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

MELT FRACTURE BEHAVIOR OF PLA FOAMED USING DIFFERENT DIE ENTRY ANGLES

Lun Howe Mark, Mo Xu, Chul B. Park, May 2012

This investigation focuses on effects of die entry angles on the melt fracture behavior of foamed Polylactic Acid (PLA). PLA is foamed using a physical blowing agent along with four dies with varying entry angles. The dies used in this study have entry angles of 60, 90, 120, and 180 degrees. A camera is placed at the die exit to capture snapshots of the extrudate to examine the nature of melt fracture.

FOAM INJECTION MOLDING OF GLASS FIBER REINFORCED POLYPROPYLENE COMPOSITES

Peter U. Jung, Chul B. Park, May 2012

This paper investigates the effects of the processing conditions on the foaming behavior of glass fiber reinforced polypropylene. Composites are injection molded by using an advanced structural foam molding machine with N2 as blowing agent. Samples are prepared with different processing parameters while mold pressure, void fraction and foam morphology are characterized. The results suggest that there is an optimal combination of these processing parameters, which can provide uniform void fraction and high cell density.

THE EFFECT OF CO2 ON THE MELT FRACTURE BEHAVIOR OF FOAMED PLA

Lun Howe Mark, Mo Xu, Medhi Keshtkar, Chul B. Park, May 2012

The melt fracture behavior of foamed Polylactic acid (PLA) with the presence of blowing agent is studied in this investigation. A CCD camera is utilized to examine how foaming processing parameters such as blowing agent content, mass flow rate and temperature can affect melt fracture behavior. Images captured are used to analyze severity and nature of extrudate distortion.

FEASIBILITY OF DOUBLE CRYSTAL MELTING PEAK GENERATION IN PLA FOR EXPANDED PLA BEAD FOAMS

Mohammadreza Nofar, Chul B. Park, May 2012

As the EPP and EPE bead foams have two crystal melting peaks, in order to manufacture expanded PLA bead foam (EPLA) with the same strategy, the feasibility of double crystal melting peak creation for PLA has been investigated in this work. The influence of various annealing temperatures and time on the double crystal melting peak creation is investigated for a linear and a branched PLA with two various degrees of crystallinity in a regular differential scanning calorimeter (DSC).

WIPER MOTOR DRIVE GEAR FAILURE ANALYSIS AND RESOLUTION

Mark A. Bennett, Todd Stromer, Joseph Kelly, May 2012

The global world of component sourcing offers many benefits to the supply chain, but can create obstacles to resolving quality problems and addressing failures. This paper describes a challenging failure analysis involving overseas manufacturing, extended usage prior to failure, an uncontrolled user environment, and only occasional failures. We discuss the investigation of the product, generation of the failure hypothesis, testing, recommendations and resolution of the issues.

IMPLEMENTATION OF A HIGHLY EFFICIENT MESHLESS METHOD FOR THE THERMAL ANALYSIS OF FOUNTAIN FLOW DURING FILLING IN INJECTION MOLDING

Juliana Restrepo, Iván D. López, May 2012

A computational model using a highly efficient local meshless technique to analyze the temperature development during a 2D slit filling is developed. Moving boundaries and the fountain flow effect are considered. The implementation is validated comparing the results with a finite element solution for a fix domain. The fountain flow thermal effect is studied, comparing the solution considering and neglecting this effect.

ASSESSMENT OF A NOVEL CO-POLYESTER RESIN THAT EXHIBITS EARLY STRAIN HARDENING BEHAVIOR

Mark A. Barger, William J. Harris, May 2012

A hydroquinone modified co-polyester resin has been shown to exhibit early strain hardening behavior relative to conventional PET analogues based on equibiaxial film stretching data. This behavior was hypothesized to offer advantages in specific blow molding processing aspects, especially preform molding. A study was completed to validate this hypothesis and to better quantify the advantages that could be ascribed to early strain hardening behavior. The results of this study are reported herein.

CREATING MOLECULAR REBAR FROM MULTI-WALL CARBON NANOTUBES

Kurt W. Swogger, Clive Bosnyak,, May 2012

Multi-wall carbon nanotubes have created much interest in theory but lack till now many applications that can create value. Designed Nanotubes has invented a process to produce high aspect ratio nanotubes in high yields called Molecular Rebar that can interact with materials and dramatically change mechanical, electrical, and heat properties of the materials demonstrating that the theory does work. Applications include tires (in development), batteries, composites and capacitors.

THE EFFECT OF TOOLING ALLOY ON THE PHYSICAL PROPERTIES OF AUTOMOTIVE POLYOLEFINS

David A. Okonski, May 2012

It is common in the automotive industry to produce injection molds from P20 steel. However, several 7,0XX-series aluminum alloys have been identified by GM as P20 alternatives. The high thermal conductivity and excellent machining characteristics of these aluminums are enablers for cost reduction. Cost reduction is only good if there is no adverse effect on quality and performance. This paper will compare and contrast physical properties of samples molded using duplicate P20 and QC10 tooling.

TROUBLESHOOTING TPU EXTRUSION FOR RATE LIMITATIONS DUE TO SOLIDS IN THE EXTRUDATE

Kun Sup Hyun, Mark A. Spalding, May 2012

The extrusion of thermoplastic polyurethane (TPU) resins can be rate limited by the occurrence of solid polymer fragments in the extrudate. This paper will discuss the problem and identify a screw and process design that can mitigate the problem and allow high rates.

