Technical Insight
How to design NIR control of greenhouse films and light transmission for crops together
A crop- and climate-specific framework for designing NIR control in greenhouse films without treating solar heat reduction and crop-light transmission as the same requirement.
Author: Aurexene Materials Engineering Team · Last updated: 2026-08-28
Quick Answer
Antimony Tin Oxide (ATO) and Cesium Tungsten Bronze (Cs0.33WO3) are the material routes. Define photosynthetically active radiation (PAR) transmission and heat-management requirements separately, then qualify the complete installed PE or EVA film for the target crop, climate, season, greenhouse, and ventilation strategy. A general “IR blocking” value is not an agronomic specification.
Problem
A film that reduces part of the solar heat load also changes the light environment seen by the crop. The useful balance depends on crop and growth stage, location, season, greenhouse geometry, ventilation, condensation, and the aged state of the cover.
Mechanism
ATO and Cs0.33WO3 alter the film spectrum through different material roles. Material concentration, aggregate state, film thickness, and layer placement govern transmitted, reflected, and absorbed energy. Compatibility with the selected PE or EVA grade, additive migration or blooming, condensation, dust, cleaning, and weathering can further change the installed spectrum.
Tradeoff
More NIR control may reduce solar heat input while also changing crop-light transmission, film temperature, color, haze, cost, process stability, or long-term optical retention. An absorbing route and a reflecting route can create different thermal behavior even when transmission appears similar.
Material Strategy
Start with the crop-light spectrum, acceptable daytime and nighttime climate behavior, film life, resin, thickness, process, and agricultural exposures. Screen ATO when a conductive-oxide role is relevant and Cs0.33WO3 as a distinct NIR-absorber route. Use ATO vs Cs0.33WO3 to frame the material choice, then validate the actual film.
Recommended Architectures
- Bulk-active film: qualify PE or EVA compatibility, extrusion stability, additive migration or blooming, film defects, mechanics, and optical uniformity.
- Coextruded functional skin: concentrate the NIR material in one layer while validating layer adhesion, blocking, and weathering.
- Coated greenhouse film: separate the active chemistry from melt processing and qualify coating adhesion, flexing, cleaning, and outdoor exposure.
Measurement & Validation
Measure the declared transmission and reflection spectra, including the specified PAR transmission basis, for new, condensation-conditioned, and aged film states. Record thickness, haze and color where relevant, migration or blooming, mechanical retention, blocking, and film defects. In a matched greenhouse trial, document outside weather, ventilation, air and canopy conditions, and crop-response measures selected before the trial. Keep the control film, greenhouse geometry, and management practices comparable.
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Downloads & Document Requests
No approved greenhouse-film application document is linked from this page. Request the current qualification documents, or request application support with the crop, location, season, film resin and construction, optical targets, and field plan.
Need to apply this boundary to a grade, formulation, test method, or production route? Discuss it with the Aurexene Materials Engineering Team.