What causes cracks in silicone coated products?

There may be many reasons for cracks in silicone coated products, and the following are some common factors:
Material issues:
The liquid silicone rubber (LSR) used is of poor quality or has deteriorated. The chemical compatibility between plastic substrate and silicone is poor.
Design defects:
Insufficient consideration of stress release areas during design resulted in stress concentration. Unreasonable structural design leads to uneven stress distribution.
Production process issues:
Improper control of injection molding temperature, pressure, and time. Improper vulcanization conditions (such as temperature and time) during the secondary molding process.
Mold issue:
Mold wear or damage, resulting in poor molding. Unreasonable mold design and uneven distribution of cooling system.
Improper post-processing:
Microcracks caused by improper operation during the cutting and trimming process. The use of cleaning agents or other chemicals can cause damage to silicone gel.
Environmental factors:
An environment with frequent changes in high and low temperatures may lead to material fatigue and crack formation. Moisture infiltration in high humidity environments may also affect adhesive strength and durability.
Aging phenomenon: Natural aging caused by long-term exposure to ultraviolet radiation or prolonged use.
Mechanical impact or excessive stretching: External forces beyond the designed tolerance range of the product can also cause cracking. Internal bubbles or shrinkage defects cannot be completely eliminated, forming stress points and further developing into cracks under specific conditions.
Inappropriate handling and storage: Improper handling and storage during the process from production completion to final use may also cause product damage

Solution
1. Improve the quality of silicone raw materials: Choose high-quality silicone raw material suppliers to ensure stable quality of silicone raw materials. At the same time, strict inspection and screening are carried out on the incoming silicone raw materials to ensure that they meet production requirements.
2. Optimize the use of additives: Select appropriate types and amounts of additives based on product characteristics and production process requirements. At the same time, pay attention to the uniformity and usage of additives to ensure that they can fully exert their effects.
3. Adjust the molding and vulcanization process parameters: Adjust the molding and vulcanization process parameters according to the product characteristics and production conditions to ensure that the silicone encapsulated products can fully flow and be vulcanized. At the same time, regular maintenance and inspection of the molds are carried out to ensure that they are in good condition.
4. Optimize product design and mold design: Fully consider the usage environment and stress conditions during product design to avoid issues such as uneven wall thickness and stress concentration. Pay attention to issues such as parting surface design and exhaust design during mold design to ensure smooth demolding and exhaust of silicone encapsulated products during the molding process.
5. Control environmental factors: During use, control the range of changes in environmental factors such as temperature and humidity to avoid excessive or insufficient temperature and humidity affecting silicone encapsulated products. At the same time, regular maintenance and inspection of silicone encapsulation products are carried out to promptly detect and address issues such as cracks.