scholarly journals Influence of Print Settings on the Critical Quality Attributes of Extrusion-Based 3D-Printed Caplets: A Quality-by-Design Approach

Pharmaceutics ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2068
Author(s):  
Silke Henry ◽  
Lotte De Wever ◽  
Valérie Vanhoorne ◽  
Thomas De Beer ◽  
Chris Vervaet

Extrusion-based 3D-printing is an easy-to-use, cheap manufacturing technique that could be used to produce tailored precision medicines. The technique has an almost unlimited versatility since a multitude of print parameters can easily be adapted. Unfortunately, little is known of the effect of these print parameters on the critical quality attributes of the resulting printlets. In this study, practical guidelines and means to adapt certain parameters in order to achieve the desired outcome (e.g., acceptable visual quality and flexible dosing) are stipulated for medical 3D-printing using a design-of-experiments approach. The current study aims at elucidating the effect of five print parameters (infill, overlap, number of shells, layer height and layer pattern) on the mechanical properties, dimensions, weight, porosity and dissolution characteristics of a fixed-size caplet consisting of Eudragit EPO (69.3%), Polyox WSR N10 (29.7%) and zolpidem hemitartrate (1%). In terms of the mechanical properties, 3D-printed caplets possessed anisotropy where the vertical compression strength and Brinell hardness exceeded the diametral strength. In general, all 3D-printed caplets possessed acceptable mechanical strength except for a small region of the knowledge space. Dimensional analysis revealed small, statistical significant differences between different runs, although the clinical relevance of this variation is likely negligible. The weight or dose of a caplet can be varied mainly using the infill and overlap and, to a lesser extent, via the layer height and number of shells. The impact on porosity was complicated as this was influenced by many factors and their interactions. Infill was the only statistically relevant factor influencing the dissolution rate of the current formulation. This study unravels the importance of the print parameter overlap, which is a regularly neglected parameter. We also discovered that small dose variations while maintaining the same dissolution profile were possible via modifying the overlap or number of shells. However, large dose variations without affecting the dissolution behaviour could only be accomplished by size modifications of the printlet.

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2456
Author(s):  
Demei Lee ◽  
Guan-Yu Wu

Three-dimensional (3D) printing is a manufacturing technology which creates three-dimensional objects layer-by-layer or drop-by-drop with minimal material waste. Despite the fact that 3D printing is a versatile and adaptable process and has advantages in establishing complex and net-shaped structures over conventional manufacturing methods, the challenge remains in identifying the optimal parameters for the 3D printing process. This study investigated the influence of processing parameters on the mechanical properties of Fused Deposition Modelling (FDM)-printed carbon fiber-filled polylactide (CFR-PLA) composites by employing an orthogonal array model. After printing, the tensile and impact strengths of the printed composites were measured, and the effects of different parameters on these strengths were examined. The experimental results indicate that 3D-printed CFR-PLA showed a rougher surface morphology than virgin PLA. For the variables selected in this analysis, bed temperature was identified as the most influential parameter on the tensile strength of CFR-PLA-printed parts, while bed temperature and print orientation were the key parameters affecting the impact strengths of printed composites. The 45° orientation printed parts also showed superior mechanical strengths than the 90° printed parts.


Pharmaceutics ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 511 ◽  
Author(s):  
Hanna Ponsar ◽  
Raphael Wiedey ◽  
Julian Quodbach

Fused deposition modeling (FDMTM) is a 3D-printing technology of rising interest for the manufacturing of customizable solid dosage forms. The coupling of hot-melt extrusion with FDMTM is favored to allow the production of pharma-grade filaments for the printing of medicines. Filament diameter consistency is a quality of great importance to ensure printability and content uniformity of 3D-printed drug delivery systems. A systematical process analysis referring to filament diameter variations has not been described in the literature. The presented study aimed at a process setup optimization and rational process analysis for filament fabrication related to influencing parameters on diameter inhomogeneity. In addition, the impact of diameter variation on the critical quality attributes of filaments (mechanical properties) and uniformity of mass of printed drug-free dosage forms was investigated. Process optimization by implementing a winder with a special haul-off unit was necessary to obtain reliable filament diameters. Subsequently, the optimized setup was used for conduction of rational extrusion analysis. The results revealed that an increased screw speed led to diameter fluctuations with a decisive influence on the mechanical resilience of filaments and mass uniformity of printed dosage forms. The specific feed load was identified as a key parameter for filament diameter consistency.


