POM/EVA Blends with Future Utility in Fused Deposition Modeling

Polyoxymethylene (POM) is one of the most popular thermoplastic polymers used in the industry. Therefore, the interest in its potential applications in rapid prototyping is understandable. Nevertheless, its low dimensional stability causes the warping of 3D prints, limiting its applications. This research aimed to evaluate the effects of POM modification with ethylene-vinyl acetate (EVA) (2.5, 5.0, and 7.5 wt.%) on its processing (by melt flow index), structure (by X-ray microcomputed tomography), and properties (by static tensile tests, surface resistance, contact angle measurements, differential scanning calorimetry, and thermogravimetric analysis), as well as very rarely analyzed emissions of volatile organic compounds (VOCs) (by headspace analysis). Performed modifications decreased stiffness and strength of the material, simultaneously enhancing its ductility, which simultaneously increased the toughness even by more than 50% for 7.5 wt.% EVA loading. Such an effect was related to an improved linear flow rate resulting in a lack of defects inside the samples. The decrease of the melting temperature and the slight increase of thermal stability after the addition of EVA broadened the processing window for 3D printing. The 3D printing trials on two different printers showed that the addition of EVA copolymer increased the possibility of a successful print without defects, giving space for further development.

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Microstructure Evaluation and Thermal–Mechanical Properties of ABS Matrix Composite Filament Reinforced with Multi-Walled Carbon Nanotubes by a Single Screw Extruder for FDM 3D Printing

Applied Sciences ◽

10.3390/app11198798 ◽

2021 ◽

Vol 11 (19) ◽

pp. 8798

Author(s):

Thai-Hung Le ◽

Van-Son Le ◽

Quoc-Khanh Dang ◽

Minh-Thuyet Nguyen ◽

Trung-Kien Le ◽

...

Keyword(s):

Carbon Nanotubes ◽

Fused Deposition Modeling ◽

Acrylonitrile Butadiene Styrene ◽

Melt Flow Index ◽

Tensile Tests ◽

Flow Index ◽

Fused Deposition ◽

Multi Walled Carbon Nanotubes ◽

Walled Carbon Nanotubes ◽

Composite Filament

This paper reports the synthesis of a new printable ABS–MWCNT composite filament, for use in fused deposition modeling (FDM), using an extrusion technique. Acrylonitrile butadiene styrene (ABS) and multi-walled carbon nanotubes (MWCNTs) were the initial materials used for fabricating the filaments. The MWCNTs were dispersed in ABS resin, then extruded through a single-shaft extruder in filament form, with MWCNT contents of 0.5%, 1%, 1.5%, 2%, 3% or 4% by weight. After extrusion, the diameter of the filaments was about 1.75 mm, making them appropriate for FDM. The as-synthesized filaments were then used in FDM to print out samples, on which tensile tests and other analyses were carried out. The results demonstrate that the sample with 2% MWCNTs had the highest strength value, 44.57 MPa, comprising a 42% increase over that of the pure ABS sample. The morphology and dispersion of MWCNTs in the composite were observed by field emission scanning electron microscopy (FESEM), demonstrating the uniform distribution of MWCNTs in the ABS matrix. The thermal behavior results indicated no significant change in the ABS structure; however, the melt flow index of the filaments decreased with an increase in the MWCNT content.

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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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3D Printed Clamps for In Vitro Tensile Tests of Human Gracilis and the Superficial Third of Quadriceps Tendons

Applied Sciences ◽

10.3390/app11062563 ◽

2021 ◽

Vol 11 (6) ◽

pp. 2563

Author(s):

Ivan Grgić ◽

Vjekoslav Wertheimer ◽

Mirko Karakašić ◽

Željko Ivandić

Keyword(s):

3D Printing ◽

Fused Deposition Modeling ◽

Tensile Tests ◽

Biomechanical Properties ◽

Testing Procedure ◽

Laboratory Equipment ◽

Fused Deposition ◽

Custom Made ◽

3D Printed

Recent soft tissue studies have reported issues that occur during experimentation, such as the tissue slipping and rupturing during tensile loads, the lack of standard testing procedure and equipment, the necessity for existing laboratory equipment adaptation, etc. To overcome such issues and fulfil the need for the determination of the biomechanical properties of the human gracilis and the superficial third of the quadriceps tendons, 3D printed clamps with metric thread profile-based geometry were developed. The clamps’ geometry consists of a truncated pyramid pattern, which prevents the tendons from slipping and rupturing. The use of the thread application in the design of the clamp could be used in standard clamping development procedures, unlike in previously custom-made clamps. Fused deposition modeling (FDM) was used as a 3D printing technique, together with polylactic acid (PLA), which was used as a material for clamp printing. The design was confirmed and the experiments were conducted by using porcine and human tendons. The findings justify the usage of 3D printing technology for parts manufacturing in the case of tissue testing and establish independence from the existing machine clamp system, since it was possible to print clamps for each prepared specimen and thus reduce the time for experiment setup.

