Investigating the Potential of Commercial-Grade Carbon Black-Filled TPU for the 3D Printing of Compressive Sensors

The present research aims to exploit commercially available materials and machines to fabricate multilayer, topologically designed transducers, which can be embedded into mechanical devices, such as soft or rigid grippers. Preliminary tests on the possibility of fabricating 3D-printed transducers using a commercial conductive elastomeric filament, carbon black-filled thermoplastic polyurethane, are presented. The commercial carbon-filled thermoplastic polyurethane (TPU), analyzed in the present paper, has proven to be a candidate material for the production of 3D printed displacement sensors. Some limitations in fabricating the transducers from a 2.85 mm filament were found, and comparisons with 1.75 mm filaments should be conducted. Moreover, further research on the low repeatability at low displacements and the higher performance of the hollow structure, in terms of repeatability, must be carried out. To propose an approach that can very easily be reproduced, only commercial filaments are used.

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DESIGN OF A 3D-PRINTED THREE-CLAW ROBOTIC GRIPPER END-EFFECTOR

ASEAN Engineering Journal ◽

10.11113/aej.v11.17865 ◽

2021 ◽

Vol 11 (4) ◽

pp. 70-79

Author(s):

Dino Dominic Forte Ligutan ◽

Argel Alejandro Bandala ◽

Jason Limon Española ◽

Richard Josiah Calayag Tan Ai ◽

Ryan Rhay Ponce Vicerra ◽

...

Keyword(s):

3D Printing ◽

Polylactic Acid ◽

Grip Force ◽

Thermoplastic Polyurethane ◽

Robotic Arm ◽

End Effector ◽

Design Considerations ◽

3D Printed ◽

Materials Used ◽

Metal Work

The development of a novel 3D-printed three-claw robotic gripper shall be described in this paper with the goal of incorporating various design considerations. Such considerations include the grip reliability and stability, grip force maximization, wide object grasping capability. Modularization of its components is another consideration that allows its parts to be easily machined and reusable. The design was realized by 3D printing using a combination of tough polylactic acid (PLA) material and thermoplastic polyurethane (TPU) material. In practice, additional tolerances were also considered for 3D printing of materials to compensate for possible expansion or shrinkage of the materials used to achieve the required functionality. The aim of the study is to explore the design and eventually deploy the three-claw robotic gripper to an actual robotic arm once its metal work fabrication is finished.

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Electrospinning on 3D Printed Polymers for Mechanically Stabilized Filter Composites

Polymers ◽

10.3390/polym11122034 ◽

2019 ◽

Vol 11 (12) ◽

pp. 2034 ◽

Cited By ~ 10

Author(s):

Tomasz Kozior ◽

Al Mamun ◽

Marah Trabelsi ◽

Martin Wortmann ◽

Sabantina Lilia ◽

...

Keyword(s):

3D Printing ◽

Thermoplastic Polyurethane ◽

High Surface ◽

Antimicrobial Properties ◽

Mechanical Damage ◽

Volume Ratio ◽

Electrospun Nanofiber ◽

Polymer Nanofiber ◽

3D Printed ◽

Nanofiber Mats

Electrospinning is a frequently used method to prepare air and water filters. Electrospun nanofiber mats can have very small pores, allowing for filtering of even the smallest particles or molecules. In addition, their high surface-to-volume ratio allows for the integration of materials which may additionally treat the filtered material through photo-degradation, possess antimicrobial properties, etc., thus enhancing their applicability. However, the fine nanofiber mats are prone to mechanical damage. Possible solutions include reinforcement by embedding them in composites or gluing them onto layers that are more mechanically stable. In a previous study, we showed that it is generally possible to stabilize electrospun nanofiber mats by 3D printing rigid polymer layers onto them. Since this procedure is not technically easy and needs some experience to avoid delamination as well as damaging the nanofiber mat by the hot nozzle, here we report on the reversed technique (i.e., first 3D printing a rigid scaffold and subsequently electrospinning the nanofiber mat on top of it). We show that, although the adhesion between both materials is insufficient in the case of a common rigid printing polymer, nanofiber mats show strong adhesion to 3D printed scaffolds from thermoplastic polyurethane (TPU). This paves the way to a second approach of combining 3D printing and electrospinning in order to prepare mechanically stable filters with a nanofibrous surface.

