Precision Harvesting Technologies for Tree Bark-Derived Bio-Based Polymers Toward Sustainable Coating Applications

Tree Bark-Derived bio-based polymers are promising renewable materials for sustainable coatings, surface protection, adhesives, and functional films. This review aims to clarify how harvesting processes affect raw-material quality and coating performance. The materials discussed include Raw Lacquer, pine resin-derived rosin, turpentine, and tree gums. Key harvesting factors, such as incision depth, tapping frequency, collection method, environmental conditions, and tree physiological status, can influence yield stability, impurity content, enzyme activity, viscosity, chemical composition, and batch consistency. These changes further affect film formation, curing behavior, adhesion, barrier properties, corrosion resistance, water sensitivity, and durability. Traditional manual harvesting is flexible but labor-intensive, skill-dependent, and difficult to standardize. Recent precision and intelligent harvesting technologies, including controlled-depth cutting, low-damage incision, multi-sensor perception, adaptive trajectory planning, and closed collection, provide new approaches for improving harvesting efficiency, reducing contamination, protecting tree health, and supplying coating-grade raw materials. This review establishes a framework linking feedstock characteristics, harvesting parameters, raw-material quality, and coating film performance, and outlines future directions for sustainable, automated, and low-damage harvesting to support high-quality bio-based coatings.