The code on the glass bottle: interpreting the meaning of the bottom mark and symbol

The numbers, letters and symbols on the bottom of the glass bottle are not randomly carved, but industrial identifications that carry production traceability and quality control. This article will analyze the deeper meaning of these marks.

1. Mold number: the key to quality tracking
The most common numbers on the bottom of the bottle (such as "1", "2" and "3") represent the mold number. A single row machine on a modern production line is usually equipped with 6-10 sets of molds for synchronous production. When quality defects (such as skewed bottle mouth and bubbles) are found in random inspections, the problem mold can be quickly located by the bottom number of the bottle to avoid scrapping the entire batch of products.

Example: A factory found that the wine bottle was skewed during quality inspection, and locked the wear of the No. 7 mold positioning pin with the "7" on the bottom of the bottle, saving 100,000 bottles.

2. Identity code: the imprint of the manufacturer and brand
There are two types of letter marks:

Manufacturer mark: such as "RT" (Ruitai Glass), "LL" (Linlang Glass)

Purchaser mark: such as "WDS" (Wandashan Custom Bottle)
The combination mark "RT-05" means: Ruitai Glass Factory No. 5 mold production.

3. Digital safety controversy: truth and misunderstanding
Rumor: Bottles with numbers ≥5 can be safely reused, and those <5 will release harmful substances.
Fact:

This grading standard actually applies to plastic bottles (such as PET marked "1")

The safety of glass bottles depends on the material (soda-lime glass/borosilicate glass), and has nothing to do with the mold number

Suggestion: When reusing glass bottles, observe whether the bottle body is worn and cracked, rather than relying on digital judgment.

4. The scientific value of the concave design (arch bottom)

Enhanced compression resistance: the concave structure increases the load-bearing capacity by 30%

Sedimentation control: the concave bottom of the wine gathers sediment, and the wine is not turbid when poured

Buffer protection: reduce the contact area of ​​the table, shockproof and heat-insulating

Note: the triangle symbol on the bottom of the bottle (internal mark 1-7) is a plastic recycling mark and has nothing to do with glass bottles.

5. Strict standards for medical glass bottles
Medicinal bottles must meet the requirements of the "Chinese Pharmacopoeia", and the core tests include:

Item Standard requirements
Heat shock resistance Borosilicate glass ≥60℃ temperature difference, soda-lime glass ≥42℃
Internal pressure resistance Withstand 0.6MPa high pressure without breaking
Internal stress Optical path difference ≤40nm/mm (anti-self-explosion)
This type of bottle is additionally marked with the material grade (such as "Class I borosilicate glass").