Stainless-steel vacuum flask generally refers the stainless-steel water bottle with a vacuum layer. It has a lid on the top and is tightly sealed. The vacuum insulation layer can delay the heat dissipation of liquids such as water inside to achieve the purpose of heat preservation.
There are many varieties of stainless-steel vacuum insulated flask on the market, and the prices are totally various. For some consumers, they do not understand the principle and often spend a lot of money to buy products that are not satisfied. How can we buy a high-quality insulated thermos bottle?
The first thing is the appearance of the thermos vacuum insulated bottle. First, check whether the inner and outer bladder surfaces are uniformly polished, and whether there are bruises and scratches. Second, look at whether the mouth welding is smooth and consistent, which is related to whether it is comfortable when drinking water. Third, look at plastic parts. Poor quality of plastic parts will not only affect the service life, but also affect drinking water hygiene. Fourth, check whether the internal seal is tight, whether the screw plug and the cup body are properly matched, whether it is free to screw in and out, and whether there is water leakage. You can pour a glass of water and invert it for four or five minutes or shake it vigorously to verify if it is leaking.
Then, look at the thermal insulation performance, this is the main technical index of the thermo flask water bottle. It can be checked by hand after filling it with hot water. The lower part of cup the body will heat up two minutes after the non-insulated cup is filled with hot water, while the insulated vacuum bottle is always cool.
Specific Identification Method
1. Simple Identification Method for Vacuum Insulation Performance
Pour boiling water into the steel vacuum flask and tighten the cork or lid clockwise for 2 to 3 minutes and then touch the outer surface of the cup with your hand. If the cup body has obvious warming, it means that the product has lost its vacuum and cannot reach a good level of insulation effect.
2. Sealing Performance Identification Method
After adding water to the steel flask bottle, tighten the stopper and lid in a clockwise direction, place the cup flat on the table, and there should be no water leakage. The screwing of the lid and the mouth of the cup should be flexible without gaps.
3. Plastic Parts Identification Method
New food grade plastics are characterized by low odor, bright surface, no burrs, long service life and not easy to age. Ordinary plastics or recycled plastics are characterized by large smell, dark color, many burrs, and plastics are easy to age and break.
4. Simple Capacity Identification Method
The depth of the inner tank is basically the same as the height of the outer shell, and the capacity is in line with the nominal value. Some low-quality vacuum flasks add sand and cement blocks to the cup to make up for the missing weight. A heavy vacuum flask is not necessarily good.
5. Simple Identification Method for Stainless-Steel Materials
There are many specifications of stainless-steel materials, 18/8 means that the composition of this stainless-steel material contains 18% chromium and 8% nickel. The material that meets this standard is a green product that meets the national food grade standard, and the product is rust and corrosion resistant. The color of the ordinary stainless-steel cup is whitish and dark. If it is soaked in 1% salt water for 24 hours, there will be rust spots. Some of the elements contained in it exceed the standard, which directly endangers human health.
Through the above techniques, we can choose a better quality vacuum steel bottle.