A study on fabrication of nanocomposite polyethylene foam through extrusion foaming procedure

2021 ◽  
pp. 026248932110409
Author(s):  
Milad Rostami ◽  
Taher Azdast ◽  
Rezgar Hasanzadeh ◽  
Milad Moradian
Keyword(s):  
Relative Density ◽  
Cell Density ◽  
Synergetic Effect ◽  
Processing Parameters ◽  
Cooling Condition ◽  
Process Conditions ◽  
Air Cooling ◽  
Foaming Process ◽  
Extrusion Foaming ◽  
Foam Properties

Foaming a polymer not only turns it into a lightweight material but also gives some special properties to it. However, the most important issue is controlling the foaming process to achieve a desirable structure with high cell density and low relative density. In the present study, the extrusion foaming process of polyethylene was studied through stepwise amendments. An innovative extrusion system was designed and implemented to produce extrusion foams under different material and process conditions using N2 as blowing agent. In the first step, the final cooling condition was investigated. The air-cooling condition led to a higher cell density/lower cell size compared to the water-cooling condition although a higher relative density was obtained. In the second step, the effects of the addition of talc and the synergetic effect of talc/nanoclay at different contents were investigated in detail. The hybrid of talc/nanoclay had a noticeably improving effect on the cellular structure. In the third step, the effects of processing parameters including the die temperature and screw speed were studied on the foam properties. Finally, up to 49.4% decrease in the relative density of samples was observed, also cell densities up to 2.5 × 104 cell/cm3 and cell sizes as small as 280 µm were achieved.

Research on the Tensile Properties of Microcellular PS with Supercritical CO2

2013 ◽  
Vol 781-784 ◽  
pp. 395-402
Author(s):  
Xin Liao ◽  
Chang Chun Wang ◽  
Xiao Miao Cao
Keyword(s):  
Tensile Strength ◽  
Relative Density ◽  
Tensile Properties ◽  
Cell Diameter ◽  
Process Conditions ◽  
Structural Variable ◽  
Foaming Process ◽  
Theory Research ◽  
Foaming Temperature ◽  
Foaming Time

Separating the influence of relative density and cell diameter on the tensile properties is very important to the theory research on mechanic properties of microcellular foamed materials. In this article, differences of the influences of relative density and cell diameter on the tensile properties are identified by the foaming PS in constrained mold. The effects of relative density and foaming process conditions such as foaming temperature, foaming time and saturated pressure on the tensile strength and Youngs modulus are analyzed. The results show that relative density is the only structural variable of Youngs modulus and Youngs modulus is not relative to cell diameter. Youngs modulus is in proportion to relative density. Tensile stress of microcellular PS is in contrast to cell diameter, decreases with increasing foaming time and foaming temperature and increases with saturated pressure.

scholarly journals Bitumen Foaming Optimisation Process on the Basis of Rheological Properties

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1854 ◽  
Author(s):  
Marek Iwański ◽  
Grzegorz Mazurek ◽  
Przemysław Buczyński
Keyword(s):  
Half Life ◽  
Expansion Ratio ◽  
Fractional Factorial ◽  
Effective Control ◽  
Maximum Expansion ◽  
Foaming Process ◽  
Original Apparatus ◽  
Foam Properties ◽  
Foamed Bitumen ◽  
Intended Use

This article discusses the results of bitumen foam properties optimisation with respect to three factors: air pressure, bitumen temperature and amount of water. The test materials were unmodified bitumen 50/70 and bitumen 50/70 modified with 2.5% synthetic wax. The experiment was designed according to the 3(3−1) fractional factorial design. The distribution of parameters of bitumen foam were measured with the authors’ original apparatus using a laser beam. This measurement method increased the accuracy of maximum expansion ratio (ER) and half-life (HL) estimation. Based on HL and ER results, it was found that the foaming process increased bitumen stiffness due to the dynamic ageing of the bitumen. The experimental design allows more effective control over the properties of foamed bitumen with respect to its intended use. The presence of synthetic wax extended the half-life of the bitumen foam.

Synthesis of ZnO Nanoparticles via Simple Wet-Chemical Routes

2013 ◽  
Vol 699 ◽  
pp. 133-137 ◽  
Author(s):  
Byeong Woo Lee ◽  
Jin Heui Koo ◽  
Tae Suk Lee ◽  
Yun Hae Kim ◽  
Jae Suk Hwang
Keyword(s):  
Single Phase ◽  
Hydrothermal Process ◽  
Processing Parameters ◽  
Zinc Nitrate ◽  
Precursor Concentration ◽  
Precipitation Process ◽  
Process Conditions ◽  
Crystallite Sizes ◽  
Zno Powders ◽  
Wet Chemical

Zinc oxide (ZnO) powders were synthesized by a simple precipitation and a hydrothermal process at the temperature range RT-100°C. In precipitation process, the powders were formed by mixing aqueous solutions of zinc nitrate with NaOH aqueous solution under controlled process conditions such as precursor concentration, reaction pH and temperature. Single phase ZnO particles can be easily synthesized in lower precursor concentration, higher reaction pH and temperature. The powders synthesized at room temperature exhibited plates, rods or pointed multipod morphologies depending on the concentration and pH. ZnO crystallites synthesized by hydrothermal process consisted mostly of well developed large or elongated crystallites of plates or rods in shape. The results reveal that the ZnO crystallite sizes and shapes would be efficiently controllable by changing the processing parameters of the preparation processes.

