2025-05-31 Pageview:83
Wax emulsion provides an effective solution to the wear and scratch resistance of waterborne one-component wood paint. The following is an analysis from four dimensions: the root cause of the problem, the mechanism of action of wax emulsion, application advantages and case verification:
1. The root cause of the wear and scratch resistance of waterborne one-component wood paint
The conflict between hardness and wear resistance
The polymer Mohs hardness of waterborne one-component wood paint is only 1-3 (much lower than metal or ceramic), and although the hardness of the paint film is improved after cross-linking, the brittleness increases, which in turn leads to a decrease in wear resistance. Experiments show that hard and brittle paint films have more serious mass loss in the Taber test.
Defects in the anti-scratch mechanism
The generation of scratches is related to the relaxation time of the polymer molecular chain. Under the action of external force, if the molecular chains do not have time to rearrange through thermal movement (relaxation time is long), permanent scratches are easily formed. Traditional paint films lack the ability of “self-repairing”, resulting in irreversible scratches.
2. Solution mechanism of wax emulsion
Surface migration to form a protective layer
After application, the wax particles (particle size 4-10μm) in the wax emulsion migrate to the surface of the paint film as the solvent evaporates to form a uniform wax layer. This layer has a low friction coefficient (polyethylene wax friction coefficient <0.1), which can effectively disperse shear force and prevent scratches from expanding.
Dynamic lubrication effect
When subjected to force, the wax layer produces microscopic plastic deformation and absorbs part of the energy. At the same time, the weak interaction between wax molecules allows local chain segments to slide and reduce stress concentration.
Balance of hardness and toughness
High-density polyethylene wax (HDPE) in wax emulsion has a high melting point (90-120℃), and forms a crystallization area after solidification, which improves the hardness of the paint film; while the stone wax-based wax emulsion compensates for the flexibility to avoid cracking of the paint film.
III. Application advantages and formulation design of wax emulsion
Quantitative data of performance improvement
Scratch resistance: Steel wool friction test (2 pound load, 50 cycles) gloss loss rate is reduced by more than 60%.
Abrasion resistance: Taber test (1000g load, 1000 cycles) mass loss is reduced by 40%.
Hand feel: The surface roughness Ra value is reduced from 0.8μm to 0.4μm, and the touch is smoother.
Key formulation parameters
Additional amount: 1%-6% (adjusted according to the type of wax, excessive amount will lead to decreased adhesion).
Particle size selection:
Fine particle size (<0.1μm): suitable for high-gloss transparent system, improve gloss.
Coarse particle size (4-10μm): enhance anti-sticking, suitable for matte effect.
Ionic matching: anionic wax emulsion has good compatibility with non-ionic water-based resin.
IV. Process optimization suggestions
Dispersion process
Wax emulsion needs to be added last, and stir at low speed (<500rpm) to avoid demulsification.
Recommended dilution ratio 1:3 to ensure uniform dispersion.
Curing conditions
Stage curing: room temperature surface drying for 15min→60℃ baking for 15min→UV curing (300mj/cm²×3 times).
Avoid high temperature sudden drying resulting in uneven distribution of wax layer.
Conclusion
Wax emulsion significantly improves the wear and scratch resistance of waterborne one-component wood paint through the triple mechanism of “surface migration-dynamic lubrication-hardness compensation”. In practical application, the formula needs to be optimized in combination with wax type, particle size and addition amount, and the effect should be verified through standard tests. For high gloss systems, it is recommended to use nanosilica dispersion (NSSD) for further synergistic enhancement.
Leave a message
We’ll get back to you soon