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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Thermoplastic Polycarbonate Based Polyurethanes
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. One drawback to standard TPU’s was heat resistance and having both oxidative and hydrolytic stability at the same time. The polycarbonate based polyurethanes can supply these characteristics.
Universal Melt Temperature Diagram
The Universal Melt Temperature Diagram (UMTD) provides the developing melt temperature versus length of an extruder based on four unique dimensionless groups. Factors included in the four groups are; the dependence of melt viscosity on shear and temperature, resin thermal properties, screw geometry, and process conditions. Melt temperature vs. extruder length is provided in a succinct format that vividly illustrates the melt temperature development process.
Squeeze-Out of Sealant During Hot Bar Sealing: Modeling Insights
Excessive pressure and temperature during hot bar sealing can result in poor seals due to squeezing out of the sealant. A model is developed that shows the amount of squeeze out increases with increasing seal bar pressure, seal temperature (by lowering the viscosity of the sealant), sealing dwell time, film thickness and decreasing seal bar width. Initial validation experiments qualitatively agree with the model predictions.
Hydrolysis Resistant PBT Products
Technological advancements by our research and development have improved the hydrolytical stability of Polyester PBT compounds. After exposing these products to 85°C, at 95% relative humidity for 1500 hours, the % retention of notched Charpy impact strength, tensile strength improved by 20% over the standard heat stabilized products. Even more significantly, the retention of ultimate elongation and tensile strength was improved by greater extend even over two fold.
Radilon® A RV500RW 339 NER: PA66-GF50 with enhanced structural performances
A new class of “Eco-Friendly metal replacement” using Polyamide 66 has been developed by Radici Scientists. This product has improved mechanical strength. The impact strength is improved by greater than 30%, and the weld line strength improved by over 20%. The ultimate tensile strength was also improved by 20% at 23°C and 150°C.
Development of a radian friction welding machine using the circular process with limited rotational motion
To extend the potential of friction welding, a new welding technology needs to be developed. In industrial cooperation an innovative friction welding method known as radian welding has now been developed. It functions according to the circular process with limited rotational motion. Apart from extending the ability to weld components with a rotationally symmetrical weld, the new technology should create additional benefits for the process and the properties of the welded component.
Thermal Aspects of PTFE Sintering
The effect of sintering time on the melt evolution of PTFE was studied using a cyclic thermal loading profile within a differential scanning calorimeter (DSC) and thermo-mechanical analyzer (TMA). PTFE exhibited non-equilibrium melt behavior at 30 °C above its melting temperature. A correlation between the DSC and TMA results was established. The cyclic thermal profile leads to a dramatic growth in enthalpy of crystallization/melting.
A Structure-Property Study of Topologically Heterogeneous Networks
This work is an initial evaluation of structure-property relationships that result from introducing topological heterogeneity into controlled epoxy networks. The topology was controlled by systematically altering the functionality and stiffness of epoxides and amines. This contribution reviews synthetic routes and summarizes basic thermal and mechanical properties.
Melt Rheological Characterization of Poly(Ethylene Terephthalate)
Dynamic melt rheology was used to characterize poly(ethylene terephthalate) (PET) supplied from manufactures across the globe. The zero shear viscosity and the molecular weight of the polymers were determined. This rheology method is more sensitive than traditional intrinsic viscosity measurements provided by the resin suppliers
Modeling and Analysis of Spin Coating on Spherical Surfaces
A formulation for modeling the spinning coating process on spherical surfaces is presented in this paper. The model can be adopted to predict film thickness profile on spherical surfaces with large central angles. The simulation results showed that the uniformity of final film thickness is not ideal with uniform initial film thickness distribution. The film thickness evolution and uniformity of film thickness were studied using this model and compared with literature to determine potential advantages of the new model.
Potential for efficiency improvements at different injection molding machines
Topic of this paper are the results of some investigations discovering potentials for improvements of two different injection molding machines with respect to the efficiency. During this investigations, the influence of process conditions on the energy consumption of two different driven injection molding machines have been focused. Finally some recommendations will be done for an improvement of the efficiency of the machines.
