MELT-SPINNING OF COPOLYAMIDE

PURPOSE:The extruded yarn of aromatic copolyamide is passed through two specific zones under the spinneret which include atmosphere kept at specific temperatures to produce undrawn yarn having good drawability and uniform yarn properties and giving high-modulus and-strength yarn. CONSTITUTION:A copolyamide containing aromatic amide units such as a copolymer from nylon 66 salt, p-phenylenediamine and terephthalic acid is melted and extruded through the spinneret kept at Ts deg.C (almost the same as that of the melted copolyamide). The resultant yarn is passed through the zone ranging from 5 to 20cm under the spinneret which is filled with an atmosphere (Hood H1) at T1 deg.C satisfying equationIand the second zone that is 10-40cm below the hood H1 and filled with an atmosphere (Hood H2) at T2 deg.C satisfying formulas II and III to produce the objective yarn. The hood H1 is preferably filled with an inert gas atmosphere and the temperature T1 is preferably lower than Ts and the difference between T1 and T2 are more than 50 deg.C. The total length of H1 and H2 is preferably 20-60cm.