2018 ◽  
Vol 777 ◽  
pp. 499-507 ◽  
Author(s):  
Ossi Martikka ◽  
Timo Kärki ◽  
Qing Ling Wu

3D printing has rapidly become popular in both industry and private use. Especially fused deposition modeling has increased its popularity due to its relatively low cost. The purpose of this study is to increase knowledge in the mechanical properties of parts made of wood-plastic composite materials by using 3D printing. The tensile properties and impact strength of two 3D-printed commercial wood-plastic composite materials are studied and compared to those made of pure polylactic acid. Relative to weight –mechanical properties and the effect of the amount of fill on the properties are also determined. The results indicate that parts made of wood-plastic composites have notably lower tensile strength and impact strength that those made of pure polylactic acid. The mechanical properties can be considered sufficient for low-stress applications, such as visualization of prototypes and models or decorative items.


2018 ◽  
Vol 24 (8) ◽  
pp. 1337-1346 ◽  
Author(s):  
Marzio Grasso ◽  
Lyes Azzouz ◽  
Paula Ruiz-Hincapie ◽  
Mauro Zarrelli ◽  
Guogang Ren

Purpose Recent advancements of 3D printing technology have brought forward the interest for this technique in many engineering fields. This study aims to focus on mechanical properties of the polylactic acid (PLA) feeding material under different thermal conditions for a typical fusion deposition of 3D printer system. Design/methodology/approach Specimens were tested under static loading within the range 20ºC to 60ºC considering different infill orientations. The combined effect of temperature and filament orientation is investigated in terms of constitutive material parameters and final failure mechanisms. The difference between feeding system before and post-3D printing was also assessed by mechanical test on feeding filament to verify the thermal profile during the deposition phase. Findings The results in terms of Young’s modulus, ultimate tensile strength (UTS), strain at failure (εf) and stress at failure (σf) are presented and discussed to study the influence of process settings over the final deposited material. Fracture surfaces have been investigated using an optical microscope to link the phenomenological interpretation of the failure with the micro-mechanical behaviour. Experimental results show a strong correlation between stiffness and strength with the infill orientation and the temperature values. Moreover, a relevant effect is related to deformed geometry of the filament approaching glass transition region of the polymer according to the deposition orientation. Research limitations/implications The developed method can be applied to optimise the stiffness and strength of any 3D-printed composite according to the infill orientation. Practical implications To avoid the failure of specimens outside the gauge length, a previously proposed modification to the geometry was adopted. The geometry has a parabolic profile with a curvature of 1,000 mm tangent to the middle part of the specimen. Originality/value Several authors have reported the stiffness and strength of 3D-printed parts under static and ambient temperature for different build parameters. However, there is a lack of literature on the combination of the latter with the temperature effects on the mechanical properties which this paper covers.


“Slicing tool” or “Slicing Software” computes the intersection curves of models and slicing planes. They improve the quality of the model being printed when given in the form of STL file. Upon analyzing a specimen that has been printed using two different slicing tools, there was a drastic variation on account of the mechanical properties of the specimen. The ultimate tensile strength and the surface roughness of the material vary from one tool to another. This paper reports an investigation and analysis of the variation in the ultimate tensile strength and the surface roughness of the specimen, given that the 3D printer and the model being printed is the same, with a variation of usage of slicing software. This analysis includes ReplicatorG, Flashprint as the two different slicing tools that are used for slicing of the model. The variation in the ultimate tensile strength and the surface roughness are measured and represented statistically through graphs. An appropriate decisive conclusion was drawn on the basis of the observations and analysis of the experiment on relevance to the behavior and mechanical properties of the specimen.


