Sewing line quality requirements and inspection methods

Quality requirements and test methods for post-press finishing
Quality requirements and test methods for thread sewing

CY/T7.5-91

Press and Publication Administration of the People's Republic of China 1991-07-01 Approved 1991-10-01 Implementation 1 Subject Content This standard specifies the quality requirements and test methods for book locks.
2 Quoting standard GB 9851 printing technology term GB 788 books and magazines and format size 3 classification 3.1 flat lock 3.1.1 manual flat lock;
3.1.2 The machine is locked flat.
3.2 cross lock 3.2.1 manual cross lock;
3.2.2 machine cross lock.
4 Quality Requirements 4.1 The sewing thread pitch and the number of stitches are shown in Table 1.
Table 1 Distance between the upper and lower needle positions and the upper and lower incisions (mm) Number of needles Needle group 8 Open 20-30 8-10 4-5 16 Open 20-30 6-8 3-4 32 Open 15 4-6 2-3 64 Open and following 10-15 4 2
The needle position should be evenly distributed on the last fold line of the signature.
4.2 Requirements of the lock line 4.2.1 The book block after the lock line is arranged correctly and neatly, with no damage, page breakage and dirty oil.
Press and Publication Administration of the People's Republic of China 1991-07-01 Approved 1991-10-01 Implementation 4.2.2 The eyes of the pinhole eyelet are smooth and have no holes.
4.2.3 The lock line is tight and loose, and the thickness of the locked signature is basically the same, and the clothes are flat and tidy. There is no large volume and title page, and the size of the contract does not exceed 2.5 mm. No needles, knuckles, breaks and coils.
4.2.4 The book block after the sewing line is not broken ring lining.
4.3 Use wire gauges and staples 4.3.1 Use 42 or 60 4-strand or 6-ply white wax towers, or nylon cords of the same size.
4.3.2 Stitching form: When the specification of the signature paper is below 4Og, it should be cross-locked; when it is more than 40g, it should be flat or cross-locked.
5 Test method 5.1 The measurement method uses a millimeter rule to check the set distance and shrinkage.
5.2 Visual inspection professional and technical personnel self-test the product quality according to the standard requirements.
Additional information:
This standard was proposed and managed by the Press and Publication Administration of the People's Republic of China.
This standard is drafted by the Chinese printing company.
Drafters of this standard are Wang Huaizhu and Shi Qunfang.