Mastering Heat Control: What IR Masterbatch Is, How It Works, and Why It Matters

The functionality of IR masterbatch is based on how its embedded additives interact with different wavelengths of infrared radiation. Infrared light can be divided into:

• Near-Infrared (NIR): 700–2500 nm

• Mid-Infrared (MIR): 2500–25,000 nm

• Far-Infrared (FIR): > 25,000 nm

Different IR additives are engineered to influence these wavelengths in specific ways:

1. Absorption of IR Radiation

IR-absorbing masterbatches contain pigments or compounds that capture IR radiation and convert it into heat.
This is achieved through:

• Electronic transitions in organic dyes

• Lattice vibrations in inorganic particles

• Selective absorption peaks tuned to long-wave IR

Working mechanism:

• Short-wave IR from sunlight passes through the plastic.

• IR additives absorb long-wave IR emitted from soil, surfaces, or objects.

• The absorbed IR is re-emitted at a slower rate, reducing heat loss.

This principle is why greenhouse films containing IR absorbers stay warmer at night.

2. Reflection of IR Radiation

IR-reflecting masterbatches use particles with high IR reflectance, often based on ceramic, metallic oxide, or pearlescent pigments.

Working mechanism:

• Additives have a refractive index mismatch with the polymer matrix.

• Instead of absorbing IR, they scatter or reflect it outward.

• The reflected IR cannot penetrate the plastic surface, reducing heat buildup.

This is especially valuable for automotive interiors, building films, and outdoor products where dark plastics become excessively hot under sunlight.

3. Transmission of IR Radiation

IR-transparent (or NIR-transparent) masterbatches are formulated using non-carbon black pigments or special dyes that appear dark but do not block infrared wavelengths.

Working mechanism:

• Additives absorb visible light but leave IR wavelengths available.

• Sensors, detectors, and NIR sorting systems can detect the plastic.

• IR signals (from remote controls, LiDAR, etc.) pass through the material with minimal attenuation.

This is essential for electronics housings, NIR-detectable black plastics, and optical system components.