2022 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ramesh Chand ◽  
Vishal S. Sharma ◽  
Rajeev Trehan ◽  
Munish Kumar Gupta

Purpose A nut bolt joint is a primary device that connects mechanical components. The vibrations cause bolted joints to self-loosen. Created by motors and engines, leading to machine failure, and there may be severe safety issues. All the safety issues and self-loosen are directly and indirectly the functions of the accuracy and precision of the fabricated nut and bolt. Recent advancements in three-dimensional (3D) printing technologies now allow for the production of intricate components. These may be used technologies such as 3D printed bolts to create fasteners. This paper aims to investigate dimensional precision, surface properties, mechanical properties and scanning electron microscope (SEM) of the component fabricated using a multi-jet 3D printer. Design/methodology/approach Multi-jet-based 3D printed nut-bolt is evaluated in this paper. More specifically, liquid polymer-based nut-bolt is fabricated in sections 1, 2 and 3 of the base plate. Five nuts and bolts are fabricated in these three sections. Findings Dimensional inquiry (bolt dimension, general dimensions’ density and surface roughness) and mechanical testing (shear strength of nut and bolt) were carried out throughout the study. According to the ISO 2768 requirements for the General Tolerances Grade, the nut and bolt’s dimensional examination (variation in bolt dimension, general dimensions) is within the tolerance grades. As a result, the multi-jet 3D printing (MJP)-based 3D printer described above may be used for commercial production. In terms of mechanical qualities, when the component placement moves from Sections 1 to 3, the density of the manufactured part decreases by 0.292% (percent) and the shear strength of the nut and bolt decreases by 30%. According to the SEM examination, the density of the River markings, sharp edges, holes and sharp edges increased from Sections 1 to 3, which supports the findings mentioned above. Originality/value Hence, this work enlightens the aspects causing time lag during the 3D printing in MJP. It causes variation in the dimensional deviation, surface properties and mechanical properties of the fabricated part, which needs to be explored.


2020 ◽  
Vol 26 (8) ◽  
pp. 1337-1344 ◽  
Author(s):  
Prashant Jindal ◽  
Mamta Juneja ◽  
Divya Bajaj ◽  
Francesco Luke Siena ◽  
Philip Breedon

Purpose 3D printing techniques have been widely used for manufacturing complex parts for various dental applications. For achieving suitable mechanical strength, post-cure processing is necessary, where the relative time duration and temperature specification also needs to be defined. The purpose of this study/paper is to assess the effects of post curing conditions and mechanical properties of 3D printed clear dental aligners Design/methodology/approach Dental long-term clear resin material has been used for 3D printing of dental aligners using a Formlabs 3D printer for direct usage on patients. Post-curing conditions have been varied, all of which have been subjected to mechanical compression loading of 1,000 N to evaluate the curing effects on the mechanical strength of the aligners. Findings The experimental studies provide significant insight into both temperatures and time durations that could provide sufficient compressive mechanical strength to the 3D printed clear dental aligners. It was observed that uncured aligners deformed plastically with large deformations under the loading conditions, whereas aligners cured between 400°C–800°C for 15–20 min deformed elastically before fragmenting into pieces after safely sustaining higher compressive loads between 495 N and 666 N. The compressive modulus ratio for cured aligners ranged between 4.46 and 5.90 as compared to uncured aligners. For shorter cure time durations and lower temperature conditions, an appropriate elevated compressive strength was also achieved. Originality/value Based on initial assessments by dental surgeons, suitable customised clear aligners can be designed, printed and cured to the desired levels based on patient’s requirements. This could result in time, energy and unit production cost savings, which ultimately would help to alleviate the financial burden placed on both the health service and their patients.


2020 ◽  
pp. 089270572094537
Author(s):  
Ravinder Sharma ◽  
Rupinder Singh ◽  
Ajay Batish

The polyvinylidene difluoride + barium titanate (BaTiO3) +graphene composite (PBGC) is one of the widely explored thermoplastic matrix due to its 4D capabilities. The number of studies has been reported on the process parameters of twin-screw extruder (TSE) setup (as mechanical blending technique) for the development of PBGC in 3D printing applications. But, hitherto, little has been reported on chemical-assisted mechanical blending (CAMB) as solution mixing and melt mixing technique combination for preparation of PBGC. In this work, for preparation of PBGC feedstock filaments, CAMB has been used. Also, the effect of process parameters of TSE on the mechanical, dimensional, morphological, and thermal properties of prepared filament of PBGC have been explored followed by 3D printing. Further, a comparative study has been reported for the properties of prepared filaments with mechanically blended composites. Similarly, the mechanical properties of 3D printed parts of chemically and mechanically blended composites have been compared. The results of tensile testing for CAMB of PBGC show that the filament prepared with 15% BaTiO3 is having maximum peak strength 43.00 MPa and break strength 38.73 MPa. The optical microphotographs of the extruded filaments revealed that the samples prepared at 180°C extruder temperature and 60 r/min screw speed have minimum porosity, as compared to filaments prepared at high extruder temperature. Further, the results of the comparative study revealed that the filaments of CAMB composites show better mechanical properties as compared to the filaments of mechanically mixed composites. However, the dimensional properties were almost similar in both cases. It was also found that the CAMB composites have better properties at low processing temperature, whereas mechanically blended composites show better results at a higher temperature. While comparing 3D printed parts, tensile strength of specimens fabricated from CAMB was more than the mechanically blended PBGC.


