Showing 11 results for 3d Printing
Volume 15, Issue 2 (5-2024)
Abstract
In recent years, significant efforts have been focused on advancements of novel biomaterials based on natural polymers and utilization of efficient methods such as skin tissue engineering for wound treatment. In this study, a 3D printed polycaprolactone (PCL) scaffold coated via immersion in a 1:4 blend of 40% silk fibroin from Bombyx mori cocoons and TEMPO-oxidized was developed. The pore size and the porosity were 180 µm and 85%, respectively. The results demonstrated an enhancement in exudate absorption (swelling and water uptake of 1342% and 80%, respectively), improvement in storage modulus (G’) from 500 to 4000 Pa, as well as viscoelasticity up to 60%, which all are favorable for wound dressing applications. Moreover, the wettability and biodegradability studies revealed an overall increase in contact angle and degradation rate of 19.9°±3, and 95%, respectively. Cell viability and migration studies on fibroblastic cells (L929) using MTT assay, DAPI/ Phalloidin staining, and scratch test showed over 90% viability up to 7 days and complete scratch repair within 24 hours. These findings show that 3D printed PCL scaffolds coated with silk fibroin and oxidized nanocellulose are promising for wound healing applications and might pave the way to natural polymer-based wound dressings.
Volume 20, Issue 3 (11-2016)
Abstract
3D printing is the process of accurate manufacture of 3D things from a digital file in the shortest time and with the least cost, which is applied in different industries. This process is performed via 3D printers and makes product the manufacturing rapid and diverse. Given its unique characteristics, the 3D printing technology is protectable in the intellectual property law system. In the mean time, it may bring about different issues as far as this system is concerned, and leads, directly and indirectly, to the infringement of the owners' exclusive rights. Hence, there is resistance from big companies to the spread of 3D printing. (because the offer of fake and infringing product, due to their incompatibility of the raw materials of printers that are not of the original products quality). Confronts the big companies with economic downturn. On the other hand, it results in the loss of consumers' confidence and even injuries. In order to provide a definitive solution to these unique issues, adopting proper legal measures and correct management to contribute to the development of this technology is an undeniable necessity.
M.e. Imanian, F. Reza Biglari ,
Volume 20, Issue 3 (2-2020)
Abstract
In this study, a selective laser sintering 3D printer has been designed and built. 3D laser printing is one of the flexible additive manufacturing methods, which can use different powdered materials. Recently, additive manufacturing technologies have been introduced into the pharmacy, and in August 2015, they received FDA approval as the three-dimensional drug products. By using additive manufacturing in the pharmacy, controlled release, dosage tailored to the characteristics of individuals, the desired morphology of the drugs can be achieved and we move toward the personalization of the medicine. One of the important issues is to determine the properties of tablets before printing. In this paper, the effect of important variables of selective laser sintering on tablet breaking force is investigated with the aid of central composite design and modeling. Using the proposed modeling, the value of each variable can be determined so that the tablets are printed with the required breaking force. The cylindrical tablets with a diameter of 1.2 cm and a height of 3.6 mm were printed for use in the experiments. To fabricate tablets, the thermoplastic polymer, Kollicoat IR (75% polyvinyl alcohol and 25% polyethylene glycol copolymer), was used and 5% paracetamol (acetaminophen) was added. Also, some edible black color was added to increase the absorption of laser light. Laser feed rate, the percentage of the tablet infill density and percentage of the added color are the studied variables. According to the results obtained in the considered range, by increasing laser feed rate, tablet breaking force decreases, but tablet braking force increases by increasing infill density and amount of added color.
M. Moradi, M. Karami Moghadam, F. Asgari,
Volume 20, Issue 4 (4-2020)
Abstract
Additive manufacturing in the modern world is progressing significantly, resulting in special applications in engineering sciences, medicine, and art. When the MIT university mixed the concept of time in the 3D printing process, time was considered as the fourth dimension. By combining the fourth dimension, the time, the smart materials made of additive manufacturing are able to a reaction to the external motivations (heat, voice, impact, etc) within a specified time. In the 4D printing process, the material configuration will be converted to a converter that will be exposed to external motivation such as heat, water, chemicals, electrical current and magnetic energy. It is expected that in the future, this technology will be widely used, requiring the application of various engineering disciplines, including mechanical engineering, in the fabrication and production of objects, because the overall perspective of the 4-D printing process is to make intelligent materials that are optimized using computational challenges and empirical knowledge. In this article, after reviewing the 3D printing and introducing smart materials, the issue of 4D printing has been investigated using this material. The mechanism, challenges, applications, and future of 4D printing has been discussed.
