Einfluß der Randbedingungen bei der Bestimmung des extrahierbaren Formaldehyds in Holzspanplatten nach der Perforatormethode

2011

Wood Sci Technol

Self Cite

The correction factor developed by Jann and Deppe (1990) to adjust the measured perforator values of particleboards and fibreboards measured at different moisture contents in the range of 3% B u B 9% to the level at 6.5% moisture content has two main deficiencies. It takes no account of the influence of the molar ratio of the resins used, which seems to remarkably impact the relationship between the moisture content and the measured perforator values. Moreover, research work revealed that the correction factor to be applied also depends on the moisture content, at which the perforator value was measured, according to an inversely proportional correlation. Besides, the correction factor according to Jann-Deppe leaves this fact unconsidered.

Section: Resultssupporting

confidence: 83%

Influence of molar ratio in aminoplastic resins on the dependence of the measured perforator values on the moisture content of wood-based panels

Johnsson¹,

Engström²,

2011

Wood Sci Technol

Self Cite

“…This is a strong indicator that the change of the measured perforator value with the moisture content is not the same for all aminoplastic-bonded boards, as originally assumed by the empirical formula published by Jann and Deppe (1990). This conclusion is in line with previous results published by Roffael and Mehlhorn (1980), who found that the molar ratio is an important factor as far as the relation between the perforator value and the moisture content is concerned, as shown in Figs. 6 and 7.…”

Section: Resultssupporting

confidence: 83%

On the measurement of formaldehyde release from low-emission wood-based panels using the perforator method

Johnsson²,

Engström³

2010

Wood Sci Technol

Self Cite

In Europe, the perforator method (EN 120) is the mostly used laboratory method of the wood-based panel industry. Usually, the measured perforator value depends on the moisture content of the boards. According to DIBt-100, the measured perforator values are corrected to a common moisture content (MC) of 6.5% using an established equation proposed by Jann and Deppe (1990). The correction factor of Jann and Deppe (1990) is based on the assumption that particle-and fibreboards change their perforator values to the same extent regardless whether increasing or decreasing the moisture content in the range of 3 B u B 9%. Application of this correction factor to particle-and fibreboards of higher moisture content than 6.5% can lead to biased corrected results in favour of low emission. The corrected values can also lead to paradoxical relation between the perforator values and emission in the low-emission region.

“…Roffael and Mehlhorn (1980) showed that between a moisture content of *3 and *14 % a more or less straight relationship exists between the measured perforator value and moisture content of the boards. Sundin (1984) pointed out the significance of the moisture content on the measured perforator value of particleboards.…”

Section: Influence Of Resin Content On the Perforator Valuementioning

confidence: 95%

On the influence of binder content in particleboards bonded with resins of high and low molar ratio on the formaldehyde release measured by the perforator method

Behn

2012

Eur. J. Wood Prod.

Self Cite