Cork powders wettability by the Washburn capillary rise method

• Published in: Powder technology 2021-07, Vol.387, p.16-21
• Main Authors: Magalhães da Silva, S.P., Oliveira, J.M.
• Format: Article
• Language: English
• Subjects: 3D printing (3DP); Binders; Contact angle; Cork; Hexanes; Liquid binder; Powder; Powders; Sample preparation; Three dimensional printing; Washburn capillary rise (WCR); Wettability; Wetting
• ISSN: 0032-5910; 1873-328X
• DOI: 10.1016/j.powtec.2021.04.005

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 μm) and Coarse powder with a narrow distribution (63–80 μm). 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° and 87.3 ± 1.5°, respectively. The obtained results showed that WCR method can successfully describe the wettability behaviour of cork powders. [Display omitted] •Cork powders wettability was successfully evaluated by the WCR method.•Hexane completely wetted cork powders in a short period of time (14–18 s).•Powders with narrow PSD exhibited a higher packing ability.•Estimated contact angle values between cork and binder were found to be 86.1–87.3°.