What is a thermos? Criteria for choosing a thermos

A thermos bottle is a utensil that can keep the temperature of food and drinks intact for a period of 12 to 24 hours, depending on the thermal retention quality of each type of bottle as well as the manufacturing technology of the manufacturers. Thermos bottles are currently popular and preferred by many people, especially students and office workers, due to their compactness, convenience, and health safety.

The operating mechanism of a thermos bottle is based on the principle of heat balance between the hot/cold food or drink contained inside the bottle and the external environment. In other words, the vacuum layer in the bottle will reduce the heat transfer of the objects inside to the outside and balance the heat between the external environment and the temperature inside the bottle, thereby slowing down the heat exchange process to keep the water in the bottle hot/cold for a longer period of time.

Structure of a thermos bottle

Usually, a thermos bottle is designed in the shape of a tall cylinder, about 20-30 cm high depending on each type, and consists of two parts: the bottle cap and the bottle body.

Bottle body: is composed of 3 layers:

• The outer layer, also known as the casing, is made of plastic with eye-catching colors or shiny stainless steel. Next is a vacuum layer for insulation, and the innermost layer is made of stainless steel 201 or 304.
• In particular, the insulating vacuum layer plays a very important role in reducing the temperature difference between the thermos bottle and the external environment, thereby prolonging the temperature preservation time for the food and drinks contained inside the bottle.
• The use of stainless steel also provides good heat retention efficiency, helps increase the heat retention ability of the product, and ensures the safety of food and the health of users.

Bottle cap: also contributes to better heat retention and minimizes heat transfer to the outside thanks to being designed with 2 layers. The outer layer of the cap is designed with a screw twist that can be screwed tightly to the bottle body. The inner layer is made of virgin plastic with an additional piece of rubber or silicone gasket to tightly seal the mouth of the bottle, keeping the heat inside the bottle. Users can pour water by opening the outer plastic layer and pressing the button located in the inner lid of the bottle.

Structure of a thermos bottle

Reasons to use a thermos bottle

Always have delicious drinks and food

For food and beverage enthusiasts who enjoy “home-cooked” food, choosing a thermos bottle is an indispensable choice. With the ability to retain heat (both hot and cold) for up to 24 hours, the thermos bottle ensures that the water in the bottle, such as smoothies, fruit juices, or hot drinks like coffee, porridge, soup, hot tea, retains its original flavor, freshness, and nutrition.

Safety and easy to use

With its compact and convenient design, a thermos bottle can be easily used by both children and the elderly, making it suitable for various age groups.

In addition, high-quality thermos bottles are made of stainless steel (stainless steel) materials that ensure high durability, no leakage or corrosion, and do not affect the quality of drinks and ensure the safety of users. Most importantly, for high-quality bottles, the inner lining is made of premium grade 304 stainless steel, which is extremely safe for health.

More cost-effective

Instead of spending money on office lunches, which can cost between 35k – 55k VND per meal, why not bring your own food from home? This will help you save a lot of money and ensure the safety of your food.

Protect the environment

If you drink a plastic bottle of water every day, you will dispose of 365 plastic bottles in a year. This has a serious impact on the living environment of everyone. You may not notice it, but future generations will be affected the most. Therefore, let’s join hands to protect the environment!

Cleanliness

Washing your own utensils ensures that every use is clean. On the other hand, if you use plastic cups, hygiene cannot be guaranteed due to the production process, transportation to consumption is not guaranteed and verified…

Fashionable, compact, and easy to carry

With its compact design and capacity ranging from 350ml, 500ml, 700ml, a thermos bottle is very convenient to carry to work, school, or outings. You just need to put the bottle in a backpack, handbag, briefcase, suitcase, or strap it to a motorbike, and you can take it anywhere.

The necessity of a thermos bottle

Criteria for choosing a good thermos bottle

Intended use

To choose a useful thermos bottle, you need to consider your intended use to maximize its effectiveness. For example:

• If you bring your own coffee to work: you should choose a small-sized bottle that is compact and lightweight. Bottles with a capacity of around 300-500ml are the best choice.
• If you bring your own lunch to work: you should use a dedicated thermal lunch box that can hold more food.
• If you bring drinks for a picnic: you should choose a bottle with a capacity of 1 liter, so that everyone can enjoy the drinks you made.

Bottle material

This is considered an important factor that determines the quality of the thermos bottle. However, there are many different types of stainless steel, such as 201, 430, 304… but not all types of bottles are made from high-quality stainless steel.

