ZWB glass is a specialized colored optical glass known for its unique ultraviolet (UV) transmission and visible light absorption properties. “ZWB” stands for “Ultraviolet Band Transmission Black Glass,” and it is designed to have good transparency in the ultraviolet range while absorbing or blocking most of the visible light. This means that ZWB glass allows UV light to pass through while filtering out or absorbing most visible light.
ZWB glass is typically classified into three main types based on its transmission characteristics: ZWB1, ZWB2, and ZWB3. Each type represents a different UV transmission range:
- ZWB1: Primarily used for short-wave UV transmission, around 254 nm.
- ZWB2: Used for long-wave UV transmission, around 310 nm.
- ZWB3: Also used for long-wave UV but with an even longer transmission wavelength, around 365 nm.
The base glass used for ZWB glass can be phosphate glass or silicate glass, depending on the required transmission characteristics. To enhance UV transmission, manufacturers add reducing agents, such as sugar or tartaric acid, during the glass melting process. These agents reduce trace amounts of Fe³⁺ to Fe²⁺, thereby decreasing UV absorption.
ZWB glass has a wide range of applications, including:
- Geological Exploration: Used for mineral detection under UV light, as many minerals exhibit fluorescence under UV light.
- Non-Destructive Testing: Employed in industry to inspect material defects, such as cracks or corrosion, because UV light can activate fluorescent dyes or penetrants, making them glow in the dark.
- Medical Analyzers: Essential in biomedical fields like blood analysis and DNA testing, where UV transmission is crucial for exciting fluorescent markers.
- UV Light Source Filtering: Used in stage lighting, photography, or artistic lighting to create specific visual effects or ensure the purity of the light source.
The black appearance of ZWB glass and its transparency under UV light make it an ideal material choice for applications where UV light is needed without visible light. Due to its unique properties, ZWB glass plays an irreplaceable role in research, industry, and art.
