How to identify the material quality of stainless steel thermos?

How to identify the material quality of stainless steel thermos?
Stainless steel thermos are popular for their heat preservation and durability, but the quality of products on the market varies greatly. It is important for consumers to know how to identify the material quality of stainless steel thermos. Here are some key factors and methods to help you identify the material quality of stainless steel thermos:

1. Check the stainless steel material label
High-quality stainless steel thermos will usually clearly mark the stainless steel material used on the bottom or packaging. According to the national standard GB 4806.9-2016 “National Food Safety Standard Metal Materials and Products for Food Contact”, the inner liner and stainless steel accessories that are in direct contact with food should be made of 12Cr18Ni9, 06Cr19Ni10 grades of stainless steel, or other stainless steel materials with corrosion resistance not less than the above specified grades. Therefore, checking whether the bottom of the thermos is marked with “304″ or “316″ is the first step to identify the material.

2. Observe the heat preservation performance of the thermos
The heat preservation performance is the core function of the thermos. The insulation performance can be identified by a simple test: pour boiling water into the thermos cup, tighten the bottle stopper or cup lid, and touch the outer surface of the cup body with your hand after 2-3 minutes. If the cup body is obviously warm, especially the heat in the lower part of the cup body, it means that the product has lost its vacuum and cannot achieve a good insulation effect.

3. Check the sealing performance
The sealing performance is another important consideration. After adding water to the stainless steel thermos cup, tighten the bottle stopper or cup lid in a clockwise direction, and place the cup flat on the table. There should be no water seepage; the rotating cup lid and the cup mouth should be flexible and there should be no gap. Put a cup of water upside down for four to five minutes, or shake it vigorously a few times to confirm whether it leaks.

4. Observe plastic accessories
Food-grade new plastic features: small odor, bright surface, no burrs, long service life, and not easy to age. Features of ordinary plastic or recycled plastic: strong odor, dark color, many burrs, easy aging and easy to break. This will not only affect the service life, but also affect the hygiene of drinking water

5. Check the appearance and workmanship
First, check whether the surface polishing of the inner and outer liner is uniform and consistent, and whether there are any bruises and scratches; second, check whether the mouth welding is smooth and consistent, which is related to whether the feeling when drinking water is comfortable; third, check whether the internal seal is tight, whether the screw plug and the cup body match; fourth, check the cup mouth, which should be smooth and free of burrs

6. Check the capacity and weight
The depth of the inner liner is basically the same as the height of the outer shell (the difference is 16-18mm), and the capacity is consistent with the nominal value. In order to cut corners, some brands add sand and cement blocks to stainless steel thermos to increase weight, which does not mean better quality

7. Check labels and accessories
Manufacturers who value quality will strictly follow the relevant national standards to clearly indicate the performance of their products, including the product name, capacity, caliber, manufacturer name and address, adopted standard number, usage methods and precautions during use

8. Conduct material composition analysis
When testing the quality of 316 stainless steel thermos, you can use the material composition analysis method to ensure that it meets the relevant food safety standards

Through the above methods, you can more accurately judge the material quality of the stainless steel thermos, so as to choose a safe, durable and high-performance product. Remember, choosing the right stainless steel material (such as 304 or 316) is the key to ensuring product safety and durability