• You should use a bottle with a structure composed of 3 layers: “Stainless steel casing – vacuum layer – stainless steel bottle liner”, which will provide better heat retention and prolong the heat preservation time for the food and drinks inside the bottle. Stainless steel 304 is a durable and reliable stainless steel, resistant to rust and does not contain harmful substances, ensuring the health of consumers. In contrast, low-quality products used to hold hot water for a long time often rust quickly.
• Another type uses an inner layer coated with a layer of silicone with better heat retention (up to 48 hours). This type is only suitable for holding water and hot food below 70 degrees Celsius, although it is not common and quite expensive.
• In addition to the bottle body, the plastic cap also affects the safety of using the thermos bottle. You should choose a bottle with a cap made of virgin plastic (usually shiny and odorless). Different from recycled plastics that are not shiny and often have an unpleasant odor. Bottles with caps made of stainless steel are also a safe choice. To maximize heat retention, the cap is usually equipped with a silicone gasket to seal the cap more tightly.

Thermos bottles have many benefits

Design style

You may want to embrace a beautiful Poodle or walk a Buffalo through the streets. Therefore, a beautiful and fashionable design will be a better choice for you.

Heat retention time

Generally, thermos bottles can retain hot or cold water for 6 to 8 hours or up to 24 hours for high-end bottles. After a period of use, if the thermos bottle no longer retains heat as it used to without the aforementioned cases, it may be that the bottle has been used for too long (2-3 years), and the heat retention layer no longer functions. In that case, you need to replace the bottle to ensure quality usage.

• If you need to retain heat during the day for work, school, outings, bottles with a capacity of 300-500ml and a heat retention time of 12-24 hours are sufficient.
• However, if you go on long trips, you should consider choosing larger capacity bottles with heat retention times exceeding 24 hours. These bottles have an additional layer of silicone, which helps extend the heat retention time up to 48 hours. However, they should only be used with temperatures below 70 degrees Celsius.

Choose the best brand

You should choose and purchase a thermos bottle from a reputable and certified brand and manufacturer to ensure safety. Some famous brands are: Lock & Lock, Elmich, Thermos…

Choose a reputable seller

After choosing the right product and brand, you should also consider where to buy them. When thermos bottles become common household items as they are today, it is inevitable to encounter counterfeit, fake, and poor-quality products.

Pricing

Finally, after choosing the appropriate thermos bottle, you will want to find the cheapest place to buy the product. I find that the prices of genuine products on the market do not differ much, usually with a difference of around 20-30k VND. Therefore, to avoid buying counterfeit or poor-quality products, I still prefer to choose a reputable and trustworthy place to buy. What about you?

Best thermos bottle brands

Lock & Lock

Lock & Lock is a leading household brand in terms of quality, elegant design, and perfect construction, making it very popular and highly regarded by users. The products are extremely practical as they can be carried anywhere at any time, have beautiful designs, and high heat retention capacities of up to 6-8 hours.

What makes users increasingly choose Lock & Lock is the absolute safety for health and environmental friendliness. From the outer design to the inside, the products meet standards that help increase heat retention and are very solid, easy to hold without slipping. And currently, when it comes to cost, Lock & Lock has a wide range of prices that are not too high, making it suitable for the Vietnamese people’s budget when they want to use high-quality and safe products.

Thermos

Established in 1904 in Japan, Thermos is currently one of the world’s leading brands in the production of thermal and leak-proof products for food and beverages, lunch boxes for children, and other consumer products.

Thermos products are considered high-end products bearing the Japanese brand, so they are also among the top 10 best thermos bottles on the market. The products are designed to be extremely modern, eye-catching, and very safe even when subjected to strong impacts or falls.

They are also highly regarded for their outstanding durability as they are made from durable, reliable stainless steel materials that are scratch-resistant and provide excellent insulation in the bottle’s cap, bottom, and insulating body, ensuring excellent heat retention during use. These superior features have made Thermos products highly rated and the best quality on the market.

Tiger

Tiger has achieved considerable success thanks to its intelligent products, making it highly popular among users, from rice cookers to thermos bottles. And when it comes to high-end, widely applied products, this brand offers users the highest level of peace of mind in terms of safety.

Tiger thermos bottles have a compact design, 2 convenient lids, and effective anti-spill properties, making them easy to clean by being able to separate the parts. With a two-layer 304 stainless steel structure, the bottles have excellent heat retention and large capacity. They also have a vacuum layer that helps with heat retention and a silver-plated inner layer for better heat retention compared to typical thermos bottles.

Elmich

Elmich is a brand from the Czech Republic and is famous in Europe, giving consumers confidence in the quality of their products. By applying advanced science and understanding the market, they have created products such as thermos bottles with a capacity of up to 1L, which are highly favored by users.

These 1L bottles are the largest and have outstanding features in terms of design: They use the highest-quality stainless steel, 304, which gives the bottles a shiny and luxurious appearance. The Elmich thermos bottle is also very sophisticated with an outer cap that has excellent fire resistance and a great pouring function when you need to pour water comfortably. In addition, with its compact size and beautiful design, the thermos bottle is highly preferred by young people for use in offices, companies, factories, etc.

