What is Window Film？
Window film is a multi-layer, functional polyester composite film material, mainly applied to the glass surfaces of buildings and automobiles. It enhances glass strength and provides thermal insulation, UV blocking, privacy protection and other functions.
Why Apply Window Film
- Thermal Insulation & Energy Saving: Blocks solar radiation and reduces air conditioning energy consumption.
- UV Blocking: Blocks 99% of ultraviolet rays, protects human skin and prevents aging and fading of auto interiors.
- Safety & Anti-theft: Prevents glass splattering in accidents and makes it difficult for thieves to break windows.
- Privacy Protection: Creates a private space.
- Aesthetic Decoration: High-quality window film gives a new look to cars and buildings.
Application Classification of Window Film
- Automotive Window Film: National standard requires a visible light transmittance of ≥70% for front windshields and 5%-50% for side and rear windows.
- Architectural Window Film: National standard requires a reflectance of <30%.
- Safety Film: With a thickness of ≥4 mils, it is used for military and police vehicles, explosion-proof shields, bulletproof sentry boxes, petrochemical plant residential areas, etc.
Product Classification of Window Film
- Nano Ceramic Window Film: A high-end product with advanced ATO nano-dispersion technology, featuring high clarity and excellent thermal insulation performance.
- Magnetron Sputtered Film: A high-end product made by ion bombardment of various metal targets to form a multi-layer dense metal film with low reflectance and high thermal insulation. Combined with composite technology, it produces products with unique stable colors and high-level selective light transmittance. The product has sufficient toughness, explosion resistance, thermal insulation and a long shelf life.
- Aluminized Film: A mid-range product manufactured by vacuum coating technology, usually with pure aluminum coating. It can be made into films with different visible light transmittance and reflectance to achieve solar control performance.
- Dyed Film: A mid-to-low end product produced by coating an adhesive layer containing carbon or dyes between two layers of PET, presenting different colors and light transmittance.
Optical Indicators
- Visible Light Transmittance (VLT): The percentage of the intensity of light transmitted through the glass to the incident light intensity in the visible spectrum range (380 nm to 780 nm).
- Visible Light Reflectance (VLR): The percentage of the intensity of light reflected by the glass to the incident light intensity in the visible spectrum range (380 nm to 780 nm).
- Infrared Transmittance (IRT): The percentage of the intensity of infrared radiation transmitted through the glass to the incident infrared intensity in the infrared spectrum range (780 nm to 2500 nm).
- UV Blocking Rate (UVC): The percentage of the intensity of blocked ultraviolet rays to the incident ultraviolet light intensity in the ultraviolet spectrum range (280 nm to 380 nm).
- Total Solar Energy Rejection (TSER): The percentage of total solar energy blocked by the film-coated glass.
- Shading Coefficient (SC): The ratio of solar radiation energy transmitted through the film-coated glass to that transmitted through 3mm clear glass. A smaller shading coefficient indicates better performance in blocking direct solar radiation.
Physical Indicators
- Thickness: The thickness of window film is generally measured in mils, with 1 mil = 0.0254 mm.
- Tensile Strength: The tensile force required for the film of unit cross-sectional area to break during tensile testing.
- Elongation at Break: The percentage of the film length increase when the film breaks during tensile fracture testing.
- Peel Strength: The force required to peel the film of unit width from the glass surface at a 90° or 180° angle.
- Puncture Strength: The force required to pierce the film with a special test needle.