3D printing Kevlar fiber layer distributions and fiber orientations into nylon composites to achieve designable mechanical strength

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.

Download Full-text

Coordinated adjustment and optimization of setting time, flowability, and mechanical strength for construction 3D printing material derived from solid waste

Construction and Building Materials ◽

10.1016/j.conbuildmat.2020.119854 ◽

2020 ◽

Vol 259 ◽

pp. 119854

Author(s):

Qamar Shahzad ◽

Xujiang Wang ◽

Wenlong Wang ◽

Yi Wan ◽

Guolin Li ◽

...

Keyword(s):

3D Printing ◽

Mechanical Strength ◽

Solid Waste ◽

Setting Time

Download Full-text

Effect of Acrylic and Epoxy Hybrid Crosslinker on the Mechanical Strength of Photocurable Resin for 3D Printing

Journal of Photopolymer Science and Technology ◽

10.2494/photopolymer.34.237 ◽

2021 ◽

Vol 34 (3) ◽

pp. 237-249

Author(s):

Miharu Ito ◽

Hirofumi Takamatsu ◽

Tatsuo Taniguchi ◽

Hiroaki Okamoto ◽

Takashi Karatsu

Keyword(s):

3D Printing ◽

Mechanical Strength

Download Full-text

Optimization of Printing Parameters for Digital Light Processing 3D Printing of Hollow Microneedle Arrays

Pharmaceutics ◽

10.3390/pharmaceutics13111837 ◽

2021 ◽

Vol 13 (11) ◽

pp. 1837

Author(s):

Essyrose Mathew ◽

Giulia Pitzanti ◽

Ana L. Gomes dos Santos ◽

Dimitrios A. Lamprou

Keyword(s):

Drug Delivery ◽

3D Printing ◽

Mechanical Strength ◽

Print Quality ◽

Digital Light Processing ◽

Uv Curable ◽

Microneedle Arrays ◽

Uv Curable Resin ◽

Viable Method ◽

Printing Parameters

3D printing is an emerging technology aiming towards personalized drug delivery, among many other applications. Microneedles (MN) are a viable method for transdermal drug delivery that is becoming more popular for delivery through the skin. However, there is a need for a faster fabrication process with potential for easily exploring different geometries of MNs. In the current study, a digital light processing (DLP) method of 3D printing for fabrication of hollow MN arrays using commercial UV curable resin was proposed. Print quality was optimised by assessing the effect of print angle on needle geometries. Mechanical testing of MN arrays was conducted using a texture analyser. Angled prints were found to produce prints with geometries closer to the CAD designs. Curing times were found to affect the mechanical strength of MNs, with arrays not breaking when subjected to 300 N of force but were bent. Overall, DLP process produced hollow MNs with good mechanical strength and depicts a viable, quick, and efficient method for the fabrication of hollow MN arrays.

Download Full-text

Heat treatment effect on the mechanical properties, roughness and bone ingrowth capacity of 3D printing porous titanium alloy

RSC Advances ◽

10.1039/c7ra13313h ◽

2018 ◽

Vol 8 (22) ◽

pp. 12471-12483 ◽

Cited By ~ 16

Author(s):

Zuhao Li ◽

Chang Liu ◽

Bingfeng Wang ◽

Chenyu Wang ◽

Zhonghan Wang ◽

...

Keyword(s):

Mechanical Properties ◽

Heat Treatment ◽

Titanium Alloy ◽

3D Printing ◽

Mechanical Strength ◽

Clinical Application ◽

Treatment Effect ◽

Bone Ingrowth ◽

Porous Titanium

The weak mechanical strength and biological inertia of Ti–6Al–4V porous titanium alloy limit its clinical application in the field of orthopedics.

Download Full-text

Effects of Cellulose Nanocrystal and Inorganic Nanofillers on the Morphological and Mechanical Properties of Digital Light Processing (DLP) 3D-Printed Photopolymer Composites

Applied Sciences ◽

10.3390/app11156835 ◽

2021 ◽

Vol 11 (15) ◽

pp. 6835

Author(s):

Sang-U Bae ◽

Birm-June Kim

Keyword(s):

Mechanical Properties ◽

3D Printing ◽

Mechanical Strength ◽

Stress Transfer ◽

Cellulose Nanocrystal ◽

Morphological Properties ◽

Precipitated Calcium Carbonate ◽

Digital Light Processing ◽

3D Printed ◽

Cellulose Nanomaterials

Photopolymer composites filled with cellulose nanocrystal (CNC) and/or inorganic nanofillers were fabricated by using digital light processing (DLP) 3D printing. To investigate the effects of different CNC lyophilization concentrations and behaviors of CNC particles in the photopolymer composites, morphological and mechanical properties were analyzed. CNC loading levels affected the morphological and mechanical properties of the filled composites. Better CNC dispersion was seen at a lower lyophilization concentration, and the highest mechanical strength was observed in the 0.25 wt% CNC-filled composite. Furthermore, nano-precipitated calcium carbonate (nano-PCC) and nanoclay were added to photocurable resins, and then the effect of inorganic nanofillers on the morphological and mechanical properties of the composites were evaluated. By analyzing the morphological properties, the stress transfer mechanism of nano-PCC and nanoclay in the photopolymer composites was identified and related models were presented. These supported the improved mechanical strength of the composites filled with CNC, nano-PCC, and nanoclay. This study suggested a new approach using wood-derived cellulose nanomaterials and inorganic nanofillers as effective fillers for DLP 3D printing.

