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Why is the Bottom of the Plastic Water Bottle Recessed?

I believe that when many careful friends choose to buy plastic water bottles, they will find that the bottom is concave. Many people think that this is because the merchant has uniformly made a concave bottom in order to reduce materials. In fact, it is not the case. The following is the answer from Dongguan Zhanyi Commodity Technology Co., Ltd.

1. Convenience in Bottle Making Technology

In the process of blowing, in order to make the thickness of the plastic bottle uniform at the bottom of the mold, it is easier to form a concave shape, reducing the waste rate and increasing the stability.

2. Material Saving

If it is made into a flat bottom, because it has to withstand the pressure of the liquid, the bottom must be thickened, resulting in a waste of materials. With the concave type, since the five corners equally share the liquid pressure, the bottom can be made thinner, saving materials.

Increase the strength of the bottom of the bottle


Why is the Bottom of the Plastic Water Bottle Recessed

3. Reduce Damage

The pentagonal concave design makes it possible to reduce damage through moderate deformation. Ensure that the convex bottom of the bottle will not be deformed due to internal pressure during product filling, later transportation and use.


The plastic water bottles produced by Dongguan Zhanyi Commodity Technology Co., Ltd. use food-grade plastic materials such as PP, PS, AS, PC, etc., with 28 injection molding machines ranging from 100 to 360 tonnage, 1 blow-injection integrated machine, and 2 Blowing machine.

We have advanced management technology and produce 100,000 water cups per day. In strict accordance with international standards, all links are implemented, and the entire production process implements a full inspection system. The scale of the factory is about 15,000 square meters and there are more than 120 technicians. The production process includes process design, injection molding, metal processing, water expansion, stretching, stamping, vacuum, electroplating, spraying, and printing. We pass ISO9001 quality system certification, Starbucks factory inspection, Nestle factory inspection, BMW factory inspection, and Huawei factory inspection.