Volume 20, Issue 136 (5-2023)
Abstract
The survival of probiotics in food products face various challenges during the production process. One of the emerging processes in the production of food products is 3D printing. The effect of this process on the viability of probiotics has not been studied so far. In this research, the effect of micro-encapsulation on cell viability during the process of 3D printing and cookie baking (based on waste from confectionery products) was investigated. First, the conditions for the production of micro-capsules were optimized by modulating the percentage of sodium alginate and calcium chloride solutions. Then, the effect of micro-encapsulation with different concentrations of micro-capsules (10, 5, 0% w/w) on the firmness of the dough texture was also investigated as an important factor in the printability of the dough. Finally, the cell viability was evaluated during the printing and baking process (150°C and 180°C for 10 minutes). The results of the microscopic images showed that with the increase in the concentration of sodium alginate and calcium chloride solution, the uniformity and sphericity of the micro-capsule increases. The efficiency of alginate-based micro-encapsulation in this method was 89.41%. The optimal concentration of micro-capsules in order to have the desired printability of baked dough, was reported as 5% w/w. Microencapsulation increased the survival rate of probiotics during 3D printing and baking. The survival percentage of microencapsulated probiotics (T2) after 3D printing and baking (150°C temperature) was 96.86% and 62.58%, respectively. Meanwhile, the survival percentage for the sample containing free cells (T1) was reported 60.77% and 43.05%, respectively. However, no viable probiotic cells were observed in both free and encapsulated cells conditions at 180°C.
Rezgar Hasanzadeh, Taher Azdast,
Volume 21, Issue 2 (1-2021)
Abstract
In this study, the mechanical properties of poly lactic acid samples produced by FDM 3D printing technique were investigated. The 3D printing process parameters were optimized using design of experiment (DOE) Taguchi approach for achieving the optimum mechanical performance. In this regard, infill percentage (at three levels of 30, 50, and 70%), raster angle (at three states of 0/90, -30/30, and -45/45 degree), and layer thickness (at three levels of 200, 250, and 300 µm) were considered as process parameters for optimization procedure. Their effects on density (as porosity degree), impact strength (as mechanical property), and specific impact strength (the impact strength to density ratio) were investigated. Analysis of variance (ANOVA) was utilized to find the most effective processing parameters. The findings revealed that the infill percentage was the most effective parameter on the density and the impact strength. The density and the impact strength were reduced with the decrease of the infill percentage. These decrements were in a way that their ratio, specific impact strength, was almost constant. The layer thickness had the most influence on the specific impact strength. The specific impact strength was improved by reducing the layer thickness due to the raster entanglement. The optimum conditions to achieve the highest mechanical performance were the raster angle of 30/-30 degree and the layer thickness of 200 µ. The optimum infill percentage depended on the application.
, ,
Volume 22, Issue 10 (10-2022)
Abstract
Nowadays using 3D printing for prototyping is well known in industrial applications and there are efforts to make functional parts with this technology to reach low volume production markets. By using pellets rather than filaments, the limitations caused by lack of variety of materials can be conquered. Also, there will be no need to make a massive part as several divided parts and then glue them together. In this article pellets of ABS, that are well known and functional in industry, are analysed for an extruder to investigate the ability of pellet material extruding. Characteristic specifications of extruder such as operating pressure, screw rotational speed and required torque for rotating the screw are achieved for they are important factors to find out the mechanism for experimental tests and selecting suitable operating parts such as motor and gearbox.
