IZOD impact properties of full-density fused deposition modeling polymer materials with respect to raster angle and print orientation

Abstract

One of the fundamental characteristics of additively processed materials is that they are naturally anisotropic; this variance in mechanical properties is primarily generated through the formulation of patterned shell and in-filled regions within the material during processing. This paper describes the formulation and results of a study to ascertain the impact strength of various full–infill polymer-based materials processed in various orientations and angles via fused deposition modeling. Ten different materials were tested using seven different hatch angles and three print orientations. Seven different pure materials were tested, as well as three composites; these were acrylonitrile butadiene styrene, standard polylactic acid, high-temperature polylactic acid, high-impact polystyrene, nylon, polyethylene terephthalate + glycol, polycarbonate, aluminum polylactic acid, wood polylactic acid, and carbon–fiber polylactic acid. All experiments were carried out using ASTM IZOD Type E tests with a 2.7J pendulum. Five replications of each test combination were collected, for a total of 1050 tests. The results showed that the shell orientation and raster angle were primary drivers in determining impact properties, as they strongly influenced the crack length and path though the material during fracture. This was especially clear for the polycarbonate, nylon, and polyethylene terephthalate + glycol which underwent large plastic deformation during the tests. It was further observed that the impact toughness was inversely correlated with test repeatability, with the toughest materials having the highest variability between test replications.

The influence of process parameters on the impact resistance of 3D printed PLA specimens under water-absorption and heat-treated conditions

“…The toughness plays a vital role in determining the energy absorbing capacity of a structure for high strain rate applications. Patterson et al (2019) investigated the impactabsorbing capacity of various materials printed at different build orientations (Table 1) and confirmed that the tougher material shows large plastic deformation before fracture. Caminero et al (2018) explained the procedure to 3D print continuous fibre composite specimens and also found the impact energy absorption by the composite (Figure 2).…”

3D printing orthopedic scoliosis braces: a test comparing FDM with thermoforming

“…At the end of the 2 weeks, the patient completed a short questionnaire about acceptance, safety, and satisfaction of the 3D printed brace, compared with the traditional brace produced by thermoforming. Moreover, thermographic images were obtained using an infrared thermal camera (One, Flir, USA) to objectively compare braces performances [18]. This study was performed in accordance with the Declaration of Helsinki, and the protocol was approved by the IRCCS E. Medea Ethics Committee.…”

“…Furthermore, impact tests are important to quantify the toughness of a material, by measuring the amount of energy absorbed during high-strain-rate conditions before failure. This behavior certainly changes with different production technologies, such as 3DP [18]. For these reasons, it is not yet possible to predict how the combination of virtual modeling and additive manufacturing processes affects the mechanical properties of a 3D printed brace.…”

Spinal Deformities and Advancement in Corrective Orthoses

“…FDM is the most suitable and least expensive method to produce scoliosis braces among these 3D printing techniques, despite having a bit less dimensional accuracy. A few studies have recommended the use of 3D printing to construct orthotic devices [ 83 , 84 , 85 ]. The majority of the researchers have fixated on the feasibility of developing devices with accurate geometrical dimensions and desired shapes, but quite a few studies have reported the cost and mechanical performances of these devices.…”

“…Moreover, it is crucial to evaluate the toughness of the material through impact tests by measuring the energy absorbed for the duration of high strain rate conditions before failure. This behavior definitely varies with different production technologies, and the materials currently used for 3D printed orthotic devices do not provide the rigidity needed to correct the spine posture [ 85 ]. For these reasons, it is not yet possible to predict how the combination of virtual modeling and additive manufacturing processes affects the mechanical properties of a 3D-printed brace.…”