Common reasons for silicone seepage include the following:
Silicone performance and formulation problems
Poor glue performance: The internal structure of the glue is unstable, and the cohesion is insufficient when the product is fitted, causing the glue to overflow from the edge.
Inappropriate viscosity: The viscosity of the silicone is too low or the fluidity is too strong, which is easy to penetrate into the gaps of the material.
Imbalanced curing agent ratio: Too much or too little curing agent is added, resulting in incomplete or too fast curing of the silicone, which may cause seepage.
Material impurities: Impurities or moisture are mixed into the silicone, affecting its fluidity and curing properties.
Operation process problems
Excessive coating amount: The amount of silicone coating exceeds the material absorption capacity, causing excess glue to overflow.
Uneven coating: Inconsistent coating strength or speed causes local silicone accumulation and increases the risk of seepage.
Improper temperature control: Too high a temperature will accelerate the flow of silicone, and too low a temperature may prolong the curing time, both of which are easy to cause seepage.
Uneven pressure: Uneven pressure distribution during molding or vulcanization may cause silicone to seep out from weak points.
Material and mold problems
Fabric material: Fabrics with rough surface or low density (such as fine velvet, mercerized cotton) are easy to absorb silicone, resulting in glue seepage.
Mold gap: If the mold gap is too large or uneven, the silicone may overflow under pressure.
Poor exhaust: The mold exhaust groove is not designed reasonably, and the gas cannot be effectively discharged, which may force the silicone to seep out of the gap.
Equipment and environmental factors
Equipment aging: Equipment wear or mold locking mechanism failure may cause the mold to be loosely closed, causing glue seepage.
Ambient temperature and humidity: High temperature and high humidity environment will accelerate the flow of silicone, while low temperature and low humidity may slow down the curing speed, both of which increase the risk of glue seepage.
Improper storage: If the silicone exceeds the shelf life or the storage conditions are improper (such as high temperature and humidity), the performance may decrease and cause glue seepage.
Suggestions for solution:
Optimize the silicone formula and adjust the viscosity and curing agent ratio.
Improve the coating process, control the coating amount and ensure uniformity.
Optimize the mold design, reduce the gap and improve the exhaust system.
Strictly control the temperature and humidity of the operating environment and maintain the equipment regularly.
Use high-quality silicone materials and avoid improper storage.