Q. Zhai et Jl. White, STUDIES OF AN AIR LUBRICATED DIE FOR EXTRUSION OF RUBBER COMPOUNDS - EFFECTS OF METAL POROSITY LEVEL AND DIE DIMENSIONS, Kautschuk und Gummi, Kunststoffe, 48(2), 1995, pp. 107-110
The application of air lubrication to reduce the die pressure drop for
rubber extrusion was investigated experimentally. Two compounds were
used in this study. They were compounded in an internal mixer and thei
r rheological properties were measured. The first was carbon-black fil
led SBR which showed a yield value; the second was oil extended, black
-filled SBR. Various levels of metal porosity were tested and the crit
ical air pressure during air-lubricated process was determined. The cr
itical air pressure decreased with increasing porosity level. Dies of
varying length and diameter were investigated. A relationship for extr
usion rate as a function of die pressure drop was obtained by curve fi
tting. The extrudate character was investigated as a function of air p
ressure.