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3D-Printable PP/SEBS Thermoplastic Elastomeric Blends: Preparation and Properties

Polymers ◽

10.3390/polym11020347 ◽

2019 ◽

Vol 11 (2) ◽

pp. 347 ◽

Cited By ~ 18

Author(s):

Shib Banerjee ◽

Stephen Burbine ◽

Nischay Kodihalli Shivaprakash ◽

Joey Mead

Keyword(s):

3D Printing ◽

Carbon Black ◽

Computer Aided Design ◽

Fused Deposition Modeling ◽

Mechanical Performance ◽

Polymeric Materials ◽

Fused Deposition ◽

3D Printed ◽

Injection Molded ◽

Preferential Location

Currently, material extrusion 3D printing (ME3DP) based on fused deposition modeling (FDM) is considered a highly adaptable and efficient additive manufacturing technique to develop components with complex geometries using computer-aided design. While the 3D printing process for a number of thermoplastic materials using FDM technology has been well demonstrated, there still exists a significant challenge to develop new polymeric materials compatible with ME3DP. The present work reports the development of ME3DP compatible thermoplastic elastomeric (TPE) materials from polypropylene (PP) and styrene-(ethylene-butylene)-styrene (SEBS) block copolymers using a straightforward blending approach, which enables the creation of tailorable materials. Properties of the 3D printed TPEs were compared with traditional injection molded samples. The tensile strength and Young’s modulus of the 3D printed sample were lower than the injection molded samples. However, no significant differences could be found in the melt rheological properties at higher frequency ranges or in the dynamic mechanical behavior. The phase morphologies of the 3D printed and injection molded TPEs were correlated with their respective properties. Reinforcing carbon black was used to increase the mechanical performance of the 3D printed TPE, and the balancing of thermoplastic elastomeric and mechanical properties were achieved at a lower carbon black loading. The preferential location of carbon black in the blend phases was theoretically predicted from wetting parameters. This study was made in order to get an insight to the relationship between morphology and properties of the ME3DP compatible PP/SEBS blends.

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Simulation and Validation of Fully 3D Printed Soft Actuators

ASME 2020 Conference on Smart Materials, Adaptive Structures and Intelligent Systems ◽

10.1115/smasis2020-2240 ◽

2020 ◽

Author(s):

Steffi Torres ◽

Julio San Martin ◽

Brittany Newell ◽

Jose Garcia

Keyword(s):

3D Printing ◽

Thermoplastic Polyurethane ◽

Pharmaceutical Products ◽

Element Analysis ◽

Strain Behavior ◽

Fea Model ◽

First Case ◽

3D Printed ◽

Soft Actuators ◽

Robotic Applications

Abstract Flexible actuators are a growing class of devices implemented in soft robotic applications, medical devices and processes involving food and pharmaceutical products. Such actuators have traditionally been manufactured using casting processes or other conventional methods requiring more than one fabrication step. The arrival of flexible 3D printing materials and 3D printing techniques has facilitated the creation of these flexible actuators via additive manufacturing. The work presented in this article displays the analytical characterization and experimental validation of two materials and two actuator designs. The first case presents a finite element analysis (FEA) simulated model of a bellows actuator using a photocurable flexible resin (TangoPlus FLX930) and studies the effect of printing orientation on the simulation. The simulation used a 5 parameter Mooney-Rivlin model to predict the strain behavior of the actuator under hydrostatic pressure. A second case is presented where a Thermoplastic Polyurethane actuator was 3D printed and simulated using the same FEA model and a second calibration of the Mooney-Rivlin 5 parameter model. In both cases experimental data was used to calibrate and validate the simulation. The resulting simulated strain was consistent when the printing orientation of actuators was parallel (0 degrees) to the strain direction of the actuators. Results were less consistent when a print orientation of 45 degrees was applied.

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3D Printing of a Self-Healing Thermoplastic Polyurethane through FDM: From Polymer Slab to Mechanical Assessment

Polymers ◽

10.3390/polym13020305 ◽

2021 ◽

Vol 13 (2) ◽

pp. 305

Author(s):

Linda Ritzen ◽

Vincenzo Montano ◽

Santiago J. Garcia

Keyword(s):

