Keywords: environmentally friendly coating, water-based paint, UV curing

The global VOC emission regulations are becoming increasingly strict, and the wooden crafts industry needs to transition from solvent based coating to water-based and solvent-free coating. However, environmentally friendly coatings have pain points such as slow drying and low hardness, which need to be solved through technological innovation.

1. Performance improvement technology for water-based paint

Crosslink density optimization:

By introducing nano silica (particle size 10-50nm) as crosslinking points, the crosslinking density of the waterborne polyurethane coating was doubled, the hardness increased from 2H to 4H, and the wear resistance (Taber abrasion tester) was increased by 50%.

Quick drying technology:

Adding film-forming aids with differential boiling points (such as composite of dipropylene glycol butyl ether and ethylene glycol butyl ether) to form a "gradient volatilization" effect, reducing the surface drying time from 2 hours to 20 minutes, suitable for assembly line production.

2. Innovative application of UV cured coatings

Development of flexible UV paint:

Traditional UV paint is brittle and prone to cracking on curved wooden parts such as curved screens. By introducing polyurethane acrylate elastomers, the elongation at break was increased from 5% to 30% while maintaining a hardness of ≥ 3H.

Dual curing system:

For shaded areas (such as inside mortise and tenon structures), a combination of "UV curing+moisture curing" process is used to ensure 100% curing of the coating and avoid hand sticking or whitening issues.

3. Biobased coating technology

Waist nut shell oil modified coating:

Using cashew shell liquid as raw material, epoxy groups are introduced through epoxidation reaction, which reacts with amine curing agents to form a dense network structure. Its chemical resistance (no change after soaking in ethanol for 72 hours) is superior to traditional nitro paint.

Lignin based UV paint:

Extracting lignin from papermaking black liquor, oxidizing and degrading it, and graft copolymerizing it with acrylic ester, the UV paint prepared has a biochar content of 40%, which meets the EU OK Compost certification standard.

4. Industry application cases

A certain children's furniture brand has fully switched to water-based paint, using the "nano silica hardening+gradient evaporation fast drying" technology to reduce the VOC content of the product from 120g/L to 8g/L. At the same time, it has passed the EN71-3 toy safety certification, and its sales have increased by 200% year-on-year.

Future trend: Self healing coating technology is currently under development, which involves encapsulating repair agents (such as dicyclopentadiene) in microcapsules. When the coating is scratched, the capsules rupture and release the repair agent, achieving self-healing at room temperature.