Melt Temperature Measurement Tips!

• Did you know that only 25% to 35% of the melt temperature comes from the heater bands- The rest comes from RPM, Backpressure, Screw design, and residence time?

• Did you know that if you increase the RPMs of the screw to get the screw back to not delay cycle time the melt temperature goes up? 

• Did you know that increasing the RPMs to help mix a color concentrate will increase your melt temperature and change the resin's viscosity?

• Did you know that if you increase the backpressure behind the screw the melt temperature will increase? 

• Did you know that screw design has a drastic effect on melt temperature?  We have seen as much as a 35 degrees difference when two different screws were used with the same input settings? 

• Did you know that a high compression screw will put more shear into the resin and will give you a higher melt temp and sometimes degrade the material?

• Did you know that the L/D (Length over Diameter) of the screw affects the melt temperature? 

• Do you know your screw design?  Most molders don’t as you order a “GP”

(general purpose) screw from the press manufacturer.  Most press and screw manufacturers have different specs for GP screws.

• Did you know that If you increase or decrease your cycle time your melt temperature will change due to the difference in residence time?