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
WELDING OF FLAME RETARDING PP
In this paper hot plate and infrared welding are considered with respect to their attainable strengths and cycle times. In recent years, the use of flame retardant polypropylene has also become more important. Further studies show that the amount of flame retardant has a large effect on the weld strength. The welding factor drops from 0.68 (PP T20) to 0.43 (PP T20 FR). In the first part of the paper, the two welding processes are compared. Based on these results, a second study is then presented which considers the influence of various operating mechanisms of flame retardants on polymers' weldability.
EXAMINATIONS ON THE INFLUENCING FACTORS ON THE FOAMABILITY USING THE PROFOAM PROCESS
Currently, a new foaming process for injection molding is developed at the Institute of Plastics Processing (IKV) Aachen, Germany. In this process, the plasticizing unit of an injection molding machine is pressurized with a blowing agent. In this paper, the effects of the type of material, its melt temperature, the type of blowing agent and the pressure are examined with regard to the foaming of the part. The influences of these parameters on the foam structure, the part's surface and the possible weight reduction are determined.
MICROFIBERS TO NANOFIBERS
Melt blowing is an extrusion process that starts with a material in resin form and creates a final web in one step. The microfibers produced in this process are in the 0.5 to 10 micron range in diameter. Applications for this technology include filtration, fluid absorption and sound management . Electrospinning is a process that is used to produce nanofibers, and most of the current work is focused on electrospinning from solutions. The work presented will deal with the structure property behavior of single component and multilayer layer melt blown webs, and melt electrospun submicron fibers and webs.
PRODUCING MICROLAYER BLOWN FILM STRUCTURES USING LAYER MULTIPLICATION AND UNIQUE DIE TECHNOLOGY
Many polymers are extruded through blown film dies to produce monolayer and multilayer films. The most popular style of die in use today to produce blown films is the spiral mandrel die. This type of die can be used effectively for many polymers in structures containing up to approximately 10 layers. This paper will discuss technology in which layer multiplication techniques are combined with unique die geometries to produce microlayer blown film structures with significantly greater numbers of layers.
PET - POLYETHERIMIDE BLENDS
Blends of polyetherimide (PEI) with polyethylene terephthalate (PET) were re-examined. Previous blends with high (>25%) PEI content and those with very low (<10%) PEI shows a single Tg giving clear films indicative of a miscible blend. The samples stayed clear on heating and did not crystallize or phase separate. Use of lower Mw PEI:PET resins opened the window of miscibility allowing clear blends to be formed with as much as 50% PET. These clear yellow resins have high strength, 145-160C Tg, good practical toughness and high flow. PEI addition is an excellent route to upgrade PET performence.
NUMERICAL ANALYSIS OF BARRELING AT CUT-ENDS OF PE PIPES AND ITS EFFECT ON ELECTROFUSION JOINTS
When a thermoplastic pipe is cut to length, residual stresses set up during cooling are released causing local bending, giving the end of the pipe a barrel shape that can be inconvenient in electrofusion joints. This paper investigates the development of barreling in terms of residual stresses through a comprehensive simulation of the post-extrusion cooling process. The model is validated with experimental data and the effect of barreling on electrofusion joints is discussed in terms of common procedures and standards.
SHEAR & EXTENSIONAL RHEOLOGY OF C18-CNT/LDPE NANOCOMPOSITES
Nanocomposites of low density polyethylene (LDPE) and C18 modified multi wall carbon nanotubes (C18-CNT) were prepared by melt blending. Previous research has shown that addition of carbon nanotubes (CNTs) increase the dynamic viscosity and reduce the extensional viscosity with increasing loading. This research work shows that C-18 modification of CNTs helps to keep low values of dynamic viscosity, maintain extensional viscosity and does not increase strain hardening even at 5.0 weight % loading.
SELLING IN A BRUTAL ECONOMY: A HUGE OPPORTUNITY AND HOW TO CAPITALIZE ON IT
Sales are off during these difficult times. This paper will give you insight as to what's happening today and why you should consider getting into social media, PLUS things you can do today, over the next 30 days and over the next few months, to build sales.
OPEN CELL MICROCELLULAR FOAMS OF POLYLACTIC ACID (PLA) BASED BLENDS WITH SEMI-INTERPENETRATING POLYMER NETWORKS
Interpenetrating polymer network structures can be used to control cell density and averaged cell size of poly-LD-lactic acid foams. Polymer systems with and without cross-linking agent were used as templates for environmentally benign batch foaming processes in the presence of supercritical carbon dioxide. The foamed samples were characterized in terms of cell density, averaged cell size, and open cell content (OCC).
USING HYPOTHESIS SETTING TO OPTIMIZE THE TROUBLESHOOTING PROCESS FOR SINGLE-SCREW PLASTICATORS
The goal of all troubleshooting operations is to restore the process to its original performance as quickly as possible. This paper describes a process that is based on developing hypotheses using verified data. Next, the hypotheses are tested using properly developed experiments. Once the root cause of the problem is identified, the best technical solution is implemented. Three case studies are presented.
