Development of hydrophobic coating on 3D printed ABS samples and surface characterization

Abstract

Manufacturers are increasingly substituting additive manufacturing for conventional manufacturing methods due to their ability to produce complex shapes. Polymer-based filament materials can be printed efficiently and inexpensively with fused deposition modeling. Coatings tend to augment the appearance of 3D printed objects as well as protect them from environmental influences. It is imperative to realize the physical and chemical properties of polymeric material like Acrylonitrile Butadiene Styrene (ABS) surfaces so as to design an optimal surface system. This work relates to the development of surface coatings on 3D-printed ABS parts. L9 orthogonal array was used with three 2 level factors for printing the samples. Specifically, the research compares surface characteristics of 3D-printed uncoated and coated ABS specimens. An aqueous solution containing Tricalcium phosphate and Chitin clear solutions in a 70:30 ratio was applied through immersion technique to create hydrophobic coatings. The coated and uncoated samples were characterized by employing various characterization tests, including dimensional accuracy (DA), surface roughness (SR), water contact angle (WCA), absorbency tests, scanning electron microscopy on fabricated parts. Assessment of wettability of 3D printed samples and impact of coating was accomplished via static contact angle measurements. In order to assess DA and SR before and after coating, digital vernier calipers were used in conjunction with a profilometer. In accordance with ASTM D570-98, water absorption tests were conducted for specified time. Results of investigation post coating showed no variation in dimensional accuracy, reduced SR and increased in WCA by ≥ 100 ̊. A reduction in water retention was observed after coating based on water absorption tests.