The bottom of the plastic bottle is recessed to allow the beverage bottle to stand firmer. If it is a flat-bottomed plastic bottle, it is easily deformed due to the hydraulic pressure, and it usually protrudes outward, so that the beverage bottle is not stable. However, if the bottom is designed in the shape of a groove, the stress area of the bottom is increased, and the pressure is reduced, so that it is not easy to deform. And even if the entire bottom does not touch the table, as long as the force is uniform, it can stand very stably. The stability of the five-claw shape is very good, so a large part of the common plastic bottles are made into a five-claw shape. Plastic bottles are usually only disposable. If you use it to hold hot water, you will notice that it will deform and either bulge or shrink. In addition to becoming strangely shaped and difficult to stand, plastic products also release toxic substances at high temperatures.