3D Printing ◽

Room Temperature ◽

Thermoplastic Polyurethane ◽

The Self ◽

Added Value ◽

Fused Deposition Modelling ◽

Full Potential ◽

Self Healing ◽

Fused Deposition ◽

3D Printed

The use of self-healing (SH) polymers to make 3D-printed polymeric parts offers the potential to increase the quality of 3D-printed parts and to increase their durability and damage tolerance due to their (on-demand) dynamic nature. Nevertheless, 3D-printing of such dynamic polymers is not a straightforward process due to their polymer architecture and rheological complexity and the limited quantities produced at lab-scale. This limits the exploration of the full potential of self-healing polymers. In this paper, we present the complete process for fused deposition modelling of a room temperature self-healing polyurethane. Starting from the synthesis and polymer slab manufacturing, we processed the polymer into a continuous filament and 3D printed parts. For the characterization of the 3D printed parts, we used a compression cut test, which proved useful when limited amount of material is available. The test was able to quasi-quantitatively assess both bulk and 3D printed samples and their self-healing behavior. The mechanical and healing behavior of the 3D printed self-healing polyurethane was highly similar to that of the bulk SH polymer. This indicates that the self-healing property of the polymer was retained even after multiple processing steps and printing. Compared to a commercial 3D-printing thermoplastic polyurethane, the self-healing polymer displayed a smaller mechanical dependency on the printing conditions with the added value of healing cuts at room temperature.

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Influence of washing on the adhesion between 3D-printed TPU and woven fabrics

Communications in Development and Assembling of Textile Products ◽

10.25367/cdatp.2021.2.p34-39 ◽

2021 ◽

Vol 2 (1) ◽

pp. 34-39

Author(s):

Jannik Störmer ◽

Daniel Görmer ◽

Andrea Ehrmann

Keyword(s):

3D Printing ◽

Strong Correlation ◽

Thermoplastic Polyurethane ◽

Cotton Fabrics ◽

Woven Fabrics ◽

Textile Fabrics ◽

Fabric Structure ◽

High Adhesion ◽

3D Printed ◽

Textile Fabric

3D printing on textile fabrics can be used to create composites with position-dependent mechanical, water-resistant, magnetic or other properties. An important prerequisite to use such composites technologically or for design purposes is a sufficient adhesion between both materials. While previous studies revealed that soft, elastic printing polymers were advantageous to prepare connections with a high adhesion, not much research has been performed yet on the dependence of the adhesion on textile fabric structure, heat post-treatment, and the influence of washing, which is necessary for most applications of such composites. Here we investigate composites from thermoplastic polyurethane (TPU) 3D-printed on two different woven cotton fabrics. Besides the expected strong correlation of the adhesion with the distance between nozzle and printing bed, we find a higher adhesion on the thinner fabric and an increase in the adhesion after one washing cycle.

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Characterization of PLA/TPU composite filaments manufactured for 3D printing with FDM

Journal of Thermoplastic Composite Materials ◽

10.1177/08927057211062561 ◽

2021 ◽

pp. 089270572110625

Author(s):

Ajay Jayswal ◽

Sabit Adanur

Keyword(s):

3D Printing ◽

Fused Deposition Modeling ◽

Thermoplastic Polyurethane ◽

Tensile Tests ◽

Optical Microscope ◽

Mechanical Analysis ◽

Uniaxial Tensile ◽

Scanning Calorimetry ◽

Fused Deposition ◽

3D Printed

Polylactic acid (PLA) and thermoplastic polyurethane (TPU) were mixed in different proportions and extruded through twin-screw and single-screw extruders to obtain composite filaments to be used for 3D printing with fused deposition modeling (FDM) method. The properties of the filaments were characterized using uniaxial tensile tests, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), rheology, polarized optical microscope (POM), and scanning electron microscope (SEM). 3D printed samples from composite filaments were tested using dynamic mechanical analysis (DMA). It was found that the tensile strength and modulus of the filaments decrease while elongation at break increases with the increasing TPU content in the composite. The analysis also showed a partial miscibility of the polymer constituents in the solution of composite filaments. Finally, a flexible structure, plain weave fabric, was designed and 3D printed using the composite filaments developed which proved that the filaments are well suited for 3D printing.

