Automation: hidden roll, roll width can be adjusted, needle distance 1/8, 1/4, 3/8 can be exchanged. Efficiency: 3 times the traditional process, can save 2 people, automatic bag opening machine 10 hours 8000. Cost performance: According to the per capita monthly salary of 3000 yuan, the annual saving of 3000x12x2=72000 yuan. Simplicity: Instead of skilled workers, fool operation, simple training can be operated, multiple processes once sewing.