SPE Library

The SPE Library contains thousands of papers, presentations, journal briefs and recorded webinars from the best minds in the Plastics Industry. Spanning almost two decades, this collection of published research and development work in polymer science and plastics technology is a wealth of knowledge and information for anyone involved in plastics.

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Conference Proceedings

Piezoelectric Foams With High Thermal Stability And Flexibility

Changchun Zeng, May 2018

This paper discusses the fabrication and characterization of a hybrid piezoelectric foams that exhibit high thermal stability whiling maintaining good flexibility.

In-Situ Visualization Of Crystal Nucleation And Growth Behaviors Of Polylactic-Acid (Pla) Under High Pressure Co2

sandra romero, May 2018

This study investigates the crystallization behaviors of polylactic-acid (PLA) under various CO2 pressures using a high-pressure differential scanning calorimeter and a novel custom-made sliding plate chamber. Results showed that the PLA crystallization growth rate and nucleation density for the PLA/pressurized CO2 system present a peak at the pressure of 3 MPa. Furthermore, PLA’s melting and crystallization temperatures were depressed when subjected to localized shear stress and CO2 pressures.

Kepital® H100

Jim DiVita, May 2018

Korea Engineering Plastics (KEP) expands its already robust line of technical polymers with the introduction of Kepital® H100, a new polyacetal homopolymer. Already a leading producer of polyacetal (POM) copolymers, KEP recognized the need for innovation in the homopolymer category. This is especially important since it has been nearly two decades since the industry last expanded homopolymer capacity. A global solutions provider focused on innovation, KEP is eager to serve those customers looking for best-in-class polyacetal homopolymers.

Super High Flow Valox For Connectors

Kenneth Thiel, May 2018

The high melt flow of polyesters allows the molding of small, intricate parts. PBT has grown well in past years in the electrical/electronics market. There is a trend towards thinner wall connectors to fully utilize space on printed circuit boards and as new designs have emerged for computers and telecommunication devices. While still maintaining heat and mechanical performance of the application.

Modification Of Pla For Improved Layer-To-Layer Adhesion In 3-D Printed Parts

Michael Thompson, May 2018

This study examines the influence that modifying the chemical structure of poly(lactic acid) can have on improving the mechanical properties of a 3-D printed part. A multi-functional chain extender was used to change the polyester such that its rheological response resembled an increasingly branched polymer chain. The modified polyesters were printed into two-layer rectangular specimens and subsequently analyzed for tensile properties as well as adhesive strength by 180 degree peel testing. With increasing chain extender content, the printed specimen exhibited increased toughness and tensile strength, along with greater adhesive strength. The more highly branched, the greater interlayer adhesion as polymer chains diffusion and entangle across the interface.

3D Printed Metal Tool For Efficient Injection Molding

Venkatesha N, May 2018

Additive Manufacturing (AM) is a fast emerging disruptive technology that has potential to redefine the conventional manufacturing processes and supply chain management globally in the future. The fundamental principle of this technology is to build the three dimensional objects directly from the 3D computer models in a layer-by-layer additive manufacturing process. This technology can be used to create prototypes, functional parts, tools and to produce production end user parts in plastic and metal materials.This technical paper will discuss the potential of AM technologies for polymer processing industry and the new space it provides for innovative thinking in plastic application development and the related tooling. At SABIC, metal tools have been 3D printed for cavities and cores with innovative conformal cooling designs. This has helped in improving the efficiency of injection molding process and thus reduced the cycle time. By going a step, further additive tooling was also integrated with heat & cool processing technology to achieve thin-wall molding and better quality parts. We will highlight the benefits of 3D printed tooling in achieving efficient injection molding process with an example case study.

Bonding Strength In Additively Manufactured Multi-Material Plastics Parts

Jakob Onken, May 2018

Multi material additive manufacturing allows the combination of different optical, haptic and mechanical properties in one part. There are several factors influencing the mechanical properties of multi material additively manufactured parts such as the sequence of material deposition, interface temperature, interface roughness and the joining mechanisms of two materials (form closure or material closure). The impact of these parameters on the bonding strength of multi material additively manufactured parts is studied. It is shown that a form closure in combination with a low viscosity of the applied material leads to the highest interfacial bonding. No significant influence of interface temperature and roughness on the bonding strength was observed.

Designing For Industrial 3D Printing

Thomas Davis, May 2018

Additive manufacturing (3D printing) offers tremendous freedom of design with organic geometries, complex features, and internal channels that can be easily created. In order to take full advantage of the benefits, designers must also account for different considerations than with traditional manufacturing. Resolution, surface finish, feature size and build orientation can significantly impact part cost and performance. It is important to first understand the limitations of the processes in order to design accordingly. This presentation will go into detail on the design considerations for direct metal laser sintering (DMLS), stereolithography (SL), and selective laser sintering (SLS), polyjet, and multi jet fusion (MJF) 3D printing.

