The UV protection of glass bottles is mainly achieved through material modification, surface treatment, and coating technology to prevent the contents (such as skincare products, drugs, alcohol, etc.) from decomposing or deteriorating due to light exposure. The following are detailed protection methods and principles:
1.The three core methods of UV protection for glass bottles
- Material modification: Adding metal oxides
Adding specific metal oxides to glass raw materials to alter their molecular structure to absorb/block ultraviolet radiation:
Cerium oxide (CeO ₂): highly effective absorption of UVA (320-400nm), widely used in medicine bottles and essence liquid bottles.
Iron oxide (Fe ₂ O3): endows glass with green or brown color and blocks some UV rays (such as beer bottles).
Titanium oxide (TiO ₂): Reflects ultraviolet light and enhances glass strength.
Effect comparison:
Glass type UV blocking rate Common uses
Transparent soda lime glass 10% -20% ordinary packaging bottle
Amber colored glass with over 90% photosensitive drugs and essential oil bottles
Black glass>99% high active ingredients (such as vitamin C essence)
- Surface coating: UV barrier coating
Spraying or vacuum depositing special coatings on glass surfaces:
Titanium dioxide (TiO ₂) coating: A nanoscale reflective layer is formed by magnetron sputtering, with a barrier rate of up to 95%.
Organic silicon resin coating: containing UV absorbers (such as benzotriazoles), low cost and high transparency.
Double sided composite film: outer layer scratch proof+inner layer UV absorption (such as perfume bottle) to avoid the coating contacting the contents.
- Physical shading: Dark glass
Filter specific wavelengths of light through color:
1.Brown/Amber: blocks ultraviolet light with a wavelength<450nm, suitable for wine and medicine.
Blue cobalt glass: mainly blocks infrared radiation, with weak UV protection.
Black/dark green: Almost full band protection, used for high-end photosensitive products.
2.Selection of UV protection solutions for different scenarios
Application Case of Content Characteristics Recommendation Scheme
Ordinary solution (non photosensitive) transparent glass+ordinary sealed mineral water bottle, seasoning bottle
Medium photosensitive (essential oil, medicine) amber glass (iron oxide) essential oil bottle, oral liquid bottle
High active ingredients (vitamin C, retinol) black glass+ceria whitening essence, anti-aging ampoule
High transparency protective transparent glass+TiO ₂ coating high-end skin care products, perfume bottles
3.Identification and detection of UV resistant glass bottles
- Appearance assessment:
Dark colored glass (brown/black/green) usually has stronger UV resistance.
Transparent UV resistant bottles may be labeled as “UV Protect” or “Amber Glass”.
- Technical testing:
UV spectrophotometer: measures the transmittance of glass in the UVA/UVB band (requirement<10%).
Accelerated light test: The control sample was exposed to UV light for 7 days to test the stability of the content components.
4.Precautions for use and storage
- Avoid prolonged exposure to light: Even when using UV resistant bottles, they should be stored in a cool and dark place.
- Regular replacement: The anti UV coating may wear out due to cleaning (especially mechanical brushing), and it is recommended to replace the bottle with a new one every 2-3 years.
- Compatibility test: if acid content (if acid essence) may corrode metal oxide coating, immersion test shall be conducted in advance.
5.Industry Innovation Trends
- Intelligent photosensitive glass: When the light exceeds the threshold, the bottle body becomes darker (such as photochromic materials).
- Environmental protection and UV protection technology: Develop bio based UV absorbers without heavy metals (such as lignin derivatives).
- Nano self-cleaning coating: Combining anti UV and hydrophobic functions to reduce stain adhesion.
