WOOD RESEARCH Volume 70, Number 1, 2025
OSMAN ÇAMLIBEL and MURAT AYDIN

INFLUENCE OF PARAFFIN ON MDF PROPERTIES AT INDUSTRIAL SCALE

In this study, the effect of paraffin addition on the modulus of rupture (MOR), modulus of elasticity (MOE), internal bond (IB), water absorption (WA), and thickness swelling (TS) properties of fiberboard by density variations was evaluated. Higher mechanical properties were calculated for the paraffin-free board. MOR and MOE of the boards decreased with the increase in density, but not linearly; indeed, fluctuations were observed. Conversely, IB values were increased with the increase in density. The adverse effect of paraffin on the mechanical properties was almost eliminated with the increase in density, particularly for the 750 kg/m³ density profile, except for IB. The WA performance of the boards was significantly increased (58.8%) with the increase in density. Furthermore, advances with the density increase were uplifted by paraffin addition. However, when water repellency properties and advances in WA were taken into consideration, paraffin addition caused the opposite behavior for TS, but around 5.1% decrease in TS was achieved for the 750 kg/m³ density profile

WOOD RESEARCH Volume 63, Number 4, 2018
Miroslav Sedlecký, Monika Sarvašová Kvietková, Richard Kminiak, and Lukáš Kaplan

Medium-density f iberboard and edge-glued panel after edge milling – surface waviness after machining with different parameters measured by contact and contactless method

This article deals with the quality of the milled surface of board edges. The quality is evaluated using the Wa (mean arithmetic deviation of the surface waviness). The Wa was measured by two methods (contact and contactless). Form Talysurf 50 Intra was used for the contact method, and the LEXT 3D measuring laser microscope OLS4100 was used for the contactless method. The variable factors whose effect on the resulting waviness was determined were the machined material, milling cutters, cutting speed and feed rate. The boards used were medium-density fiberboard, medium-density fiberboard with single-sided lamination and spruce edge-glued panel. Three different cutters were used for the milling, all of which were made of sintered carbide, and one of them was coated (CrTiN). The cutting speeds were 20, 30, 40 and 60 m.s-1, and the feed rates were 4, 8 and 11 m.min-1. All the above-mentioned factors as well as their mutual interaction had an effect on the waviness. There was no significant difference between the two methods for determining the waviness. In terms of waviness, both methods are interchangeable.