Debinding of Stereolithographically Printed Ceramic Parts: Supercritical Carbon Dioxide as Solvent
Nurmi, Nonna (2022)
2022
Materiaalitekniikan DI-ohjelma - Master's Programme in Materials Engineering
Tekniikan ja luonnontieteiden tiedekunta - Faculty of Engineering and Natural Sciences
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Hyväksymispäivämäärä
2022-12-22
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:tuni-202212229727
https://urn.fi/URN:NBN:fi:tuni-202212229727
Tiivistelmä
Cleaning, pre-conditioning and thermal debinding of 3D-printed ceramic parts takes a significant amount of time and ways to shorten the manufacturing time are scarce. The thermal debinding could be made more economical by extracting some of the slurry substances prior to thermal debinding, creating flow channels for gases to exit.
Supercritical carbon dioxide (scCO2) was used with different chemicals to find out which ones dissolve from the stereolithographically printed part without cracking and part deformation. The scCO2 extracted samples were tested with TGA, DSC, FTIR, stereomicroscope, SEM, and the sample mass and dimensions were measured before and after the extraction test. The scCO2 extraction testing time, co-solvent, monomer fractions and slurry contents were varied.
PEG400, PEG200 difunctional methacrylate, uncured 3,4-Epoxycyclohexylmethyl 3,4-
epoxycyclohexanecarboxylate, uncured 1,10-decanediol diacrylate, and paraffin oil were successfully extracted. With these substances included in the recipe and removed using scCO2, as a result of extraction the parts shrank. The substance removal rate was enhanced with ethanol as a co-solvent in polymeric samples, but in samples containing alumina, the rate was de-creased, and co-solvent caused delamination between the print layers. Isopropanol showed better extraction results with less delamination in ceramic samples.
Supercritical carbon dioxide (scCO2) was used with different chemicals to find out which ones dissolve from the stereolithographically printed part without cracking and part deformation. The scCO2 extracted samples were tested with TGA, DSC, FTIR, stereomicroscope, SEM, and the sample mass and dimensions were measured before and after the extraction test. The scCO2 extraction testing time, co-solvent, monomer fractions and slurry contents were varied.
PEG400, PEG200 difunctional methacrylate, uncured 3,4-Epoxycyclohexylmethyl 3,4-
epoxycyclohexanecarboxylate, uncured 1,10-decanediol diacrylate, and paraffin oil were successfully extracted. With these substances included in the recipe and removed using scCO2, as a result of extraction the parts shrank. The substance removal rate was enhanced with ethanol as a co-solvent in polymeric samples, but in samples containing alumina, the rate was de-creased, and co-solvent caused delamination between the print layers. Isopropanol showed better extraction results with less delamination in ceramic samples.