Assessment of Manufacturing Parameters for New 3D-Printed Heating Circuits Based on CNT-Doped Nanocomposites Processed by UV-Assisted Direct Write

This work consists of the development of an easy strategy to transform any structure into an efficient surface heater by the application of a low voltage over 3D printed nanocomposite circuits. To this end, the electrical conductivity and self-heating capabilities of UV-Assisted Direct Write 3D printed circuits doped with carbon nanotubes were widely explored as a function of the number of printed layers. Moreover, an optimization of the printing process was carried out by comparing the accuracy and printability obtained when printing with two different configurations: extruding and curing the ink in the same stage or curing the extruded ink in a second stage, after the whole layer was deposited. In this regard, the great homogeneity and repeatability of the heating showed by the four-layer printed circuits, together with their excellent performance for long heating times, proved their applicability to convert any structure to a surface heater. Finally, the deicing capability of the four-layer circuit was demonstrated, being able to remove a 2.5 mm thick ice layer in 4 min and 4 s.

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Influence of Manufacturing Parameters and Post Processing on the Electrical Conductivity of Extrusion-Based 3D Printed Nanocomposite Parts

Polymers ◽

10.3390/polym12040733 ◽

2020 ◽

Vol 12 (4) ◽

pp. 733 ◽

Cited By ~ 1

Author(s):

Rubén Paz ◽

Rocío Moriche ◽

Mario Monzón ◽

Joshua García

Keyword(s):

Electrical Conductivity ◽

Cross Section ◽

Acrylonitrile Butadiene Styrene ◽

Post Processing ◽

Cross Section Area ◽

Surface Electrical Conductivity ◽

Consequent Reduction ◽

3D Printed ◽

The Individual ◽

Manufacturing Parameters

The influence of manufacturing parameters of filament extrusion and extrusion-based Additive Manufacturing (AM), as well as different post processing techniques, on the electrical conductivity of 3D printed parts of graphene nanoplatelets (GNP)-reinforced acrylonitrile butadiene styrene (ABS) has been analyzed. The key role of the manufacturing parameters to obtain electrically conductive filaments and 3D printed parts has been demonstrated. Results have shown that an increase in extrusion speed, as well as lower land lengths, induces higher extrudate swelling, with the consequent reduction of the electrical conductivity. Additionally, filaments with lower diameter values, which result in a higher surface-to-cross-section ratio, have considerably lower electrical conductivities. These factors tune the values of the volume and surface electrical conductivity between 10−4–100 S/m and 10−8–10−3 S/sq, respectively. The volume and surface electrical conductivity considerably diminished after 3D printing. They increased when using higher printing layer thickness and width and were ranging between 10−7–10−4 S/m and 10−8–10−5 S/sq, respectively. This is attributed to the higher cross section area of the individual printed lines. The effect of different post processing (acetone vapor polishing, plasma and neosanding, which is a novel finishing process) on 3D printed parts in morphology and surface electrical conductivity was also analyzed.

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3D printing of spent coffee ground derived biochar reinforced epoxy composites

Journal of Composite Materials ◽

10.1177/00219983211002237 ◽

2021 ◽

pp. 002199832110022

Author(s):

Ahmed Alhelal ◽

Zaheeruddin Mohammed ◽

Shaik Jeelani ◽

Vijaya K Rangari

Keyword(s):

3D Printing ◽

Flexural Modulus ◽

Flexural Properties ◽

Direct Write ◽

Thermal And Mechanical Properties ◽

Spent Coffee Grounds ◽

Coffee Grounds ◽

Spent Coffee Ground ◽

Coffee Ground ◽

3D Printed

Semi-crystalline carbon biochar is derived from spent coffee grounds (SCG) by a controlled pyrolysis process at high temperature/pressure conditions. Obtained biochar is characterized using XRD, SEM, and TEM techniques. Biochar particles are in the micrometer range with nanostructured morphologies. The SCG biochar thus produced is used as reinforcement in epoxy resin to 3 D print samples using the direct-write (DW) method with 1 and 3 wt. % loadings. Rheology results show that the addition of biochar makes resin viscous, enabling it to be stable soon after print; however, it could also lead to clogging of resin in printer head. The printed samples are characterized for chemical, thermal and mechanical properties using FTIR, TGA, DMA and flexure tests. Storage modulus improved with 1 wt. % biochar addition up to 27.5% and flexural modulus and strength increased up to 55.55% and 43.30% respectively. However, with higher loading of 3 wt. % both viscoelastic and flexural properties of 3D printed samples drastically reduced thus undermining the feasibility of 3D printing biochar reinforced epoxies at higher loadings.

