Method for determining a value for the description of the compression of a moldable material

Abstract

In a method for determining at least one parameter for the description of the compression behavior of a material processed in a molding machine, at least a part of the processed material is introduced into a mold cavity via a distribution system and a gate, and the processed material solidifies in the mold cavity. A compression test is performed in which a volume storing the material is modified and a measurement of the resulting pressure modification is conducted or a pressure applied onto the material is modified and a measurement of the resulting modification of the volume is conducted. A parameter for the description of the compression behavior is calculated based on the result of the compression test by using a mathematical model. The compression test is conducted when the gate is at least substantially solidified or when the hot runner is closed.

1 - 11 . (canceled) 
     
     
         12 . A method for operating a molding machine, wherein depending on at least one parameter for the description of a compression behavior of a material processed in the molding machine, the method comprises:
 calculating a realistic injection volume and/or a realistic injection volume flow, and/or   calculating a decompression lift, and/or   calculating a dwell time of the melt in the molding machine, and/or   parameterizing a pressure regulator, and/or   determining a pressure dependency of the compression behavior, and/or   determining a temperature of the melt, and/or   controlling the velocity of the plasticizing screw so that a predetermined filling volume flow is reached, and/or   determining a material characteristic of the melt, wherein the material characteristic is a composition, a phase state, a viscoelasticity, a solids content, a proportion of low-molecular substances, or a chemical modifications of the polymer structure.   
     
     
         13 . (canceled) 
     
     
         14 . The method according to  claim 12 , wherein the molding machine is one of an injection molding machine or a transfer molding machine. 
     
     
         15 . The method according to  claim 12 , further comprising determining the at least one parameter for the description of the compression behavior of the material processed in the molding machine, the determining comprising:
 introducing at least a part of the processed material into a mold cavity via a distribution system and a gate, wherein the processed material solidifies in the mold cavity;   executing at least one compression test in which a modification of a volume storing the material is made and a measurement of a resulting pressure modification or a pressure applied onto the material is modified and a measurement of the resulting modification of the volume storing the material is conducted; and   calculating the at least one parameter for the description of the compression behavior based on the result of the at least one compression test by using a mathematical model,   wherein the at least one compression test is conducted when the gate is at least substantially solidified or—if the molding machine comprises a closable hot runner arranged at the gate—when the hot runner is closed, so that a dead volume which reaches till the gate is considered in the calculation of the at least one parameter for the description of the compression behavior.   
     
     
         16 . The method according to  claim 15 , wherein the molding machine comprises a plasticizing screw arranged in a plasticizing cylinder and functioning as a piston, wherein the modification of the volume storing the material is effected by modifying a position of the plasticizing screw in the plasticizing cylinder. 
     
     
         17 . The method according to  claim 15 , wherein the molding machine comprises a plasticizing screw arranged in a plasticizing cylinder and functioning as a piston, wherein the modification of the pressure applied onto the material is effected by the plasticizing screw. 
     
     
         18 . The method according to  claim 16 , wherein the molding machine comprises a piston arranged in a material storage space, wherein the modification of the volume storing the material is effected by modifying a position of the piston in the material storage room. 
     
     
         19 . The method according to  claim 15 , wherein the molding machine comprises a piston arranged in a material storage space, wherein the modification of the pressure applied onto the material is effected by the piston. 
     
     
         20 . The method according to  claim 15 , wherein the mold cavity is provided in a molding tool, wherein the modification of the pressure and/or the volume is effected by a movable molding tool element, preferably a core pull or an ejector. 
     
     
         21 . The method according to  claim 15 , wherein at least two compression tests are executed under different boundary conditions. 
     
     
         22 . The method according to  claim 15 , wherein the at least one determined parameter of the compression behavior is displayed. 
     
     
         23 . The method according to  claim 15 , wherein the at least one compression test is executed independently from a production cycle of the molding machine. 
     
     
         24 . The method according to  claim 15 , wherein the at least one compression test is executed in a production cycle of the molding machine. 
     
     
         25 . The method according to  claim 24 , wherein the at least one compression test is executed in the form of a pressure reduction at the end of a holding pressure phase and/or during a pressure relief before or after a dosing operation.