Bottled beverages have been developed for more than 100 years, from glass bottles to aluminum cans and plastic bottles. In 1963, aluminum cans were invented in the United States. Based on the previous filling method, a pull ring was designed on the top. This is a practical invention that brings great convenience to people, so it quickly became popular.
Then the question arises. The can body materials of canned beverages are mainly aluminum, tinplate and other metals. However, carbonated beverages, tea, milk and other substances are acidic or weakly alkaline. If they are stored in metal materials, they will corrode the metal materials. So how can we prevent the beverage from being corrosive?
Let's use the aluminum can thermal analyzer to unlock the secrets
Experimental conditions: Cut a small piece of about Φ5mm from the aluminum can, and then analyze the sample with a thermal analyzer.
First, we used a thermogravimetric-differential thermal analyzer for analysis: the results showed that weight loss occurred at about 200℃. Metals such as iron and aluminum will definitely not decompose at 200℃. What is the component of this weight loss? This component is the polymer multilayer film coated on the inner wall of the can to prevent beverage corrosion.
Then we used a thermomechanical analyzer for analysis: using a needle-penetrating probe, the softening temperature caused by the glass transition and melting of the coating layer can be evaluated. In addition, it can be known that the thickness of the coating layer is about 20μm.
It can be seen that the polymer multilayer film contained in the Φ5mm material is very small, and the measured weight is about 0.292mg. Using a differential scanning calorimeter for analysis, it can be seen that even if the content is small, the composite sample of the coating layer and the can can clearly measure the melting peak of the coating layer.
In summary, the aluminum can thermal analyzer has the advantages of good baseline stability and high sensitivity. Even for trace samples, it can accurately capture small changes and trace changes.
