3D printing technology is one of the new manufacturing methods that can be used to build folding structures. Folding structures are made flat and deformed into three-dimensional shapes by an actuator. FDM process is one of the most common and cheap 3D printing processes that in this study, the most effective parameters of this process were investigated. For this purpose, the optimal values of printing parameters including printing pattern, thickness of each layer, filling percentage and nozzle temperature to achieve maximum deformation (curvature) were determined by Taguchi experiment design. Then, by adjusting these parameters, the effect of printing speed and total thickness on curvature was investigated. The results showed that with incr

In this study, poly (ε‐caprolactone) (PCL) scaffolds were printed and reinforced, simultaneously, with biodegradable poly glycolic acid (PGA) suture yarn, as a continuous reinforcing fiber, in the Fused Deposition Modeling (FDM) 3D printing process. Albeit PCL is a suitable material for biomedical applications, its low mechanical properties, and low degradation rate have limited its usage. A biocompatible suture yarn was used as the reinforcing material to enhance the mechanical properties and biodegradation characteristics, via an innovative method of continuous fiber embedding in the FDM process. The reinforced PCL samples were 3D printed with the setting porosity value of 60% and 0?/60?/120? lay-down pattern. The mechanical and biolog

In the present study, Poly l-lactic acid (PLLA) resin compatible with digital light processing (DLP) 3D printing method was synthesized to produce hard tissue scaffolds. PLLA has been chosen as a decent material to mimic biological structures due to its relatively high strength as well as proper biocompatibility and biodegradation rate. After synthesis and functionalization of PLLA, using a facile method, porous models with 600-micron pore size and 70 % nominal porosity were designed and fabricated via DLP technique in order to investigate the effects of the two process parameters, light exposure time and dye concentration, on compressive strength and morphological features of the printed samples. The experimental results were then reconcil

The main aim of this paper is to assess the impacts of design, porosity, and biodegradation on the mechanical and morphological properties of triply periodic minimal surface (TPMS) scaffolds. The TPMS scaffolds were designed and manufactured with different porosities by using fused deposing modeling (FDM) technique. The biodegradation test on the scaffolds was performed for four and six months. The mechanical properties were assessed employing ASTM standard compression test and an in-situ mechanical testing stage. Microcomputed tomography (Micro-CT) technique was used to investigate detailed morphological properties of the scaffolds in 3D. Results indicate that the Schwarz-D scaffolds exhibit the highest compressive strength in lower porosi

The main aim of this study was to assess the influence of adding BCP particles on enhancing essential properties of PLLA matrix scaffolds for bone grafting purpose. Poly L-lactic acid (PLLA)/biphasic calcium phosphate (BCP) scaffolds were fabricated via a digital light processing (DLP) 3D printer, with 70% porosity and 600 ?m pore size. DLP method was utilized to generate scaffolds with sophisticated geometry, and the bio-composite material was introduced to benefit from positive aspects of polymeric/inorganic substances for bone regeneration. The selected BCP contents were 22.5, and 45?wt% compared with the control specimens with no content. Morphology, exact amount of BCP concentration as well as their distribution were assessed using com

This experimental study investigates the effect of filling pattern on tensile and flexural strength and modulus of the parts printed via fused deposition modeling (FDM), 3D printer. The main downside of the printed products, with an FDM 3D printer, is the low strength compared to the conventional processes such as injection molding and machining. The issue stems from the low strength of thermoplastic materials and the weak bonding between deposited rasters and layers. Selection of proper filling pattern and infill percentage could highly influence the final mechanical properties of the printed products that were experimentally explored in this research work. Concentric, rectilinear, hilbert curve, and honeycomb patterns and filling percenta

Bamboo-derived biocarbon (BA900) and wood-derived biocarbon (THOC700) have exhibited graphite-like characteristics through transmission electron microscopy, X-ray diffraction (XRD), and Attenuated Total Reflectance (ATR) spectroscopy analysis. Lightweight composites of biocarbons were manufactured by a mechanism of shear controlled melt-phase mixing, ensuring the preservation of biocarbon pore structures and simultaneously taking full advantage of low density polyolefin substrates. Effective tensile strength was improved by approximately 10% in the polypropylene-based bamboo carbon composite, whereas no appreciable improvement was observed in the tensile and impact strength of bamboo-derived biocarbon formulations compared to neat polymer.