2020 ◽  
Vol 26 (6) ◽  
pp. 1113-1129
Author(s):  
Lai Jiang ◽  
Xiaobo Peng ◽  
Daniel Walczyk

Purpose This paper aims to summarize the up-to-date research performed on combinations of various biofibers and resin systems used in different three-dimensional (3D) printing technologies, including powder-based, material extrusion, solid-sheet and liquid-based systems. Detailed information about each process, including materials used and process design, are described, with the resultant products’ mechanical properties compared with those of 3D-printed parts produced from pure resin or different material combinations. In most processes introduced in this paper, biofibers are beneficial in improving the mechanical properties of 3D-printed parts and the biodegradability of the parts made using these green materials is also greatly improved. However, research on 3D printing of biofiber-reinforced composites is still far from complete, and there are still many further studies and research areas that could be explored in the future. Design/methodology/approach The paper starts with an overview of the current scenario of the composite manufacturing industry and then the problems of advanced composite materials are pointed out, followed by an introduction of biocomposites. The main body of the paper covers literature reviews of recently emerged 3D printing technologies that were applied to biofiber-reinforced composite materials. This part is classified into subsections based on the form of the starting materials used in the 3D printing process. A comprehensive conclusion is drawn at the end of the paper summarizing the findings by the authors. Findings Most of the biofiber-reinforced 3D-printed products exhibited improved mechanical properties than products printed using pure resin, indicating that biofibers are good replacements for synthetic ones. However, synthetic fibers are far from being completely replaced by biofibers due to several of their disadvantages including higher moisture absorbance, lower thermal stability and mechanical properties. Many studies are being performed to solve these problems, yet there are still some 3D printing technologies in which research concerning biofiber-reinforced composite parts is quite limited. This paper unveils potential research directions that would further develop 3D printing in a sustainable manner. Originality/value This paper is a summary of attempts to use biofibers as reinforcements together with different resin systems as the starting material for 3D printing processes, and most of the currently available 3D printing techniques are included herein. All of these attempts are solutions to some principal problems with current 3D printing processes such as the limit in the variety of materials and the poor mechanical performance of 3D printed parts. Various types of biofibers are involved in these studies. This paper unveils potential research directions that would further widen the use of biofibers in 3D printing in a sustainable manner.


Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4066
Author(s):  
Marta Czajkowska ◽  
Ewa Walejewska ◽  
Łukasz Zadrożny ◽  
Monika Wieczorek ◽  
Wojciech Święszkowski ◽  
...  

This study was conducted to test possibilities of application of 3D printed dental models (DMs) in terms of their accuracy and physical properties. In this work, stone models of mandibles were cast from alginate impressions of 10 patients and scanned in order to obtain 3D printed acrylic replicas. The diagnostic value was tested as matching of model scans on three levels: peak of cusps, occlusal surface, and all teeth surfaces. The mechanical properties of acrylic and stone samples, specifically the impact strength, shore D hardness, and flexural and compressive strength were investigated according to ISO standards. The matching of models’ surfaces was the highest on the level of peaks of cusps (average lack of deviations, 0.21 mm) and the lowest on the level of all teeth surfaces (average lack of deviations, 0.64 mm). Acrylic samples subjected to mechanical testing, as expected, showed higher mechanical properties as compared to the specimens made of dental stone. In the present study we demonstrated that 3D printed acrylic models could be ideal representatives in the case of use as a diagnostic tool and as a part of medical records. The acrylic samples exhibited not only higher mechanical properties, but also showed better accuracy comparing to dental stone.


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