WauTechFocusing on stainless steel processing and manufacturing
WauTechFocusing on stainless steel processing and manufacturing
The coating and composite technologies for the inner liner of stainless steel vacuum flasks aim to address issues such as corrosion, the leaching of heavy metals (like lead and cadmium), and residual odors that may arise from prolonged contact between stainless steel and complex beverages (like tea, coffee, milk).
The main technologies can be divided into two broad categories: inner surface coating technologies and metal composite liner technologies. The core distinctions and a comparative selection guide between them are as follows:
| Technology Type | Primary Technology/Material | Core Purpose & Characteristics | Main Advantages & Disadvantages |
| Inner Surface Coating Technology | SiO₂ Glass Coating | Forms a stable isolation layer via the sol-gel method, significantly reducing heavy metal leaching. | Advantages: Strong corrosion resistance, high safety. Disadvantages: Complex process, demands high adhesion. |
| Ceramic/Enamel Coating | Forms a dense glaze layer through high-temperature sintering, offering corrosion resistance and odor prevention, suitable for various beverages. | Advantages: Comprehensive performance, smooth and easy-to-clean surface. Disadvantages: Higher cost, coating susceptible to damage from impacts. |
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| Nanoscale Hydrophobic Coating | Utilizes a hydrophobic surface with a contact angle >120° to reduce residue adherence, facilitate cleaning, and prevent odors. | Advantages: Easy to clean, effective anti-staining. Disadvantages: Hydrophobic layer may wear with use. |
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| Metal Composite Liner Technology | Titanium-Steel Composite Liner | Inner layer (contacting beverage) is pure titanium, outer layer is stainless steel. Leverages titanium's extremely high corrosion resistance to fundamentally prevent heavy metal leaching. | Advantages: Intrinsically safe, long lifespan, lightweight. Disadvantages: High material and composite process costs. |
| Multi-layer Composite Liner (Titanium/Copper/Steel) | Inner layer is titanium, middle is a high thermal conductivity copper/aluminum layer, outer layer is stainless steel. Builds on safety to enhance heat exchange efficiency (faster water boiling/cooling). | Advantages: Balances safety and thermal conductivity speed. Disadvantages: Complex structure, highest manufacturing cost. |
How to Choose and Future Trends
These two technological paths have different emphases:
Coating technology involves an "addition" to the stainless steel substrate, enhancing performance by applying functional layers; it is currently the mainstream in the market.
Composite technology involves a "multiplication" at the material level, achieving functionality through metal lamination; it is a high-end solution oriented towards the future.
Overall, the technology is evolving towards being "safer and healthier" and offering "more integrated functionalities".
