High-Quality Pet Diffusion Film for Superior Light Distribution

• Customization: Available
• Adhesive Classification: Silica Gel
• Compatible Brand: General
• Model NO.: YLD108H
• Function: AG Frosting Membrane, Anti-View Protetor, AR Anti Glare / Radiation, Def Protective Film
• Material: PET
• Property: Self Adhesive Film
• To Fit Screen Size: Screen Size
• Viscosity: High Viscosity
• Base Material Thickness: 188
• Aggregate Thickness: 220
• Light Transmittance: 78%
• Haze: 95%
• Transport Package: Carton
• Specification: YLD108H
• Trademark: NO
• Origin: China
• HS Code: 3920620000

Product Description

Introduction to Diffusion Films

Definition and Basic Principles

A diffusion film is a thin film material formed on a substrate through physical or chemical methods, featuring a specific structure and function. Its basic principle is to scatter light on the surface, spreading it out softly and evenly. The basic structure of most diffusion films is to coat optical diffusing particles on both sides of a transparent substrate (such as PET). After the light source passes through the diffusion material, it can be transformed into a larger area, more uniform, and color-stable secondary light source.
Classification and Application Scenarios

By LCD Display Type

- Edge-lit: The diffusion material used in edge-lit displays is called a diffusion film (or diffusion sheet).
- Direct-lit: In direct-lit backlight sources, two types of diffusion materials are applied: diffusion films and diffusion plates.

By Application Field

- Optical Films: Mainly used in optical devices, displays, and other fields. For instance, in LCD backlight modules, diffusion films are essential components, primarily diffusing the light from the light guide plate, enabling line light sources (CCFL) or point light sources (LED) to be distributed as uniform surface light sources. Generally, an LCD requires two diffusion films: one upper diffusion film and one lower diffusion film. The lower diffusion film should have high light transmittance and low scattering, while the upper diffusion film requires higher diffusion and also has the functions of eliminating the patterns of the prism sheet and

protecting the prism sheet.

- Electronic Films: Used for the packaging and protection of electronic components.
- Functional Films: Widely applied in multiple fields such as new energy, environmental protection, and biomedicine.
Characteristics of Diffusion Films

Diffusion films are thin films with specific optical properties. Their main features include the following aspects:

1. Light Diffusion Characteristics

The core feature of diffusion films is their light diffusion ability. They can diffuse incident point or line light sources into uniform surface light sources, thereby improving the uniformity of light and visual comfort. This characteristic is mainly achieved by creating micro-structured concave and convex surfaces on the film or by adding scattering particles inside the film. When light passes through these structures, refraction, reflection, and scattering occur, resulting in an overall optical diffusion effect.

2. Semi-transparency and Matte Surface

Diffusion films are typically semi-transparent and have a matte surface. This characteristic allows light to pass through the film without generating mirror-like reflections, thereby reducing glare and reflection spots and improving display quality.

3. High Light Transmittance and Wide Haze Adjustment Range

Diffusion films have high light transmittance, meaning that most incident light can pass through the film. At the same time, the haze of diffusion films can be adjusted to control the degree of light scattering. This characteristic enables diffusion films to meet the requirements for light uniformity in various application scenarios.

4. Chemical Resistance and Temperature Resistance

Diffusion films are usually made of materials with good chemical resistance and temperature resistance, such as polyester (PET) or polycarbonate (PC). This ensures that diffusion films can operate stably in various environmental conditions and are not easily affected by chemical substances or temperature changes.

5. Multiple Specifications and Sizes

Diffusion films can be provided in various specifications and sizes according to different application requirements. For example, large-sized diffusion films are mainly used in TV backlight units, medium-sized ones in laptops and monitors, and small-sized ones in mobile phones and navigation devices.

6. Classification into Upper and Lower Diffusion Films

In LCD backlight modules, diffusion films are classified into upper and lower diffusion films. The main function of the lower diffusion film is to diffuse the light emitted from the light guide plate or the point or line light sources of direct-lit backlights into uniform surface light. The upper diffusion film mainly protects the brightness enhancement film and further diffuses the light concentrated by the brightness enhancement film to improve light uniformity.

7. Diverse Preparation Methods

Diffusion films can be prepared through various methods, including particle-coated type and micro-lens array type. Particle-coated type diffusion films have advantages such as high light transmittance, wide haze adjustment range, and good appearance quality, and are currently the main production process for diffusion films. Micro-lens array type diffusion films are formed by transferring patterns onto the film surface using a mold and UV-curable resin, and then curing with UV light.

Diffusion film structure

Basic structure

The basic structure of a diffusion film is to coat relevant materials on a transparent substrate. Common transparent substrates include polyester (PET) film or polycarbonate (PC) film. On both surfaces of these films, uniform functional coatings with concave-convex structures and anti-sticking coatings are made. When light continuously passes through these coatings, due to the diffuse reflection and scattering of the concave-convex structured medium, point light sources are transformed into uniform surface light sources. This causes refraction, reflection, and scattering of light, resulting in an overall optical diffusion effect.

Three-layer structure composition

Diffusion films are mainly composed of three layers: the anti-scratch layer, the transparent PET substrate layer, and the diffusion layer. Light enters from the bottom anti-scratch layer, then penetrates the highly transparent PET substrate, and is scattered by the diffusion particles in the diffusion coating to form a uniform surface light source. Most of the diffusion particles are spherical, functioning similarly to convex lenses. When light passes through these particles, it is focused within a certain exit angle, thereby enhancing the brightness of the emitted light. Additionally, particles of different sizes in the diffusion layer ensure that light does not exit the diffusion film directly, thus achieving a fogging effect.Characteristics of diffusion membranes

Diffusion film is a kind of thin film material with special optical properties, which is widely used in lighting, display, advertising and other fields. The following are some main characteristics of the diffusion membrane:

Optical performance

One of the main characteristics of the diffusion film is its excellent optical performance. It can evenly diffuse the incident light over the entire surface, reduce light loss and improve the utilization rate of light. For instance, the light diffusion efficiency of the red adhesive light diffusion film can reach over 95%.

Weather resistance

Diffusion films are usually made of weather-resistant materials and can be used for a long time in outdoor environments without being affected by factors such as ultraviolet rays, rain, and temperature, ensuring the service life of the product.

Bonding performance

Diffusion films often come with a backing adhesive and have excellent bonding performance. They can be firmly bonded to various substrates such as metals, plastics, and glass, facilitating construction.

Material properties

The material properties of diffusion membranes vary depending on the specific type. For instance, PC diffusion films have high transparency, can withstand high temperatures, and possess excellent chemical resistance.