Thermomechanical (TMP) and Chemo-Thermomechanical Pulps (CTMP) for Medium Density Fibreboards (MDF)

Abstract

Summary Thermomechanical (TMP) and chemo-thermomechanical pulps (CTMP) were prepared from spruce under different pulping conditions. The fibres were dried at 70 °C and medium density fibreboards (MDF) were made therefrom in pilot plant scale using urea-formaldehyde resins as a binder. The results of testing the physical-mechanical properties reveal that the pulping temperature has a significant influence on the thickness swelling and water absorption of the boards. MDF prepared from fibres produced at high pulping temperature (180 °C) generally show lower thickness swelling and water absorption than MDF made from fibres produced at low pulping temperature (140°C and 160 °C). However, high pulping temperature may have a negative effect on the internal bond strength of the boards. In general, CTMP leads to MDF with higher internal bonding strength compared to those derived from TMP. In addition, the influence of different drying conditions (150 °C and 170 °C) of TMP and CTMP on the physical-mechanical properties of MDF was assessed. MDF made from CTMP showed lower thickness swelling when dried under high temperature.

Spruce fiber properties after high-temperature thermomechanical pulping (HT-TMP)

“…After this, the fibers are commonly treated with thermosetting resins and pressed to boards with high strength and low swelling when exposed to water (Widsten et al 2004). Furthermore, higher pulping temperature (180°C compared with 140°C and 160°C) has been reported to result in reduced swelling and water absorption of boards (Roffael et al 2001). The objective of the present article is to characterize fibers derived from HT-TMP in the context of SEC values of the process, focusing on morphology, bonding ability, and surface composition of the fibers in view of their possible application in fiber-reinforced composites.…”

Within-process and seasonal changes during industrial production of high-density fibreboard. Part 2: PLS modelling of chemical alterations, refining conditions and panel thickness swell

“…Ten random samples for 24 h thickness swell (TS) tests (TS % , European standard 1993) were cut from produced HDF boards following European standard 1994. TS was chosen because of its susceptibility to hemicelluloses (Roffael et al 2001 ). Table 1 contains a descriptive summary of all variables considered in the models.…”

Medium Density Fibreboard Made from Kenaf (Hibiscus cannabinus L.) Stem: Effect of Thermo-mechanical Refining and Resin Content

“…Krug and Kehr (2001) reported that increasing the steam pressure resulted in shorter fiber lengths, lower strength, and lower elastic properties but improved long-term swelling properties. Roffael et al (2005) found that high pulping temperature resulted in lower TS and WA of MDF panels. The results from Deng et al (2006) and Xing (2006) indicated that both MOE and MOR could be improved when refining steam pressure increases.…”