Phenolic panels various products

For the production of wood-based panels various adhesives are in use like aminoplastic resins (UF, MU(P)F), phenolic resins (PF) or isocyanate (PMDI). The proper choice of the adhesive depends on the required properties of the wood-based panels, on the working conditions during the production as well as often on the costs for the adhesive system this not only means the net price of the adhesive but the overall costs of the gluing system including glue spread factor. 

The two-hour desiccator and Perforator test results shown in Table II are also indicative of very low formaldehyde levels for phenolic panels. As with most of the results obtained in dynamic chamber tests, the uniformity of these test results, both within and between studies, indicates that the various phenolic panel products are quite similar with respect to their emitting potential. 

Formaldehyde as a pollutant in the indoor air is usually connected with the use of formaldehyde based resins in e.g. building materials and in furniture. This article presents measurements of the formaldehyde emission from various products containing urea-formaldehyde (UF) or phenol-formaldehyde (PF) resins. The emission from all test objects have been measured in a ventilated test chamber at the standardized testing atmosphere 23 C, 50 % RH according to the International Organization for Standardization (ISO). The emission from woodbased panels and other materials have been measured at a loading factor of 1.0 m /m and at an air change rate of 1.0 h . ... 

For the production of wood-based panels various adhesives are in use, including aminoplastic resins (UF, MUF, MUPF), phenolic resins (PF), and isocyanate (PMDI). 

By far the preponderance of the 3400 kt of current worldwide phenolic resin production is in the form of phenol-formaldehyde (PF) reaction products. Phenol and formaldehyde are currently two of the most available monomers on earth. About 6000 kt of phenol and 10,000 kt of formaldehyde (100% basis) were produced in 1998 [55,56]. The organic raw materials for synthesis of phenol and formaldehyde are cumene (derived from benzene and propylene) and methanol, respectively. These materials are, in turn, obtained from petroleum and natural gas at relatively low cost ([57], pp. 10-26 [58], pp. 1-30). Cost is one of the most important advantages of phenolics in most applications. It is critical to the acceptance of phenolics for wood panel manufacture. With the exception of urea-formaldehyde resins, PF resins are the lowest cost thermosetting resins available. In addition to its synthesis from low cost monomers, phenolic resin costs are often further reduced by extension with fillers such as clays, chalk, rags, wood flours, nutshell flours, grain flours, starches, lignins, tannins, and various other low eost materials. Often these fillers and extenders improve the performance of the phenolic for a particular use while reducing cost. 

Currently, existing pilot plants in Canada, Netherlands, UK utilize mainly well defined non contaminated biomass fractions such as wood particles, saw dust, and bark. The performed investigations in this work should broaden the knowledge of the pyrolytic behaviour of various industrial biomass waste. This wilt facilitate the introduction of flash pyrolysis processes into existing industrial processes. Therefore, a new way of biomass exploitation will be demonstrated. In cooperation with several companies different biomass waste such as cocoa shell, wood waste, fibre sludge and panel boards with a high content of phenol-foimaldehyde resin were decomposed by flash pyrolysis into smaller molecules to use them for the production of energy and/or chemicals. 

Table III. Summary of Formaldehyde Test Data for Various Phenolic-Bonded Panel Products...

Then investigations were carried out to examine the cure time requirements of various copolymer resins and to determine whether the amount of phenol replacement could or should be increased. The copolymer resins synthesized from extracts, phenol and formaldehyde, were made with 40% by weight (vs. 20% in previous experiments) of the phenol replaced with extracts. The resin synthesis process as well as the veneer types, method of panel production and glueline evaluation were the same as outlined in preceding paragraphs. However, press times of 2, 3 and 4 minutes were used. 

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