If sprues are fixed in the mold by cooling, the type of demolding determines the required temperature compensation (e.g. prevention of sticking by "post-melting").
Demolding systems (ejection, overpressing of undercuts) may cause molded parts to deform impermissibly as a result of local pressures or other stresses.
In the case of uneven mold tempering, so-called hot spots (hot zones) can be the cause of demolding difficulties.