T.S. McCracken, Covestro, Pittsburgh, PA 01.07.19
Abstract
The wood composite industry has been using PMDI since the 1970s, most notably in oriented strand board products. With current formaldehyde emission reduction initiatives, PMDI has been moving into the particle board and medium density fiberboard areas as well. The industry has been looking for a fast curing PMDI to compete with the catalyzed urea/melamine resins with the goal to reduce press times. When using PMDI for wood composites, the process comprises combining wood particles with a PMDI resin, followed by molding or compressing the coated combination of wood particles. PMDI prepolymers are useful as single component binders as they do not require separate catalyst or polyol streams to be metered into the resin at the mill facilities which would require additional personnel to monitor the process. The binders are advantageous in that they may be used to reduce press times without the addition of a catalyst, may be run with higher wood moisture contents, and provide longer shelf life (when stored properly) when compared to the other commonly known catalyzed wood binder systems. This paper looks at various single com
The wood composite industry has been using PMDI since the 1970s, most notably in oriented strand board products. With current formaldehyde emission reduction initiatives, PMDI has been moving into the particle board and medium density fiberboard areas as well. The industry has been looking for a fast curing PMDI to compete with the catalyzed urea/melamine resins with the goal to reduce press times. When using PMDI for wood composites, the process comprises combining wood particles with a PMDI resin, followed by molding or compressing the coated combination of wood particles. PMDI prepolymers are useful as single component binders as they do not require separate catalyst or polyol streams to be metered into the resin at the mill facilities which would require additional personnel to monitor the process. The binders are advantageous in that they may be used to reduce press times without the addition of a catalyst, may be run with higher wood moisture contents, and provide longer shelf life (when stored properly) when compared to the other commonly known catalyzed wood binder systems. This paper looks at various single com
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