scholarly journals Acoustic Performance of 3D Printed Nanocomposite Earmuff

2015 ◽  
Vol 8 (1) ◽  
pp. 180 ◽  
Author(s):  
Saeid Ahmadi ◽  
Parvin Nassiri ◽  
Ismaeil Ghasemi ◽  
Mohammad R. Monazzam Ep

INTRODUCTION: Hearing protection devices are one of the primary noise reduction tools in developing countries. This study is intended to produce and apply acrylonitrile butadiene styrene (ABS)/clay nanocomposites to fabricate a laboratory single cup earmuffs and then compare it with double cup and single cup pure ABS earmuffs in terms of noise attenuation performance and comfort. In addition, the noise attenuation performance of single cup pure ABS earmuffs is compared with double cup pure ABS earmuffs. METHODS: ABS/nanoclay filament was fabricated using a twin screw extruder. A three dimensional (3D) printing machine and a 3D model of earcup, designed by solid work software, were applied to print single and double cup earmuffs using ABS/nanoclay composite and pure ABS filaments. Finally, using an acoustic test fixture, objective noise attenuation test was performed on three different types of earmuffs, including with and without nano material and a secondary cup. Moreover, earmuffs weight was measured as a comfort component. RESULTS: Insertion loss and calculated noise reduction rating (NRR) of single cup ABS/nanoclay earmuffs (NRR=19.4 dB) and double cup pure ABS earmuffs (NRR=18.93 dB) were improved in comparison with single cup pure ABS earmuffs (NRR=15.7 dB). Additionally, both single cup earmuffs were significantly lighter than double cup earmuffs. Although single cup nano and double cup earmuffs had nearly the same attenuation performance, single cup nano earmuffs were 74 gr lighter than double cup earmuffs, so with reference to comfort, single cup nano earmuffs will probably be more acceptable. CONCLUSIONS: From this survey it might be concluded that, even though single cup ABS/nanoclay earmuffs was lighter than double cup pure ABS earmuffs, it had approximately more attenuation performance in comparison with double cup pure ABS earmuffs. Consequently, users are probably more prone to wear light- weight single cup ABS/nanoclay earmuffs as a result of improved comfort. In short, ABS/nanoclay composite can be considered a good choice in products with the necessity of high acoustic performance and low weight.CallSend SMSAdd to SkypeYou'll need Skype CreditFree via Skype

Author(s):  
Rupinder Singh ◽  
Inderpreet Singh ◽  
Ranvijay Kumar

The utilization of thermosetting waste is a serious issue as it is not recycled commercially due to inherent molecular properties and high technology cost. This research details the study of the mechanical behavior and surface analysis with energy-dispersive X-ray spectroscopy and scanning electron microscope of three-dimensional printed parts of the waste thermosetting polymer, bakelite (BAK) as the reinforcement along with ceramic particles (SiC and Al2O3) in recycled thermoplastic acrylonitrile butadiene styrene matrix for sustainability. The process involves twin-screw extrusion for the preparation of filament, followed by 3D printing of functional prototypes on fused deposition modeling setup. The 3D printed parts prepared with fused deposition modeling were used for the testing of mechanical, thermal, and morphological properties. The results of the present study suggests that for commercial applications recycling of thermoplastic up to 10 wt% can be easily performed without a change in any hardware/ software configuration of the fused deposition modeling setup and the ceramic concentration in thermoplastic-thermosetting blends further led to better mechanical and surface properties.


Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1559
Author(s):  
Mohammad Reza Khosravani ◽  
Jonas Schüürmann ◽  
Filippo Berto ◽  
Tamara Reinicke

Application of Additive Manufacturing (AM) has significantly increased in the past few years. AM also known as three-dimensional (3D) printing has been currently used in fabrication of prototypes and end-use products. Considering the new applications of additively manufactured components, it is necessary to study structural details of these parts. In the current study, influence of a post-processing on the mechanical properties of 3D-printed parts has been investigated. To this aim, Acrylonitrile Butadiene Styrene (ABS) material was used to produce test coupons based on the Fused Deposition Modeling (FDM) process. More in deep, a device was designed and fabricated to fix imperfection and provide smooth surfaces on the 3D-printed ABS specimens. Later, original and treated specimens were subjected to a series of tensile loads, three-point bending tests, and water absorption tests. The experimental tests indicated fracture load in untreated dog-bone shaped specimen was 2026.1 N which was decreased to 1951.7 N after surface treatment. Moreover, the performed surface treatment was lead and decrease in tensile strength from 29.37 MPa to 26.25 MPa. Comparison of the results confirmed effects of the surface modification on the fracture toughness of the examined semi-circular bending components. Moreover, a 3D laser microscope was used for visual investigation of the specimens. The documented results are beneficial for next designs and optimization of finishing processes.


Author(s):  
Kamaljit Singh Boparai ◽  
Gurpartap Singh ◽  
Rupinder Singh ◽  
Sarabjit Singh

Abstract In this work, 3D printed master patterns of acrylonitrile butadiene styrene (ABS) thermoplastic material have been used for the preparation of Ni-Cr based functional prototypes as partial dentures (PD). The study started with patient specific three dimensional (3D), CAD data (fetched through scanning). This data was used for preparation of .STL file for printing of master patterns on fused deposition modeling (FDM) setup. The 3D printed master patterns were further wax coated to reduce the surface irregularities (as cost effective post processing technique). The hybrid patterns were subjected to investment casting for the preparation of Ni-Cr based PD. The finally prepared functional prototypes as PD were optimized for dimensional accuracy, surface finish and surface hardness as responses. The results are visualized and supported by photomicrographs and in-vitro analysis.


2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Mina Karami ◽  
Mohsen Aliabadi ◽  
Rostam Golmohammadi ◽  
Morteza Hamidi Nahrani

Abstract Objective This study aimed to investigate the effect of hearing protection devices (HPDs) on speech intelligibility in Persian work environments. Three current earmuffs and three earplugs and one of the prototypes of molded earplug were tested on 15 male subjects which were randomly selected. The noise reduction of HPDs was measured based on the Real Ear Attenuation at Threshold (REAT) method. Speech intelligibility during using HPDs was determined based on the speech discrimination score (SDS) at two signal to noise (S/N) ratios (0 and + 5). Data were analyzed using SPSS 22. Results The actual to nominal noise reduction rating values were from 47 to 84% for HPDs. At two S/N ratios, no significant differences were observed in speech intelligibility using HPDs (p > 0.05). At S/N ratio = 0, the speech intelligibility descriptively has been only improved by using common earmuffs up to 9.07%. There was a significant difference up to 21.27% in speech intelligibility for proposed molded earplugs at S/N ratio = 0 (p < 0.05). Increasing the HPDs' noise attenuation values led to an increase in speech interference (p < 0.05). The HPDs with the minimum required noise attenuation while maintaining acceptable speech intelligibility should be worn by employees exposed to medium noise levels.


2017 ◽  
Vol 139 (2) ◽  
Author(s):  
Vana Snigdha Tummala ◽  
Ahsan Mian ◽  
Nowrin H. Chamok ◽  
Dhruva Poduval ◽  
Mohammod Ali ◽  
...  

