Production of components through microcellular processing

2021 ◽  
Author(s):  
◽  
Gethin John Llewelyn
Keyword(s):  
Surface Roughness ◽  
Injection Moulding ◽  
Mechanical Performance ◽  
Processing Parameters ◽  
Experimental Results ◽  
Simulation Accuracy ◽  
Foaming Agents ◽  
Blowing Agents ◽  
Blowing Agent ◽  
Microcellular Foams

The manufacture of light weight plastic components is gaining relevance within the polymer industry as component weight savings of up to 15% can be achieved. Foam Injection Moulding (FIM) is one technology solution that delivers weight saving through the introduction of microcellular structures within components. FIM differs from conventional injection moulding whereby blowing agents are added to the polymer during processing to create a cellular structure. The first part of this research aims to benchmark Unfilled and Talc-filled Copolymer Polypropylene (PP) samples through low-pressure FIM. The research analyses the process response when utilising a chemical blowing agent, a physical blowing agent and a novel hybrid foaming (combination of said chemical and physical foaming agents). The experimental results concluded that Unfilled PP foams produced through chemical blowing agent exhibited superior mechanical characteristics due to larger skin wall thicknesses. However, the hybrid foaming produced superior microcellular foams for both PP variations due to calcium carbonate (CaCO3) enhancing the nucleation phase. The next section of research initially varied then subsequently optimised the main processing parameters to determine their effect on Surface Roughness, Young’s Modulus and Tensile Strength. The experimental results show that the mechanical performance can be improved when processing with higher Mould Temperatures and longer Holding Times. Also, when utilising the CBA, surface roughness is comparable to conventionally processed components. The final stage of the research investigated the ability of an industry standard simulation package to accurately predict the process response when processing with a variety of blowing agents. Initial simulations results failed to accurately replicate physical mouldings which can be attributed to microcellular structure overestimations within the simulation. Through an iterative process, simulation settings have been identified that provide clear correlations to improve the simulation accuracy of FIM.

scholarly journals A Design of Experiment Approach for Surface Roughness Comparisons of Foam Injection-Moulding Methods

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2358
Author(s):  
Gethin Llewelyn ◽  
Andrew Rees ◽  
Christian Griffiths ◽  
Martin Jacobi
Keyword(s):  
Surface Roughness ◽  
Injection Moulding ◽  
Surface Defects ◽  
Mechanical Performance ◽  
Processing Parameters ◽  
Melt Temperature ◽  
Foaming Agents ◽  
Pressure Surface ◽  
Blowing Agent ◽  
Physical And Chemical

The pursuit of polymer parts produced through foam injection moulding (FIM) that have a comparable surface roughness to conventionally processed components are of major relevance to expand the application of FIM. Within this study, 22% talc-filled copolymer polypropylene (PP) parts were produced through FIM using both a physical and chemical blowing agent. A design of experiments (DoE) was performed whereby the processing parameters of mould temperatures, injection speeds, back-pressure, melt temperature and holding time were varied to determine their effect on surface roughness, Young’s modulus and tensile strength. The results showed that mechanical performance can be improved when processing with higher mould temperatures and longer holding times. Also, it was observed that when utilising chemical foaming agents (CBA) at low-pressure, surface roughness comparable to that obtained from conventionally processed components can be achieved. This research demonstrates the potential of FIM to expand to applications whereby weight saving can be achieved without introducing surface defects, which has previously been witnessed within FIM.

Study on Surface Roughness Transformation during Metal Rolling

2012 ◽  
Vol 706-709 ◽  
pp. 2517-2522
Author(s):  
Saud Almotairy ◽  
Dong Bin Wei ◽  
Zheng Yi Jiang
Keyword(s):  
Surface Roughness ◽  
Quality Factor ◽  
Processing Parameters ◽  
Experimental Results ◽  
Thin Strip ◽  
Manufacturing Processes ◽  
Strip Surface ◽  
New Findings ◽  
Cold Rolled

Increasing the demand for cold rolled ultra thin strip as feedstock for miniaturized products has encouraged researchers to investigate the ways to increase the quality of such products, especially those related to strip surface roughness. Surface is known as quality factor in most of manufacturing processes. In this paper, the effect of the rolling parameters on the surface roughness transformation during metal rolling has been studied. The experimental results demonstrate that the surface roughness transformation during the metal rolling is highly affected by the designation of the processing parameters such as finishing temperature, reduction, rolling passes and lubrication. The results have been discussed to verify the validity of the new findings.

