News

Company News

Application Mind Map

Test Report

Technical Article

Industry News

How to Control the Coating Quality of UV Wood Primer

Release time:

2026-04-01 07:00

How to Control the Coating Quality of UV Wood Primer

The quality of the UV wood primer coating directly affects the performance and service life of the entire coating system. However, since the primer layer is covered by the topcoat, quality issues are often only detected during subsequent processes, leading to rework and material waste. Therefore, establishing a comprehensive quality-control system that ensures rigorous oversight from raw-material receipt through to the finished product is essential for maintaining consistent coating quality. Quality control spans three key stages—incoming-material inspection, in-process control, and final-product inspection—each with its own specific control points and methodologies.

I. Raw Material Inspection

Quality inspection of primer upon arrival at the factory is the first line of quality control. Only by ensuring that raw materials meet the specified requirements can subsequent production be reliably assured.

1. Viscosity Testing: Viscosity testing is a commonly used inspection method. The viscosity of the coating is measured using a viscosity cup or a rotational viscometer to determine whether it falls within the specified range. Viscosity that is too high or too low can adversely affect coating application and film performance.

2. Solid Content Testing: This test involves heating and drying the coating under specified conditions to measure the mass fraction of the residue, thereby determining the solid content of the coating. The stability of the solid content directly affects the coating application rate and material costs.

3. Curing Speed Test: This test involves applying the coating to a small sample, irradiating it with ultraviolet light, and observing the curing behavior to determine whether the curing reaction activity is within the normal range. Curing that is too fast or too slow can both adversely affect production efficiency and the quality of the cured film.

II. Process Control

Quality control throughout the production process is the core element in ensuring coating stability. By monitoring and adjusting critical process parameters, deviations can be promptly identified and corrected, thereby preventing the occurrence of batch-quality issues.

1. Coating Weight Control: Coating weight control is a critical aspect of process control. By adjusting equipment parameters and regulating the coating supply rate, it is ensured that the coating weight per unit area remains within the specified range. Insufficient coating weight can result in inadequate sealing or incomplete fill, while excessive coating weight may lead to sagging, incomplete curing, and increased costs. During production, the weight of workpieces should be periodically measured before and after coating to monitor the stability of the coating weight.

2. Curing Energy Control: Curing energy control involves monitoring the output energy of the UV lamp to ensure that the irradiation energy meets the curing requirements. Insufficient energy may result in incomplete curing, with a sticky coating surface and an uncured interior; excessive energy, on the other hand, can lead to yellowing and embrittlement of the coating. The lamp output should be regularly measured with an energy meter to maintain stable curing energy.

3. Sanding Quality Control: Sanding quality control involves inspecting the flatness and roughness of the sanded surface to ensure it meets the requirements for subsequent coating applications. Insufficient sanding can compromise the smoothness of the topcoat, while excessive sanding may abrade through the primer layer. The sanding finish should be evaluated visually and by touch; where necessary, a profilometer should be used for quantitative measurement.

III. Finished Product Inspection

After coating is completed, the primer layer must undergo quality inspection to verify that the product meets the specified requirements, thereby providing a reliable guarantee for subsequent topcoat application.

1. Visual Inspection: Visual inspection involves visually examining the coating surface under appropriate lighting conditions to identify defects such as sagging, orange-peel texture, bubbles, particulates, and areas with incomplete coating. Such visual defects not only affect the aesthetic appearance but may also compromise the protective performance of the coating.

2. Adhesion Test: The adhesion test is conducted using the grid-cut method, in which a grid is cut into the coating surface with a grid cutter, a tape is applied and then peeled off, and the percentage of the coated area that has detached is observed. Adhesion is a critical parameter for assessing the bond strength between the primer and the substrate, and it directly affects the service life of the coating system.

3. Sandability Test: The sandability test is conducted by performing actual sanding operations to evaluate whether the primer layer exhibits good sanding performance. Good performance is characterized by ease of sanding, fine dust generation, and no sticking to the sandpaper. Sandability directly affects production efficiency and the adhesion of subsequent topcoats.

IV. Conclusion

Quality control of UV wood primers is a systematic undertaking that encompasses incoming material inspection, process control, and final product inspection. Incoming material inspection ensures that raw materials meet specified requirements; process control guarantees the stability of manufacturing processes; and final product inspection verifies the ultimate quality level. These three stages are interrelated and build upon one another, together forming a comprehensive quality-control system. In actual production, all inspection and control measures must be rigorously implemented to promptly identify and resolve issues, thereby ensuring the consistency and reliability of primer coating quality.

Disclaimer: The above content is sourced from the internet and is provided for reference only. If any infringement occurs, please contact us, and we will remove the content promptly.

Boxing 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.

Share to:

Advantages of UV Wood Primer

Common Applications of UV Wood Primer