Hello Kitty

With its cute design and being a product of the Lock & Lock brand, the Hello Kitty thermos bottle is suitable for many different age groups, especially young children who go to school. The product guarantees quality as a thermos bottle with a high heat retention capacity and great durability thanks to its premium stainless steel material, ensuring high safety.

Zebra

Zebra is a brand from Thailand. Zebra thermos bottles are designed to be compact, eye-catching, and provide high-quality for a heat retention time of 6 hours and cold retention for up to 8 hours. The 2-mode bottle makes it easier for you to use whether you are traveling or using it in the office.

Rang Dong

Rang Dong is a Vietnamese brand and is well-known to the public as a leading company in the production and supply of LED lighting systems. Despite having to compete with many foreign brands, Rang Dong’s thermos bottles have been able to maintain their position in the market for many years and are highly trusted by many customers due to being a Vietnamese product with affordable prices and good quality.

When to replace a thermos bottle?

The cap or rubber gasket is damaged:

When the rubber piece (silicone) that tightly seals the bottle mouth expands or is damaged, it will not guarantee the air-tightness for maintaining the water temperature inside the bottle, and it can cause leakage, spilling water, affecting the users’ experience. In this case, you should replace the bottle to ensure safety.

The bottle is dented due to impacts or falls:

If the bottle is dropped or hit somewhere during use, causing dents, it will affect the material of the layers inside the bottle, reducing the heat retention ability and function of the thermos bottle.

When to replace a thermos bottle

Rusting bottle:

If the bottle is made of low-quality materials, it may rust after a few uses. Besides, during long-term use, improper cleaning methods can also lead to rust. If it cannot be fixed, you should replace the bottle to avoid affecting your health.

The bottle no longer retains heat for a long time:

Thermos bottles typically retain hot water or cold drinks for 6 to 8 hours, or even up to 24 hours for high-end bottles. After a period of use, if the heat retention time of the bottle is no longer as good as before without the aforementioned cases, it may be used for too long (2-3 years), and the heat retention layer is no longer effective. To avoid affecting your daily water needs, you should replace it with a new bottle.

Instructions for using and maintaining a thermos bottle

Proper use of a thermos bottle

• If it is a newly purchased product, before use, clean it with dishwashing liquid or baking soda powder or vinegar to wash away any new product odor inside the bottle. This way, when using the water storage bottle, it will not affect the taste and quality of the water.
• Avoid storing fruit juices with high vitamin C content such as orange juice, lemon juice, apple juice in the bottle because the acid in the fruit juice can erode and dissolve the heavy metals remaining in the bottle, especially arsenic, copper, lead, and mercury, all of which are harmful substances to the body.
• Also, when storing tea or coffee in the bottle, you need to clean it thoroughly because these drinks often leave residues that are difficult to remove. You can use the following methods:
• Use vinegar with eggshells. Just put these two things inside the bottle, shake for a while and then rinse with warm water. Your thermos bottle will be completely clean and odorless.
• To remove coffee or milk odors, just put 1 tablespoon of rice in the bottle and add a little hot water, shake well. After that, rinse with cold water to remove all the unpleasant odors.

Cleaning a thermos bottle

If you only store regular filtered water, you can use a small amount of detergent to clean the bottle, then rinse it thoroughly and let it dry before reuse. This simple cleaning method will help prolong the life of your thermos bottle. Absolutely do not use strong cleaning agents, corrosive liquids (cleaning agents, acetone, etc.) for cleaning.

If your bottle contains coffee, milk, etc., which can leave odors and are difficult to clean, you can try the following methods:

• Use vinegar with eggshells, just put these two things inside the bottle, shake for a while, and then rinse with water. Your thermos bottle will be completely clean and odorless.
• To remove coffee or milk odors, you can put 1 tablespoon of rice into the bottle and add a little hot water, shake it well. After that, rinse with cold water, and the unpleasant smell will disappear completely.

Storing a thermos bottle

Avoid strong impacts:

Whether the thermos bottle has a glass or stainless steel liner, you should avoid strong impacts on the bottle. With thermos bottles with glass liners, the liner can crack or break, and the bottle cannot be used. With thermos bottles with stainless steel liners, the structure of the bottle will be damaged, causing dents, instability or displacement, which also reduces the heat retention function of the bottle.

Avoid microwave usage:

Thermos bottles are designed to keep the temperature inside and are not designed to withstand heat from the outside. Putting the bottle in a microwave oven (high temperatures) will cause the bottle to expand. The bottle can become hot, melt, deform, or even explode. Therefore, pour water into a ceramic cup before putting it in the microwave oven.

Avoid putting a thermos bottle in the microwave oven

Thermos bottles can keep both hot and cold water. However, when using them properly, do not pour cold water immediately after pouring hot water or vice versa. You should give the bottle a breathing time of about 15 minutes between storing hot and cold water. The sudden temperature change of the bottle will cause sudden expansion of the different materials inside the bottle and reduce the service life of your thermos bottle.