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Mechanical, Thermal and Rheological Properties of Polyethylene-Based Composites Filled with Micrometric Aluminum Powder

Materials ◽

10.3390/ma13051242 ◽

2020 ◽

Vol 13 (5) ◽

pp. 1242

Author(s):

Olga Mysiukiewicz ◽

Paulina Kosmela ◽

Mateusz Barczewski ◽

Aleksander Hejna

Keyword(s):

Mechanical Properties ◽

Melt Flow Index ◽

Tensile Tests ◽

Mechanical Analysis ◽

Flow Index ◽

Scanning Calorimetry ◽

Metal Composites ◽

Pre Treatment ◽

The Impact ◽

Properties Of Composites

Investigations related to polymer/metal composites are often limited to the analysis of the electrical and thermal conductivity of the materials. The presented study aims to analyze the impact of aluminum (Al) filler content (from 1 to 20 wt%) on the rarely investigated properties of composites based on the high-density polyethylene (HDPE) matrix. The crystalline structure, rheological (melt flow index and oscillatory rheometry), thermal (differential scanning calorimetry), as well as static (tensile tests, hardness, rebound resilience) and dynamic (dynamical mechanical analysis) mechanical properties of composites were investigated. The incorporation of 1 and 2 wt% of aluminum filler resulted in small enhancements of mechanical properties, while loadings of 5 and 10 wt% provided materials with a similar performance to neat HDPE. Such results were supported by the lack of disturbances in the rheological behavior of composites. The presented results indicate that a significant content of aluminum filler may be introduced into the HDPE matrix without additional pre-treatment and does not cause the deterioration of composites’ performance, which should be considered beneficial when engineering PE/metal composites.

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Comparison of mechanical and morphological properties of 3-D printed functional prototypes: Multi and hybrid blended thermoplastic matrix

Journal of Thermoplastic Composite Materials ◽

10.1177/0892705720925136 ◽

2020 ◽

pp. 089270572092513 ◽

Cited By ~ 2

Author(s):

Sudhir Kumar ◽

Rupinder Singh ◽

TP Singh ◽

Ajay Batish

Keyword(s):

Fused Deposition Modeling ◽

Melt Flow Index ◽

Tensile Specimen ◽

Morphological Properties ◽

Flow Index ◽

Fused Deposition ◽

Type Iv ◽

Deposition Modeling ◽

American Society ◽

Functional Prototype

This article reports the comparison for mechanical and morphological properties of 3-D printed tensile specimen with fused deposition modeling by using multiblended and hybrid blended polylactic acid (PLA) matrix. The multiblended PLA matrix was 3-D printed as tensile specimen (as per American Society for Testing and Materials 638 type IV) comprising of 06 layers (01 layer PLA + 01 layer of PLA + polyvinyl chloride + 02 layers of PLA + wood powder + 02 layers of PLA + Fe3O4) each with layer thickness of 0.53 mm. The hybrid blended PLA matrix was also 3-D printed with similar dimensions and printing conditions. The composition/proportion of hybrid blended and multimaterial blended matrix has been selected on the basis of similar melt flow index (MFI) range and the final matrix was compared on basis of equal number of layers (06), similar rheological range (MFI: 40–45 g/10 min) and volume of product (same dimension of prototype). The results of study suggested that the 3-D printed functional prototype of multiblended PLA matrix has better mechanical and morphological properties than hybrid blended PLA matrix. The peak strength and break strength of hybrid blend-based prototype were observed to be 29.56 MPa and 26.60 MPa, respectively, whereas for the multimaterial-based functional prototypes, it was 46.28 MPa and 41.65 MPa, respectively. The results are also supported with scanning electron microscopy-based images, 3-D rendered images, and energy-dispersive X-ray analysis analysis.

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Thermomechanical investigations of PEKK-HAp-CS composites

Proceedings of the Institution of Mechanical Engineers Part H Journal of Engineering in Medicine ◽

10.1177/0954411919877979 ◽

2019 ◽

Vol 233 (11) ◽

pp. 1196-1203

Author(s):

Rupinder Singh ◽

Gurchetan Singh ◽

Jaskaran Singh ◽

Ranvijay Kumar ◽

Md Mustafizur Rahman ◽

...

