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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Crosslinked polyethylene (PEX) pipes and multilayer pipes of PEX and ethylene-vinyl alcohol copolymer (EVOH) as a high oxygen barrier are used for hot water pipes. The long-term performance of them was evaluated in hot water and air. It was found that the yield stress of PEX and multilayer pipes increased with elapsed time due to crystallization. It was also found that multilayer pipes had a blister at the interface between PEX and EVOH.
Mohamad Reza Barzegari, Nemat Hossieny, Mehdi Keshtkar, Nathali Chapleau, Chul B. Park, May 2012
The extrusion foaming behavior of polyethylene terephthalate (PET) with CO2 was evaluated. The foaming morphologies of PET/nanocomposites and PET/chain extenders were also assessed. The foamed extrudates were analyzed for expansion ratio, cell structure, and degree of crystallinity using scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). Finally, the effect of the die temperature on the cell structure of the PET foam samples was studied.
This study’s purpose was to develop a process for screen printing PVC film with UV-curing ink. PVC film is made with plasticizers that migrate to the surface and reduce ink adhesion. Surface treatments and ink additives were investigated. The study showed for recently manufactured film, poor ink adhesion was a result of incomplete cure. The ink’s high pigment loading impeded penetration of UV radiation. Dilution of the pigment with clear base enabled complete cure
A plastic ratchet-type hose clamp had failed catastrophically while in service, causing water damage. The investigation revealed that the cracking occurred within a relatively short period of time due to creep rupture. Additional testing was performed to substantiate the cause of failure. This paper will focus on the steps used to characterize the mode of failure, and how accelerated testing methods were utilized to predict the life of the part.
Nemat Hossieny, Mohammadreza Nofar, Mohamad Reza Barzegari, Chul Park, May 2012
The hard segments in thermoplastic polyurethanes (TPUs) are statistically distributed in the soft matrix phase. This distribution can be changed by processing the TPU material at various conditions such as melt processing or isothermal treatments. Furthermore, the hard segments contribute to the microcrystalline phase in TPUs. In this study, the foaming behaviour of “as received” and “processed” TPUs has been investigated using n-butane as a blowing agent.
Tomokazu Sasaki, Yuqiu Yang, Toshikazu, Kazushi Yamada, May 2012
This study is to clarify the adhesion mechanism as target. Various surface treatments on the metal were carried out to investigate its effect on the adhesion property of insert moldings. It is found that the surface roughness of metal could be changed by the chemical agent with different ratio of nitric hydrofluoric acid and immersion time. Optimum surface treatment exists to obtain high adhesion property between polymer and metal.
Thin polymer films are under consideration as materials for use in roof top mounted solar thermal collectors. The fracture behavior of these materials is of particular concern for this application. When exposed to UV light, film degradation can lead to reduced fracture toughness. In this paper, a method for evaluating the fracture behavior of thin films as a function of the extent of degradation is described. Pilot study results for fracture behavior of polyethylene film are presented.
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.
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.
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.
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).
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.
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.
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.
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.
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.
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.
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.
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
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.
Any article that is cited in another manuscript or other work is required to use the correct reference style. Below is an example of the reference style for SPE articles:
Brown, H. L. and Jones, D. H. 2016, May.
"Insert title of paper here in quotes,"
ANTEC 2016 - Indianapolis, Indiana, USA May 23-25, 2016. [On-line].
Society of Plastics Engineers
Available: www.4spe.org.
Note: if there are more than three authors you may use the first author's name and et al. EG Brown, H. L. et al.
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