Processing parameters

Temperature settings for cylinder and mold

Injection unit
Desmopan® and Texin™ should be processed at melt temperatures of between 190 and 220 °C. With some hard grades, a melt temperature of up to 240°C may be needed. The melt temperature ranges for the individual Desmopan® grades can be found in the relevant product information sheets.

Figure 1 shows guide values for the settings for cylinder and nozzle heating in relation to the Shore hardness. As a rule, small injection molding machines need a higher temperature setting than large ones.

Fig. 1: Temperature profile according to hardness range

Mold
The mold temperature has a major influence on the quality of the surface and the demolding behavior. It also affects shrinkage and internal (frozen-in) stresses in the final component. Mold temperatures of between 20 and 40 °C are generally employed. A number of modified and glassfiber grades of Desmopan® and Texin™ require mold temperatures of up to 60 °C in order to achieve an optimum surface finish.

With thick-walled articles, cooling down to approx 5 °C can bring a reduction in cycle time.