Evaluation of Thermal Properties of 3D Spacer Technical Materials in Cold Environments using 3D Printing Technology

Novel materials have been recently developed for coping with various environmental factors. Generally, to improve the thermal comfort to humans in cold environments, securing an air layer is important. Therefore, this study analyzed the thermal properties of 3D spacer technical materials, 3D printed using thermoplastic polyurethane, according to the structural changes. Four 3D spacer technical material structures were designed with varying pore size and thickness. These samples were moved into a cold climate chamber (temperature 5 ± 1 °C, relative humidity (60 ± 5)%, wind velocity 0.2 m/s) and placed on a heating plate set to 30 °C. The surface and internal temperatures were measured after 0, 10, 20, and 30 min and then 10 min after turning off the heating plate. When heat was continuously supplied, the 3D spacer technical material with large pores and a thick air layer showed superior insulation among the materials. However, when no heat was supplied, the air gap thickness dominantly affected thermal insulation, regardless of the pore size. Hence, increasing the air gap is more beneficial than increasing the pore size. Notably, we found that the air gap can increase insulation efficiency, which is of importance to the new concept of 3D printing an interlining.

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The research of the thermal and mechanical properties of materials produced by 3D printing method

Thermal Science ◽

10.2298/tsci19s4211g ◽

2019 ◽

Vol 23 (Suppl. 4) ◽

pp. 1211-1216

Author(s):

Adam Gnatowski ◽

Agnieszka Kijo-Kleczkowska ◽

Henryk Otwinowski ◽

Piotr Sikora

Keyword(s):

Mechanical Properties ◽

Thermal Properties ◽

3D Printing ◽

Thermoplastic Polyurethane ◽

Polymeric Materials ◽

Poly Lactic Acid ◽

Thermal And Mechanical Properties ◽

Scanning Calorimetry ◽

Properties Of Materials ◽

Butadiene Styrene

A comparative analysis of thermal properties of semi-crystalline and amorphous polymeric materials was carried out. Samples were produced using 3D printing technology on the SIGNAL-ATMAT printer. The following polymeric materials were used to make the samples: thermoplastic polyurethane elastomer, acryloni-trile-butadiene-styrene copolymer, Laywood, ethylene terephthalate, poly (lactic acid). The materials were tested for their thermal and mechanical properties. The research included the analysis of thermal properties by differential scanning calorimetry of manufactured materials. The tensile strength also was determined.

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The Changes in Thermal Transmittance of Window Insulating Glass Units Depending on Outdoor Temperatures in Cold Climate Countries

Energies ◽

10.3390/en14061694 ◽

2021 ◽

Vol 14 (6) ◽

pp. 1694

Author(s):

Karolis Banionis ◽

Jurga Kumžienė ◽

Arūnas Burlingis ◽

Juozas Ramanauskas ◽

Valdas Paukštys

Keyword(s):

Thermal Properties ◽

Peak Power ◽

Cold Climate ◽

External Temperature ◽

Modern Times ◽

Thermal Transmittance ◽

Cold Environments ◽

U Value ◽

Design Value ◽

Glass Unit

Windows, which have a U-value that is governed by an insulating glass unit (IGU) U-value, must be a building’s only enclosure element, which has no design value concept. The declared U-value, which is calculated or measured with 0 °C of external ambient temperature, is used instead of the design value. For most of a building’s elements, its thermal transmittance with a decrease in the external temperature diminishes a little, i.e., improves. However, for modern window IGUs with Low-E coatings, it is the opposite: the thermal transmittance with a lowering external temperature increases. Therefore, for calculating the peak power for the heating of buildings it is necessary to pay attention to this phenomenon and, therefore, it would be wise to introduce the concept of design U-value for windows, recalculation rules, or affix their declared U-values. This is especially the case in modern times with the prevailing architectural tendencies for enlargement of transparent building elements. For IGUs with Low-E coatings and inert gas fillers, the thermal transmittance depends on the temperature difference between warm and cold environments. When the external temperature is −30 °C instead of 0 °C, the thermal transmittance of the IGU can increase by up to 35%. This study presents the thermal properties of windows’ IGUs depending on the changes in outdoor temperatures by using guarded a hot box climate chamber and presents the proposed simplified methodology for determining the thermal properties of windows’ glass units. The accuracy of the composed simplified methods, comparing the calculated thermal transmittances of IGUs with those measured in the “hot box”, were up to 1.25%.

