**9. Microstructural of composite board from compressed oil palm fronds**

The microstructural observation of the composite board from compressed oil palm fronds was carried out with the help of high-performance microscopy, and a more detailed structure has been observed by scanning electron microscopy (SEM). More attention has been done to the microscopic resin penetration of the composite board from compressed oil palm fronds. The macroscopic structural characteristics of the composite board are the features that are using high-performance microscopy to magnify from 0.75 to 8.0 times. **Figures 24** and **25** show the roughly structural composite board from compressed oil palm fronds at the longitudinal sectional view for phenol and urea-formaldehyde composite board that had been observed under high-performance microscopy.

**Figure 24** showed that the reddish colour of the composite board had been affected by phenol-formaldehyde resin colour naturally, and the same goes for the urea-formaldehyde composite board that shown whitish in the colour of its

#### **Figure 25.**

*High-performance micrograph of the urea-formaldehyde composite board from compressed oil palm fronds at the longitudinal sectional view (2 magnification).*

*Processing and Properties of Oil Palm Fronds Composite Boards from* Elaeis guineensis *DOI: http://dx.doi.org/10.5772/intechopen.98222*

appearances according to **Figure 25**. Appearances comparison among both of them resulted in the composite board from urea-formaldehyde resin, which gave better appearance quality than the composite board from phenol-formaldehyde resin, which is one reason why urea-formaldehyde resin has been used for internal usage of mostly wood-based composites. This composite board is formed layer by layer like laminated veneer lumber (LVL) because of its parallel arrangement among the compressed oil palm fronds. A more complex arrangement of this composite board has been presented in **Figures 26** and **27** under SEM observation at different magnification levels.
