This landscape tracks 26 patent families published between 2015 and mid-2026 that combine molded fiber or moulded pulp packaging claims with moisture resistance, humidity durability, wet strength retention or water resistance language. That is a small, still-forming dataset compared with mature packaging-materials fields, meaning individual filings can meaningfully shift the competitive picture. Family counts, rather than raw document counts, are used here because they neutralise duplicate filings of the same invention across jurisdictions.

The trend is flat rather than growing: filings started at 3 in 2017, fell to zero at the 2022 midpoint, and only reached a peak of 5 in 2024. That pattern looks more like sporadic, product-launch-driven filing than a sustained industry-wide R&D push. Because publication lags filing by roughly eighteen months, the most recent year's low count should not be read as a genuine drop-off — it is simply incomplete.

Pulp and paper composition claims under IPC D21H dominate, appearing in 25 of the 26 tracked families, often paired with container and packaging claims under B65D. Mechanical forming and carton-construction codes such as B29C and B31B each appear in only a single family, indicating that additive and coating chemistry is far more heavily claimed than the physical shaping or forming process itself. That imbalance is useful for anyone deciding where a novel claim is less likely to collide with existing prior art.

EP3524537B1, filed by Toyo Aluminium Ekco Products and granted in 2024, covers a fiber-molded container and its manufacturing method, sitting at the intersection of moisture-resistance chemistry and forming process that defines this dataset. Its practical effect is to occupy claim space where a durability treatment is tied to a specific molding method rather than a standalone additive formulation. Anyone designing a similar container-and-process combination should review its claim scope closely before finalising a forming method.

Based on the classification mix, the clearest gaps sit outside core pulp chemistry: mechanical wet-strength forming methods, laminate barrier-layer combinations under B32B, coating-free hydrophobic additive systems, and carton-forming process integration under B31B all show minimal filing activity relative to D21H compositions. Geographically, China, India and Japan carry lighter filing density than the US and Europe, though that may reflect deliberate strategy rather than open opportunity. A first claim in these areas would need to tie a specific mechanical or process step to a measurable durability outcome to stand apart from the existing chemistry-heavy art.