A continuous polymerization process for PA6 resin comprises: heating, stirring and mixing caprolactam, water, a catalyst and a molecular weight regulator to obtain an auxiliary solution, which is sent to a storage tank and heated for heat preservation; mixing and preheating caprolactam and the auxiliary solution, then pumping the mixture into the top of a polymerization tube for catalytic ring-opening polymerization; pumping into a vertical thin-film devolatilizer for high-vacuum devolatilization; feeding into a single-screw or ribbon extruder for high-vacuum devolatilization; then feeding into a multi-screw extruder for screw extrusion devolatilization, cooling, pelletizing and drying to obtain PA6 resin pellets. The process of the invention can replace and reduce four major processes: water extraction for caprolactam recovery, deionized water preparation, recovered monomer refining and post-polymerization. The product has high intrinsic viscosity and low content of monomers and low-molecular-weight substances, close to the level of the existing hydrolysis polymerization process. The process is simple, with short production cycle, low energy consumption and low investment, suitable for industrial production.

Country Code: CN

Application Number: CN202111264409.0