Mulch Film: Survive a Season, Yet Be Recoverable

I. The core paradox of mulch: three goals conflict with each other

Industry's real constraint: average national farmland mulch-film residue intensity is about 3.45 kg/mu, about 5.16 kg/mu in Northwest China, and up to 13.64 kg/mu in Xinjiang; national average mulch recovery rate is below 70%, recovered mulch impurity rate is as high as 70–90%, and cleaning-and-pelletizing cost already exceeds 5,500 yuan/ton, giving low cost-performance versus ordinary PE pellets. The policy direction is to raise the minimum thickness (8 µm → 10 µm → push toward 15 µm and above high-strength recyclable film). This means: the thicker the mulch, the more it must resist aging—a thick film that can be rolled up whole must have sufficient toughness. This is a fundamental turn from the pre-2015 logic of "thinner and cheaper is better."

II. What actually tortures mulch in the field

Recovered mulch's high impurity rate and cleaning-pelletizing cost exceeding 5,500 yuan/ton is the hardest link in the whole chain—and much of that cost is already determined at the formulation stage.

III. Three technical routes for mulch, and what Tiangang offers for each

Route A: high-strength recyclable (current policy main push)

15 µm and above, goal is "no break in a season, whole-sheet recovery at harvest." The key is not "more weatherability" but "resist aging yet not embrittle"—retain toughness and sheet integrity so recovery machinery can roll it smoothly. Requirements for the additive: low-dosage high-efficiency, low basicity (avoid protonation in soil acid), no migration into soil (migration means loss and possible detectable residue).

Route B: short-cycle thin type (traditional 8–10 µm)

Cost first, mostly black or silver-black film; carbon black itself provides strong UV screening. Little additive headroom; the focus is to supplement the bands carbon black cannot cover at the lowest dosage, and ensure no brittle breakage during high-speed laying.

Route C: controlled degradation (fully biodegradable film)

Complies with GB/T 35795. Note the industry reality: "biodegradable" does not equal rapid complete degradation in real fields. Low field temperature, drought and insufficient soil contact significantly limit microbial activity; studies show about 30% of PLA mulch may convert to microplastics within two years, and the fully mineralized fraction remains limited; EN 17033 certification requires ≥90% mineralization under controlled culture in two years. Cost is about 3× ordinary film, farmer acceptance is low, and some products' degradation cycle is out of sync with crop growth, instead worsening microplastic pollution. Therefore this route is currently more suitable for specific crops and demonstration scenarios, not a general solution.

Tiangang solution & products