The use of natural wood veneer is becoming more and more widespread. The quality of wooden products is closely related to the veneer application process. Improper veneer application methods will not only waste precious veneer materials but also significantly reduce the quality of wooden products. Therefore, the techniques for using manual veneer adhesive are quite particular. Below I will introduce them.
1. For wood veneers with a thickness of 0.6-1.0mm, the application amount of manual veneer adhesive is 100-130g/m². A higher adhesive amount is suitable for thicker veneers, with the most appropriate amount being when there is only slight adhesive bleed-through. Too little adhesive can easily lead to adhesive shortage and cause dry bond failure. Too much adhesive will cause bleed-through contaminating the wood surface, making it difficult to achieve a good finishing effect.
2. Assembly time: complete pressing within 10 minutes at 25°C.
3. Hot press temperature: 105-110°C for multi-opening hot presses, 120-125°C for single-opening fast hot presses.
4. Hot press time: For wood veneer 0.8mm thick, 3 to 4.5 minutes for multi-opening hot presses. For wood veneer 0.65mm thick, 3 to 4 minutes for multi-opening hot presses.
5. Hot press pressure: 8-12 kg/cm². Generally 10 kg/cm². Adjust according to wood species: pine uses 7-8 kg/cm², hardwoods like Oak, Cherry, Ash use 10-12 kg/cm², and extra hard woods and species with large thickness variation like Mapa burl, Ash burl use 12-15 kg/cm².
6. In winter, increase the temperature by 5°C and extend the heating time by 10-30 seconds. Immediately after pressure release, conduct a peel test. Wood failure is required to confirm complete curing of the adhesive. For oily wood veneers like pine, lower the temperature to 90-100°C. Because pine is generally 1-1.2mm thick, thicker than usual, and the hot press temperature is lower, the hot press time needs to be extended.
7. Wood moisture content (before hot pressing): 6-10% is most suitable for Oak, Ash; 6-8% is most suitable for Cherry, Pecan, Walnut, Black Walnut, etc. For fiberboard and particleboard, moisture content of 6-8% is most suitable. Moisture content that is too high or below standard often leads to poor bonding.
8. The thickness tolerance of wood veneer should be within 0.1mm. The sanding thickness flatness difference for PB and FB boards should be within 0.15mm. Exceeding the above standards will greatly increase the defect rate. Avoid overlapping tape. A maximum of 2 layers. 3 layers of tape will cause the moisture in the veneer to rise too high, and being too thick will also cause excessive pressure and insufficient heat transfer, preventing the adhesive from curing completely. This is the main reason for cracking or lifting at the veneer splicing lines.