This article is suitable for the technical column of the company's official website. It is professional and rigorous, oriented to customers of paper mills, packaging companies, and R&D institutions. It focuses on a single track of papermaking, taking into account the mechanism, process path, performance indicators, industry pain points, industrialization solutions and technical advantages, and can be published directly. Abstract Under the background of dual carbon, the papermaking industry is facing common bottlenecks such as raw material degradation, strength attenuation of recycled fibers, difficulty in recycling traditional petroleum-based barrier coatings, and strength loss caused by high filler addition. Nanocellulose (NC, including cellulose nanofibrils CNF and cellulose nanocrystalline CNC) has become a new generation of papermaking functional additives and coating substrates due to its ultra-high aspect ratio, huge specific surface area, abundant surface hydroxyl groups, complete biodegradability, and homologous compatibility with pulp fibers. Starting from the interface bonding mechanism of nanocellulose in the papermaking system, this article systematically elaborates on the three mainstream industrial application paths of in-pulp reinforcement, retention and filtration assistance, and surface functional coating, and quantitatively analyzes their effects.

Under the industrial trends of water-based, low-carbon and high-performance, the coatings and polymer composite materials industries are continuing to look for new functional additives that combine reinforcement, rheology control, and green traceability. Nanocellulose (CNF/CNC) relies on its natural biomass source, high aspect ratio, abundant surface hydroxyl groups, and customizable modification characteristics to become a valuable green functional component in coating systems, resins, and elastomer composites. A small amount of addition can simultaneously optimize key indicators such as processing rheology, mechanical strength, and weather resistance. It can replace some traditional synthetic rheology agents and inorganic powder reinforcing fillers to help reduce carbon emissions and upgrade formulas. Value and application in coating systems Nanocellulose plays four major roles in water-based coatings: rheology regulation, anti-sedimentation, film-forming reinforcement, and weather resistance improvement. It is suitable for water-based acrylic, water-based polyurethane, industrial anticorrosive paint, wood paint, architectural coatings, inorganic mineral coatings, functional protective coatings and other systems. Resting state

在双碳目标引领下，造纸行业正加速向低碳化、高性能化、功能化方向转型。 As a nanofunctional material derived from natural biomass, nanocellulose has become an important new functional additive and reinforcing substrate in the paper industry due to its renewable, biodegradable, excellent mechanical strength, large specific surface area, and outstanding film-forming barrier properties. It provides new solutions for improving quality, reducing costs, and green transformation of special paper, packaging paper, cultural paper, coated paper, and other categories. Nanocellulose uses wood pulp and agricultural and forestry biomass fibers as raw materials, and is disassembled to the nanometer scale through mechanical dissociation, enzymatic hydrolysis or chemical modification processes. It is mainly divided into two mainstream categories: cellulose nanofibrils (CNF) and cellulose nanocrystals (CNC). The raw materials are derived from plant fibers, which are the most abundant natural polymers on the earth. Different from petroleum-based chemical additives, they are low-carbon, environmentally friendly, and fully compatible with the clean production and recycling development of the paper industry.