Effect of Sanding and Plasma Treatment of 3D-Printed Parts on Bonding to Wood with PVAc Adhesive.

Mirko Kariž,Milan Šernek,Daša Krapež Tomec,Manja Kitek Kuzman,Jure Žigon,Sebastian Dahle

doi:10.3390/polym13081211

Abstract

Additive manufacturing is becoming increasingly important for manufacturing end products, not just prototyping. However, the size of 3D-printed products is limited due to available printer sizes and other technological limitations. For example, making furniture from 3D-printed parts and wooden elements requires adequate adhesive joints. Since materials for 3D printing usually do not bond very well with adhesives designed for woodworking, they require special surface preparation to improve adhesion. In this study, fused deposition modelling (FDM) 3D-printed parts made of polylactic acid (PLA), polylactic acid with wood flour additive (Wood-PLA), and acrylonitrile-butadiene-styrene (ABS) polymers were bonded to wood with polyvinyl acetate (PVAc) adhesive. The surfaces of the samples were bonded as either non-treated, sanded, plasma treated, or sanded and plasma treated to evaluate the effect of each surface preparation on the bondability of the 3D-printed surfaces. Different surface preparations affected the bond shear strength in different ways. The plasma treatment significantly reduced water contact angles on all tested printing materials and increased the bond tensile shear strength of the adhesive used. The increase in bond strength was highest for the surfaces that had been both sanded and plasma treated. The highest increase was found for the ABS material (untreated 0.05 MPa; sanded and plasma treated 4.83 MPa) followed by Wood-PLA (from 0.45 MPa to 3.96 MPa) and PLA (from 0.55 MPa to 3.72 MPa). Analysis with a scanning electron microscope showed the smooth surfaces of the 3D-printed parts, which became rougher with sanding with more protruded particles, but plasma treatment partially melted the surface structures on the thermoplastic polymer surfaces.

Highlights

The applicability of available fused deposition modelling (FDM) 3-dimensional (3D)printers is still limited, in terms of upscaling
In this study, fused deposition modelling (FDM) 3D-printed parts made of polylactic acid (PLA), polylactic acid with wood flour additive (Wood-PLA), and acrylonitrile-butadiene-styrene (ABS) polymers were bonded to wood with polyvinyl acetate (PVAc) adhesive
Analysis with a scanning electron microscope showed the smooth surfaces of the 3D-printed parts, which became rougher with sanding with more protruded particles, but plasma treatment partially melted the surface structures on the thermoplastic polymer surfaces

Summary

Introduction

The applicability of available fused deposition modelling (FDM) 3-dimensional (3D)printers is still limited, in terms of upscaling. It is necessary to assemble the final product from smaller 3D-printed parts, combining parts produced by conventional manufacturing methods with less costly materials such as wood. For these approaches, it is important to create a sufficient bond between 3D-printed and wooden parts. AM allows new designs to be created with the rational use of materials and opens up new possibilities for designers, engineers, and do-it-yourself enthusiasts This is aided by the fact that 3D printers are becoming more accurate, easier to use and more economic, making them more available to a variety of customers and applications. Even large-scale AM processes with build volumes of 90 m3 and more have been demonstrated, including automotive and building applications [1,2]

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