Crown Cap Raw Material Introduction

Production Raw Material – Iron

Thickness: Typically 0.23-0.24mm, deviation within ±4%

Size: 903.04*1017.6mm, cap diameter 26.0mm

Rockwell Hardness: Typically T-4 CA, T-5 CA, or T-5 BA

Key points for iron materials: stable thickness, stable bending strength, good dimensional consistency, and no obvious appearance defects.

Production Raw Material – Granules

1. Oxygen Absorber: The granules contain oxygen-absorbing substances. Under high temperature or high humidity conditions, the oxygen absorption activity is activated, and it slowly begins to absorb oxygen that seeps into the beer during storage, maintaining or reducing the oxygen content in the bottle neck.

2. Non-Oxygen Absorber: Polyethylene copolymer without added oxygen-absorbing substances. The gasket has higher high-temperature resistance than PVC gaskets and generally higher hardness.

3. Key Quality Points for Granulated Materials

1) Sealing Performance: Comparison of instantaneous pressure, chronic leakage, and leakage rate after use;

2) Odor: Different materials have different inherent odors; no odor should be detected by smell; the evaluation requirement is no odor after boiling in water;

3) Melt Flow Index: The melt flow index of the granules should be tested using a dedicated melt flow indexer. If it is within the technical standard range, it reflects the flowability and stability of the granules. Typically, it is 6-9 g/10 min.

During cap making, the gasket should be formed completely, smoothly, and hygienically, without affecting the cap making speed.