How do white diffuser screens for greenhouses balance light transmittance and uniformity?
Publish Time: 2025-09-16
In modern agricultural facilities, greenhouse light management is a key factor in determining crop growth efficiency and quality. With the increasing demand for refined light environment control, white diffuser screens for greenhouses are widely used in various greenhouse systems as a key internal shading or diffuser cover material. Their core function is to optimize sunlight distribution and achieve more uniform canopy illumination.
Light transmittance: Related to energy input and crop photosynthetic potential
Light transmittance directly determines the total amount of solar radiation entering the greenhouse and is a fundamental parameter affecting crop photosynthetic efficiency. High light transmittance means more light energy is available for plant growth, especially in winter or in areas prone to frequent rainy weather. Every unit of light energy lost can affect yield. Therefore, an ideal diffuser screen should diffuse light while minimizing absorption and reflection losses of the total light flux. Traditional transparent films, while having high light transmittance, can easily create strong direct light spots, causing localized plant burns or uneven light distribution across the canopy. White diffuser screens for greenhouses, by adding special scattering particles or employing a microstructured surface design, diffusely reflect incident light from multiple angles, thereby breaking the concentration of direct sunlight. However, this process inevitably results in some light loss—the scattering particles themselves absorb a small amount of light, and multiple reflections can also increase the probability of light being blocked by the structure. Therefore, optimizing the material formulation and process to maximize scattering efficiency and minimize absorption is key to improving light transmittance.
Light Uniformity: Eliminating Shadows and Improving Photosynthetic Efficiency
Light uniformity refers to the even distribution of light within the greenhouse. In traditional greenhouses without diffuser screens, sunlight enters directly, resulting in excessive brightness near the light source and darkness in areas away from the light source. This is particularly evident in the shadows cast by structural support poles, growing racks, or beneath dense canopies. This uneven lighting not only limits photosynthesis in the lower leaves but can also lead to excessive crop growth and uneven fruit coloring. White diffuser screens for greenhouses function precisely through diffusion, transforming concentrated sunlight into a soft, diffuse light throughout the space. This "skylight" effect allows light to penetrate the canopy from multiple angles, significantly improving light conditions for mid- and lower-level leaves and boosting overall photosynthetic efficiency. Studies have shown that in greenhouses growing tall crops such as tomatoes and cucumbers, using high-quality diffuser screens can increase light intensity at the base of the canopy by over 30%, effectively reducing physiological fruit drop and disease.
The Path to Balance: Collaborative Innovation in Materials Science and Structural Design
Achieving the optimal balance between transmittance and uniformity relies on the deep integration of materials science and optical design. First, high-end diffuser screens utilize nanoscale scattering particles whose size matches the wavelength of visible light, enabling efficient scattering without significantly reducing transmittance. Second, a two- or multi-layer composite structure design allows one layer to diffuse light while another provides strength support, achieving a balanced balance between performance and durability. Furthermore, controlling the diffusion angle is crucial. Excessive scattering can lead to excessive light dispersion, reducing effective illumination; insufficient scattering can prevent shadow elimination. Therefore, modern diffuser screens often achieve the ideal "high transmittance and high diffusion" by precisely controlling the ratio of haze and total transmittance (T%), for example, maintaining a transmittance above 85% while achieving a haze above 90%.
White diffuser screens for greenhouses don't simply sacrifice brightness for uniformity; instead, they intelligently redistribute light energy through advanced material engineering. They seek the optimal balance between transmittance and uniformity, essentially artificially optimizing natural sunlight.
