Study of factors affecting the 3D printing of polylactic acid onto textile fabrics.

Abstract

The emergence of 3D printing has advanced industrial production processes. 3D printing or additive manufacturing is a technology that constructs objects in layers. It exhibits much saving in the design and manufacturing steps and has been applied in several fields including medical, aerospace and textiles. In recent times, textile substrates have been combined with 3D printed polymers to create multicomponent textiles. These structures have brought about the possibility of using polylactic acid (PLA), an environmentally friendly biodegradable polymer, as an alternative to dyes and pigments in decorative textiles. However, there has been a challenge with the adherence of the polymer to the textile substrate. The aim of this study was to design and produce a cotton/PLA structure through the Fused Deposition Modelling (FDM) 3D printing technique, to determine the effect of fabric parameters and 3D printing parameters on the adhesion and tensile properties of the structure as well as to characterize the mechanical properties of the structure. The printed PLA structure was designed using Solidworks, converted to a Standard Tessellation File (STL) and then sliced for 3D printing using the Cura software. 3D printing was done using an Athena FDM 3D printer. The printing was first done on 15 woven fabrics with different properties. Cotton woven fabric was used in this study since it exhibited the highest adhesion force for the 3D printed structures. The particulars of the fabric included 355.2 g/m 2 , 50 Tex warp, 37 Tex weft and a thickness of 0.19 mm. A four-variable, five level Central Composite Rotatable Design was used for the optimization of extrusion temperature, printing speed, fill density and model height. The resulting cotton/PLA structures were tested for adhesion force before and after washing as well as tensile strength. The experimental data was used to develop regression models to predict the properties of the cotton/PLA structures. The model for adhesion force before washing yielded a coefficient of determination (R 2 ) value of 0.75, a P value of less than 0.05 and an optimum force of 50.06 N/cm. The model for adhesion force after washing had an R 2 value of 0.84, a P value of less than 0.05, an optimum force of 42.91 N/cm and showed a reduction in adhesion force after washing. Adhesion forces before and after washing, were both positively correlated to extrusion temperature. However, they reduced with an increase in printing speed and model height. Tensile strength yielded an R 2 value of 0.94, a P value of less than 0.05 and an optimum tensile strength of 346.22 MPa. From the results of this study it was concluded that the fabric parameters and the 3D printing parameters have an effect on the properties of the structures. Future work should study the effects of more fabric and 3D printing parameters and characterize more properties of the fabric/polymer structure. A cost analysis should also be done to compare the costs involved with costs of current textile decorative techniques.