Effects of Processing Parameters on Microstructure and Properties of Aluminum-Silicon Alloy ADC12

2018 ◽  
Vol 777 ◽  
pp. 300-305
Author(s):  
Kasem Charoenrut ◽  
Chaiyasit Banjongprasert
Keyword(s):  
Mechanical Properties ◽  
Die Casting ◽  
Processing Parameters ◽  
Shrinkage Porosity ◽  
Process Conditions ◽  
Chemical Compositions ◽  
Silicon Alloy ◽  
Aluminum Silicon Alloy ◽  
Casting Pressure ◽  
Aluminum Silicon

Aluminum-Silicon Alloy, ADC12 is one of the most popular alloys for pressure die casting due to its high castability and high productivity. ADC12 is a hypoeutectic aluminum-silicon alloy that contains 10-12wt% of Si and has an occasional problem for a mechanical properties failure such as crack and shrinkage porosity. This study presents the investigation of the microstructure of ADC12 parts produced by pressured die casting with different process parameters and chemical compositions. The microstructure was observed using optical microscopy (OM) and scanning electron microscopy (SEM) with energy – dispersive X-ray (EDX) and electron backscatter diffraction (EBSD) to determine phases, grain, and crystallographic information in order to understand the microstructural evolution after die casting with different process conditions. Changes in casting pressure and a reduction of iron content contributed to enhanced mechanical properties and less shrinkage porosity. This was due to different processing parameters, mainly casting pressure. The average grain size of aluminum matrix was also reduced due to a higher pressure during casting with a moderately fast cooling rate.

scholarly journals Ultrasonic-Assisted Laser Metal Deposition of the Al 4047Alloy

Metals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1111 ◽  
Author(s):  
Zhang ◽  
Guo ◽  
Chen ◽  
Kang ◽  
Cao ◽  
...  
Keyword(s):  
Relative Density ◽  
Laser Power ◽  
Tensile Ductility ◽  
Processing Parameters ◽  
Metal Deposition ◽  
Ultrasonic Power ◽  
Laser Metal Deposition ◽  
Ultrasonic Assisted ◽  
Cast Alloys ◽  
Cast Parts

Ultrasonic-assisted laser metal deposition(UALMD) technology was used to fabricate Al 4047 parts. The effect of the powder feeding laser power, remelting laser power and ultrasonic power on the relative density of the parts was investigated. The relative density, microstructure and mechanical properties of the specimens obtained by the optimized process parameters were compared with the corresponding properties of the cast alloys. The results showed that dense alloys with a maximum density of 99.1% were prepared using ultrasonic vibration and by remelting the previously deposited layer with the optimized processing parameters, and its density was almost equivalent to that of the cast parts. The microstructure of the samples using optimal laser parameters presented columnar Al dendrites and equiaxed Si particles at the boundary of each deposited layer, while the supersaturated Al solid solution was transformed into equiaxed crystal surrounded by fine fibrous Si phases at the center of the layer. Moreover, the size of the primary Al and the Si particles in the samples produced by UALMD was remarkably refined compared to that of the primary Al and Si particles in the cast structure, resulting in grain refining strengthening. The observed variation in the microstructure had an obvious impact on the tensile properties. The mechanical behavior of the deposit obtained by UALMD revealed superior tensile strength, yield strength and tensile ductility values of 227 ± 3 MPa, 107 ± 4 MPa and 12.2 ± 1.4%, which were approximately 51%, 38% and 56% higher than those of the cast materials, respectively.

scholarly journals Shape-Memory-Recovery Characteristics of Microcellular Foamed Thermoplastic Polyurethane

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 351
Author(s):  
Chang-Seok Yun ◽  
Joo Seong Sohn ◽  
Sung Woon Cha
Keyword(s):  
Shape Memory ◽  
Cell Density ◽  
Shape Recovery ◽  
Structural Changes ◽  
Thermoplastic Polyurethane ◽  
Testing Machine ◽  
Base Material ◽  
Memory Mechanism ◽  
Foaming Process ◽  
Dog Bone

