Woven Fabric · Substrate · Shade Net

I. What they share: orientation stress + high surface area

The warp-weft difference of woven structures means aging performance must be evaluated separately in machine and transverse directions; single-direction testing easily masks problems.

II. The specifics of the three product types

2.1 Woven fabric / weed-control fabric: long-term contact with soil

The service environment of weed-control, anti-seepage and horticultural cover fabrics is the soil surface: long-term high humidity, soil-mineral catalyzed oxidation, rhizosphere microbial activity, and frequent repeated trampling and agricultural-tool scraping. Service life is typically claimed at 3–8 years, far longer than mulch—which is exactly why its requirements for long-term extraction and hydrolysis resistance are higher. Under southern acid soils and northern saline-alkali conditions, conventional basic HALS are more readily protonated.

Common failure modes: surface loses gloss and turns dull, feels hard and brittle, powders and cracks after sun exposure—typical signs of additive exhaustion or recycled-material admixture. When purchasing, require the supplier to provide material specifications and factory test parameters, and prioritize virgin-material products when sampling.

2.2 Substrate fabric: greenhouse inner liner, ground cushion, thermal-blanket liner

Substrate fabrics sit "between film and soil" or "between greenhouse film and thermal blanket"; two features make them different from outer-layer materials:

• Long-term light blockage: low illuminance and low temperature mean low photo-aging pressure, but near-saturated humidity makes it a purely aqueous-vapor environment—where antioxidant and hydrolysis stability matter more than UV resistance.
• Friction and adhesion with the film surface: an embrittled substrate fabric gets torn away together when the film is removed, or its debris stays on the original film. Here, surface friction and anti-migration directly determine the use experience.

The thermal-blanket liner has another special risk: long-term low temperature + high humidity + repeated folding; at low temperature molecular-chain mobility is limited and the activation efficiency of the antioxidant system drops, making embrittlement risk higher than at room temperature.

2.3 Shade net: the only category where "color must also be managed"

Shade nets, green nets and black nets have clear appearance and color-fastness selling points; distributors first check whether the color is uniform and whether it fades. This is completely different from greenhouse and mulch films. At the same time, they are often in the same greenhouse with chlorine-based disinfectants and sulfur-containing pesticides, so chemical resistance in anti-corrosion and anti-mold scenarios is also a variable.

III. Tiangang products & acceptance recommendations

Acceptance method recommendations

• Use xenon lamp, not QUV: woven and shade-net types face long-term outdoor exposure; lifetime extrapolation needs the support of GB/T 16422.2 xenon-arc method; QUV is only for formulation screening.
• Test machine and transverse directions separately: woven structures differ in warp and weft performance; samples must be prepared separately.
• Extraction test is mandatory: do water extraction (simulating rain washing) and IR/liquid analysis on samples before and after aging to confirm the additive is still there—this is the most easily skipped key item for nonwoven and woven types.
• Evaluate color fastness with xenon, not QUV: color change involves visible light and the colorant system; QUV only reflects the UV band, while xenon's full spectrum is closer to real sunlight fading behavior.