News

Company News

Application Mind Map

Test Report

Technical Article

Industry News

Common Defects in UV Wood Coatings (10)

Release time:

2026-03-17 06:50

In the field of wood coating, UV wood coatings have become the preferred choice for numerous furniture manufacturers and interior decoration companies thanks to their rapid curing, high energy efficiency, and outstanding physicochemical properties. They not only impart a brilliant gloss and a pleasing tactile finish to wood surfaces but also significantly enhance the durability and aesthetic appeal of wood products. However, in practical applications, UV wood coatings do not always deliver the desired results; various defects frequently occur, with “undercutting” being particularly prominent. Undercutting not only severely compromises the visual quality of wood finishes and reduces product market value but can also trigger a cascade of subsequent problems, creating substantial challenges for production. Therefore, a thorough investigation into the manifestations and underlying causes of undercutting in UV wood coatings is crucial for effectively preventing and resolving this issue and for improving the overall quality of wood coatings.

I. Description of the Phenomenon

When applying the next coat of paint, abnormalities may appear in the previously cured paint film. The most typical manifestation is wrinkling on the primer surface, presenting as irregular ripples or an orange-peel texture; in severe cases, distinct bumps and depressions develop. Another common symptom is localized blistering of the primer, with blisters varying in size and sometimes containing solvent inside. In the most serious instances, the primer lifts off and peels away from the substrate, exposing the wood surface. Primer burn-in typically occurs within a few minutes after applying the topcoat, with symptoms gradually becoming apparent as the solvent evaporates and penetrates. In areas affected by primer burn-in, the paint film completely loses its smoothness and cannot be repaired through subsequent coating steps. During spray or dip application, primer burn-in frequently occurs at edges, corners, and other areas where the paint film is thin, or in regions where the coating application rate is excessively high.

II. In-depth Analysis of the Root Causes

1. Poor solvent resistance of the primer

If the primer has insufficient curing energy and remains in a semi-cured state, its crosslinking density will be inadequate to resist the solvent attack from the topcoat. Solvents in the topcoat can penetrate the primer, causing it to swell and increase in volume, which generates internal stresses and leads to wrinkling of the primer or delamination from the substrate.

Even if the primer is fully cured, limited swelling may still occur upon contact with high-concentration solvents if the resin system itself exhibits poor solvent resistance.

2. Extensive solvent contact

When the topcoat application thickness is excessive, a large amount of solvent comes into immediate contact with the primer, increasing the likelihood of primer dissolution and lifting. This effect is particularly pronounced at edges and corners, where the primer layer is thinner, allowing the solvent to penetrate more readily into the underlying coat.

3. Interlayer Curing Compatibility Issue

After the primer has fully cured, its surface becomes inert and cannot form a chemical bond with the topcoat. Solvents in the topcoat can accumulate at the interface, potentially causing abnormal shrinkage of the topcoat itself and resulting in wrinkle-like defects on the surface that resemble “primer bite.”

III. Conclusion

The root cause of substrate blistering is solvent-induced degradation of the primer that exceeds its tolerance limit. When solvents from the topcoat penetrate the primer, causing it to swell and undergo volumetric changes, internal stresses accumulate and are released during non-uniform expansion, resulting in wrinkling and bubbling. Insufficient curing energy in the primer leads to inadequate crosslink density, thereby compromising its resistance to solvents. Moreover, excessive application thickness accelerates the rapid influx of large amounts of solvent, intensifying the degradation process—particularly in vulnerable areas such as edges and corners. Even if the primer is fully cured, a resin system with inherently poor solvent resistance will still succumb to swelling. Together, these factors conspire to cause the otherwise layered coating system to disintegrate under solvent attack.

