| 摘要 |
1287036 Shearing polyethylene BADISCHE ANILIN- & SODA-FABRIK AG 30 Jan 1970 [31 Jan 1969] 4548/70 Heading C3P Molten high pressure polyethylene is subjected to shearing in a shearing unit at a temperature of 200‹ to 300‹ C. and a viscosity of 5 Î 10<SP>3</SP> to 1 Î 10<SP>5</SP> poises in the absence of atmospheric oxygen, wherein the shearing surfaces contacting the polyethylene melt are at a temperature at least equal to that of the polyethylene melt entering the shearing unit and shearing is effected with such speed that the product of shearing speed and residence time is 5 x 10<SP>2</SP> to 5 x 10<SP>4</SP>. The unit may be a screw extruder. The polymer may contain 0À01 to 0À5 weight per cent of residual ethylene which may react with radicals formed in the shearing zone. The products may be made into films. |
