In simple terms: The rubber hot water bag must be vulcanized; otherwise, it simply cannot be used.
1.What exactly did sulfurization do?
Natural rubber originally was:
- Soft and lacking in strength
- Becomes sticky when heated and brittle when cooled
- Prone to aging and breaks easily when stretched
Sulfurization involves adding sulfur to the rubber and heating it to allow the molecules to "cross-link" into a network structure, transforming it into:
- Elastic, resistant to stretching
- Resistant to high temperatures and hot water
- Non-sticky,
- Excellent air tightness, no water leakage
2. Why are hot water bags necessarily made through vulcanization?
- Resistant to hot water: When exposed to 80-100℃ hot water for a long time, it will soften, deform and leak very quickly without undergoing vulcanization.
- Adequate strength: After being filled with water, it will expand and compress. Only after vulcanization will it be less likely to break.
- Long lifespan: Resistant to aging and fatigue. It is not prone to cracking even when repeatedly bent or subjected to alternating cold and heat.
Summary in one sentence:
Sulfurization = "strengthening + shaping + heat resistance" for rubber. This is the key process that makes rubber hot water bags safe and durable.
