What Causes Silicone Oil Spots?
Table of Contents
What are silicone oil spots?
Silicone oil spots are uneven oily marks or local silicone accumulation formed on the surface of glass, rubber or medical plastic parts after siliconization. These spots are local thick silicone oil layers, which may shed silicone droplets and bring particle risk for pharmaceutical packaging. Even using medical-grade Liveo™360 silicone oil, improper operation will still lead to silicone oil spots.
Main application scenarios
Prefilled syringe siliconization production, rubber stopper coating process, glass vial inner surface treatment, medical component quality inspection, siliconization process failure analysis, cleanroom production troubleshooting.
Core knowledge
Improper spray parameter: Too high spray flow rate, uneven nozzle atomization will cause local over-deposition of silicone oil and form oil spots.
Excessive silicone oil dosage: Over-spraying is the most common cause. Too much silicone oil cannot spread uniformly and gathers into oily spots.
Unclean substrate surface: Dust, static residue or contamination on glass / rubber surface will prevent silicone oil film from spreading smoothly and form isolated oil spots.
Unsuitable dilution formula: Incorrect solvent mixing ratio leads to poor spreading performance of diluted Liveo™360 silicone oil, resulting in surface uneven coating.
Improper baking condition: Unreasonable temperature or heating time during baked siliconization makes silicone oil shrink and aggregate to form spots.
Mechanical friction & vibration during transportation: After siliconization, friction and shaking may peel off part of silicone film and re-form local oil spots.
Quality reminder: Silicone oil spots will increase silicone migration risk, which is critical for protein and biologic drug packaging. Optimize spray and baking process to avoid this defect.
Previous: What Is Emulsification？
