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.
Dow is exploring new uses for polyethylene-acrylic acid (EAA) based copolymer dispersions. The use of hard water during the synthesis and dilution of EAA dispersions can cause precipitation leading to both technical and economic challenges. This report documents the characterization of the cross-linked reaction product generated from a model EAA copolymer dispersion with calcium ions.
In this work, we consider the effect of the addition of functionalized silica particles to a poly (tetramethylene oxide) (PTMO) based polyurethane that is a candidate to be used as for flexible storage containment for a variety military fuels. We have synthesized urethanes with silica concentrations varying from 0% to 40% by weight and evaluated the diffusion of commercial gasoline and their mechanical properties.
Four case studies are presented to illustrate failures associated with the interaction between plastic components and metal fasteners. The use of metal fasteners to secure and assemble plastics is widespread. The presented cases illustrate how the failure analysis process was used to identify the failure mechanism as well as the primary factors responsible for the failures. The four cases depict representative failures involving varied designs and service conditions.
Formulating the wide variety of Colors in demand today for thin section injection molding can be challenging. Customers require dimensionally stable parts that often must match or nest in assembly. Colorant selection is critical to meeting today’s demands and this paper describes a system to achieve these goals.
Thermal gravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) techniques were used to detect thermal degradation of polyester-polycarbonate blends at the weld interface after laser transmission welding. TGA and FTIR were found to be the most sensitive and able to differentiate between degraded and non-degraded material.
Blends of LLDPE (linear low density polyethylene) and LDPE (low density polyethylene) are used in many film applications. This paper shows how several high performance LDPE resins can be used as a blending component to increase output or throughput on blown film lines. In addition, some of these LDPE resins are utilized in shrink films, providing a good combination of shrink and optics, and are also used in foams and extrusion coating among other applications.
Thermoplastic polyurethanes (TPUs) are a class of thermoplastic elastomers (TPEs) that are used in a variety of applications (1). TPUs exhibit low temperature flexibility, excellent abrasion resistance, high tensile strength and good processing characteristics. The current medical grade TPU’s have unique property that the flex modulus decreases (softens) when placed in the body. A new resilient non-soften (RNS) thermoplastic polyurethane has been developed that does not soften like the current grades.
This study shows the effect of viscoelasticity on the flow uniformity in a film die. Flow simulations were conducted on flat die geometries based on the rheology of different resins with different viscoelasticity characteristics. The results have shown that viscoelasticity can have a significant influence on flow uniformity and flow distribution becomes less uniform as the elasticity of the resins increases.
A newly developed extrusion die optimization software is used to optimize a sheet die and a square profile die with non-uniform wall thickness. The optimization software successfully optimized the two die geometries such that a uniform velocity distribution is obtained at the die exit without exceeding a pre-specified pressure drop across the die.
This paper investigated how polyolefin resin properties affect holding force performance for stretch hood film application. In this study, the effect of density/crystallinity and composition distribution on the holding force and elastic recovery of ethylene copolymers was examined. A large number of resins from different families were investigated in this study.
Polymer adhesion to a metal plate using an intermediate polymeric reactive layer was evaluated. A novel in-house adhesive powder coating was applied and compared with commercial ones, the influence of metal surface and a subsequent annealing process of the samples on the adhesive strength was also assessed through atomic force microscopy (AFM), mechanical test and differential calorimetry (DSC). Interesting results were obtained in terms of successful adhesion between the polymer and the metal, especially in samples that were annealed with the in-house coating.
Maddock-style mixers are used extensively on singlescrew extruder screws to disperse materials into the molten resin matrix. Since the time LeRoy invented the device and Maddock perfected and commercialized it, the device has undergone several innovations. Two of these innovations have created processing issues. The goal of this paper is to describe the optimal flute geometry and mixing undercut dimension for a Maddock mixer with the goal of mitigating degradation gels and maximizing dispersive mixing stresses.
The world of laser technology continues to develop and grow. In the past 10 years lasers have evolved from CO2 and Nd:YAG systems to diode pumped and fiber lasers. The latest expansion is taking place in lasers that produce super short pulses. Some of these pulses are measured in the Pico and Femto second range.
This paper will look at what are the characteristics of a short pulsed laser, how the pulse width effects applications, and the applications that are using these lasers.