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Structural and thermal properties of the amaranth starch granule obtained by high-impact wet milling

International Journal of Food Engineering ◽

10.1515/ijfe-2020-0024 ◽

2020 ◽

Vol 0 (0) ◽

Author(s):

Diego Fernando Roa Acosta ◽

José Fernando Solanilla Duque ◽

Lina Marcela Agudelo Laverde ◽

Héctor Samuel Villada Castillo ◽

Marcela Patricia Tolaba

Keyword(s):

Thermal Properties ◽

Structural Changes ◽

Starch Granule ◽

Amorphous Region ◽

Extraction Yield ◽

High Impact ◽

Degree Of Crystallinity ◽

Wet Milling ◽

Starch Structure ◽

Structure Changes

AbstractIn this study, amaranth starch was extracted by high-impact wet milling and its structural and thermal properties and the effect of NaOH and SDS concentrations on extraction yield were evaluated. The best condition was 55 g of starch/100 g of amaranth, with a decrease from 2.5 to 3.5 kJ/g using different milling energies. The decrease in the protein content of the starch granule is due to an effect of the interaction between surfactant and alkali, preventing the destruction of granules. All starches presented a degree of crystallinity between 21 and 28%. The internal structural changes of the starch granule were monitored by attenuated total reflectance - Fourier-transform infrared (ATR-FTIR) in the region of 990 to 1060 cm−1. Spectra showed significant differences between the peaks at 1032 and 1005 cm−1, corresponding to the crystalline/amorphous region of the starch structure. Changes in viscosity profiles were observed between 0.302 and 1.163 Pa s.

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Effects of 3D Printing-Line Directions for Stretchable Sensor Performances

Materials ◽

10.3390/ma14071791 ◽

2021 ◽

Vol 14 (7) ◽

pp. 1791

Author(s):

Chi Cuong Vu ◽

Thanh Tai Nguyen ◽

Sangun Kim ◽

Jooyong Kim

Keyword(s):

3D Printing ◽

Thermoplastic Polyurethane ◽

Three Dimensional ◽

Optimal Solution ◽

Human Motion ◽

Repeated Measurements ◽

Fused Filament Fabrication ◽

And Performance ◽

The Times ◽

Stretchable Sensors

Health monitoring sensors that are attached to clothing are a new trend of the times, especially stretchable sensors for human motion measurements or biological markers. However, price, durability, and performance always are major problems to be addressed and three-dimensional (3D) printing combined with conductive flexible materials (thermoplastic polyurethane) can be an optimal solution. Herein, we evaluate the effects of 3D printing-line directions (45°, 90°, 180°) on the sensor performances. Using fused filament fabrication (FDM) technology, the sensors are created with different print styles for specific purposes. We also discuss some main issues of the stretch sensors from Carbon Nanotube/Thermoplastic Polyurethane (CNT/TPU) and FDM. Our sensor achieves outstanding stability (10,000 cycles) and reliability, which are verified through repeated measurements. Its capability is demonstrated in a real application when detecting finger motion by a sensor-integrated into gloves. This paper is expected to bring contribution to the development of flexible conductive materials—based on 3D printing.

