Neither melt temperature nor viscosity significantly affects the residual wall thickness in the area of the gas bubble. The results of a study using Durethan® PA-6 are shown in the graph below. The graph shows that a 50°C increase in melt temperature, for the same material, had only a slight affect on wall thickness even though the temperature change caused the viscosity to decrease by roughly 65%. Also the graph indicates that when the viscosity is doubled, by changing materials, there is little change in the wall thickness. The shaded areas at the top of the bars represent standard deviations.

Similar results were obtained in a study using Makrolon® 2458 polycarbonate. Although the wall thickness did decrease with an increase in melt temperature the decrease in wall thickness was less than 0.5mm.