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.
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.
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.
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.
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.
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.
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.
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
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.
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.
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.
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.
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.
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.
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.
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.
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.
Initial fiber orientation distribution (FOD) and fiber length distribution (FLD) of a fiber glass reinforced polypropylene charge for a D-LFT compression molded part were measured using image processing techniques. The FOD was measured from ?-CT scans using two different image processing approaches. These results are intended to be used in compression molding simulations.
With the increasing demands on masterbatches the DIN EN13900-5 standard has been used as a more stringent and objective indicator of dispersion quality in a polymer matrix. Introduced within the last 7 years this method is being widely adopted in the industry. This paper will examine the history and the key components needed to assess the dispersion of a colorant in a masterbatch as well as equipment considerations.
Determination of damping parameters from uniaxial extensional flow data per K-BKZ/PSM model are evaluated for high molecular weight HDPE resins. It was found that the damping properties depend on strain rate. The strain dependence, however, cannot be represented reproducibly as the relaxation mode-dependent ?k per Luo-Tanner from SER data. More efficient description of the strain dependency remains to be further explored.
Laser transmission welding is a well established joining technique for molecular diagnostic devices such as lab on a chip. This paper provides an overview about the effects of the injection molding parameters and the joining process parameters on weld strength. Design of experiments was used to maximize the weld strength. Additional optical and microscopic tests are required to validate the process for medical devices.
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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
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