Drying of oak wood lamellas: Part 1. Analysis of the process in a dehumidification kiln

Abstract

The subject of this paper is to analyse the drying process of oak lamellas, which are the solid wood top layer of engineered wood flooring. The focus of the first part of the paper is on dehumidification kilns. Drying in a dehumidification kiln is an interesting alternative to conventional drying of thin solid oak wood with the aim of reaching high drying quality in a reasonable time. Drying tests were done in an industrial dehumidification kiln, and drying parameters were compared with the drying in the conventional kiln. Simultaneously, a drying test at a higher temperature was done in the programmable climate chamber. It was demonstrated that thin oak lamellas (approx. 5 mm thick) could be successfully dried in a dehumidification kiln in a relatively short time and with high drying quality. With the applied drying schedule (initial temperature of 36?C, final temperature of 46?C), the drying cycle will last 2 to 5 days, depending on the amount of wood and the initial MC. Due to the high rate of water evaporation and the inability of the kilns to remove it fast enough, the drying of lamellas in both dehumidification and conventional kilns takes place at a higher equilibrium moisture content than the set values.

Drying of oak wood lamellas: Part 2. Influence of temperature on the drying quality and wood colour

“…Drying was carried out in a programmable climatic chamber (Kambič KK-105 CH), and high initial temperatures were used in both groups (45°C in group A and 50°C in group B). As with the drying schedule described in the first part of the paper (Milić et al 2021), the drying schedule for both groups was carried out in three phases and lasted a total of 60 hours. In addition to the higher initial temperature, group B had lower EMC in the first two phases compared to group A.…”

Capacity of surface production of band sawing in manufacture of oak floor upper layers

“…In this case, narrow kerf frame sawing machines are being replaced by band sawing machines in which narrow kerf band saws are applied (DSB Singlehead 2022). This reduces the kiln drying time of wood from a period of 4 to 6 weeks, even to one week (Milić et al 2021;Solak and Greinke 2022). Hence, the simultaneous use of saws with narrow kerf overall sets and wet technologies of re-sawing operations is an example of sustainable development of manufacture in sawmilling.…”