1 Wood defects and putty repairs
Repairing plays a crucial role in flooring production. Workers remove soft tissues with a scraper and fill gaps using putty. Knots and cracks are the areas that typically need repair.
Knots form naturally as trees grow or due to environmental influences. They divide into sound knots and dead knots. Sound knots connect to trunk tissue and share the wood’s properties. Dead knots come from branches that die and separate from the trunk. In veneer, dead knots appear as holes or cracks, which require filling.
Cracks can also form during wood growth or veneer processing. Short cracks or lower-grade boards can still be used after repair.
2. Putty for Wood Flooring
Wood flooring putty, a non-critical raw material in flooring production, is a multiphase mixture with no fixed composition. The putty needs to meet the following performance requirements:
- Strong Adhesion: The putty should have good adhesion, firmly sticking to the wood surface without easily debonding.
- Durability: The putty should have a long service life, maintaining its performance over time without cracking, peeling, or discoloring.
- Easy Sanding: The putty should be easy to sand once dry, leaving a smooth, flat surface that does not affect subsequent painting processes.
- Good Filling Ability: The putty should effectively fill holes, cracks, and uneven areas on the wood surface, making it smooth and uniform.
- Water Resistance: In high-humidity environments, the putty should maintain its performance without dissolving, swelling, or deforming.
- Low Shrinkage: The putty should minimize shrinkage during drying to avoid cracks or depressions.
- Moderate Drying Speed: The drying speed of the putty should be moderate—neither too fast to limit working time nor too slow to affect processing.
- Environmental Friendliness: The putty should use environmentally friendly materials, reducing the release of volatile organic compounds (VOCs) and being harmless to human health and the environment.
- Good Coloring Performance: The putty should be compatible with wood coatings, not affecting subsequent coloring and finish.
These performance requirements ensure that the wood putty delivers optimal results during use, extends the wood’s service life, and provides excellent appearance and protection.
Current putty formulations for flooring primarily include 25-45% fillers (wood powder, talc, titanium dioxide), 35-65% water-based resins (acrylic, polyurethane, epoxy resin, polyvinyl acetate), additives (emulsifiers, pH adjusters, defoamers, film-forming agents, thickeners, dispersants), pigments, and water.
3. Putty Colors
The color of the putty can be adjusted using colorants and applied to different areas. Floor repairs typically use natural wood-colored putty and black putty.
Wood-colored putty is suitable for small dead knots or localized crack filling.
Black putty is used for dead knot holes or larger cracks.
4. Conclusion
Workers use different colored putties to repair specific defects, maintaining the wood’s natural appearance as much as possible. The repaired areas blend seamlessly with the wood grain, showcasing the craftsmen’s meticulous attention to detail and their connection to the soul of the wood.
