Injection Using Moldflow - Essay Example

Injection Using MoldflowBrief SummaryThe production of undefaced parts depends on injection processing and mold design. Each mold is designed for a specific plastic grade. This is because each plastic grade has its own characteristic and rheology properties and therefore, producing high quality and outstanding plastic grade parts requires mold design. Additionally, the market is looking for new and better plastics frequently, especially for consumer products and different plastic grades meet different market needs satisfactorily.

To understand the role of mold design, the case of a renowned chair manufacturer that tried to replace plastic grade in a specific mold without considering any modification in the mold is crucial. The process resulted in the production of a failed part and the chair factory requested support to solve this problem from a plastics’ manufacturing company. Deep investigation and analysis with the help of moldflow software were conducted and the conclusion was that the machine used for the production of this chair was incapacitated to produce parts identical to the target grade due to low tonnage capacity[Sho06].

ConclusionNot all plastic have identical physical and rheology properties. As a results, selecting a suitable grade for an application is an essential step before designing molds. Each mold can run only few range of plastic grade within same properties[Sho06]. In general high viscose material like PC need large machine tonnage capacity unlike low viscose material that require lesser machine tonnage.EvaluationSpeakerThe speaker had a clear objective and his findings were presented with lots of confidence as evident in the constant eye contact kept with the audience.

In addition, the speaker confidently verified and ensured that the audience understood his results, while retaining an audible voice. Furthermore, the speaker also allowed the audience to express their opinion, while taking feedback and questions arising from the presentation. As for discussions and knowledge exchange, the presenter used a presentation perspective that encouraged brainstorming amongst participants in the audience.SlidesThe presentation slides had a background that perfectly contrasted the font causing clear and legible slide contents.

In addition, the presenter used a font type and size that was uniform through all slides, while the additional or supporting visuals aids like pictures, graph, and animation slides were characterized by high quality resolution. For the presenter, the high resolution aids permitted the audience to use multiple curves in one graph to assess and understand the variation and comparison analysis as anticipated. The main drawback for this presentation was, the lack of text in the presenter’s slides, and this was supplemented using varying animation files that accounted for the huge number of slides used.

Advance Topics in ABAQUSBrief SummaryABAQUS is a Finite element software used to represent a wide range of physical phenomena virtually. The presenter explained the numerous advanced capabilities that ABAQUS can handle at a glance and this report will comments on two of these items.• Meshing techniques• Translation package for moldflowThese items will be discussed because of their significance in ABAQUS compared to the other items. Furthermore, the items are frequently used in the plastic development and design discipline. a. Meshing TechniquesMeshing is a principal aspect in the performance of any finite element analysis.

The accuracy of the simulation results is high depending on the mesh quality. The default automatic mesh generation provides acceptable results within simple structural analysis and small displacement. However, in large deformation (plastic deformation) and excess distortion of elements, meshing will not be valid anymore as it causes inaccurate outputs, and maybe unacceptable results. Therefore, ABAQUS provides three different alternatives solutions for meshing generation.• Arbitrary Lagrangian-Eulerian (ALE)• Mesh to Mesh Solution mapping (rezoning)• Adaptive remeshingThese three techniques are referred to as adaptive meshing.

Adaptive meshing assists in the optimization or rebuilding of the mesh in order to obtain high quality solution while controlling the analysis cost. The description of each method will be addressed in brief:i. Arbitrary Lagrangian-Eulerian (ALE)This method adapts the aspect of element distortion from the mesh techniques. It maintains the same mesh topology, and therefore the number of elements and nods do not change. The program re-meshes the domain and relocates the nodal coordinates to avoid sharp angles or high aspect ratio of the elements resulting from the loads applied.

Examples of instances where these techniques is applied are Impact, Penetration, Forging, Extrusion and Rolling.ii. Mesh to Mesh Solution mapping (rezoning)Mesh to Mesh is a method available for mapping the results from a specific mesh to a completely different mesh within the same domain. With this process, the number of elements and nodes are not necessarily matched with the original mesh. This method interpolates the findings from the old mesh to the new mesh to resume the analysis. Actually, this method constitutes of two steps.

First is the conversion of the loads on the original mesh at external surface, then re-distribution of the loads and displacement in the new nodes.iii. Adaptive re-meshingThe method adapts the mesh based on output accuracy. Practically, the rate of change in the results between any two elements in the domain indicates where the mesh needs refinement. The refinement process is conducted automatically until the target accuracy is reached. The software will then, evaluate the output error and minimize it to the target level by refining mesh size.