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Preparation and Characterization of Talc Filled Thermoplastic Polyurethane/Polypropylene Blends

Journal of Polymers ◽

10.1155/2014/289283 ◽

2014 ◽

Vol 2014 ◽

pp. 1-8 ◽

Cited By ~ 7

Author(s):

Emi Govorčin Bajsić ◽

Vesna Rek ◽

Ivana Ćosić

Keyword(s):

Thermal Properties ◽

Thermoplastic Polyurethane ◽

Mechanical Analysis ◽

Degree Of Crystallinity ◽

Scanning Calorimetry ◽

Polypropylene Blends ◽

Pp Blends ◽

The Degree Of Crystallinity ◽

Better Than

The effect of the addition of talc on the morphology and thermal properties of blends of thermoplastic polyurethane (TPU) and polypropylene (PP) was investigated. The blends of TPU and PP are incompatible because of large differences in polarities between the nonpolar crystalline PP and polar TPU and high interfacial tensions. The interaction between TPU and PP can be improved by using talc as reinforcing filler. The morphology was observed by means of scanning electron microscopy (SEM). The thermal properties of the neat polymers and unfilled and talc filled TPU/PP blends were studied by using dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). The addition of talc in TPU/PP blends improved miscibility in all investigated TPU/T/PP blends. The DSC results for talc filled TPU/PP blends show that the degree of crystallinity increased, which is due to the nucleating effect induced by talc particles. The reason for the increased storage modulus of blends with the incorporation of talc is due to the improved interface between polymers and filler. According to TGA results, the addition of talc enhanced thermal stability. The homogeneity of the talc filled TPU/PP blends is better than unfilled TPU/PP blends.

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Mechanical and Thermal Properties of Kenaf Reinforced Thermoplastic Polyurethane (TPU)-Natural Rubber (NR) Composites

Fibers and Polymers ◽

10.1007/s12221-018-7737-7 ◽

2018 ◽

Vol 19 (2) ◽

pp. 446-451 ◽

Cited By ~ 10

Author(s):

A. M. Noor Azammi ◽

S. M. Sapuan ◽

M. R. Ishak ◽

M. T. H. Sultan

Keyword(s):

Thermal Properties ◽

Natural Rubber ◽

Thermoplastic Polyurethane ◽

Mechanical And Thermal Properties

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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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3D Printed SiOC(N) Ceramic Scaffolds for Bone Tissue Regeneration: Improved Osteogenic Differentiation of Human Bone Marrow-Derived Mesenchymal Stem Cells

International Journal of Molecular Sciences ◽

10.3390/ijms222413676 ◽

2021 ◽

Vol 22 (24) ◽

pp. 13676

Author(s):

Yuejiao Yang ◽

Apoorv Kulkarni ◽

Gian Domenico Soraru ◽

Joshua M. Pearce ◽

Antonella Motta

Keyword(s):

Stem Cells ◽

Mesenchymal Stem Cells ◽

3D Printing ◽

Pore Size ◽

Osteogenic Differentiation ◽

Bone Tissue ◽

Low Cost ◽

Human Mesenchymal Stem Cells ◽

Bone Tissue Regeneration ◽

Gene Expressions

Bone tissue engineering has developed significantly in recent years as there has been increasing demand for bone substitutes due to trauma, cancer, arthritis, and infections. The scaffolds for bone regeneration need to be mechanically stable and have a 3D architecture with interconnected pores. With the advances in additive manufacturing technology, these requirements can be fulfilled by 3D printing scaffolds with controlled geometry and porosity using a low-cost multistep process. The scaffolds, however, must also be bioactive to promote the environment for the cells to regenerate into bone tissue. To determine if a low-cost 3D printing method for bespoke SiOC(N) porous structures can regenerate bone, these structures were tested for osteointegration potential by using human mesenchymal stem cells (hMSCs). This includes checking the general biocompatibilities under the osteogenic differentiation environment (cell proliferation and metabolism). Moreover, cell morphology was observed by confocal microscopy, and gene expressions on typical osteogenic markers at different stages for bone formation were determined by real-time PCR. The results of the study showed the pore size of the scaffolds had a significant impact on differentiation. A certain range of pore size could stimulate osteogenic differentiation, thus promoting bone regrowth and regeneration.

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