Study on Surface Roughness Transformation during Metal Rolling

2011 ◽  
Vol 418-420 ◽  
pp. 897-902
Author(s):  
Saud Almotairy ◽  
Dong Bin Wei ◽  
Zheng Yi Jiang
Keyword(s):  
Surface Roughness ◽  
Quality Factor ◽  
Processing Parameters ◽  
Experimental Results ◽  
Thin Strip ◽  
Manufacturing Processes ◽  
Strip Surface ◽  
New Findings ◽  
Cold Rolled

Increasing the demand for cold rolled ultra thin strip as feedstock for miniaturized products has encouraged researchers to investigate the ways to increase the quality of such products, especially those related to strip surface roughness. Surface is known as quality factor in most of manufacturing processes. In this paper, the effect of the rolling parameters on the surface roughness transformation during metal rolling has been studied. The experimental results demonstrate that the surface roughness transformation during metal rolling is highly affected by the designation of the processing parameters such as finishing temperature, reduction, rolling passes and lubrication. The results have been discussed to verify the validity of the new findings.

scholarly journals A Novel Hybrid Foaming Method for Low-Pressure Microcellular Foam Production of Unfilled and Talc-Filled Copolymer Polypropylenes

Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1896 ◽  
Author(s):  
Llewelyn ◽  
Rees ◽  
Griffiths ◽  
Jacobi
Keyword(s):  
Injection Molding ◽  
Mechanical Characteristics ◽  
Low Pressure ◽  
Microcellular Foam ◽  
Foaming Agents ◽  
Blowing Agent ◽  
Weight Saving ◽  
Microcellular Foams ◽  
Foam Injection Molding ◽  
Foam Production

Unfilled and talc-filled Copolymer Polypropylene (PP) samples were produced through low-pressure foam-injection molding (FIM). The foaming stage of the process has been facilitated through a chemical blowing agent (C6H7NaO7 and CaCO3 mixture), a physical blowing agent (supercritical N2) and a novel hybrid foaming (combination of said chemical and physical foaming agents). Three weight-saving levels were produced with the varying foaming methods and compared to conventional injection molding. The unfilled PP foams produced through chemical blowing agent exhibited the strongest mechanical characteristics due to larger skin wall thicknesses, while the weakest were that of the talc-filled PP through the hybrid foaming technique. However, the hybrid foaming produced superior microcellular foams for both PPs due to calcium carbonate (CaCO3) enhancing the nucleation phase.

Effect of Processing Parameters on Surface Roughness in Ultrasonic Deep Rolling 6061-T6 Aluminum Alloy with Longitudinal-Torsional Vibration

2014 ◽  
Vol 722 ◽  
pp. 60-63 ◽  
Author(s):  
Ya Li Hou ◽  
Chuan Shao Liu ◽  
Si Qi Liu
Keyword(s):  
Surface Roughness ◽  
Aluminum Alloy ◽  
Response Surface ◽  
Torsional Vibration ◽  
Mathematic Model ◽  
Processing Parameters ◽  
Experimental Results ◽  
Deep Rolling ◽  
Surface Method ◽  
Orthogonal Experiments

Orthogonal experiments of ultrasonic deep rolling with Longitudinal-torsional vibration (UDR-LTV) and conventional deep rolling (CDR) 6061-T6 aluminum alloy were carried out. The experimental results were analyzed by orthogonal-response surface methodology to study the effects of processing parameters on surface roughness. The results show that the values of surface roughness obtained by UDR-LTV are smaller than that of CDR with the same processing parameters. Meanwhile, feed-rate has a marked effect on surface roughness, and static pressure has a little effect on surface roughness. The quadratic regression method is used to construct the mathematic model of surface roughness based on the experimental results. The interactions between the processing parameters are analyzed using response surface method. The optimal parameters for the lowest surface roughness are given, which provide technical support for proper parameters in practical processing.

Microcellular Polycarbonate with Improved Notched Impact Strength Produced by Injection Moulding with Physical Blowing Agent

2008 ◽  
Vol 27 (6) ◽  
pp. 327-345 ◽  
Author(s):  
A.K. Bledzki ◽  
M. Rohleder ◽  
H. Kirschling ◽  
A. Chate
Keyword(s):  
Impact Strength ◽  
Injection Moulding ◽  
Microcellular Foam ◽  
Processing Technologies ◽  
Compact Material ◽  
Blowing Agent ◽  
Microcellular Foams ◽  
Test Parameters ◽  
Injection Moulding Process ◽  
The Impact

Polycarbonate has the reputation of having a tough breaking behaviour, but it is often unknown that this applies only to special conditions. The impact strength of polycarbonate depends on the temperature, the thickness (with a tough brittle transition at thickness increases), contribution of notch tip radius, impact speed, physical blowing agent, molecular weight of the polymer and the processing parameters. Research results indicated that microcellular foams produced by injection moulding with physical blowing agent (MuCell™ Technology by Trexel) shows significant higher notched impact strength than compact polycarbonate, if the compact material is brittle under the same test parameters. However, if the compact polycarbonate breaks toughly, the notched impact strength of the foamed material is always lower. Therefore, it is highly important to pay attention to the test parameters and conditions when comparing the toughness of the foamed with the compact material. The toughness of microcellular foams shows similar properties to PC/ABS and PC/PP blend systems, which provides the possibility to combine the higher impact strength with the advantages of microcellular foaming like weight reduction, lower shrinkage, shorter cycle times, lower clamp forces and reduced melt viscosity. In order to use technologies and conditions which are applied in the polymer industry, all materials were produced by an injection moulding process. Special processing technologies like gas counter pressure and precision mould opening were used in order to reach microcellular foam structures with cell diameters around 10 μm. These technologies yield exactly adjustable foam morphologies. Special morphologies are required to improve the notched impact strength of the foamed material. Two different equivalent models were extracted from the analyses, which indicate significant higher notched impact strength than the compact material under the same test conditions. The knowledge of the ideal foam morphologies enables the industry to produce foamed materials with improved mechanical properties.

