     
     
         2 . The process of  claim 1 , wherein the molding compound is comprised of recycled green scrap material.  
     
     
         3 . The process of  claim 1 , wherein the molding compound is comprised of dry, virgin feedstock materials.  
     
     
         4 . (Cancel).  
     
     
         5 . (Cancel).  
     
     
         6 . (Cancel).  
     
     
         7 . (Cancel).  
     
     
         8 . (Cancel).  
     
     
         9 . (Cancel).  
     
     
         10 . The process of  claim 1 , wherein the injection molding process characteristic is green strength.  
     
     
         11 . The process of  claim 1 , wherein the injection molding process characteristic is ease of flow.  
     
     
         12 . The process of  claim 1 , wherein the product property is shrinkage.  
     
     
         13 . (Cancel).  
     
     
         14 . (Cancel).  
     
     
         15 . (Cancel).  
     
     
         16 . (Cancel).  
     
     
         17 . (Cancel).  
     
     
         18 . A molding compound, comprising the product made by the process of  claim 1 .  
     
     
         19 . (Cancel).  
     
     
         20 . The process of  claim 1  wherein the step of exposing the molding compound to water comprises exposing the molding compound to a water-based rehydration solution until equilibrium is reached.  
     
     
         21 . The process of  claim 20  wherein the step of exposing the molding compound to a water-based rehydration solution comprises immersing the molding compound in the water-based rehydration solution at a temperature of from 4 to 60° C.  
     
     
         22 . The process of  claim 21  wherein the step of exposing the molding compound to a water-based rehydration solution comprises immersing the molding compound in the water-based rehydration solution at room temperature.  
     
     
         23 . The process of  claim 1  wherein the step of exposing the molding compound to water comprises spraying the molding compound with water.  
     
     
         24 . The process of  claim 23  wherein the step of exposing the molding compound to water comprises spraying the molding compound with a water-based rehydration solution.  
     
     
         25 . The process of  claim 1  further comprising granulating the molding compound.  
     
     
         26 . The process of  claim 25  wherein the molding compound is granulated after it is exposed to water.  
     
     
         27 . The process of  claim 25  wherein the molding compound is granulated before it is exposed to water.  
     
     
         28 . The process of  claim 20  wherein the water-based rehydration solution comprises at least one of water-soluble additives or biocides.  
     
     
         29 . The process of  claim 1  wherein the molding compound is a ceramic powder-based molding compound.  
     
     
         30 . The process of  claim 1  comprising measuring the water content.  
     
     
         31 . The process of  claim 1  comprising measuring the additive content.  
     
     
         32 . The process of  claim 30  wherein the measured water content of the molding compound is 8 wt % or less.  
     
     
         33 . A process for adjusting the processing characteristics and product properties of a water-based ceramic powder-based molding compound, comprising: 
 d) providing a ceramic powder-based molding compound that is at least one of green material or dry virgin feedstock material;    e) exposing the molding compound to water; and    f) measuring at least one of water content or additive content in the molding compound to produce a molding compound having a water content of 8 wt % or less.