This is a good question that many people want to know. PET, short for Polyethylene Terephthalate, is a recyclable plastic. When it comes to manufacturing beverage bottles, the advantages of PET materials make it one of the best choices. Here are some of the main advantages of PET materials: 

1. Lightweight: Beverage bottles must be light to better transport and preservation, PET material is very light, which is one of the reasons why it is very popular.

2. Safety: PET material is non-toxic and does not negatively affect the quality of the beverage. It is widely used and is considered to be very safe.

3. Low production cost: The production cost of PET material is relatively low, and this is another reason why it is widely used.

4. Recyclable: PET can be recycled and reused, which means it has a relatively small impact on the environment. By recycling PET bottles, the number of landfills can be reduced.

5. Good transparency: The transparency of PET material is very good, which can let people clearly see the drink in the bottle, which is one of the reasons why it is widely used in beverage bottles.

In short, why drink bottles are made of PET material is because of its many advantages. It is a very lightweight, safe, low cost, recyclable and transparent material. These advantages make it one of the best materials for beverage bottles. We should make full use of the advantages of PET materials and do our part to protect the environment.