Keyword(s):

Melt Flow Index ◽

Extrusion Process ◽

Flow Index ◽

Fused Deposition Modelling ◽

Index Test ◽

Melt Flow ◽

Scanning Calorimetry ◽

Fused Deposition ◽

Ether Ketone ◽

Input Variables

In this experimental study, a composite of poly-ether-ketone-ketone by reinforcement of hydroxyapatite and chitosan has been prepared for possible applications as orthopaedic scaffolds. Initially, different weight percentages of hydroxyapatite and chitosan were reinforced in the poly-ether-ketone-ketone matrix and tested for melt flow index in order to check the flowability of different compositions/proportions. Suitable compositions revealed by the melt flow index test were then taken forward for the extrusion of filament required for fused deposition modelling. For thermomechanical investigations, Taguchi-based design of experiments has been used with input variables in the extrusion process as follows: temperature, load applied and different composition/proportions. The specimens in the form of feedstock filament produced by the extrusion process were made to undergo tensile testing. The specimens were also inspected by differential scanning calorimetry and photomicrographs. Finally, the specimen showing the best performance from the thermomechanical viewpoint has been selected to extrude the filament for the fused deposition modelling process.

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Medical-Grade PCL Based Polyurethane System for FDM 3D Printing—Characterization and Fabrication

Materials ◽

10.3390/ma12060887 ◽

2019 ◽

Vol 12 (6) ◽

pp. 887 ◽

Cited By ~ 20

Author(s):

Agnieszka Haryńska ◽

Justyna Kucinska-Lipka ◽

Agnieszka Sulowska ◽

Iga Gubanska ◽

Marcin Kostrzewa ◽

...

Keyword(s):

3D Printing ◽

Fused Deposition Modeling ◽

Extrusion Process ◽

C2c12 Cells ◽

Hexamethylene Diisocyanate ◽

Scanning Calorimetry ◽

Thermoplastic Polyurethanes ◽

Fused Deposition ◽

Medical Grade

The widespread use of three-dimensional (3D) printing technologies in medicine has contributed to the increased demand for 3D printing materials. In addition, new printing materials that are appearing in the industry do not provide a detailed material characterization. In this paper, we present the synthesis and characterization of polycaprolactone (PCL) based medical-grade thermoplastic polyurethanes, which are suitable for forming in a filament that is dedicated to Fused Deposition Modeling 3D (FDM 3D)printers. For this purpose, we synthesized polyurethane that is based on PCL and 1,6-hexamethylene diisocyanate (HDI) with a different isocyanate index NCO:OH (0.9:1, 1.1:1). Particular characteristics of synthesized materials included, structural properties (FTIR, Raman), thermal (differential scanning calorimetry (DSC), thermogravimetric analysis (TGA)), mechanical and surfaces (contact angle) properties. Moreover, pre-biological tests in vitro and degradation studies were also performed. On the basis of the conducted tests, a material with more desirable properties S-TPU(PCL)0.9 was selected and the optimization of filament forming via melt-extrusion process was described. The initial biological test showed the biocompatibility of synthesized S-TPU(PCL)0.9 with respect to C2C12 cells. It was noticed that the process of thermoplastic polyurethanes (TPU) filaments forming by extrusion was significantly influenced by the appropriate ratio between the temperature profile, rotation speed, and dosage ratio.

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Tuning of HDPE Properties for 3D Printing

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.773.67 ◽

2018 ◽

Vol 773 ◽

pp. 67-71 ◽

Cited By ~ 3

Author(s):

Paweesinee Chatkunakasem ◽

Panisa Luangjuntawong ◽

Aphiwat Pongwisuthiruchte ◽

Chuanchom Aumnate ◽

Pranut Potiyaraj

Keyword(s):

3D Printing ◽

Melt Flow Index ◽

Flow Index ◽

Melt Blending ◽

X Ray Diffraction ◽

Screw Extruder ◽

Scanning Calorimetry ◽

Crystalline Polymers ◽

Twin Screw ◽

Low Crystalline

The objective of this study is to improve high density polyethylene (HDPE) properties for 3D printing by addition of graphene and low density polyethylene (LDPE). Graphene was prepared by modified Hummer’s method. The prepared graphene was characterized by the infrared spectroscopy and the X-ray diffraction analysis (XRD). Graphene/HDPE and LDPE/HDPE composites were successfully prepared through the melt-blending technique using a twin-screw extruder. The melt flow index (MFI) and differential scanning calorimetry (DSC) were employed to characterize neat HDPE and the modified HDPE. FTIR and XRD results show that graphite was successfully changed into graphene completely and MFI of graphene/HDPE and LDPE/HDPE decreased as the amount of graphene and LDPE in the composite blends increased. DSC results show that the addition of low crystalline polymers can reduce a crystallization temperature and crystallinity content.