Engineered porous structures are being used in many applications including aerospace, electronics, biomedical, and others. The objective of this paper is to study the effect of three-dimensional (3D)-printed porous microstructure on the dielectric characteristics for radio frequency (RF) antenna applications. In this study, a sandwich construction made of a porous acrylonitrile butadiene styrene (ABS) thermoplastic core between two solid face sheets has been investigated. The porosity of the core structure has been varied by changing the fill densities or percent solid volume fractions in the 3D printer. Three separate sets of samples with dimensions of 50 mm × 50 mm × 5 mm are created at three different machine preset fill densities each using LulzBot and Stratasys dimension 3D printers. The printed samples are examined using a 3D X-ray microscope to understand pore distribution within the core region and uniformity of solid volumes. The nondestructively acquired 3D microscopy images are then postprocessed to measure actual solid volume fractions within the samples. This measurement is important specifically for dimension-printed samples as the printer cannot be set for any specific fill density. The experimentally measured solid volume fractions are found to be different from the factory preset values for samples prepared using LulzBot printer. It is also observed that the resonant frequency for samples created using both the printers decreases with an increase in solid volume fraction, which is intuitively correct. The results clearly demonstrate the ability to control the dielectric properties of 3D-printed structures based on prescribed fill density.


Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1589 ◽  
Author(s):  
Nectarios Vidakis ◽  
Markos Petousis ◽  
Athena Maniadi ◽  
Emmanuel Koudoumas ◽  
Marco Liebscher ◽  
...  

In order to enhance the mechanical performance of three-dimensional (3D) printed structures fabricated via commercially available fused filament fabrication (FFF) 3D printers, novel nanocomposite filaments were produced herein following a melt mixing process, and further 3D printed and characterized. Titanium Dioxide (TiO2) and Antimony (Sb) doped Tin Oxide (SnO2) nanoparticles (NPs), hereafter denoted as ATO, were selected as fillers for a polymeric acrylonitrile butadiene styrene (ABS) thermoplastic matrix at various weight % (wt%) concentrations. Tensile and flexural test specimens were 3D printed, according to international standards. It was proven that TiO2 filler enhanced the overall tensile strength by 7%, the flexure strength by 12%, and the micro-hardness by 6%, while for the ATO filler, the corresponding values were 9%, 13%, and 6% respectively, compared to unfilled ABS. Atomic force microscopy (AFM) revealed the size of TiO2 (40 ± 10 nm) and ATO (52 ± 11 nm) NPs. Raman spectroscopy was performed for the TiO2 and ATO NPs as well as for the 3D printed nanocomposites to verify the polymer structure and the incorporated TiO2 and ATO nanocrystallites in the polymer matrix. The scope of this work was to fabricate novel nanocomposite filaments using commercially available materials with enhanced overall mechanical properties that industry can benefit from.


2021 ◽  
pp. 004051752110592
Author(s):  
Meng-jie Wu ◽  
Chao Zhi ◽  
Li Tu ◽  
Yong-zhen Wang ◽  
Yang Dai ◽  
...  

There is a large somatosensory gap between the three-dimensional (3D) printing of clothing and traditional garments due to the limitations (e.g., air permeability and skin-friendliness) of the printing materials. For this reason, the application of traditional textile materials in 3D printing has become a hot topic in the field of 3D printed clothing. Based on the above, this work prepared four kinds of cotton-containing composite solutions and then impregnated thermoplastic polyurethane core yarns in these solutions to obtain four types of 3D printed cotton-containing composite core yarns (3Dp-C-CYs). Afterward, based on the two-dimensional (2D) braiding method, four kinds of cotton-containing 3D printing wires used for fused deposition molding technology were prepared by wrapping low-melting polyester filaments around the different 3Dp-C-CYs. After comparing the printing performance of the four cotton-containing 3D printing wires, the wire containing cotton powders had the best comprehensive performance and was selected to print the cotton-containing 3D printed fabrics. The results showed that the cotton-containing 3D printed fabric has good flatness and contains a large number of cotton powders; in addition, compared with the traditional polylactic acid and acrylonitrile butadiene styrene copolymer 3D printed fabrics, the 3D printed fabric made up of cotton-containing 3D printing wire can provide a closer wearing experience to that of cotton fabric. The 3D printing wire produced by the 2D braiding method offers a new idea for applying traditional textile materials in 3D printing, showing great application potentials in the field of 3D printing of clothing.


