Supercritical dyeing of wood is a smart green technology. Beyond being of interest to wood industry, it could help to preserve tropical forests and decrease the environmental pollution from overseas shipping. However, scCO₂ dyeing is still in its infancies. This paper demonstrates at the example of three major European hardwood species and the dye Naphthazarin that the uptake of colorants can be improved if scCO₂ is complemented with small amounts of DMSO. The latter triggers micro-swelling of wood, thereby improving dye penetration. Systematic variation of process parameters revealed that optimal colouration is reached at 20.0 MPa and 85 °C. Colour gradients as observed in the interior of halved specimen were evaluated by two methods. While the Euclidean distance ΔE (CIELAB) represents relative colour change only, a recently proposed scanning densitometric approach translates colour depth into absolute dye surface concentration. Morphological investigations conceal this study investigating the impact of selected process conditions.

木材的超临界染色是一种明智的绿色技术。除了对木材工业感兴趣之外，它还可以帮助保护热带森林并减少海外运输对环境的污染。但是，scCO ₂染色仍处于初期阶段。本文以欧洲三种主要阔叶树种和萘酚染料为例进行了说明，如果scCO ₂辅以少量DMSO ，则可以提高着色剂的吸收。后者引发木材的微溶胀，从而提高染料的渗透性。工艺参数的系统变化表明，在20.0 MPa和85°C时达到了最佳着色。通过两种方法评估在减半样品内部观察到的颜色梯度。而欧几里德距离ΔE（CIELAB）仅代表相对的颜色变化，最近提出的扫描光密度法将颜色深度转换为绝对的染料表面浓度。形态学调查掩盖了这项研究，调查了所选工艺条件的影响。