Snap buttons are key connecting components for products like clothing and luggage, and their quality directly impacts the safety and durability of the finished product. To ensure they meet industry standards, snap buttons undergo a systematic inspection process, comprehensively evaluating everything from appearance to performance.
Step 1: Appearance Inspection
Inspectors first conduct a visual inspection of the snap buttons, focusing on surface defects such as cracks, burrs, oxidation, or plating loss. They also verify that the dimensions, including the length and width of the buckle body and the accuracy of the hole diameter, meet design requirements to ensure consistency with product specifications.
Step 2: Dimensional Measurement
Using a vernier caliper or high-precision electronic measuring instrument, key snap button dimensions are quantitatively inspected, such as the inner diameter of the buckle ring, the thickness of the buckle body, and the opening and closing gap. This data must be compared with the design drawing, and deviations must be within the allowable range (typically ±0.1mm) to ensure compatibility with other components.
Step 3: Physical Performance Testing
A tensile tester applies axial tension to the buckle, simulating the stress experienced in actual use, to test its tensile strength and fatigue resistance. The acceptance standard typically requires the buckle body to remain unbroken or deformed under sustained tension, with the specific value varying depending on the material type (e.g., metal or plastic). Furthermore, the buckle's opening and closing flexibility is tested to ensure smooth operation after repeated use.
Step 4: Chemical and Weathering Testing
Metal buckles undergo salt spray testing to assess their corrosion resistance; plastic buckles undergo high-temperature and aging resistance testing. These tests simulate extreme environments (such as humidity and UV exposure) to ensure the buckle's long-term stability.
Step 5: Factory Inspection
The final step is a random re-inspection. Combining all the above criteria, samples are randomly selected from each batch for re-verification. Qualified products are accompanied by a quality inspection report, while unqualified products are isolated for rework or scrapped, ensuring strict factory quality control.
Through the above standardized process, the quality of the buckle can be fully guaranteed, laying the foundation for the reliability of the terminal product.