2020 ◽  
Vol 6 (2) ◽  
Author(s):  
Yijun Wong ◽  
Yihua Xu ◽  
Lifeng Kang ◽  
Kevin Yi-Lwern Yap

This study explored the potential of three-dimensional printing (3DP) technology in producing a three-dimensional (3D) medication label for blind and visually impaired (BVI) patients to ease their drug administration. Different variations of label wordings, dosing instructions, and medication identifiers were designed with reference to guidelines by the American Foundation for the Blind. Shapes and symbols were used as dosing instructions and medication identifiers to the patient’s medical conditions. Prototype designs were created with common graphics computer-assisted drafting software and 3D-printed using acrylonitrile butadiene styrene as the polymer filament. Feedback was then obtained from five people with normal vision and four BVI persons. The initial prototype comprised four components, namely, medication name and strength, patient’s name, dosing instruction, and medication identifier. A revised label comprising the latter two components was developed after feedback by BVI persons. Words were in all uppercase and regular font type, with a 5-mm center-to-center letter spacing. Elevation heights of the letters alternated between 1 mm and 1.5 mm. A half sphere represented the medication dose unit, while vertical lines and a horizontal center line with alternating elevation of arrowheads represented the frequency of administration and the medication’s consumption in relation to food, respectively. Symbols based on target organs were used as medication identifiers. With rapid advancements in 3DP technologies, there is tremendous potential for producing 3D labels in patients’ medication management.


2020 ◽  
Author(s):  
Mina Karami ◽  
Mohsen Aliabadi ◽  
Rostam Golmohammadi ◽  
Morteza Hamidi Nahrani

Abstract Objective: This study aimed to investigate the effect of hearing protection devices (HPDs) on speech intelligibility in Persian work environments. Three current earmuffs and three earplugs and one of the prototypes of molded earplug were tested on 15 male subjects which were randomly selected. The noise reduction of HPDs was measured based on the Real Ear Attenuation at Threshold (REAT) method. Speech intelligibility during using HPDs was determined based on the speech discrimination score (SDS) at two signal to noise (S/N) ratios (0 and +5). Data were analyzed using SPSS 22.Results: The actual to nominal noise reduction rating values were from 47% to 84% for HPDs. At two S/N ratios, no significant differences were observed in speech intelligibility using HPDs (p >0.05). At S/N ratio=0, the speech intelligibility descriptively has been only improved by using common earmuffs up to 9.07 %. There was a significant difference up to 21.27% in speech intelligibility for proposed molded earplugs at S/N ratio=0 (p <0.05). Increase the HPDs' noise attenuation values lead to increase interference in the speech (p <0.05). The HPDs with the minimum required noise attenuation while maintaining acceptable speech intelligibility should be worn by employees exposed to medium noise levels.


2020 ◽  
Author(s):  
Mina Karami ◽  
Mohsen Aliabadi ◽  
Rostam Golmohammadi ◽  
Morteza Hamidi Nahrani

Abstract Objective: This study aimed to investigate the effect of hearing protection devices (HPDs) on speech intelligibility in Persian work environments. Three current earmuffs and three earplugs and one of the prototypes of molded earplug were tested on 15 male subjects which were randomly selected. The noise reduction of HPDs was measured based on the Real Ear Attenuation at Threshold (REAT) method. Speech intelligibility during using HPDs was determined based on the speech discrimination score (SDS) at two signal to noise (S/N) ratios (0 and +5). Data were analyzed using SPSS 22.Results: The actual to nominal noise reduction rating values were from 47% to 84% for HPDs. At two S/N ratios, no significant differences were observed in speech intelligibility using HPDs (p >0.05). At S/N ratio=0, the speech intelligibility descriptively has been only improved by using common earmuffs up to 9.07 %. There was a significant difference up to 21.27% in speech intelligibility for proposed molded earplugs at S/N ratio=0 (p <0.05). Increasing the HPDs' noise attenuation values led to an increase in speech interference (p <0.05). The HPDs with the minimum required noise attenuation while maintaining acceptable speech intelligibility should be worn by employees exposed to medium noise levels.


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