Mostafa Abdolalizade, Parvaz,
Volume 22, Issue 10 (10-2022)
Abstract
With the development of additive manufacturing technology, the quantity of devices that can be used in small office with the commercial or educational purposes increases. In this research, the goal is to build a desktop 3D printer with selective laser sintering technology, which can be used for research purposes. The main concentration is focused on fabrication with parts that can be manufactured in the country or can be procured from the domestic market. It is also tried to make the 3D printer compatible with the common open-source additive manufacturing softwares. The fabricated 3D printer has the ability to work with all kinds of common polymer powders. In addition, it is easy to update the device's firmware according to the researcher's needs. The capabilities of the device was tested with Glucose powder, paraffin wax powder, and thermoplastic-ceramic material combinations. It is currently used for research on fabricating ceramic parts with indirect laser sintering.
Mohammad Mahdi Salehi, Mohammad Reza Movahhedy,
Volume 23, Issue 4 (3-2023)
Abstract
Nowadays using 3D printing for prototyping is well known in industrial applications and there are efforts to make functional parts with this technology to reach low volume production markets. By using pellets rather than filaments, the limitations caused by lack of variety of materials can be conquered. Also there will be no need to make a massive part as several divided parts and then glue them together.
In this article pellets of ABS, that are well known and functional in industry, are analysed for an extruder to investigate the ability of pellet material extruding. Characteristic specifications of extruder such as operating pressure, screw rotational speed and required torque for rotating the screw are achieved for they are important factors to find out the mechanism for experimental tests and selecting suitable operating parts such as motor and gearbox. At the end, the experimental tests on designed system are done and the result approved the trends of theoretical data.
Kiandokht Mirasadi , Davoud Rahmatabadi, Esmaeil Ghasemi , Majid Baniassadi , Mostafa Baghani ,
Volume 23, Issue 10 (10-2023)
Abstract
In this research, processing and 3D printing of PETG-ABS- Fe 3 O 4 nanocomposites reinforced with iron oxide nanoparticles in three different weight percentages of iron oxide nanoparticles with PETG70-ABS30 polymer matrix was done. This research was carried out with the aim of strengthening the shape memory properties, thermal properties, mechanical properties and adding the ability to indirectly stimulate the background matrix through the addition of iron oxide nanoparticles. SEM images confirmed that the mixture of PETG-ABS is immiscible and adding nanoparticles does not change the compatibility and miscibility of the base polymer, and this result is consistent with the DMTA analysis was also checked and confirmed. With increasing amount of iron oxide, the tensile strength and elongation decrease, and this decrease in mechanical properties is more pronounced in the sample of 20% by weight of iron oxide compared to the sample of 10% by weight. Nevertheless, the final strength of the samples is around 25 to 32 MPa, which indicates a suitable and acceptable distribution of nanoparticles up to 15% by weight in the polymer field. By increasing the amount of iron oxide nanoparticles, the amount of shape recovery increases and the nanocomposites containing 10, 15 and 20% by weight show shape recovery of 63.77%, 88.48 and 93.33%, respectively.
Kiandokht Mirasadi , Davoud Rahmatabadi , Esmaeil Ghasemi , Majid Baniassadi , Mostafa Baghani ,
Volume 23, Issue 10 (10-2023)
Abstract
Smart materials can react to environmental changes like living organisms and adapt themselves to environmental conditions and changes such as changes in temperature, electric current, magnetic field, light, humidity, etc. Using 3D printing to process smart materials is a new approach known as 4D printing. In this research, processing, manufacturing and 3D printing of PETG-ABS in three weight percentages of 70/30, 50/50 and 30/70 were done. The results of SEM also confirmed the compatibility of these two polymers. In all PETG-ABS mixtures, a combination of sea-island and drop-matrix morphology was observed, and for the 30/70 and 30/70 blends, phase droplets dispersed in the matrix were clearly observed. The results of mechanical properties also showed that as the percentage of ABS in the mixture increases, the tensile strength increases and the elongation decreases. The results obtained from the shape memory test indicate the existence of the ability to program the shape memory property in 4D printing mixtures. As expected, the increase in the weight percentage of ABS was associated with the disorder in the recovery of the mixtures, so the mixture with 70% by weight of PETG and 30% by weight of ABS showed the most favorable shape memory properties.
