Experimental and statistical investigation of the surface quality of 3D printed products using STH filament material

Abstract

Three dimensional (3D) printers have entered every aspect of our lives. Especially home users use 3D printers in many projects within the scope of do-it-yourself (DIY) projects. In addition, as a control mechanism in the transition from design to production, especially in areas such as prototyping, it almost eliminates the margin of error. However, the types of raw materials that can be used in 3D printing processes are relatively limited compared to other production methods. Features such as suitability for production in layers and rapid solidification come to the fore. Additionally, cooling deformations such as shrinkage also reduce the variety of materials that can be used. ABS, which is the most commonly used thermoplastic material, is also used in 3D printers. However, since ABS material has high cooling deformations such as shrinkage in production, errors occur frequently. This makes the use of the material difficult. In addition, the gases released during production cause discomfort to people. For this reason, PLA material was developed as a biomaterial based on corn starch. Easy to produce, shrinkage and cooling errors are almost non-existent. It is environmentally friendly and there is no gas released during production. However, when using PLA material, certain properties of the products such as abrasion, thermal resistance and hardness are weak in meeting the needs. For this reason, STH filament material was introduced to the market with the aim of developing a material with high thermal stability like ABS and easy to produce like PLA. Just like PLA, STH filament material is also a biomaterial and was developed for industrial use. Compared to ABS material, it is more resistant to impact environments and its thermal resistance is approximately twice that of PLA material. For this reason, in our study, parameter optimization was carried out to optimize the surface quality of 3D printed products using STH material. Layer thickness (0.15 - 0.25 mm), printing speed (60 - 100 mm/s) and extrusion width (0.35 - 0.45 mm) were preferred as variable parameters affecting the surface quality. An experimental setup consisting of 20 experiments was created using the Response Surface Method (RSM), keeping all other parameters constant. The printed 25x25x25 mm cube samples were subjected to surface roughness measurement in 3 axes. According to the results, as a result of statistical calculations, the impact ratios of the effective parameters and the most effective production parameters were estimated.