Thermic calculations
Basic rules for cartridge
Adjustment of the CCHC
Mould heating example
Heat loss by natural convection



Example of calculation
of power in order to heat a steel mould.

Technical data > Thermic calculations > Mould heating example > Calculation of the thermal balance


4. Determination of the power to install.

a.     To start

The necessary power to start includes :

-         The power for the setting of temperature of the mould and of the upper and lower plates. This power is particularly important given that temperature rises quickly.

-         The power to balance losses by conduction, convection and radiation. During the starting period, it is equal to 2/3 of the total losses of the permanent regime.

P = (F1 + 2/3 F3) 1,1

Where :

F1 = heat for the setting of temperature
F3= total of heat losses
1,1= coefficient of safety
P= (3711 + 2/3 x 2686) 1,1
Power to start = 6052 W

 b.     Working power

The working power is equal to :

-         The power to heat plastic.
-         The power to balance heat losses.

P = (F2 + F3) 1,1

Where :

F2    = power to heat plastic
3    = power to balance heat losses
1,1     = coefficient of security
P       = (94 + 2686) 1,1

Working power = 3058 W