DESIGN INNOVATIONS OF HIGH DENSITY POLYETHYLENE PIPE GRADE RESINS

Sarah E. Patterson, Mark A. Spalding, May 2012

The continued innovations in the molecular design of high density polyethylene resins have resulted in the development of PE 4710 bimodal resins. These high density bimodal resins have improved the physical attributes of polyethylene pipe such as increased durability, longer design life, increased pressure rating, and increased hydraulic capacity for plastic piping systems. In addition, the high performance achieved can be leveraged to various applications that require the same physical attributes.

RIGID POLYMERIC FOAM BOARDSTOCK TECHNICAL ASSESSMENT

Dan Schroer, Michelle Hudack, Mark Soderquist, Inken Beulich, May 2012

Phenolic foam insulation is commercially available in Europe and Asia. Recently, a study was conducted that assessed the performance of European and Asian sourced phenolic foam versus North American extruded polystyrene (XPS), and polyisocyanurate (PIR) insulation products. This paper discusses the performance aspects of Phenolic foam insulation relative to both polyisocyanurate (PIR) and extruded polystyrene (XPS) foam. The findings are summarized and discussed herein: POLYMER ANALYSIS D33

NEW METHOD TO DETECT COLD FUSION JOINTS IN HIGH DENSITY POLYETHYLENE PIPE

Robert Stakenborgh, May 2012

This paper describes an innovative apparatus and method that uses electromagnetic energy in the microwave frequency range to volumetrically examine dielectric materials, including high density polyethylene piping fusion joints. This paper describes the theory of use and presents several HDPE inspection case studies. Specifically, this paper describes the mechanics of cold fusion joint detection and in several cases the inspection results are compared to mechanical test results that confirm the accuracy of the examination.

NEW DEVELOPEMNTS IN CO-ROTATING TWIN-SCREW EXTRUSION ELEMENTS FOR HIGH WEAR APPLICATIONS

Tom Kvinge, May 2012

Co-rotating twin screw extruders are the industry standard for processing filled resins. Rapid wear to high pressure sections in the extruder lowers product quality and increases downtime to change worn elements. More wear resistant element materials have been developed to lengthen the time between machine teardown requirements. A new HVOF method offers up to four times more wear resistance than standard options. This paper compares this new HVOF method of tungsten carbide protection with standard wear resistant options

POLYBUTYLENE WATER SERVICE PIPE: THE OTHER SIDE OF THE STORY

Donald E. Duvall, Dale B. Edwards, May 2012

Polybutylene pipe was once widely used in potable water distribution systems. However, problems occurred with the pipe's performance. It was claimed that the root cause of PB water pipe failures was in-service oxidative degradation of the material. These allegations ignored major problems with the installation of the PB water lines. This paper will show that installation issues far outweighed PB oxidation as the root cause of failure of PB water service lines.

PRODUCING NANO AND MICRO FIBERS BY USING JETS OF GAS

Rafael E. Benavides, Sadhan C. Jana , Darrell Reneker, May 2012

In this work, a new process -Gas Jet Fibers (GJF)- that uses a high speed jet of gas to produce nanofibers from a nozzle is presented. In operation, a continuous layer of fiber precursor is fed on a flat surface, whereby the material is stretched and fibers are launched by the action of the high speed air flow field of the jet. Fiber morphology, diameter, and length can be easily controlled by varying the jet conditions, nozzle geometry, and fiber precursor physical properties.

PREDICTING CAPILLARY DIE SWELL OF HIGH MOLECULAR WEIGHT HDPE RESINS FOR BLOW MOLDING APPLICATIONS

Tieqi Li, Carmine D’Agostino, Wen Lin, Tracy Li, May 2012

Capillary die swell of high molecular weight HDPE resins was measured and compared to the prediction based on various rheological models. The predictions based on stress ratio per Leonov model tend to overestimate the capillary die swell while those through Wagner model underestimate. Predictions per Doi- Edwards model were applicable only at low shear rate. This study reveals the need to further assess damping parameters in addition to the relaxation spectrum.

DEGRADATION MECHANISM OF GFRP AT HOT WATER

Shun Sato, Tatsuro Morita, Yoshimichi Fujii, Hiroyuki Nishimura, May 2012

This study was conducted to understand the degradation mechanisms of GFRP at hot water. Surface and cross section of immersed in hot water samples were observed in detail, and weight change rate and bending strength were researched. The samples were also conducted ultrasonic wave inspection to understand degradation nondestructively. Then, the ultrasonic echo parameter V value was used, and it was understood that V value could show generation or growth of debondings or delaminations.

IMPROVED SCRATCH AND CHEMICAL RESISTANCE ACRYLIC FOR AUTOMOTIVE MOLD-IN-COLOR APPLICATIONS

H. Reid Banyay, May 2012

This paper explores the performance of a grade of Mold-In-Color PMMA used for automotive applications. The focus is improvement vs. traditional PMMA and coating technologies during various scratch and mar abrasion evaluations. Information on solvent stress craze resistance is also reviewed. Various scratch and mar evaluation methods used during this investigation are compared.

ENTREPRENUERSHIP, INNOVATION, AND MANAGEMENT

Stephen O. Bozzone, Bonnie J. Bachman, May 2012

Innovation is one of the most misused and poorly defined terms when discussing economic growth and development. It’s a buzzword used by politicians with hopes that by just saying it will somehow magically break free us from the mire of the current global economic downturn. There’s no mystery to innovation and at the surface it is rather simple. Innovation simply stated is people implementing ideas to create value. It is easy to understand yet vastly more challenging to do well.