Caution: if you have singularity, the software will run until it crashes. ConclusionThe slides covered the adaptive re-meshing techniques available and demonstrated how to use them. However, the presenter did not dig into theoretical parts of logarithm technique used in each method.b. Translation package for moldflowFor the translation of data from moldflow to ABAQUS; the presenter could not show how to convert or map the results from injection molding process (moldflow software) to ABAQUS for further analysis.

From observation, it was clear that the translation tools required for moldflow to ABAQUS were not available in the basic license. Thus, the presenter tried to run scripts and modify input files to simulate the residual stress resultant from the injection molding process, manually[Sho06]. The goal was to convert displacement fields that were imported from moldflow at a specific location in the domain while displacement acted on specific locations of the part. Finally, the presenter successfully managed to resolve the issue by applying variable pressure on the displacement fields on the new domain.

ConclusionAutomatic Meshing generation tools used in Finite element software is not mature enough to provide accurate results in all physics problems. Verifying the mesh generated by FE software is an essential step of performing successful analysis. ABAQUS has an alogarithm to improve results and time for FE analysis based on element shape, nodes coordinate, and nodes value. Mesh to mesh mapping from external source is not a feature available in ABAQUS basic license.EvaluationSpeakerThe speaker’s appearance was formal and this matched his clear accent of English and voice.

Furthermore, the speaker was well prepared for the topics covered in his slides. Though he lacked a clear understanding of the audience’ level of expertise in the topic and presented an unclear topic objective, the presenter was an expert in the topic and handled all off-road questions professionally. Professionalism was also evident in the presenter’s smooth voice characterized by few fluctuations. However, the smooth voice made it impossible to control the audience and side talk and the distractions caused him to drift away from the main presentation theme frequently.

In order to minimize side talks, the presenter used live examples to demonstrate the topic and this perfectly encouraged discussions and exchange knowledge while causing the audience to be controllable.SlidesThe slides had a clear background that contrasted with font, and the font type and size were uniform through all slides. The presenter supported the presentation using visual aids like pictures, graph, and animation slides. The slides contained high quality resolution aids, while the slides’ text varied from notes to large paragraphs.

3D Printing TechnologyBrief SummaryThe objective of this report is to provide a summary of 3D printing technology speech. The exhibition was led by Stratasys and Autodesk, and targeted the public and home use printers. In general the exhibition showed several newly established small size company and few midsize printer manufacturers, besides the established number of printing service providers. In addition, there were a couple of 3D scanning machines showing in this exhibition and ranging between low to high-resolution scanning systems.

CNC and subtracting technology for making part were also showing in some booths as rapid prototyping solutions. However, high performance and professional 3D printers did not appear in this exhibition. These 3D printers have widely used steel, polymers, and ceramic as raw materials for printing. Nevertheless, there are some companies manufacturing other printers that utilize different material such as concrete, gems, and clay. Technically, there are new and different printing technologies present in the market that include FDM, SLS, SLA, SDL, and Polyjet.

Why is that? There are reasons why we see huge number of low cost printers using FDM today.. Actually, FDM technology patent expired in 2009 thus, several company have the right to use this technique. However, this technology has limitations that will be discussed later in this report. On the other hand, SLS and SLA technology patent expired recently in year 2014. Therefore, more printers will slowly, in the near future, use these technologies as they have more capability compared to FDM. In addition, print part technologies have increased and some of them are discussed below. a. FDM: Fused Deposition ModellingTechnology uses natural convection to solidify melted polymer and is the cheapest technology amongst all print part technologies.b. PolyJet: Multi Nozzles inject liquid polymerThis technology uses UV light to solidify the photopolymer drop from the multi nozzles head and is the preferred choice of multi material in same part among all other print part technologies.c. SLA: Stereo Lithograph ApparatusThis technology uses UV light to solidify Liquid polymer and has the best surface finish of all print part technologies.d. SLS: Selective Laser Sintering These technology uses Laser to melt/solidify the powder polymer, and unlike other technologies, SLS clearly prints the most complex parts.

SpeakerThe speaker was excited to share his information. He spoke English fluently and his voice was audible. He began by presenting an outline, followed by a well-structured topic. The presenter illustrated his topic with high quality pictures and he handled the difficult questions professionally. He kept walking towards the audience and used joke to attract the audience’ attention. He also showed his competence and expertise in this topic as he incorporated live examples to demonstrate the topic.

The presenter also encouraged discussions and knowledge exchange and set the pace by sharing his knowledge in 20 minutes.SlidesThe slides had a clear background that contrasted with the font. The font type and size was also uniform throughout all slides. The text presentation was also supported with high quality illustration slides that contained brief and short sentences.ReferencesSho06: , (Shoemaker, 2006),