High Impact Strength Polycarbonate Filament For Additive Manufacturing

Sarah Grieshaber, May 2018

Fused filament fabrication (FFF) is an additive manufacturing technology that uses thermoplastic filament extrusion to build part designs that are often not achievable through other methods such as injection molding. However, the filament material types available for use in FFF on industrial and desktop printers are limited, and mechanical properties such as impact strength can be significantly lower than properties of injection molded parts. This presentation will focus on polycarbonate-based materials used for achieving improved notched Izod impact strength up to four times higher than parts printed with existing filaments at 23 °C and up to three times higher at -30 °C, while maintaining other mechanical properties as well as the ability to function with existing polycarbonate support materials and printer settings. The improvements in impact strength allow this material to be considered for tooling, guides, and fixtures in the automotive and aerospace markets as well as end use parts that require practical toughness during use. An additional benefit for part manufacturers is the potential to reduce part failures during support removal and secondary operations.

A Closed Form Solution For Predicting Final Part Strength Of Fused Deposition Modeling

Steven Devlin, May 2018

This article reviews the development of a molecular healing model coupling squeeze flow and intermolecular diffusion to predict final part strength of thermoplastic parts created using fused filament fabrication (FFF). Additive manufacturing (AM) is an innovative group of technology processes with the potential to help companies design products that meet specific customer requirements. In this research, an experimental study and numerical modeling were developed and utilized to drive and validate a closed form heat transfer solution for FFF processes. Parts were printed from polylactic acid (PLA) at various temperatures and print speeds and tested for tensile strength. These strengths were then used to validate the model. It was found that the coupled model was in good agreement with experimental values for a wide range of extrusion temperatures and higher head speeds.

Influence Of The Layer Time On The Resulting Part Properties In The Fused Deposition Modeling Process

Frederick Knoop, May 2018

The Fused Deposition Modeling (FDM) process by Stratasys is an additive manufacturing (AM) technique that can be used to produce complex thermoplastic parts without the need of a forming tool. A big challenge of this process is that there are several influencing factors with unknown effect on the resulting part properties. One of these factors is the layer time. The aim of this study is to examine the influence of the layer time on the resulting dimensional accuracy and mechanical properties of FDM components manufactured with the amorphous polymer ABS-M30. For this purpose a special job layout was designed to vary the layer time within a certain range. The investigations in this paper show a significant influence on the dimensional accuracy and also on the mechanical properties.

Assessing The Performance Of Continuously Reinforced Acrylonitrile Butadiene Styrene With A Thermotropic Liquid Crystalline Polymer In Fused Filament Fabrication

Mubashir Ansari, May 2018

This work is concerned with the processing of wholly thermoplastic and continuously reinforced filaments in Fused Filament Fabrication (FFF), a form of extrusion based Additive Manufacturing (AM). Acrylonitrile Butadiene Styrene (ABS) was continuously reinforced with a Thermotropic Liquid Crystalline Polymer (TLCP), composed of terephthalic acid (TA), 4-hydroxybenzoic acid (HBA), hydroquinone (HQ) and hydroquinone derivatives (HQ-derivatives), using a novel dual extrusion system. The processing conditions for FFF were determined by performing dynamic mechanical analysis on the pure TLCP. Rectangular specimens were printed using the reinforced filaments with all the roads aligned in one direction. Tensile testing was performed on the filaments as well as the printed specimens to determine improvement in the mechanical properties.

How To Approach Material Validation For Production Parts

Mike Vasquez, May 2018

As more organizations incorporate additive manufacturing systems to produce production parts, it is becoming clear that successfully moving beyond prototyping requires a more advanced and thoughtful material's strategy. To achieve the desired outcomes, organizations now need to learn how to build a methodical and scalable system for measuring and characterizing materials that are going into your processing systems. This talk will discuss best practices and standards for developing and executing a successful strategy for both metals and polymers -- from benchmarking properties, to creating appropriate operating/storage instructions, to testing and then ultimately tracking the lifecycle of materials throughout your production workflow.

3D Printed Capsules For On-Site Formulations

Derrick Smith, May 2018

Drug Product development is a long and expensive process which eventually translates into a higher cost to the payer. Thus, any opportunity to reduce the development timeline is beneficial for the company and the patients. Here, a novel 3D printed (3DP) capsule strategy is disclosed which we believe could enable more informed drug product development with potential to positively impact development timelines. To print these small images, software engineering is required to manufacture defect-free capsules. Additionally, further consideration may be required beyond the normal processing conditions of temperature, speed and quench rate, to realize robust capsules. These capsule walls can be varied to result in burst releases with controlled delay times ranging from immediate to up to 2.5 hours.