PROCESS DEVELOPMENT OF THE PROJECTILE INJECTION TECHNIQUE (PIT)
The projectile injection technique is a new powerful process variant of the well established fluid injection technique for the production of hollow shaped polymer parts. For suitable part designs the PIT allows to increase the economical efficiency and process capability significantly. First research results show that it is possible to reproducibly form hollow shaped geometries independent from the rheological properties of the used polymers.
INFRARED WELDING OF ENGINEERING PLASTICS VIA SHORT-WAVELENGTH IR EMITTERS
To demonstrate the feasibility of infrared welding of engineering thermoplastics, studies on PA66 and PBT were conducted. The weldability of engineering thermoplastics is demonstrated in the investigations carried out. Important process parameters such as pressure control, change-over times and tolerances in positioning the IR emitter were identified. It is remarkable, that engineering plastics (PBT & PA66) that are similar in use have a totally different melting behavior. The melting process has to be adapted accurately to meet the specific requirements of the material.
FREE-RADICAL INTERMEDIATES IN THE NONOXIDATIVE THERMAL DEHYDROCHLORINATION OF POLY(VINYL CHLORIDE)
Kinetic analyses based on resonance delocalization energies are used to rule out the Arlman and Winkler-Stromberg mechanisms for the growth of conjugated polyenes during the thermolysis of poly(vinyl chloride) under nonoxidizing conditions. Possible sources of radicals during the thermolysis are described, and the radicals that cause the greatest reduction in thermal stability are concluded to be those that result from the reaction of polyenes with HCl. The acceleration of dehydrochlorination by these radicals is discussed.
HEAT RESISTANT POLYLACTIC ACID WITH GOOD CLARITY
A heat resistant polylactic acid (PLA) is obtained by directly modifying regular PLA through extrusion process. The heat resistant PLA does not contain any inorganic filler and the total amount of additives is less than 5wt.%. The heat distortion temperature (HDT)???of modified PLA is more than 120oC. The modified PLA exhibits much higher crystallization rate than neat PLA. Meanwhile the heat resistant PLA still keeps good clarity and high impact strength. The heat resistant products of PLA can be directly molded through injection molding machine.
NANOPOROUS POLYCARBONATE FILM WITH HIGH ASPECT RATIO PREPARED BY ION TRACK ETCHING TECHNIQUE
Polycarbonate (PC) films with nanopores of a highly regulated size and shape were successfully prepared by ion track etching technique. The pores penetrated the films with a thickness of up to 100m, and the aspect ratio of the pores was nearly a thousand, which is outstanding result among those reported to date. Optimized etching conditions led to the effective etching of the ion tracks, and the addition of surfactant into the etching solution also heavily influenced the constitution of the pores.
MATERIAL COST REDUCTION FOR LARGE AREA AUTOMOTIVE COMPONENT MOLDING
Advances in material feeding and molding equipment enable auto component makers to use tailor made masterbatches to mold large area components along with specially designed polypropylene resins. This paper discusses and compares properties of compound made by traditional way and masterbatches blended by tumble mixing with polypropylene resins. This approach will help automotive industry to achieve cost reduction
NUMERICAL SIMULATION OF MORPHOLOGY EVOLUTION OF CRYSTALLIZATION IN RAPID THERMAL RESPONSE MOLDED PARTS
Compared with conventional injection molding (CIM) associated with the constant temperature of mold, Rapid Thermal Response Molding (RTRM) often has a rapid heating and cooling system and the molded part will experience a different thermal and mechanical history. As a result, the microstructure of RTRM part, especially the crystallization morphology for the semi-crystalline polymer, is different from that of CIM. In this paper, the crystallization morphology of RTRM part is simulated numerically using a non-isothermal crystallization model.
PREDICTING THE NEAR-EQUILIBRIUM SOLUBILITIES OF OILS IN OLEFIN BLOCK COPOLYMERS
INFUSE Olefin Block Copolymers (OBCs) are a family of new materials that are finding increased utility in soft compounds. Oil loading is considered a primary variable when tuning the hardness of such compounds, and as such, we will discuss the near-equilibrium oil solubility in OBCs as a function of the viscosities, specific gravities and refractive indices of process oils.
A NEW CLOSED LOOP MOLD TEMPERATURE CONTROL TECHNIQUE BY MEANS OF ONLINE THERMOGRAPHY
In injection molding, the precise control of the mold temperature distribution is a crucial prerequisite for the quality of the final products. A new approach to achieve an excellent repeat accuracy of the mold temperature is to use infrared images of demolded parts to realize a closed loop control. Without the necessity for changes in the mold the automatic control can help to improve the quality, to keep cycle times short and to avoid scrap.
CHOOSING A SPRAY APPLICATOR AND FLUID DELIVERY SYSTEM
This paper will help choose a spray applicator and fluid delivery system for a coating process. Each type of applicator will be explained along with the fluid delivery system necessary for the applicator. The strengths and weakness of each atomizing method will be used to guide the reader to choose the atomizer that best suits their coating needs.
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