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Main Types of UV Wood Primer

Release time:

2026-03-31 07:26

UV wood primers can be classified into various types based on their functional characteristics and application scenarios. These different types exhibit significant differences in formulation design, performance, and suitable applications; therefore, a thorough understanding of these types and their respective features is essential for selecting the appropriate primer.

I. Putty Primer

Putty primer is a specialized type of primer that combines filling and priming functions, making it ideal for substrates with numerous surface pores and poor flatness, such as particleboard, fiberboard, and medium-density fiberboard. Compared with conventional putty, putty primer not only offers excellent filling performance but also enhances adhesion and sealing capabilities typical of primers, enabling both filling and priming to be completed in a single application.

Putty primer is characterized by its high viscosity and the inclusion of a certain proportion of inorganic fillers, such as talc and calcium carbonate, which effectively fill the substrate’s pores and micro-defects. At the same time, its resin system ensures excellent adhesion and sealing performance; upon curing, it forms a solid, well-filled layer that provides a smooth, dense substrate for subsequent coating applications. Putty primer cures rapidly and exhibits good sandability, which can significantly simplify the coating process and reduce the number of coating passes.

In practical applications, putty primers are suitable for products that have high filling requirements but relatively lower demands on transparency and wood-grain clarity, such as solid-color coatings or priming for dark-colored furniture. During application, one to two coats are typically applied, with each coat being UV-cured before sanding.

II. Sanding Primer

Sanding primer is a specially formulated type of primer whose defining characteristic is its exceptional sandability. By incorporating specialized sanding aids into the formulation, the cured film not only exhibits adequate hardness and density but also lends itself readily to sanding—resisting adhesion to sandpaper and delivering markedly improved sanding efficiency.

The primary advantages of sanding primers lie in enhanced production efficiency and cost control. In large-scale, continuous manufacturing, sanding primers reduce the frequency of sandpaper changes and lower sandpaper consumption; moreover, their superior sanding performance ensures a smoother sanding process, thereby minimizing rework caused by incomplete sanding. Sanding primers are particularly well suited for coating systems that require multiple primer coats and multi-pass sanding operations.

The selection of sanding primer should take into account the requirements of the subsequent topcoat. For high-gloss topcoats, a sanding primer that delivers a smoother surface after sanding is recommended; for matte topcoats, the requirements for the sanding primer are relatively more relaxed. During application, it is important to control the sanding pressure to avoid over-sanding and damage to the primer layer.

III. Primer for Adhesion

Adhesion-promoting primer is a specialized type of primer designed to enhance intercoat adhesion, making it ideal for applications where strong adhesion between the substrate and the topcoat is critical—such as solid wood furniture, outdoor wood products, and other products with specific adhesion requirements.

The core feature of adhesion primers lies in the molecular design of their resin system. By incorporating polar functional groups into the resin, these primers can form hydrogen bonds or chemical bonds with the hydroxyl groups on the wood surface, thereby achieving strong interfacial adhesion. At the same time, the surface energy of the adhesion primer is optimized to facilitate wetting by the topcoat, ensuring excellent intercoat adhesion. Furthermore, the curing shrinkage of the adhesion primer is tightly controlled to prevent excessive shrinkage stress from compromising adhesion.

The application value of adhesion primers lies in enhancing the reliability of the coating system. For outdoor wood products subjected to significant environmental fluctuations, adhesion primers can effectively prevent coating delamination; for high-gloss topcoats and other coatings with stringent adhesion requirements, adhesion primers are a critical measure for ensuring coating quality. Typically, a single coat of adhesion primer is sufficient to achieve optimal adhesion, but the application rate should not be excessive to avoid compromising drying and curing performance.

IV. White Primer

White primer is a type of primer formulated with white pigments such as titanium dioxide, primarily used for white furniture, light-colored wood veneer finishes, and applications that require high opacity. Combining the adhesion and sealing properties of a primer with the coloration and hiding power of a topcoat, white primer is an essential component of solid-color coating systems.

The core performance indicators of white primers include hiding power, whiteness, yellowing resistance, and adhesion. Hiding power depends on the titanium dioxide content and dispersion quality; high-quality white primers can achieve excellent substrate coverage with a relatively thin coating film. Whiteness determines the final color appearance of the product and requires the use of high-whiteness titanium dioxide and an appropriate resin system. Yellowing resistance is a critical property of white primers, necessitating the incorporation of anti-yellowing resins such as aliphatic polyurethane acrylates to prevent yellowing over long-term service. Adhesion, in turn, must be ensured through optimization of the resin formulation.