scholarly journals Smoothing additive manufactured parts using ns-pulsed laser radiation

2021 ◽  
Author(s):  
Florian Kuisat ◽  
Fernando Lasagni ◽  
Andrés Fabián Lasagni
Keyword(s):  
Surface Roughness ◽  
Mechanical Performance ◽  
State Of The Art ◽  
Pulsed Laser ◽  
Industrial Applications ◽  
Laser Source ◽  
Pulsed Laser Radiation ◽  
Current State ◽  
The Impact

AbstractIt is well known that the surface topography of a part can affect its mechanical performance, which is typical in additive manufacturing. In this context, we report about the surface modification of additive manufactured components made of Titanium 64 (Ti64) and Scalmalloy®, using a pulsed laser, with the aim of reducing their surface roughness. In our experiments, a nanosecond-pulsed infrared laser source with variable pulse durations between 8 and 200 ns was applied. The impact of varying a large number of parameters on the surface quality of the smoothed areas was investigated. The results demonstrated a reduction of surface roughness Sa by more than 80% for Titanium 64 and by 65% for Scalmalloy® samples. This allows to extend the applicability of additive manufactured components beyond the current state of the art and break new ground for the application in various industrial applications such as in aerospace.

scholarly journals Long-fibre reinforced polymer composites by 3D printing: influence of nature of reinforcement and processing parameters on mechanical performance

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Francis Dantas ◽  
Kevin Couling ◽  
Gregory J. Gibbons
Keyword(s):  
Carbon Fibre ◽  
Polymer Composites ◽  
Mechanical Performance ◽  
Flexural Modulus ◽  
Matrix Material ◽  
Processing Parameters ◽  
Fibre Reinforcement ◽  
Reinforced Polymer ◽  
Unreinforced Material ◽  
Fibre Reinforced Polymer

Abstract The aim of this study was to identify the effect of material type (matrix and reinforcement) and process parameters, on the mechanical properties of 3D Printed long-fibre reinforced polymer composites manufactured using a commercial 3D Printer (Mark Two). The effect of matrix material (Onyx or polyamide), reinforcement type (Carbon, Kevlar®, and HSHT glass), volume of reinforcement, and reinforcement lay-up orientation on both Ultimate Tensile Strength (UTS) and Flexural Modulus were investigated. For Onyx, carbon fibre reinforcement offered the largest increase in both UTS and Flexural Modulus over unreinforced material (1228 ± 19% and 1114 ± 6% respectively). Kevlar® and HSHT also provided improvements but these were less significant. Similarly, for Nylon, the UTS and Flexural Modulus were increased by 1431 ± 56% and 1924 ± 5% by the addition of carbon fibre reinforcement. Statistical analysis indicated that changing the number of layers of reinforcement had the largest impact on both UTS and Flexural Strength, and all parameters were statistically significant.

scholarly journals Fused Deposition Modelling of Fibre Reinforced Polymer Composites: A Parametric Review

2021 ◽  
Vol 5 (1) ◽  
pp. 29
Author(s):  
Narongkorn Krajangsawasdi ◽  
Lourens G. Blok ◽  
Ian Hamerton ◽  
Marco L. Longana ◽  
Benjamin K. S. Woods ◽  
...  
Keyword(s):  
Process Parameters ◽  
Mechanical Performance ◽  
Fibre Length ◽  
Processing Parameters ◽  
Thermoplastic Composite ◽  
Fused Deposition Modelling ◽  
Layer By Layer ◽  
Fused Deposition ◽  
Fibre Reinforced Polymer ◽  
Printing Parameters

Fused deposition modelling (FDM) is a widely used additive layer manufacturing process that deposits thermoplastic material layer-by-layer to produce complex geometries within a short time. Increasingly, fibres are being used to reinforce thermoplastic filaments to improve mechanical performance. This paper reviews the available literature on fibre reinforced FDM to investigate how the mechanical, physical, and thermal properties of 3D-printed fibre reinforced thermoplastic composite materials are affected by printing parameters (e.g., printing speed, temperature, building principle, etc.) and constitutive materials properties, i.e., polymeric matrices, reinforcements, and additional materials. In particular, the reinforcement fibres are categorized in this review considering the different available types (e.g., carbon, glass, aramid, and natural), and obtainable architectures divided accordingly to the fibre length (nano, short, and continuous). The review attempts to distil the optimum processing parameters that could be deduced from across different studies by presenting graphically the relationship between process parameters and properties. This publication benefits the material developer who is investigating the process parameters to optimize the printing parameters of novel materials or looking for a good constituent combination to produce composite FDM filaments, thus helping to reduce material wastage and experimental time.

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