Method of making a die cast part using a mold release agent

Abstract

A die cast mold release lubricant comprises a silicone compound. A method of application of the lubricant to a die cast mold as a release agent is disclosed where a die casting machine has a mold with mold halves forming a mold cavity when the mold halves abut against one another, a shot sleeve and a plunger which pushes molten material through the shot sleeve and into the mold cavity. The mold release agent is placed into the shot sleeve remote from the mold cavity, molten material is introduced into the shot sleeve, and the molten material and the mold release agent are forced into the mold cavity by movement of the plunger into the shot sleeve. The silicone compound preferably has a melting point of about 90-220° F., and a molecular weight of about 5500-50,000.

1 . A die casting method for making a part in a die casting machine having a mold with mold halves forming a mold cavity when the mold halves abut against one another, a shot sleeve with a pour hole to receive molten material, and a plunger which pushes molten material through the shot sleeve and into the mold cavity comprising, in combination, the steps of
 placing a mold release agent into the shot sleeve remote from the mold cavity;   introducing molten material into the shot sleeve; and   forcing the molten material and the mold release agent into the mold cavity by movement of the plunger into the shot sleeve, wherein the mold release agent has a molecular weight from about 5,500 to 50,000.   
   
   
       2 . The die casting method of  claim 1  wherein the mold release agent comprises a compound which is at least 95% by weight of the die cast release agent. 
   
   
       3 . The die casting method of  claim 2  wherein the mold release agent comprises a silicone compound. 
   
   
       4 . The method of  claim 3  wherein the silicone has alkyl side groups. 
   
   
       5 . The die cast release agent of  claim 4  wherein the alkyl side groups have at least 18 carbon atoms. 
   
   
       6 . The method of  claim 1  further comprising the step of applying the mold release agent to a runner connecting the mold cavity to the shot sleeve. 
   
   
       7 . The method of  claim 1  further comprising the step of applying the mold release agent to a gate inlet connected to the mold cavity. 
   
   
       8 . The method of  claim 1  further comprising
 a runner connecting the mold cavity to the shot sleeve;   wherein the molten material is introduced adjacent the runner.   
   
   
       9 . The method of  claim 1  wherein the mold release agent is further applied remote from the pour hole.