⑴Specification requirements:

①Internal dimensions (±0.15mm): thread inner diameter, inner plug outer diameter, top wall thickness
②External dimensions (±0.30mm): the outer diameter of the cover, the overall height of the cover
③Other indicators: single weight (±0.10g)

⑵ Appearance requirements:
① Cover surface: full molding, complete structure, no material shortage, no obvious damage, burrs and deformation;
②The color of the cover body: it conforms to the allowable limit of the standard sample, and the color is uniform;
③Sealing ring: no damage, deformation, strain;
④Side seal and top seal: no air bubbles or damage;
⑤Thread: Slight strain on the thread at the non-starting point is allowed, not less than the lower limit of the inner diameter of the thread;
⑥Connecting bridges (tangent points): no breakpoints, adhesions or not full;
⑦ Gate (injection cover): no perforation or cracking, no obvious gate residue or depression;
⑧ Pollution: no oil, dirt, rust, impurities;
⑨Printing: The pattern is clear, there are no defects such as missing printing, missing printing, etc., which meets the allowable limit of poor color registration, cross-inking, and pattern color, and the allowable center deviation of partial printing is ±0.3mm.

(3) Printing pattern adhesion performance:
①Hot water immersion method (hot filling cover): no obvious discoloration
② Peracetic acid soaking method (sterile cover): no obvious decolorization
③Tape sticking and peeling method: no obvious discoloration