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 it 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
Gloss topcoat
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-163	Modified epoxy acrylate	Good flexibility, excellent pigment wetting, and strong adhesion.
B-165	Modified epoxy acrylate	Good flexibility and strong adhesion
B-21C	Active amine photosensitizing promoter	Low color number, antioxidant and polymerization inhibitor, and enhanced curing rate
B-301	Aromatic Polyurethane Acrylate	Fast curing, good toughness, and excellent grindability.
B-302	Aromatic Polyurethane Acrylate	Fast curing, high strength, good toughness, and excellent grindability.
B-574C	Polyester acrylate	Low viscosity, low odor, excellent wettability; suitable for LED UV.
B-601	Aromatic Polyurethane Acrylate	High hardness, scratch resistance, chemical resistance, and excellent cost performance.
B-609	Aliphatic polyurethane acrylate	Fast curing, high hardness, scratch resistance, and chemical resistance.
B-868	Organosilicon UV-Curable Resin	Excellent leveling, smooth finish, fast curing, and stain resistance.
B-868H	Organosilicon UV-Curable Resin	Excellent leveling, smooth finish, fast curing, and stain resistance.
B-910A2	Aliphatic polyurethane acrylate	Low viscosity, yellowing resistance, chemical resistance, and steel-wool resistance.
B-912	Aliphatic polyurethane acrylate	Fast curing, high hardness, good toughness, and excellent chemical and wear resistance.
Matte topcoat
Product Model/English Abbreviation	Product Name/Product Type	Product Features
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-21C	Active amine photosensitizing promoter	Low color number, antioxidant and polymerization inhibitor, and enhanced curing rate
B-328M	Aliphatic polyurethane acrylate	Low gloss, low viscosity, excellent wettability, and a pleasant hand feel.
B-328R	Aliphatic polyurethane acrylate	Low gloss, excellent matting, good wetting, and a fine, smooth, and silky hand feel.
B-333	Aliphatic polyurethane acrylate	Low viscosity, excellent matting effect, good wettability, and good flexibility.
B-572	Polyester acrylate	Low viscosity, low odor, excellent wettability; suitable for LED UV.
B-650A	Aliphatic polyurethane acrylate	Low viscosity, excellent matting effect, fast curing, and good wettability.
B-868	Organosilicon UV-Curable Resin	Excellent leveling, smooth finish, fast curing, and stain resistance.
B-868H	Organosilicon UV-Curable Resin	Excellent leveling, smooth finish, fast curing, and stain resistance.
B-910A2	Aliphatic polyurethane acrylate	Low viscosity, yellowing resistance, chemical resistance, and steel-wool resistance.
B-912	Aliphatic polyurethane acrylate	Fast curing, high hardness, good toughness, and excellent chemical and wear resistance.
Bright White Finish
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-301	Aromatic Polyurethane Acrylate	Fast curing, good toughness, and excellent grindability.
B-302	Aromatic Polyurethane Acrylate	Fast curing, high strength, good toughness, and excellent grindability.
B-560	Polyester acrylate	Fast curing and excellent pigment wetting
B-574C	Polyester acrylate	Low viscosity, low odor, excellent wettability; suitable for LED UV.
B-601	Aromatic Polyurethane Acrylate	High hardness, scratch resistance, chemical resistance, and excellent cost performance.
B-868	Organosilicon UV-Curable Resin	Excellent leveling, smooth finish, fast curing, and stain resistance.
B-868H	Organosilicon UV-Curable Resin	Excellent leveling, smooth finish, fast curing, and stain resistance.
B-912	Aliphatic polyurethane acrylate	Fast curing, high hardness, good toughness, and excellent chemical and wear resistance.
Adherent
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-05	Phosphate ester acrylate	Enhances adhesion to substrates such as metal, glass, and plastic.
B-509B	Polyester acrylate	Good adhesion, good flexibility, and excellent pigment wetting.
B-531	Polyester acrylate	Good adhesion, impact resistance, excellent flexibility, and yellowing resistance.
B-535	Polyester acrylate	Excellent adhesion, rapid curing, good flexibility, and yellowing resistance.
B-546	Polyester acrylate	Good adhesion, fast curing, and excellent flexibility.
B-590	Polyester acrylate	Excellent adhesion, rapid curing, and good pigment wetting.
Filler type
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.
B-529	Polyester acrylate	Good adhesion, low shrinkage, and excellent resin compatibility.
Color correction
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-560	Polyester acrylate	Fast curing and excellent pigment wetting
