Buyers trust a supplier more when they understand how the product is built. A vacuum flask looks simple, but getting reliable insulation and a leak-free seal takes a real production line. Here is the process, step by step, the way it runs on our floor.
1. Forming the Bodies
It starts with food-grade 18/8 stainless steel tube. The tube is stretched, drawn and shaped into the inner and outer bottle bodies, then the necks and bottoms are formed. This metalworking stage sets the wall thickness and shape accuracy that everything else depends on.
2. Welding Inner and Outer
The inner and outer bodies are precision-welded together at the mouth. A clean weld here is critical — it is what holds the vacuum and prevents leaks for the life of the bottle.
3. Drawing the Vacuum
The air between the two walls is pumped out through a small port to create the vacuum gap, and the port is sealed. This vacuum is the actual insulation; getter material is added to maintain it over time. This step is why a true vacuum flask costs more than a single-wall bottle.
4. Insulation Testing
Finished bodies are tested for temperature retention and for leaks. Anything that does not hold its vacuum or fails the seal test is pulled before it ever reaches coating. This is where quality is won or lost.
5. Coating and Finishing
Bodies are cleaned and then coated — spray paint, powder coat or electroplating — and cured. Colour matching and even coverage are checked against the approved sample.
6. Branding, Assembly and QC
Your logo is applied by laser, silk-screen, UV or heat transfer; lids and accessories are assembled; and the bottles pass our 3-stage quality control — incoming material (IQC), in-process (IPQC) and final (FQC) — before packing. Buyers can request a video QC walkthrough or third-party inspection (SGS, BV, Intertek) before shipment.
If you would like to see your product move through this line, we are glad to share QC video before shipment. MOQ is 500 pieces per design.
Sourcing drinkware? Talk to Beyond at Jupeng — factory-direct pricing, FDA/LFGB/EU/Prop 65 certs ready, MOQ from 500 pcs, 30-day production. We usually reply within 24 hours.
Written by the Jupeng Drinkware team — Yongkang, Zhejiang, China. Manufacturing drinkware since 1998. Contact Beyond: [email protected] | WhatsApp +86 156 5791 8881