Ensuring Mechanical Reliability Of Additively Manufactured Parts Through Testing And Simulation

Mark Oliver, May 2018

Additively manufactured polymers are increasingly being used in mechanically demanding applications. As this trend accelerates, engineers will need to be able to better predict the deformation and failure of polymeric AM materials in service. This involves understanding the properties that often govern failure (fracture, fatigue, creep, etc.) as well as being able to accurately simulate part deformation using finite element analysis.In the first part of this talk, I will discuss how to predict mechanical behavior of polymeric AM parts using non-linear finite element analysis. I will discuss how to measure mechanical behavior, calibrate anisotropic material models, and validate those models using a case study of simulating the strength of a polymeric AM part designed using topology optimization.The second part of my presentation will focus on fatigue and fracture of AM polymers. These properties are not often listed on data sheets but are critical to engineering reliable parts for structural applications. I will present some of the unique attributes of fracture and fatigue in various AM polymers and share new data on materials processes using MJF, CLIP, and SLS.

To Print Or Not To Print, That Is The Additive Manufacturing Question

Jim Allen, May 2018

Additive manufacturing (AM) is becoming a larger part of manufacturing, particularly plastics and metals. New technologies and new materials are being introduced on a regular basis. In a few short years, AM has become a more accepted way of producing end use parts and not just prototypes. How can companies that produce plastic parts stay ahead of the curve? How do you know when to produce a part additively versus injection molding or other more traditional technique? What if there was a tool that did this automatically? 3YOURMIND has developed the first automated AM analysis platform. Now decades of AM experience are available in a streamlined platform to inform smart 3D production decisions.We will talk about:• The use of quantitative methods for evaluation as a key turning point in AM production• How early adopters are actively integrating this new technology• The potential savings in time and money by automating this process• How we envision automated AM evaluation will shift in the industry in the next 3-5 years

Effective Subtraction Before Additive Manufacturing: The Art Of Leveraging Constraints

Ravi Kunju, May 2018

For highly engineered components, the topological shapes that are generated based on the loads and boundary conditions, can be impacted by the many choices of constraints that are set. Over the years Altair’s Optistruct has developed the broadest set of constraints, and has recently introduced ‘overhang’ constraints for 3D printing so the resulting structure is grown to avoid a specified overhang angle (example: of 45 degrees typically), to minimize areas requiring support. Before embarking on creating a topological shape it is necessary to identify the direction of print, which is a sensitive variable by itself. With a variety of constraints available to a designer, a holistic approach needs to be developed wherein the entire process of manufacturing the part, including post processing operations, are carefully considered including the entire geometry that is printed along with the support structure. A fine balance between the interplay of choosing the right constraints, defining design & non-design space, and the right penalty factors, are critical for generating optimal topological shapes that accommodate, for example: areas for holding the 3D printed part for post-processing; or effectively evacuating the powder in plastic printing; or remove supports in metal printing. In this presentation, examples will be highlighted to showcase how to leverage the latest computational methods to efficiently subtract as much before additively manufacturing components, with a goal to develop an effective and repeatable product design strategy.

Material Selection, Testing And Validation Of Additively Manufactured Components

Johannes Wiener, May 2018

In order to successfully develop a structurally loaded component via additive manufacturing it is necessary to include several vital aspects. Currently, most attention is given to the geometrical reproduction of a design with as little deviation as possible. While for parts produced purely for aesthetic reasons or display this may be sufficient, it can lead to poor results for components used in structural or medical applications. Therefore, a careful material selection, rigorous testing and validation have to accompany the whole process, from the idea to the final component. This work presents an overview over the most important aspects that have to be considered for the material selection and testing in extrusion-based additive manufacturing of structural parts.

Structure And Property Relationships Of Additively Manufactured Polyphenylene Sulfide With Carbon Fiber Reinforcement

Peng Liu, May 2018

The objective of this work is to investigate the microstructure of carbon fiber (CF) reinforced polyphenylene sulfide (PPS) resulted from extrusion-based large-scale additive manufacturing (AM) process. This study attempts to establish a fundamental understanding on the role of AM process in transferring a set of intrinsic material properties to the macroscopic properties of the final part. Questions on development of morphology focus on polymer crystal orientation and carbon fiber alignment in proximity to the interface of successive layers. Our findings demonstrated that PPS at the interface has lower crystal perfectness compared to the layer region; the carbon fiber shows higher level of preferred orientation at the interface. Successive layers along the building z-direction present lower storage modulus as it is demonstrated in the dynamic mechanical analysis (DMA).

Critical Capillary Number In A Hyperbolic Converging Nozzle For Polymer Based Additive Manufacturing

Aditya N Sangli, May 2018

Use of immiscible liquids in a polymer based additive manufacturing method is explored. A scaled up version of a converging hyperbolic nozzle is built, and the deformation seen by a droplet of Silicone oil in a bulk fluid of Castor oil is observed. Two different droplet injection positions in the channel are explored. Simulation studies showed the existence of pure extension along the centerline and a combined shear and extensional effect in the offset position. Non-dimensional plots of deformation measures vs. Capillary number showed an asymptotic trend towards a critical Capillary number for the centerline experiments. Offset deployment experiments resulted in a large degree of droplet stretch. These results advance our understanding of immiscible liquid behavior in hyperbolic converging nozzles for additive manufacturing applications