The Effect of Post-Heat Treatment in MDF Panels

Abstract

This study was to evaluate the effect of post-heat treatment on the physical and mechanical properties of MDF (Medium Density Fiberboard) panels. Commercial MDF panels were produced in Brazil using Pinus wood and urea-formaldehyde (UF) adhesive. The post-heat treatments were carried in a factorial 3 x 2 (three temperatures of heat treatment -200, 225 and 250 °C, and two times -5 and 10 minutes), and a control treatment (without heat treatment). Subsequently, the physical and mechanical tests were performed. From the results it can be concluded that: 1) The most effective thermal post-treatment for improving the dimensional stability of the MDF was applied at 225 ° C and 10 min; 2) All the thermally treated panels revealed a significant decrease in the modulus of rupture and modulus of elasticity (MOR and MOE) to bending when compared with the control panels without post-heat treatment.

Effect of the post-heat treatment on the properties of medium density particleboard of Eucalyptus sp.

“…The pressure used was 0.5 kgf/cm² to promote a good contact between the press plates and the sample and hence facilitate the temperature conduction. The parameters evaluated in this study were based on Oliveira et al (2017) and Carvalho et al (2015).…”

“…Vilela AP, Surdi PG, Sabino TPF, Metzker SLO, Coelho NPF of panels, i.e., in the particles (Ayrilmis et al, 2011;Mendes et al, 2013a;Mendes et al, 2013b;Ribeiro et al, 2020), and (ii) the post-treatment performed in the panels after being consolidated and stabilized (Mendes et al, 2013b;Carvalho et al, 2015;Oliveira et al, 2017;Hill et al, 2021). Therefore, regardless of how it is applied, the heat treatment consists of the application of temperature between 100 and 250 °C in the wood or wood products (Kocaefe et al, 2010;Silva et al, 2018;Wang et al, 2018).…”

“…Thus, some researches have been aiming to evaluate its influence on MDP (Carvalho et al, 2015;Melo et al, 2018), medium density fiberboard -MDF (Lee et al, 2015;Oliveira et al, 2017;Wang et al, 2020), Plywood (Lunguleasa et al, 2018;Bekhta, 2020) and oriented strand board -OSB (Okino et al, 2007;Mendes et al, 2013ab). The results were promising in most cases and the heat treatment in already consolidated panels provided an improvement in material's dimensional stability and resistance to the attack of xylophagous organisms, despite decreasing the mechanical properties.…”

Influência dos parâmetros de fabricação nas Propriedades Físicas e Mecânicas de Paineis de Partícula de Média Densidade

“…Estes painéis são constituídos de madeira processada (partículas, lascas ou lamelas) e resina, unidas à quente sob pressão [8][9][10]. As resinas utilizadas no processo de fabricação podem ser acetato de polivinila (PVA), fenol formaldeído (FF), resorcinol formaldeído (RF), ureia formaldeído (UF), difenilmetano diisocianato (MDI) e poliuretana (PU) à base de óleos de origem vegetal [3, [11][12][13][14][15][16], destacando-se a resina ureia formaldeído, utilizada na fabricação de paineis comerciais [12,[17][18][19].…”

Insulation Panels Made from Thermally Modified Bark

“…The longer the treatment, the better the dimensional stability became. Oliveira et al (2017) evaluated the effect of post-heat treatment on the physical and mechanical properties of MDF panels. The dimensional stability of the MDF increased, but all the thermally treated panels revealed a significant decrease in their MOR and MOE.…”