In this study, an innovative method was devised and implemented to produce continuous glass fiber–reinforced thermoplastic composites via a fused deposition modeling three-dimensional printer to enhance the mechanical properties of the printed products. In the extrusion-based, or filament-based, additive manufacturing process, namely, fused deposition modeling, the parts are basically formed via deposition of the material in the molten state, and thus embedding continuous fiber, in a solid form, is highly challenging. Hence, a nozzle system was designed and manufactured to feed the continuous fiber into the molten polymer simultaneously, which is called, here, in-melt simultaneous impregnation. With the presence of continuous fibers in th

The main purpose of this research is to bolster mechanical properties of the parts, produced by an extrusion-based 3D printer, or fused deposition modeling machine, via increasing the content of continuous fiber yarn to its practical limit. In-melt continuous glass fiber yarn embedding was applied as a reliable and consistent method for simultaneous impregnation to produce continuous fiber-reinforced thermoplastic composites in the fused deposition modeling process. It is well known that the main weakness in the fused deposition modeling 3D printed products is their low strength compared to the manufactured ones by conventional methods such as injection molding and machining processes. This characteristic can be related to both inherent wea

In this work, the effects of processing parameters including temperature, time, and pressure on the properties of amorphous polyvinyl chloride (PVC)/fiberglass thermoplastic composite laminates were evaluated. The film stacking and hot pressing procedure was used to produce the composite laminates, and samples with [0/90] 10 layup and thickness of 3 mm were produced. Flexural strength and modulus of the samples were measured using three-point bending test (according to ASTM D790 standard test method), and microscopic images were used to evaluate the failure mechanisms and impregnation quality. The effects of the parameters on the strength were studied using analysis of variance (ANOVA), and it was found that processing temperature has the m

In this study the effects of foaming process on the shape memory properties of Polylactic acid/thermoplastic polyurethane/cellulous-nanofiber bio-nanocomposites were investigated. The samples of cylindrical shapes as well as sheets were manufactured and foamed. The results indicated that while the foaming process presented a microcellular structure, it can cause a tangible increase (up to 40%) in force recovery ratio and an intense reduction (up to 10 times) in actuation force. It is statistically shown that the existence of cellulose nano-fibers within the foamed matrix causes a significant increase in actuation force and reduction in the force recovery ratio. Analytical evaluation on the sheet form samples, in the foamed state using rheol

This paper presents design and manufacture of a modular die to produce profiles of wood plastic composites (WPCs) reinforced with continuous glass fibers. As the strength and fracture toughness of WPCs are not convincing for load bearing applications, strengthening WPC profiles with continuous fibers could provide sufficient strength to meet the requirements. In this study, a modular profile die with various cross sections, i.e., I‐, U‐, and rectangular‐shaped was designed and manufactured. The approach to balance the flow for the various sections was to implement a flow restricting mechanism along the melt flow path. Impregnated glass rovings (IMGRs) were introduced continuously into the flow to reinforce the profiles through special

This paper presents an experimental study on the effects of printing parameters on the tensile strength of the polymer-metal composites printed via Fused Deposition Modeling (FDM) technique. In the recent years, 3D printer systems have been widely employed in various industries. FDM is one of the most widely used 3D printer systems worldwide due to its simplicity and lower cost. Although extensive research works have been carried out in the area of 3D printing, less efforts have been reported in developing new materials and their use in FDM process. The materials utilized in this study consisted of Cu particles in ABS polymeric matrix with a constant 25 wt.% of metal powder. The filament production line was implemented to accustom with the

This study dedicates to foaming of biocompatible blends of polylactic acid and thermoplastic polyurethane reinforced with bio-degradable cellulose nanofibers. This research primarily was associated with fabrication of PLA-TPU nanocomposites using a low weight fraction of cellulose nanofibers as a biodegradable reinforcement. Microstructural and mechanical properties of fabricated nanocomposites were examined and diffractometry was utilized to verify formation of percolated nanocomposites. Microcellular foaming was then performed with CO2 as a blowing agent. Central composite design was applied in designing the experiments to evaluate the effects of main operating variables consisting of saturation pressure and time, heating time and foaming

In this research work, foaming behavior of selected polyethylene blends was studied in a solid-state batch process, using CO2 as the blowing agent. Special emphasis was paid towards finding a relationship between foamability and thermal and rheological properties of blends. Pure high-density polyethylene, linear low-density polyethylene, and their blends with two weight fraction levels of high-density polyethylene (10 and 25%wt.) were examined. The dry blended batches were mixed using an internal mixer in a molten state, and then the disk-shaped specimens, 1.8 mm in thickness, were produced for foaming purposes. The foaming step was conducted over a wide range of temperatures (120–170℃), and the overall expansion and cellular morpholo

Non-invasive x-ray micro-computed tomography was employed for thorough quantitative and qualitative analysis of the cellular structure of foams made of linear low density polyethylene (LLDPE), high density polyethylene (HDPE) and their blends. Special emphasis was given to the differences between the results of 3D and 2D analyses, to evaluate the possible errors while studying the morphology using conventional 2D techniques (eg SEM). Blends with the weight compositions of 90% LLDPE/10% HDPE and 75% LLDPE/25% HDPE were produced at different rotor speeds of 10, 60 and 120 rpm and batch foaming was examined over a wide range of temperature. The void fraction values from 2D and 3D analysis were found to agree well with those obtained with the A