Parameters influencing the temporal behavior of adhesion on the build plate in fused filament fabrication

ABSTRACTFused filament fabrication, also known as material extrusion, is an additive manufacturing process used in many industries. Despite its widespread application, common issues like an unwanted deformation of the part to be printed during the process are rarely investigated. These failures, called warping, can be avoided by a sufficient adhesion between build surface and part. Although printing processes can last up to several days, the time dependencies and the mechanism causing adhesion are poorly understood. For this reason, the time dependence of adhesion between polylactic acid and polyamide as printing materials and different building surfaces will be investigated. The adhesion forces can change up to 60% within 20 minutes dependent on the build surface temperature. Higher build surface temperatures lead to a stronger change. These results indicate that besides mechanical adhesion other mechanisms could be involved. Adhesion measurements before and after sandblasting the build surfaces support this. For brass and borosilicate glass as build surface materials, a complete loss of adhesion was observed, whereas it did not change for Pertinax. These overall results lead to the assumption that adhesion occurs because of ionic bond onto brass surfaces and because of hydrogen bond onto borosilicate glass and Pertinax.KEYWORDS: Fused filament fabricationbuild surface adhesionwarping AcknowledgmentsWe would like to thank the working group of Macromolecular and Paper Chemistry of Markus Biesalski and especially Sunna Möhle-Saul for access to DSC measurements and consultation regarding setup and interpretation.Disclosure statementNo potential conflict of interest was reported by the author(s).Additional informationFundingThis work was supported by the Federal Ministry for Economic Affairs and Climate Action within the Central Innovation Programme for small and medium-sized enterprises (SMEs) under Grant 16KN084521.