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

A method for determining at least one parameter for a description of a compression behavior of a processed material in a molding machine, said method comprising:

• introducing at least a part of the processed material from a material storage space into a mold cavity of a mold via a gating system, the mold cavity being defined by at least two mold portions of the mold, the gating system including a distribution system and an ingate forming an inlet port of the mold cavity, the ingate and at least a portion of the distribution system of the gating system being located within at least one of the mold portions of the mold, the ingate being configured to allow the mold cavity to communicate with the distribution system, wherein the processed material solidifies in the mold cavity;
• executing at least one compression test in which (i) a modification of a volume of the material is made and a measurement of a resulting pressure modification is conducted, or (ii) a pressure applied onto the material is modified and a measurement of the resulting modification of the volume of the material is conducted, the material storage space remaining open to the gating system during the at least one compression test;
• and
• calculating at least one parameter for the description of the compression behavior based on a result of the at least one compression test by using a mathematical model, wherein the at least one compression test is conducted (i) when the ingate is at least partially solidified or (ii) when a closable hot runner arranged at the ingate is closed, so that a dead volume which extends up to the ingate is considered in said calculating the at least one parameter for the description of the compression behavior.