Influence of Selected Resin and Bonding Factors on Flakeboard Properties

Factors associated with the bonding process in particleboard production such as resin type, resin spray, time, use of catalyst, press closure time, and conditioning treatment were studied with regard to their effects on static bending, internal bond, and dimensional stability. The resin type had a significant effect upon internal bond but not upon static bending, or dimensional stability. The resin spray time significantly affected static bending, but not internal bond or dimensional stability. The use of catalyst significantly affected internal bond and dimensional stability, but not static bending. Rapid press closure improved all three properties. A period of 150?F. conditioning treatment, after pressing, reduced the internal bond strength for all resins but strongly improved dimensional stability for all uncatalyzed resins while showing little effect upon the catalyzed resin. The effect upon static bending was not assessed. Those factors which lead to a more complete resin cure (catalyst, aged resin, and elevated temperature conditioning) improved dimensional stability. The same is true for internal bond except for the elevated temperature conditioning effect. Static bending was not affected by these factors. High temperature conditioning increases the set in compressed flakes, thus reducing the swelling force. Specimens subjected to this treatment retained good dimensional stability but suffered reduction in internal bond strength. Rapid press closure leads to increased bending strength. The effect of elevated temperature conditioning on internal bond implies that continued cure of a resin, although it may become more water resistant, can lead to embrittlement. Dimensional stability was improved by rapid press closure, by the use of catalyst in the resin, and by conditioning at 150?F. Factors leading to completeness of cure in particleboard, it was concluded, will produce improved dimensional properties.

You must be logged in to download any documents. Please login (login accounts are free) or learn how to Become a Member