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Evaluation of the Mechanical Properties of Porous Thermoplastic Polyurethane Obtained by 3D Printing for Protective Gear

Advances in Materials Science and Engineering ◽

10.1155/2019/5838361 ◽

2019 ◽

Vol 2019 ◽

pp. 1-10 ◽

Cited By ~ 2

Author(s):

Hyojeong Lee ◽

Ran-i Eom ◽

Yejin Lee

Keyword(s):

Tensile Strength ◽

3D Printing ◽

Thermoplastic Polyurethane ◽

Three Dimensional ◽

Protective Equipment ◽

Shock Absorption ◽

Protective Gear ◽

Compression Properties ◽

Impact Deformation ◽

3D Printed

Three-dimensional (3D) printing is an efficient and sustainable technology useful in various manufacturing fields. The aim of this study was to investigate the applicability of thermoplastic polyurethane (TPU) as a 3D printing material and the conditions related to the use of TPU as personal protective equipment. The tensile strength, shock absorption, and compressibility were evaluated for different infill and thickness conditions. An increase in the infill rate led to an increase in the tensile strength, regardless of the sample thickness. Similarly, the compression energy increased as the infill increased. Both the shock absorption and compression properties increased as the thickness decreased under identical infill conditions. The actual shock absorption test data were compared to the results of structural analyses, which confirmed the potential for predicting impact deformation through the analysis of the tensile characteristics and the basic properties of a 3D printed material.

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Automated draping analysis of 3D printed flexible isogrid structures for textile applications

Textile Research Journal ◽

10.1177/00405175211006210 ◽

2021 ◽

pp. 004051752110062

Author(s):

Jordan Kalman ◽

Kazem Fayazbakhsh ◽

Danielle Martin

Keyword(s):

Image Processing ◽

3D Printing ◽

Large Range ◽

Thermoplastic Polyurethane ◽

Small Scale ◽

Fused Filament Fabrication ◽

3D Print ◽

3D Printed

Fused filament fabrication (FFF) 3D printing can be used for manufacturing flexible isogrid structures. This work presents a novel draping analysis of flexible 3D printed isogrids from thermoplastic polyurethane (TPU) using image processing. A small-scale multi-camera automated draping apparatus (ADA) is designed and used to characterize draping behavior of 3D printed isogrid structures based on draping coefficient (DC) and mode. Circular specimens are designed and 3D printed that accommodate up to eight additional weights on their perimeters to enhance draping. Five infill patterns, three infill percentages, and three loading cases are explored to evaluate their impact on specimens’ draping coefficient and mode, resulting in 45 tests. The range of DCs in this study is 21.9% to 91.5%, and a large range of draping modes is observed. For the lowest infill percentage, specimen mass is not the sole contributor to the DC values and the infill pattern has a significant impact for the three loading cases. Considering draping modes, the maximum number of convex and concave nodes observed for 25% infill specimens with added weights is three. The draping behavior characterization developed in this study can be followed to design and 3D print new flexible isogrids with textile applications.

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Manufacturing and Examination of Vaginal Drug Delivery System by FDM 3D Printing

Pharmaceutics ◽

10.3390/pharmaceutics13101714 ◽

2021 ◽

Vol 13 (10) ◽

pp. 1714

Author(s):

Petra Arany ◽

Ildikó Papp ◽

Marianna Zichar ◽

Géza Regdon ◽

Mónika Béres ◽

...

Keyword(s):

Drug Delivery ◽

3D Printing ◽

Thermoplastic Polyurethane ◽

Pairwise Comparison ◽

Active Pharmaceutical Ingredient ◽

Dissolution Profile ◽

Vaginal Drug Delivery ◽

Industrial Manufacturing ◽

Vaginal Rings ◽

3D Printed

Vaginal drug delivery systems can provide a long-term and constant liberation of the active pharmaceutical ingredient even for months. For our experiment, FDM 3D printing was used to manufacture the vaginal ring samples from thermoplastic polyurethane filament, which enables fast manufacturing of complex, personalized medications. 3D printing can be an excellent alternative instead of industrial manufacturing, which is complicated and time-consuming. In our work, the 3D printed vaginal rings were filled manually with jellified metronidazole or chloramphenicol for the treatment of bacterial vaginosis. The need for manual filling was certified by the thermogravimetric and heatflow assay results. The manufactured samples were analyzed by an Erweka USP type II Dissolution Apparatus, and the dissolution profile can be distinguished based on the applied jellifying agents and the API’s. All samples were considered non-similar based on the pairwise comparison. The biocompatibility properties were determined by prolonged MTT assay on HeLa cells, and the polymer could be considered non-toxic. Based on the microbiological assay on E. coli metronidazole and chitosan containing samples had bactericidal effects while just metronidazole or just chitosan containing samples bacteriostatic effect. None of these samples showed a fungistatic or fungicide effect against C. albicans. Based on our results, we successfully manufactured 3D printed vaginal rings filled with jellified metronidazole.

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