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On comparison of recycled LDPE and LDPE–bakelite composite based 3D printed patch antenna

Proceedings of the Institution of Mechanical Engineers Part L Journal of Materials Design and Applications ◽

10.1177/14644207211060465 ◽

2021 ◽

pp. 146442072110604

Author(s):

Rupinder Singh ◽

Sanjeev Kumar ◽

Amrinder Pal Singh ◽

Yang Wei

Keyword(s):

Patch Antenna ◽

Fused Deposition Modeling ◽

Melt Flow Index ◽

Attenuated Total Reflection ◽

Flow Index ◽

Patch Antennas ◽

Sensor Applications ◽

Fused Deposition ◽

Sensing Applications ◽

3D Printed

In the past two decades number of studies have been reported on the use of thermoplastics as a substrate for 3D printed patch antennas. However, no work has been reported on the thermoplastic-thermosetting composite-based substrate for 3D printed patch antennas and their mechanical, morphological, rheological, and radiofrequency (RF) characterization for sensing applications. In this study low-density polyethylene (LDPE) and LDPE-5% bakelite (BAK) composite-based patch antenna (resonating frequency 2.45 GHz) were printed (for secondary recycling) on fused deposition modeling (FDM) setup. The RF characteristics were measured using a vector network analyzer (VNA). Ring resonator test was used for measuring the dielectric properties of substrates (which suggests that the dielectric constant ([Formula: see text]) and loss tangent ([Formula: see text]) for LDPE was 2.282 and 0.0045, whereas for LDPE-5%BAK the calculated [Formula: see text] and [Formula: see text] was 2.0663, 0.0051 respectively). This study highlights that for the LDPE-5%BAK composite there was a marginal increase in the size of the patch antenna; but this resulted in improved transmittance, gain, and return loss for typical sensor applications. As regards to printability of substrate, 5% BAK resulted in a melt flow index (MFI) of 9.96 g/10 min in contrast to 12.208 g/10 min for a neat LDPE sample. The selected LDPE-5%BAK composite resulted in peak strength (PS) and break strength (BS) of 16.08 MPa and 14.47 MPa (at 180 °C screw temperature, 110 rpm, and 11 kg load) while processing with a twin-screw extruder (TSE), which was observed better than the neat LDPE (PS 11.98 MPa, BS 10.79 MPa). The results were supported with porosity (%), surface roughness (Ra) analysis based upon scanning electron microscopy (SEM) and bond strength using attenuated total reflection (ATR) based Fourier transformed infrared (FTIR) analysis.

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Fused Deposition Modeling of Polyamides: Crystallization and Weld Formation

Polymers ◽

10.3390/polym12122980 ◽

2020 ◽

Vol 12 (12) ◽

pp. 2980

Author(s):

Andrea Costanzo ◽

Umberto Croce ◽

Roberto Spotorno ◽

Seif Eddine Fenni ◽

Dario Cavallo

Keyword(s):

3D Printing ◽

Crystallization Kinetics ◽

Fused Deposition Modeling ◽

Degree Of Crystallinity ◽

Temperature History ◽

Weld Strength ◽

Processing Conditions ◽

Scanning Calorimetry ◽

Fused Deposition ◽

Deposition Modeling

International newspapers and experts have called 3D printing the industrial revolution of this century. Among all its available variants, the fused deposition modeling (FDM) technique is of greater interest since its application is possible using simple desktop printers. FDM is a complex process, characterized by a large number of parameters that influence the quality and final properties of the product. In particular, in the case of semicrystalline polymers, which afford better mechanical properties than amorphous ones, it is necessary to understand the crystallization kinetics as the processing conditions vary, in order to be able to develop models that allow having a better control over the process and consequently on the final properties of the material. In this work it was proposed to study the crystallization kinetics of two different polyamides used for FDM 3D printing and to link it to the microstructure and properties obtained during FDM. The kinetics are studied both in isothermal and fast cooling conditions, thanks to a home-built device which allows mimicking the quenching experienced during filament deposition. The temperature history of a single filament is then determined by mean of a micro-thermocouple and the final crystallinity of the sample printed in a variety of conditions is assessed by differential scanning calorimetry. It is found that the applied processing conditions always allowed for the achievement of the maximum crystallinity, although in one condition the polyamide mesomorphic phase possibly develops. Despite the degree of crystallinity is not a strong function of printing variables, the weld strength of adjacent layers shows remarkable variations. In particular, a decrease of its value with printing speed is observed, linked to the probable development of molecular anisotropy under the more extreme printing conditions.

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