The processing flow of stainless steel cups involves many steps, from raw material preparation to final product packaging, each link needs precise operation and quality control. The following is a typical process flow:
1. Preparation of raw materials
Material selection: Commonly used stainless steel models (such as 304/316 food-grade stainless steel) to ensure corrosion resistance and non-toxicity.
Plate/pipe cutting: the stainless steel plate is cut into blanks with the required size by laser cutting, punching or shearing machine.
2. Cup forming
Stretch forming (deep drawing):
Use a hydraulic press or a mechanical punch, and cooperate with the mold to stretch the flat blank into a cup shape for many times (multiple processes may be needed).
The stretching ratio should be controlled to avoid material cracking or uneven thickness.
Spinning forming: for special shapes (such as conical cups), spinning machining is used.
Welding (if necessary): If the cup body is spliced by two parts (such as a double-layer vacuum cup), argon arc welding (TIG) or laser welding is required to ensure that the weld is smooth and free of impurities.
< strong>3. Processing of cup bottom
Stamping forming: punch out the cup bottom separately, and then weld it with the cup body.
Laser welding: weld the cup bottom and the cup body with high precision to ensure sealing (especially for thermos cups).
4. Surface treatment
Polishing:
Rough polishing: use grinding wheel or abrasive belt to remove welding marks.
Fine polishing: cloth wheel+polishing paste to achieve mirror or wire drawing effect.
Sandblasting/wire drawing: Use sand grains with different mesh numbers to achieve sanding or texture effect.
Electroplating /PVD coating (optional): add color or wear-resistant layer (such as rose gold and black coating).
< strong>5. Parts manufacturing
Processing of cup cover: injection molding (plastic cover) or stamping (metal cover), which may include silicone sealing ring.
Handle/accessory: welded or riveted (matching cup body needs polishing).
< strong>6. Assembly and inspection < /strong>
Sealing test: vacuum test of vacuum flask (helium mass spectrometer or water test).
Pressure test: simulate the use environment to check the risk of water leakage.
Appearance quality inspection: check scratches, dents and polishing uniformity.
7. Cleaning and packaging
Ultrasonic cleaning: remove oil and metal debris.
Drying and disinfection: high temperature drying ensures hygiene.
Packaging: labeling (material identification, brand), dust-proof bag, boxed.
< strong > key process considerations
Food-grade safety: avoid pollution of harmful substances such as lead and cadmium in the whole process.
Special technology of thermos cup: double-layer vacuumizing and copper foil welding (to improve thermal insulation).
Automation trend: laser cutting and robot welding improve efficiency.
Different styles (such as single-layer cups, thermos cups and coffee accompanying cups) may have extra steps (such as vacuum insulation assembly), but the core process is basically the same.