Status of the release technology of OSB bonded with MDI-based binders

This paper will describe an effective technology for the production of 100 percent polymeric diphenylmethane diisocyanate (pMDI) oriented standboard (OSB) through the use of a 'self releasing' pMDI-based resin. The basis for the technology is a modification to the base chemistry of the pMDI. Release tests show that efficient release performance in the production of OSB can be obtained using such a modified isocyanate with significantly reduced level of application of any external release agent relative to the control pMDI resins. The system is also robust: even with a simulated failure of the external application system effective release continues, providing a remarkable level of security in the production. In addition, the reduced level of external release agent has a beneficial effect on the appearance of the panels. Panels have been prepared under conditions appropriate to both European and North American composite production to investigate the impact of the modified resin technology on the final physical properties of the composites. The data confirms that the modified isocyanate technology has no impact on the physical properties of the composites and provides superior performance to traditional resin systems based on phenol formaldehyde.