Optimization of Wire Drawing Die�s Cooling System

Wire drawing die wear is measured by the dilatation of die gap diameter. Many factors that contribute to wire
drawing die wear, one of them is temperature of the wire during drawing process. Therefore, die cooling system have to be
considered to reduce die wear. Water that is cooled by cooling tower is usually used as die coolant. If the heat is not
transferred well to the coolant, then the die wear will happen faster and the die needs replacement more often. ASM
International gives suggestion to maintain the die gap or the wire�s temperature at 137oC during drawing process. At this
temperature, die wear will be 0.01 mm for 500 km of drawing wire that contains 0.08 % Carbon. In a wire company that
produces AISI 1010, wire was drawn from diameter 5.5 mm to 4.75 mm and die wear was 0.05 mm for 332.1 km of drawing
wire. This die wear showed the existing die cooling system was not enough. Assessment of existing cooling system and
numerical simulation were conducted to find solution. From the assessment, the cooling tower�s average effectiveness was
only 25.9%. Numerical simulation using Gambit, ANSYS Workbench, and ANSYS Fluent was conducted to obtain die
gap surface temperature and some improvement of the cooling system. The mesh used in simulation is 0.7 mm interval and
Standard K-Epsilon (SKE) is chosen as the viscous model. From the simulation, die gap or wire temperature was found
159.3oC. This value is much higher than 137oC that is recommended by ASM International. Some improvement proposed
to the existing cooling system are: 1) Replacing the cooling tower or using water chiller to produce water flowing into die
box at rate of at least 0.332 l/s and maximum temperature of 25oC; 2) Changing the die box shape into cylindrical shape.