Download Full-text

The Study of Physico-Mechanical Properties of Polylactide Composites with Different Level of Infill Produced by the FDM Method

Polymers ◽

10.3390/polym12123056 ◽

2020 ◽

Vol 12 (12) ◽

pp. 3056

Author(s):

Anna Gaweł ◽

Stanisław Kuciel

Keyword(s):

Mechanical Properties ◽

3D Printing ◽

Mechanical Strength ◽

Elevated Temperatures ◽

Mechanical Energy ◽

Hydrolytic Degradation ◽

Physiological Saline ◽

Light Weight ◽

Strength Variability ◽

Printing Method

The aim of this study was to evaluate the changes in physical-mechanical properties of the samples manufactured by 3D printing technology with the addition of varying degrees of polylactide (PLA) infill (50, 70, 85 and 100%). Half of the samples were soaked in physiological saline. The material used for the study was neat PLA, which was examined in terms of hydrolytic degradation, crystallization, mechanical strength, variability of properties at elevated temperatures, and dissipation of mechanical energy depending on the performed treatment. A significant impact of the amount of infill on changeable mechanical properties, such as hydrolytic degradation and crystallization was observed. The FDM printing method allows for waste–free production of light weight unit products with constant specyfic strength.

Download Full-text

3D printing of nanocellulose hydrogel scaffolds with tunable mechanical strength towards wound healing application

Journal of Materials Chemistry B ◽

10.1039/c8tb01757c ◽

2018 ◽

Vol 6 (43) ◽

pp. 7066-7075 ◽

Cited By ~ 41

Author(s):

Chunlin Xu ◽

Binbin Zhang Molino ◽

Xiaoju Wang ◽

Fang Cheng ◽

Wenyang Xu ◽

...

Keyword(s):

Wound Healing ◽

3D Printing ◽

Mechanical Strength ◽

Fibroblast Cells ◽

Hydrogel Scaffolds

Hydrogel scaffolds with tunable mechanical strength were prepared by 3D-printing of 1 wt% one-component-only wood derived nanocellulose, and may support fibroblast cells’ proliferation.

Download Full-text

3D printed mesh reinforcements enhance the mechanical properties of electrospun scaffolds

Biomaterials Research ◽

10.1186/s40824-019-0171-0 ◽

2019 ◽

Vol 23 (1) ◽

Cited By ~ 3

Author(s):

Nicholas W. Pensa ◽

Andrew S. Curry ◽

Paul P. Bonvallet ◽

Nathan F. Bellis ◽

Kayla M. Rettig ◽

...

Keyword(s):

Mechanical Properties ◽

Extracellular Matrix ◽

3D Printing ◽

Mechanical Strength ◽

Bone Graft ◽

Clinical Applications ◽

Foreign Body Response ◽

Poly Lactic Acid ◽

Electrospun Scaffolds ◽

3D Printed

Abstract Background There is substantial interest in electrospun scaffolds as substrates for tissue regeneration and repair due to their fibrous, extracellular matrix-like composition with interconnected porosity, cost-effective production, and scalability. However, a common limitation of these scaffolds is their inherently low mechanical strength and stiffness, restricting their use in some clinical applications. In this study we developed a novel technique for 3D printing a mesh reinforcement on electrospun scaffolds to improve their mechanical properties. Methods A poly (lactic acid) (PLA) mesh was 3D-printed directly onto electrospun scaffolds composed of a 40:60 ratio of poly(ε-caprolactone) (PCL) to gelatin, respectively. PLA grids were printed onto the electrospun scaffolds with either a 6 mm or 8 mm distance between the struts. Scanning electron microscopy was utilized to determine if the 3D printing process affected the archtitecture of the electrospun scaffold. Tensile testing was used to ascertain mechanical properties (strength, modulus, failure stress, ductility) of both unmodified and reinforced electrospun scaffolds. An in vivo bone graft model was used to assess biocompatibility. Specifically, reinforced scaffolds were used as a membrane cover for bone graft particles implanted into rat calvarial defects, and implant sites were examined histologically. Results We determined that the tensile strength and elastic modulus were markedly increased, and ductility reduced, by the addition of the PLA meshes to the electrospun scaffolds. Furthermore, the scaffolds maintained their matrix-like structure after being reinforced with the 3D printed PLA. There was no indication at the graft/tissue interface that the reinforced electrospun scaffolds elicited an immune or foreign body response upon implantation into rat cranial defects. Conclusion 3D-printed mesh reinforcements offer a new tool for enhancing the mechanical strength of electrospun scaffolds while preserving the advantageous extracellular matrix-like architecture. The modification of electrospun scaffolds with 3D-printed reinforcements is expected to expand the range of clinical applications for which electrospun materials may be suitable.

Download Full-text