Cork powders wettability by the Washburn capillary rise method

The applicability of Washburn capillary rise (WCR) method on cork powders wettability was investigated. An adapted sample preparation method was also developed to guarantee measurements accuracy and reproducibility. The processing of cork powders by 3D Printing (3DP) presents a clear challenge related to cork wettability. The common liquid binders used in 3DP printers are composed mainly by water (95% w/w). Two sets of cork powders with different particle size distributions (PSD) were prepared and studied, namely Full Range powder with a wider distribution (20-100 mu m) and Coarse powder with a narrow distribution (63-80 mu m). Among the studied wetting liquids, hexane revealed to be the wetting liquid with higher ability to completely wet cork powders in a short period of time (14-18 s). Coarse powder exhibited higher packing ability based on the calculated parameter C values. Contact angles between a commercial binder and Full Range and Coarse powders were estimated as 86.1 +/- 2.1(circle) and 87.3 +/- 1.5(circle), respectively. The obtained results showed that WCR method can successfully describe the wettability behaviour of cork powders. (c) 2021 Elsevier B.V. All rights reserved.

Automated summary

The study found that the Washburn capillary rise method can successfully describe the wettability behavior of cork powders. Hexane was identified as a wetting liquid with the ability to completely wet cork powders in a short period of time, while coarse powder exhibited higher packing ability. The contact angles between different particle size distributions of cork powders and a commercial binder were estimated to be 86.1 and 87.3 degrees, respectively.