Do you know the secret at the bottom of plastic cups?

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On the market, every style and type of plastic cup bears various numbers and environmental‑friendly symbols on its bottom. But do you know what these numbers and markings mean? And what precautions or considerations should you keep in mind when using each type of cup? Next, we’ll walk you through some basic information on this topic.

First, mold number

The number on the bottom of the cup may be the mold number. During the cup‑making process, the molds are mounted on a rotary table, and each mold is assigned a unique number. These numbers are used to identify the mold’s batch and position, facilitating quality control and issue tracing throughout production.

Second, the production date or batch information.

The numbers on the bottom of some cups may indicate the date of manufacture or batch information. For example, on certain products, the numbers at the base might represent a serial code, the year of production, the day of production, or the production batch number.

Third, quality standards or manufacturer’s code

In some cases, the number at the bottom of a cup may be a manufacturer’s code or a quality‑standard marking. For example, certain glass cups have numbers on their bases that indicate the manufacturer’s code, ensuring the product meets international standards.

Fourth, material labeling

The numbers printed on the bottom of plastic cups typically indicate the type of plastic material. These numbers (1–7) are used to identify different plastics, helping consumers understand the cup’s material and any usage precautions.