Options
1978
Conference Paper
Titel
Progress in the elimination of formaldehyde liberation from particleboards
Abstract
One of the main disadvantages of using urea-formaldehyde (UF) resins as a binder for particleboards is formaldehde release. Formaldehyde emanates sloly from particleboards over a long period of time. The rate of formaldeyde liberation increases under hot and humid conditions. The concentration of formaldehyde emitted from poor-grade particleboards can reach levels which are intolerable to humans. Consequently, there has been a growing reluctance by the wood-working trades to risk the use of UF-bonded particleboards. This subject has been discussed throughly in both the technical literature and the mass media. For indoor use of particleboards, a permissible limit of 0.1 parts per million (ppm) for formaldehyde has been proposed by national health authorities in West Germany. However, no definite action has been taken to date. Moreover, the rate and the extent of formaldehyde liberation from particleboards is influenced by a large number of parameters including molar ratio of formaldehyde to urea, resin level, catalyst level and catalyst composition, moisture content and moisture distribution prior to pressing, board post treatment, and duration of storage before use. This paper will discuss two test methods now being used for determining formaldehyde release, the effect of decreasing the molar ratio of formaldehyde tourea in UF-resins, the influence of aging on the reduction of formaldehyde release, partial substitution of UF-resins by other binders, and the use of formaldehyde scavengers.
Konferenz