Reifenhauser: Die heaters keep film gauge under control
A new automatic blown-film die from Reifenhauser Inc. uses closely spaced cartridge heaters around the die to adjust thickness profile by means of temperature changes. The new REIcotherm system raises the die temperature a few degrees at thick spots in the wall, reducing the melt viscosity and encouraging greater local thinning. A 20-in. diam. blown-film die has 104 temperature-control segments. Thickness is measured by a capacitance gauge oscillating around the bubble. It has a coated roller to protect sticky or easily scratched film surfaces.