Chemo-thermomechanical pulps (CTMP) from oak wood release more formic and acetic acid than thermomechanical pulps (TMP) made from the same wood. In contrast, the emission of formaldehyde from CTMP is lower than that from TMP. Medium density fibreboards (MDF) made from TMP and CTMP emit less formic...

Thermo-mechanical pulps (TMP) and chemo-thermo-mechanical pulps (CTMP) were prepared from chips of oak wood with more than 70% heartwood. The fibres retrieved by both processes were separated by sieve analysis into different fibre fractions [≤0.1 mm (fine fraction) and >1 mm (coarse fraction)]....

Washing of CTMP-pulps ahead of board making decreases the amount of extractable acetate and formate ions from the boards. The decrease in the amount of releasable acetic acid due to washing is enormous, whereas washing seems to have no detectable effect on the releasable amount of formic acid. This ...

Application of the correction factor developed by Jann and Deppe (1990) to particleboards and fibreboards of moisture contents higher than 6.5% can lead to biased results in favour of low emission as the correction factor goes beyond offsetting the moisture effect. Moreover, the correction factor...

Emission of volatile organic compounds (VOCs) from medium density fibreboards (MDF) containing different proportions of softwoods (SW) and hardwoods (HW) was evaluated. The results reveal that decreasing the proportion of HW in MDF elevates the emission of terpenes and aliphatic aldehydes. The...

Fibres obtained by the TMP- and CTMP-process from old oak (200-250 years) contain higher amounts of cold water extractives than those obtained from young oak (20-30 years). Moreover, water soluble extractives from old oak fibres are, in general, more reactive towards formaldehyde. This result...

The gas analysis method (EN 717-2:1994), originally destined for measuring the formaldehyde release from wood-based panels, can also be used to determine the emanation of volatile organic acids such as acetic acid. However, the profile of release of formaldehyde and acetic acid seems to be quite...

Thermo-mechanical (TMP) and chemo-thermo-mechanical pulps (CTMP) were prepared from pine wood and from UF-bonded MDF made from pine wood. For preparing TMP pine chips as well as UF-bonded MDF were digested under pressure at 170°C. Thereafter, the digested chips and MDF were defibrated at 170°C...

The work aimed to study the influence of replacing virgin wood fibres by recycled fibres, made from recovered medium-density fibreboards (MDF) by thermo-mechanical pulping, on the physical-mechanical properties and formaldehyde release of urea-formaldehyde (UF)-bonded MDF. It was found that...

Wood contains primary extractives, which are present in all woods, and secondary extractives, which are confined in certain wood species. Extractives in wood play a major role in wood-bonding processes, as they can contribute to or determine the bonding relevant properties of wood such as acidity...