Harden
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-301	Aromatic Polyurethane Acrylate	Fast curing, good toughness, and excellent grindability.
B-302	Aromatic Polyurethane Acrylate	Fast curing, high strength, good toughness, and excellent grindability.
B-560	Polyester acrylate	Fast curing and excellent pigment wetting
B-574C	Polyester acrylate	Low viscosity, low odor, excellent wettability; suitable for LED UV.
B-601	Aromatic Polyurethane Acrylate	High hardness, scratch resistance, chemical resistance, and excellent cost performance.
B-912	Aliphatic polyurethane acrylate	Fast curing, high hardness, good toughness, and excellent chemical and wear resistance.
Matte
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-328M	Aliphatic polyurethane acrylate	Low gloss, low viscosity, excellent wettability, and a pleasant hand feel.
B-328R	Aliphatic polyurethane acrylate	Low gloss, excellent matting, good wetting, and a fine, smooth, and silky hand feel.
B-329D	Aliphatic polyurethane acrylate	Low irritation, low viscosity, excellent wettability, and a pleasant feel.
B-333	Aliphatic polyurethane acrylate	Low viscosity, excellent matting effect, good wettability, and good flexibility.
B-650A	Aliphatic polyurethane acrylate	Low viscosity, excellent matting effect, fast curing, and good wettability.
Solid-color paint
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-519	Self-curing polyester acrylate	Self-initiated photopolymerization performance
B-530	Polyester acrylate	Low viscosity, excellent hydrophobicity, thixotropy, and improved ink misting
B-560	Polyester acrylate	Fast curing and excellent pigment wetting
Yellowing resistance
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-160D	Modified epoxy acrylate	Good flexibility, yellowing resistance, and excellent adhesion.
B-431	Cycloaliphatic Specialty Acrylates	Yellowing resistance, excellent wettability, low viscosity, and fast curing
Dip coating
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-160D	Modified epoxy acrylate	Good flexibility, yellowing resistance, and excellent adhesion.
Roll coating
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-100	Bisphenol A epoxy acrylate	High hardness, high gloss, excellent chemical resistance, and high fullness.
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-165	Modified epoxy acrylate	Good flexibility 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.
Solvent-free spraying
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-251	Aromatic Polyurethane Acrylate	Fast curing, excellent flexibility, and good wetting of black ink pigments.
B-520	Polyester acrylate	Low viscosity, high gloss, excellent wettability, and cost-effective
B-574C	Polyester acrylate	Low viscosity, low odor, excellent wettability; suitable for LED UV.
LED-UV
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-21C	Active amine photosensitizing promoter	Low color number, antioxidant and polymerization inhibitor, and enhanced curing rate
B-241	Aliphatic polyurethane acrylate	Fast curing, excellent skin feel, and yellowing resistance.
B-27	Active amine photosensitizing promoter	Low color number, benzene-free, low odor, antioxidant and anti-polymerization
B-570	Polyester acrylate	Low viscosity, benzene-free, low odor, suitable for LED UV
B-574	Polyester acrylate	Benzene-free, low odor, and VOC levels meet cigarette pack standards.
B-574C	Polyester acrylate	Low viscosity, low odor, excellent wettability; suitable for LED UV.
Excimer lamp
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-241	Aliphatic polyurethane acrylate	Fast curing, excellent skin feel, and yellowing resistance.
Skin feel
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-165	Modified epoxy acrylate	Good flexibility and strong adhesion
B-241	Aliphatic polyurethane acrylate	Fast curing, excellent skin feel, and yellowing resistance.
B-328M	Aliphatic polyurethane acrylate	Low gloss, low viscosity, excellent wettability, and a pleasant hand feel.
B-328R	Aliphatic polyurethane acrylate	Low gloss, excellent matting, good wetting, and a fine, smooth, and silky hand feel.
B-574C	Polyester acrylate	Low viscosity, low odor, excellent wettability; suitable for LED UV.
B-868	Organosilicon UV-Curable Resin	Excellent leveling, smooth finish, fast curing, and stain resistance.
B-868H	Organosilicon UV-Curable Resin	Excellent leveling, smooth finish, fast curing, and stain resistance.
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:

Solutions for Defects in UV Wood Coatings (Part 1)

Common Defects in UV Wood Coatings (9)