Abstract: In this paper, the properties of a styrene modified sizing agent, which is prepared with emulsion polymerization method, are tested and the molecular structure of the sizing agent was analyzed by infrared spectroscopy. A sizing experiment was carried out on polyester filament (155dtex/36f). The test results show that this sizing agent for water-jet loom has good water proofness and obvious bundling effect on polyester filament, so it can meet the requirements of water-jet weaving of polyester filament.

Key words: polyester filament; infrared spectroscopy; sizing agent for water-jet weaving