Laser Direct Structuring LCP for Mobile Antenna Applications
The rapid growth and global demand for wireless communication and increasing need for more functionality in smart phones have created a need for advanced engineering resin to meet new antenna requirements for mobile devices. This paper discusses performance of new laser direct structuring LCP grades and developmental grades with improved mechanical, thermal properties and dielectric properties engineered to meet new challenges of increased functionality and reduction in antenna size.
An Expanded Residence Stress Distribution Study in a Twin-Screw Extruder: The Effect of Stress Bead Strength
The ability to measure Residence Stress Distribution (RSD) in real time provides a greater understanding of the extrusion process. A method has been developed to characterize stress history within a 28-mm co-rotating twin-screw extruder (CoTSE) through the use of stress beads that break at critical stresses. Three different strength stress beads were used to provide an expanded and robust methodology. A Design of Experiment (DOE) approach was used to present the bead breakup results.
Residence Stress Distribution Study Using a Robust Design of Experiment Approach
A real time method of measuring Residence Stress Distribution (RSD) within in an 18-mm fully intermeshing, co-rotating twin-screw extruder (CoTSE) has been developed using stress beads. A Design of Experiment (DOE) grid allowed the results of the percent breakup of beads to be evaluated statistically. Further experiments have now been run to expand the mixing regimes inspected. The augmented range of operating conditions tested enabled a more robust and rigorous analysis of bead breakup trends.
Modeling of Single Ply Thermoplastic Polyolefin Roofing
A finite element simulation is developed to model the stress distribution of heat seamed Single Ply thermoplastic polyolefin (TPO) composite under FM wind uplift test conditions. Separate models are developed for the TPO layers, reinforcement layer, and lap-joint geometry in order to obtain an integrated TPO composite model. TPO membrane material and attachment parameters are evaluated for wind uplift enhancement. Good correlation is observed between model prediction and real wind uplift test results.
Resin Design for High Stiffness and High ESCR Performance in Rotational Molding Applications
This paper presents new developments in the design of ethylene copolymers for rotational molding applications with higher stiffness and ESCR requirements. The performance of novel ethylene copolymers is discussed based on phenomena fundamental to the rotomolding process and on the relative impact of the choice of comonomer, manufacturing technologies and resin design strategy.
Relating Polymer Viscoelastic Properties to Thermoforming Process: A Short Review
This paper reviews the relation between polymer viscoelastic properties and the plug-assist thermoforming process. One of the important attributes of polymers is their macromolecular interaction. Molecular interaction provides enhanced networks of molecules that contribute to minimizing polymer deformation at high temperatures. As a result, sheet sagging will be reduced during thermoforming. Additionally, molecular interaction could enhance the melt strength of the polymer by reducing its molecular mobility.
Upgrading the Capacity of an Existing Extrusion System
Several low-cost techniques are readily available to upgrade the capacity of an existing extrusion system. These techniques include upgrading a screw to restore the flight clearance due to wear, changes to the motor drive train system, and the use of high-performance screws. The technique used will depend on the rate limitation and the current process.
Troubleshooting and Mitigating Gels in Polyolefin Film Products
The term “gel” is commonly used to refer to any small defect that distorts a film product. Eliminating gel defects from extruded polyolefin film products can be difficult, time consuming, and expensive due to the complexity of the problem and the high levels of off specification product produced. This paper discusses the identification of gel types, the common root causes for gels, and the technical solutions for mitigating gels in film products produced using single-screw extruders.
Comparison Study of Talc and Nanosilica as Nucleating Agents for Low-Expansion Foaming Applications
This paper compares the effectiveness of talc and nanosilica as nucleating agents for generating polypropylene foams with high cell density and low expansion. Experiments were conducted in two stages: 1) In-situ foaming observation in a batch system; 2) Extrusion foaming. Nanosilica was more effective than talc in inducing cell nucleation under static conditions. However, in extrusion, their effectiveness in enhancing cell nucleation was similar due to the presence of extensional and shear stresses.
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