A novel silicon based synergist, DynaSil™, was used in glass-fiber reinforced polyamide 66 which is flame-retarded with organic phosphinate and traditional synergists. Mechanical, physical and thermal properties, as well as fire testing results, are reported. DynaSil™ helps to lower the using amount of organic phosphinate and traditional synergists in flame retardant glass-fiber reinforced polyamide 66 composites, meanwhile improving properties and fire performance and lowering the cost of the composites.
Polymer Dynamix has developed a novel thermoplastic compound which combines an appealing soft, silky feel combined with flexibility. The results demonstrate that reactive modification decreases the Shore Hardness and increases the flexibility and soft, silky feel of a thermoplastic elastomer.
Learn how 3D printed tools for injection molding can be used to save you time and money when creating short run prototypes from production grade plastics. This paper, will discuss the business rational behind this solution, show how some of our customers are using it and provide technical tips and tricks for success. We will also touch on a few of the future developments we see for this solution.
While the physical properties of LLDPE are highly desired for many blown and cast film applications, it lacks the melt strength compared with LDPE. While LDPE can be blended with LLDPE to improve melt processability, key properties are sacrificed. This paper describes a proven technique for obtaining LCB or HMS LLDPE by means of high energy electron beam modification that increases the melt strength of reactor grade LLDPE by 5-7 times without secondary compounding and without creating gels. These materials can be used as stand alone film grades or as melt strength modifiers for conventional LLDPE and other polyolefins.
Standardization is a cornerstone of modern civilization. The weathering testing industry of today exists because of the work of standards writers around the world. However, there can be too much of a good thing. Test standards in weathering sometimes get in the way of innovation. For example, the most common cycle for testing polymeric materials in xenon arc test chambers is the 102/18 cycle. That is, the test is run for 102 minutes with light only, followed by 18 minutes of light plus water spray. Users of weathering standards assume the prevalence of this test cycle must mean that it has been carefully validated for a wide variety of materials over the decades. They may also assume that this cycle was developed to provide good correlation to natural outdoor weathering, with extensive scientific research and statistical analysis to support its broad application. They assume incorrectly. The origin of this cycle dates back to the Victorian era when the first carbon arc weathering test chambers were developed. Rotating racks completed one revolution in two hours, and specimens were sprayed with water for 18 minutes as they moved past the fixed spray nozzles in the chamber. In other words, the 102/18 cycle was set in stone a century ago and has rarely been questioned since then.
Standards have also hindered innovation by overstepping their boundaries. For decades automotive OEMs bemoaned the lack of correlation between their laboratory tests and real outdoor test results. Through the development of SAE J1960 and similar standards, OEMs wrote their testing requirements around specific pieces of hardware rather than test conditions designed to simulate and accelerate natural weathering conditions. Flaws and limitations in the old technology thus became standardized, precluding any improvements to the test methods. A few of the OEMs decided to do something about it, and this was the origin of ASTM D7869, which is a true state of the art weathering test standard fo
Chlorinated polyvinylchloride (CPVC) is widely used for many piping systems including potable water, hydronic heating/cooling, corrosive liquid drains, and fire suppression systems. CPVC is popular because of its ease of installation and corrosion resistance. However, as with all plumbing products, occasionally pipes or fittings may fail. Our goal as forensic scientists is to determine the root cause of failure of the CPVC piping and to provide the client with data that will help them select the most appropriate remediation option for their building. This paper presents four unique case studies, the forensic tools we used to evaluate the CPVC piping systems, and the logic behind the remediation option selected by the client.
A finite element model was developed to simulate dynamic stress distributions in thermoplastic polyolefin (TPO) roofing systems subjected to severe impact events, e.g., hail and hard object strikes. In order to build an integrated TPO layered composite roofing system model, separate sub-models are developed that include: the TPO membrane, polyester reinforcement scrim, low modulus closed-cell foam and fiber-glass stiffened facer sheets. A hyperelastic Mooney-Rivlin model of the TPO membrane is utilized to simulate the membrane’s large-deformation mechanical response during simple impact tests. Straightforward force-contact measurements on the TPO membrane material and low modulus foam backing, using spherical indenters, are shown to provide sufficient material properties for the impact model of interest. It is demonstrated that the local failure modes for the layered composite roofing system can be adequately characterized by using relatively simple failure criterion for each of the individual component layers in this type of roofing system. Both high-speed indentation and ice ball impact experimental tests have been performed to evaluate and verify the predicted performance of a single ply TPO roofing system. Excellent correlation is obtained between model predictions and experimental dynamic indentation tests.
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
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.
If you need help with citations, visit www.citationmachine.net