Soft rubber, the white opaque bicycle water bottle that accounts for a large market share is made with it. Put the kettle upside down and you will find some symbols printed with material descriptions. If you don’t even have these, and a blank one, it is recommended to call 12315 immediately to report the fake and shoddy goods... Generally, there is a small triangle mark on the bottom of the plastic container. There is also an Arabic numeral in the middle of the logo, from 1 to 7.
Generally, the soft rubber water bottle is made of HDPE of “2” or LDPE of “4”. "2" plastic is relatively stable and can heat up to 120°C, but "4" plastic cannot be directly filled with boiling water, and the maximum water temperature cannot exceed 80°C, otherwise it will release plastic preparations that cannot be decomposed by the human body.
Hard rubber, the most famous representative of which is nalgene's transparent bicycle kettle OTG, which is known as the "non-breaking kettle". It claims that it will not explode even if it is run over by a car, and it is heat-resistant and cold-resistant. Its bottom number is "7". "7" is the PC code, because it is transparent and resistant to fall, and is widely used in making water bottles, water cups, and baby bottles.
Pure aluminum, the most famous is the Swiss SIGG sports water bottle, which also produces bicycle water bottles, and France’s Zefal aluminum water bottle. It is also a high-end aluminum kettle. Upon closer inspection, it has a coating on the inner layer, which is said to prevent bacteria and prevent direct contact between aluminum and boiling water to generate carcinogens.
When aluminum encounters acidic liquids (juices, sodas, etc.), harmful chemicals are produced. Long-term drinking of aluminum pots may cause memory loss and mental decline. On the other hand, pure aluminum is relatively soft, and it is most afraid of bumps and bumps when dropped. The appearance is not a big problem. The most feared is that the coating will be cracked and lose its original protective function. This is no use.
In contrast, stainless steel kettles do not have the problem of coating, and can be made into double-layer insulation. In addition to heat preservation, the double layer has the advantage that hot water is not hot. Don't think that you don't drink hot water in summer. Sometimes in places where you can't reach the village or the shop, the experience of hot water is far better than that of cold water. In an emergency, the single-layer stainless steel pot can be directly set on fire to boil water.
This is something other kettles cannot do. Many domestic stainless steel kettles are of very good quality and are more resistant to bumps. However, stainless steel water bottles are heavier and heavier when filled with water. Generally, the plastic bottle cages on bicycles may not be able to bear it. It is recommended to replace them with aluminum alloy bottle cages.