Adhesive Industry Market Research Report

The development of wood adhesives has had a positive impact on the growth of the wood industry, including particleboard and fiberboard production. It has enabled the full utilization of small-diameter logs, branch and limb materials, thinning wood, and wood-processing residues, thereby enhancing the overall wood utilization rate and improving wood performance. Adhesives have become a critical factor determining the level of advancement in particleboard and fiberboard manufacturing. The implementation of new production processes, the enhancement of production efficiency, and the improvement of working conditions are all closely linked to adhesives and bonding technologies.

The most prominent feature of wood adhesives is their large consumption volume. The cost, variety, and quality of wood adhesives directly affect the cost, quality, and application scope of engineered wood products. Consequently, the vast majority of China’s wood-processing enterprises have established their own adhesive production workshops, with urea-formaldehyde resin adhesive, phenol-formaldehyde resin adhesive, and melamine resin adhesive being the primary types of adhesives they produce. Meanwhile, as the variety of wood-based composite products continues to expand and quality requirements keep rising, specialized adhesive manufacturing enterprises are emerging one after another.

[Artificial Synthetic Adhesives]

(1) Adhesives for the engineered wood panel industry

Urea-formaldehyde resin, along with phenol-formaldehyde resin and melamine-formaldehyde resin, is known as one of the three major adhesives used in the engineered wood panel industry; among these, urea-formaldehyde resin is the most important and dominant variety.

① Urea-formaldehyde (UF) resin adhesive

Urea-formaldehyde resin adhesives are renowned for their low cost, simple production process, ease of use, light color that does not contaminate the finished products, excellent bonding performance, and wide range of applications. However, artificial boards made with urea-formaldehyde resins generally suffer from two major problems: first, the formaldehyde gas released by these boards pollutes the environment; second, their water resistance—especially their resistance to boiling water—is poor. Scholars both domestically and internationally have conducted extensive research on ways to reduce formaldehyde emissions from urea-formaldehyde resin-based boards. They have proposed new synthesis processes involving a sequence of strong acid–weak acid–alkali (neutral) conditions; controlling the molar ratio of formaldehyde to urea; adopting a secondary polycondensation process for formaldehyde; adding formaldehyde scavengers to the finished adhesive; and performing post-processing treatments after the boards have been manufactured. To improve their water resistance, researchers have employed methods such as copolymerization and blending with modifying agents to alter the resin’s water-resistant properties, and have also introduced certain amounts of isocyanates (PMDI) or borax into the synthesis process.

② Phenol-formaldehyde (PF) resin adhesive

Phenolic resin adhesives are made from readily available raw materials and exhibit excellent weather resistance. However, they have several drawbacks, including high hot-pressing temperatures, long curing times, and stringent requirements for the moisture content of wood veneers. To reduce costs without significantly compromising performance, modifiers and substitutes can be introduced. Additionally, accelerating the curing speed and lowering the curing temperature represent key research directions for phenolic resin adhesives.

③ Melamine-formaldehyde (MF) resin adhesive

Melamine-formaldehyde resin adhesives exhibit excellent water resistance, weather resistance, high bonding strength, and high hardness. They also cure faster than phenolic resins. Moreover, melamine-formaldehyde resin films maintain their color and gloss even at high temperatures. However, melamine-formaldehyde resin adhesives have several drawbacks: they are relatively expensive, brittle and prone to cracking, lack sufficient flexibility, and suffer from poor storage stability. By introducing a modifier—methyl glucoside—into melamine-formaldehyde resins, not only can the storage stability of the resin be enhanced, but the cost can also be reduced. Additionally, this modification improves the resin’s plasticity, increases its flowability, and lowers the content of free formaldehyde.

④ Polyurethane (PU) Adhesive

Polyurethane adhesives are broadly categorized into two major types: polyisocyanates and polyurethanes. They are reactive adhesives with outstanding bonding performance and have become a focal point of research in this field. Currently, they are widely used in particleboard, oriented strand board, medium-density fiberboard, engineered wood products, various composite boards, and surface decorative panels, with their usage rapidly increasing. In particular, they exhibit excellent performance when applied to man-made boards made from agricultural crop residues. Previously, these adhesives were mainly used for bonding the core layers; however, in recent years, their application has gradually expanded to cover the entire board. Nevertheless, due to the high cost of polyurethane adhesives and their significant content of organic solvents—which can pollute the environment and pose health risks—widespread adoption has been hindered. In recent years, there has been growing interest in the development and application of low-cost, high-performance, environmentally friendly waterborne polyurethanes.

⑤ Thermoplastic resin adhesive

Research on the manufacture of engineered wood panels using various plastics or recycled plastics (thermoplastic resins) as adhesives in China began in the early 1990s. Production lines for thermoplastic resin-based plywood (wood-plastic composite plywood) and formaldehyde-free solid wood composite flooring based on this type of plywood have been successively built and put into operation.