We investigated the shape-recovery characteristics of thermoplastic polyurethane (TPU) with a microcellular foaming process (MCP). Additionally, we investigated the correlation between changes in the microstructure and the shape-recovery characteristics of the polymers. TPU was selected as the base material, and the shape-recovery characteristics were confirmed using a universal testing machine, by manufacturing dog-bone-type injection-molded specimens. TPUs are reticular polymers with both soft and hard segments. In this study, we investigated the shape-memory mechanism of foamed polymers by maximizing the shape-memory properties of these polymers through a physical foaming process. Toward this end, TPU specimens were prepared by varying the gas pressure, foaming temperature, and type of foaming gas in the batch MCP. The effects of internal structural changes were investigated. These experimental variables affected the microstructure and shape-recovery characteristics of the foamed polymer. The generated cell density changed, which affected the shape-recovery characteristics. In general, a higher cell density corresponded to a higher shape-recovery ratio.

Experimental Investigation on the Nickel-Based Metal Components Fabricated by Laser Cladding

2008 ◽  
Vol 375-376 ◽  
pp. 338-342 ◽  
Author(s):  
Xia Ji ◽  
Jian Zhong Zhou ◽  
Hua Feng Guo ◽  
Da Peng Xu
Keyword(s):  
Experimental Investigation ◽  
Laser Cladding ◽  
Orthogonal Design ◽  
Hardness Measurement ◽  
Processing Parameters ◽  
Process Conditions ◽  
Micro Hardness ◽  
Hardness Tester ◽  
Cladding Layer ◽  
Powder Feed

This paper presents an experimental investigation on the metal components fabricated by laser cladding. In the present study, two process of laser cladding were conducted, that is pre-placed powder cladding and coaxial powder-feed cladding. The effect of processing parameters was studied and optimum set of parameters for the superior surface quality was established by employing the orthogonal design. The fabricated components were subjected to metallographic examinations and micro-hardness measurement. Results indicated that the microstructure of coaxial cladding components was finer than pre-placed powder cladding components. The micro-hardness of the fabricated specimen along and vertical the scanning direction were measured using a HVS-1000 micro-hardness tester with a 200 g applied load. Analysis of the physical properties provided further evidence of differences in micro-hardness produced by different process conditions, and the average micro-hardness value of pre-placed power cladding layer was lower than the coaxial powder-feed cladding layer.

Study of the Structure and Oxygen Permeability of Cellulose Packaging Films from NMMO-Solutions

2011 ◽  
Vol 380 ◽  
pp. 148-151
Author(s):  
Pei Fang Cheng ◽  
Jian Qing Wang ◽  
Wen Ming Ren
Keyword(s):  
Fruits And Vegetables ◽  
Oxygen Permeability ◽  
Processing Parameters ◽  
High Oxygen ◽  
Raw Material ◽  
Coagulation Bath ◽  
Process Conditions ◽  
Packaging Films ◽  
Cellulose Films ◽  
And Performance

This paper is concerned with the preparation of cellulose packaging films with high oxygen permeability. The films were prepared from cotton pulp and wood pulp by the cast-wiped method using N-methymorpholine-N-oxide (NMMO) as a solvent. The effects of processing parameters on the structure and performance of cellulose films were also studied. The results show that for optimum processing of the films cotton pulp was the preferred raw material, the optimum pulp concentration in the casting solution was 5%, and the optimum temperature for the coagulation bath was 40°C. Using the above process conditions resulted in packaging films with high oxygen permeability making them suitable for use in packaging fruits and vegetables.

scholarly journals Simulation of Ingotless Rolling-Extruding of Rods from Alloy of Al-Zr System and Investigating into their Properties

2020 ◽  
Vol 837 ◽  
pp. 3-8
Author(s):  
Vadim Bespalov ◽  
Sergey Sidelnikov ◽  
Ruslan Sokolov ◽  
Alexander Chumak ◽  
Denis Voroshilov ◽  
...  
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Computer Simulation ◽  
Software Package ◽  
Processing Parameters ◽  
Process Conditions ◽  
Laboratory Unit ◽  
Deformation Parameters ◽  
3D Software ◽  
Deform 3D

Computer simulation of the process of ingotless rolling-extruding (IRE) of aluminum alloy rods with a content of 0.15% zirconium in the Deform 3D software package performed. The temperature, speed and deformation parameters of the treatment of the investigated alloy determined under different process conditions. To check the adequacy of the models, rod samples were made on a CRE-200 laboratory unit at specified processing parameters. Using the Deform 3D software package, the forces acting on the rolls and the extruding die during the IRE determined and their comparison with tensometric experimental data presented. The mechanical properties, electrical resistivity of semi-finished products after processing by the method of ingotless rolling-extruding and for conditions of their heating to 230 °C investigated. Technological recommendations for the manufacture of deformed semi-finished products using the method of ingotless rolling-extruding are proposed.

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