| 摘要 |
Continuous production of polyamide 6 or copolyamides containing at least 70 wt.% of repeating units derived from epsilon -caprolactam comprises (a) providing starting materials, (b) forming a prepolymer and polycondensing the prepolymer to obtain a main melt stream, (c) granulating the polymer melt, (d) extracting the polyamide granule and (e) drying the extract, where in the process a portion of the side-stream, in an extruder, is mixed with a defined amount of an additive. Continuous production of polyamide 6 or copolyamides containing at least 70 wt.% of repeating units derived from epsilon -caprolactam comprises (a) providing starting materials, (b) forming a prepolymer and polycondensing the prepolymer to obtain a main melt stream, (c) granulating the polymer melt, (d) extracting the polyamide granule and (e) drying the extract, where in the process: a portion of the main melt stream is removed; a portion of the side-stream, in an extruder, is mixed with a defined amount of an additive; the modified side-stream downstream is recycled into the main melt stream before the step (c); and an aqueous extract solution containing epsilon -caprolactam, from the step (d), is concentrated and recycled into the step (a). An independent claim is included for a device for carrying out the above process comprising at least one dosing unit (100a, 100b), at least one condensing device (110), at least one granulating device (120a, 120b,120c), at least one extraction device (130a, 130b, 130c) and at least one drying unit (140a, 140b, 140c), where between the condensing device and the granulating device, an extruder (150) in a bypass (160) is arranged and the extracting device is connected with at least one evaporation unit (170). |
