I. Core Functions Handheld sewing thread uses polyester staple fiber as the core raw material, designed specifically for manual or semi-automatic sewing scenarios of various packages. Its core functions include: Reinforcement and Sealing : Through the high-strength fiber structure, it achieves tight sewing of packaging bags (such as woven bags, paper bags, cloth bags), preventing materials from leaking, getting damp or contaminated during storage and transportation; Convenien