The aim of this study was to use bleaching chemicals to remove the discoloration occurring on the surface of wood after heat treatment in order to restore the natural color of the wood. For this purpose, samples prepared from Scots pine (Pinus sylvestris L.), sessile oak (Quercus petraea L.), Eastern beech (Fagus orientalis L.), and Uludağ fir (Abies bornmuelleriana Mattf.) were exposed to heat treatment at temperatures of 140 and 160 °C for time periods of 3, 5, and 7 h. Bleaching solutions S1 (NaOH + H2O2), S2 (NaSiO3 + H2O2), and S3 (H2C2O4) at a concentration of 18% were then applied to the surface of the materials and the color change was determined according to ASTM D 2244 standard. Depending on the heat treatment temperature and duration, an increase in total color change values was detected on the surfaces of the materials and the color of the samples became darker. The total color change values decreased after bleaching with the S2 solution in the heat-treated Scots pine and fir samples, with the S3 solution in the beech samples, and with the S1, S2, and S3 solutions in the oak samples. The findings showed that by using bleaching chemicals to lighten wood materials darkened after heat treatment, it is possible to obtain results close to the natural color values.

中文翻译：

---

测定漂白化学品对某些热处理木材的变色效果

这项研究的目的是使用漂白剂去除热处理后木材表面上的变色现象，以恢复木材的自然色。为此，将由苏格兰松树（Pinus sylvestris L.），无梗橡树（Quercus petraea L.），东部山毛榉（Fagus Orientalis L.）和Uludağfir（Abiesbornmuelleriana Mattf。）制备的样品暴露于高温下在140、160°C下持续3、5和7小时。然后将漂白剂溶液S1（NaOH + H2O2），S2（NaSiO3 + H2O2）和S3（H2C2O4）浓度为18％施加到材料表面，并根据ASTM D 2244标准确定颜色变化。根据热处理温度和持续时间，在材料表面检测到总颜色变化值增加，样品颜色变深。在经过热处理的苏格兰松树和冷杉样品中使用S2溶液，山毛榉样品中使用S3溶液以及橡木样品中使用S1，S2和S3溶液漂白后，总颜色变化值降低。研究结果表明，通过使用漂白剂使经过热处理后变黑的木质材料变浅，可以获得接近自然色值的结果。