When applying white primer, the following key points should be observed: the application rate must be sufficient to achieve uniform coverage, but not so thick as to cause curing shrinkage and increased costs; the curing energy must be appropriately balanced—insufficient energy may compromise coating performance, while excessive energy can lead to yellowing; sanding must be carried out with precision to avoid over-sanding that exposes the substrate and compromises coverage. For products with extremely high requirements for whiteness and yellowing resistance, a white topcoat can be applied over the white primer to further enhance performance.

V. Conclusion

The preceding section has introduced several common types of UV wood primers, each with its own specific functional role and suitable application scenarios. In practical applications, it is essential to select and combine the appropriate primer types based on the condition of the substrate, coating requirements, and production conditions, in order to achieve the desired coating performance.

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Bossin Recommended Products – UV Wood Coatings
Putty primer
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-113	Bisphenol A epoxy acrylate	High hardness, high gloss, high fullness, contains 20% TPGDA
B-520	Polyester acrylate	Low viscosity, high gloss, excellent wettability, and cost-effective
B-522	Polyester acrylate	Low shrinkage, excellent flexibility, strong adhesion, and high cost-effectiveness.
Sanding primer
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-113	Bisphenol A epoxy acrylate	High hardness, high gloss, high fullness, contains 20% TPGDA
B-160D	Modified epoxy acrylate	Good flexibility, yellowing resistance, and excellent adhesion.
B-163	Modified epoxy acrylate	Good flexibility, excellent pigment wetting, and strong adhesion.
B-520	Polyester acrylate	Low viscosity, high gloss, excellent wettability, and cost-effective
B-522	Polyester acrylate	Low shrinkage, excellent flexibility, strong adhesion, and high cost-effectiveness.
Apply primer
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-02	Phosphate ester acrylate	Enhances adhesion to substrates such as metal, glass, and plastic.
B-05	Phosphate ester acrylate	Enhances adhesion to substrates such as metal, glass, and plastic.
B-113	Bisphenol A epoxy acrylate	High hardness, high gloss, high fullness, contains 20% TPGDA
B-165	Modified epoxy acrylate	Good flexibility and strong adhesion
B-522	Polyester acrylate	Low shrinkage, excellent flexibility, strong adhesion, and high cost-effectiveness.
B-535	Polyester acrylate	Excellent adhesion, rapid curing, good flexibility, and yellowing resistance.
B-546	Polyester acrylate	Good adhesion, fast curing, and excellent flexibility.
White primer
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-113	Bisphenol A epoxy acrylate	High hardness, high gloss, high fullness, contains 20% TPGDA
B-160D	Modified epoxy acrylate	Good flexibility, yellowing resistance, and excellent adhesion.
B-520	Polyester acrylate	Low viscosity, high gloss, excellent wettability, and cost-effective
B-522	Polyester acrylate	Low shrinkage, excellent flexibility, strong adhesion, and high cost-effectiveness.
B-529	Polyester acrylate	Good adhesion, low shrinkage, and excellent resin compatibility.
B-560	Polyester acrylate	Fast curing and excellent pigment wetting
Single-item recommendation
Product Model/English Abbreviation	Product Name/Product Type	Product Features
BM2223 (TPGDA)	Di(propylene glycol) diacrylate	Good flexibility and low volatility
BM2224 (EO-HDDA)	Ethoxylated 1,6-hexanediol diacrylate	Good adhesion to plastics, good dilutability, and low volatility.
BM3231 (TMPTA)	Trimethylolpropane triacrylate	High crosslink density, high hardness, high gloss, and excellent wear resistance.
BM3235 (PET3A)	Pentaerythritol triacrylate	Fast curing, high crosslink density, high hardness, and excellent chemical resistance.
BM3380 (3EO-TMPTA)	Tripropylene Glycol Triacrylate	More flexible and less irritating than TMPTA.
BM6261 (DPHA-80)	Dipentaerythritol hexaacrylate	High crosslink density, high hardness, chemical and wear resistance, and water resistance.
BM6263 (DPHA-90)	Dipentaerythritol hexaacrylate	High crosslink density, high hardness, chemical and wear resistance, and water resistance.

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