Investigation of the Effect of Bonding Parameters on the Mechanical Strength of the Joint in the Adhesive Bonding of PLA Materials Produced by Additive Manufacturing

Abstract

From the past to the present, plastic materials are used extensively in all areas of the industry, thanks to their shaping capabilities. Especially in the last 10 years, with the proliferation of desktop type 3D printers in the additive manufacturing sector, thermoplastics have become the most widely used plastic material. Therewith, the assembly of materials produced by this method has gained so much importance. Since plastic materials have low surface energy, there are difficulties in performing the adhesive bonding process, which is a popular joining method, and some issues (adhesive type, surface cleaning, etc.) should be carefully considered. In this study; PLA sheets were produced by means of additive manufacturing method and joined with two different adhesives (Loctite 9492 and Terason 9225). For surface preparation, mechanical sanding was performed using 320 and 600 grit size SiC sandpaper. Adhesive bonding joints were created from PLA-PLA material with three different adhesive thicknesses (0.3, 0.18 and 0.1mm). Joints were subjected to tensile test and their mechanical properties were examined. The results showed that high fill ratio in 3D printing increases the strength of parts. In addition, the strength of the adhesively bonded surfaces is affected by the variation of the adhesive thickness and the adhesive type. Whilst an increase in the adhesive thickness increases the strength of Loctite EA 9492 joints; just an opposite effect in Teroson PU 9225 joints was observed.