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3D-Printed Graphene Antennas and Interconnections for Textile RFID Tags: Fabrication and Reliability towards Humidity

International Journal of Antennas and Propagation ◽

10.1155/2017/1386017 ◽

2017 ◽

Vol 2017 ◽

pp. 1-5 ◽

Cited By ~ 6

Author(s):

Han He ◽

Mitra Akbari ◽

Lauri Sydänheimo ◽

Leena Ukkonen ◽

Johanna Virkki

Keyword(s):

Rfid Tags ◽

High Humidity ◽

Direct Write ◽

Uhf Rfid ◽

Printed Antenna ◽

Passive Uhf Rfid ◽

Measurement Results ◽

One Step ◽

3D Printed ◽

Wireless Measurement

We present the possibilities of 3D direct-write dispensing in the fabrication of passive UHF RFID graphene tags on a textile substrate. In our method, the graphene tag antenna is deposited directly on top of the IC strap, in order to simplify the manufacturing process by removing one step, that is, the IC attachment with conductive glue. Our wireless measurement results confirm that graphene RFID tags with printed antenna-IC interconnections achieve peak read ranges of 5.2 meters, which makes them comparable to graphene tags with epoxy-glued ICs. After keeping the tags in high humidity, the read ranges of the tags with epoxy-glued and printed antenna-IC interconnections decrease 0.8 meters and 0.5 meters, respectively. However, after drying, the performance of both types of tags returns back to normal.

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Tequila Still Distillation Fractioned Residual Streams for Use in Biorefinery

Energies ◽

10.3390/en13236222 ◽

2020 ◽

Vol 13 (23) ◽

pp. 6222

Author(s):

Edgardo Martinez-Orozco ◽

Pablo Gortares-Moroyoqui ◽

Norberto Santiago-Olivares ◽

Juan Napoles-Armenta ◽

Ruth Gabriela Ulloa-Mercado ◽

...

Keyword(s):

Electrical Conductivity ◽

Gas Chromatography ◽

Energy Analysis ◽

Oxygen Demand ◽

Solid Content ◽

Co2 Production ◽

Second Stage ◽

Stage Process ◽

Very High ◽

Tequila Vinasses

Tequila vinasses is a mixture made from up to six still distillation two-stage process residual effluents. First stage fractions: residual must (60%), heads (0.9%) and tails (20.0%); second stage fractions: non-evaporated (8.0%), heads (0.1%) and tails (1.0%); the result is a more complex effluent for its treatment or biorefining. The objectives of this study were to: (a) characterize the five still distillation volatile streams in the Tequila 100% Agave processing; compounds: methanol, ethanol, acetaldehyde, ethyl acetate, sec-butanol, n-propanol, iso-butanol, n-butanol, iso-amyl, n-amyl, and ethyl lactate were detected by gas chromatography; calculated chemical oxygen demand from chemical composition had very high values (53,760–1,239,220 mg/L); measurement of pH (3.24–4.80), color (38.6 UC Pt-Co max), turbidity (46.1 max), electrical conductivity (3.30–172.20 μS/cm), and solid content (0 mg/L) was also made; (b) report an energy analysis (2.02 × 109 KWh) and CO2 production (429 × 106 kg) in the Tequila industry during 2019; (c) up to date residues (365.2 × 106 kg agave bagasse, 1146.1 × 106 kg agave leaves and 3300.0 × 106 L agave vinasse) in 2019; (d) economic analysis, current tequila vinasses treatment price is 16.00 USD/m3 but could reach a considerable fraction value if is bio-refined, a break down component analysis reach for five volatile streams $51.23–$140.00 USD/m3.

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