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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Poly(lactic acid) (PLA) and Poly(propylene carbonate) (PPC) polyol were melt-compounded to fabricate a novel polymer blend with balanced mechanical properties (tensile strength and ductility). Blend with 90wt.% PLA/10wt.% PPC polyol and 70wt.% PLA/30wt.% PPC polyol were prepared and evaluated in terms of mechanical performance. As for the blend with 30wt.% PPC polyol, two residence time have been applied (1min and 2min). It was found that 10wt.% loading of PPC polyol has an adverse effect on both tensile strength and elongation at break of the blend. Overall mechanical performance deteriorated with only 10wt.% PPC polyol. Major finding was that with incorporating 30wt.% PPC polyol in the polymer blend system, the ductility (elongation at break) of the blend significantly improved by 5000%. However, the tensile strength decreased drastically. The morphology of the blend was investigated through scanning electron microscopy (SEM).
Development of bioactive and stimuli responsive materials in the form of implant/scaffold is the urgent need that mimics the natural bone structure and function. To achieve such novel smart biomaterials ?PVP-CMC-CaCO3? scaffold was prepared using PVP-CMC hydrogel as a matrix, following the biomimetic mineralization process i.e. simple liquid diffusion technique. The main concern of this study is to establish its stimuli responsive nature as it is one of the important factor of biomaterials. The swelling-deswelling capacity of ?PVP-CMC-CaCO3? scaffold was carried out at 37oC using physiological solution. The morphological changes which occurred in the biomineralized scaffold during swelling-deswelling-reswelling and deswelling steps were confirmed using scanning electron microscopy. The obtained results concerning shape-size and thickness indicated that PVP-CMC-CaCO3, a hydrogel based scaffold is a true stimuli responsive biomaterial.
Bulk polymerization of thermoplastic polyurethanes (TPU) in reactive extrusion is a very complicated topic. Understanding how to efficiently produce TPUs is dependent upon the relationship between the extrusion process and the polymerization. The goal of this study was to determine the response of the polymerization kinetics to both composition and shear rates. Rheological measurements were taken while concurrently collecting in situ Fourier transform infrared (FT-IR) spectra. The results indicated that polymerization kinetics were sensitive to both the hard segment (HS) composition of the system and the shear rate imposed on the system.
General Cable Corporation recently committed to a multi-year effort on development and qualification of 60-year life Class 1E cables. The major milestones achieved in the development include (a) Introduction of 60-year life nuclear cables in the industry (b) Approval of 60-year cables for service in the new nuclear power stations (Vogtle site and V.C. Summer site) and (c) Use in a new generation nuclear reactor power plant AP1000 designed and sold by Westinghouse Electric Company. Cable constructions tested were 600V cables, 2 kV cables and 15kV MV power cables. This paper presents the scope of overall qualification program and test results conducted per IEEE standards and end-user specifications. The cable testing will be discussed in relation to thermal aging and radiation exposure followed by DBE (Design Basis Event) accident conditions.
Acrylonitrile butadiene styrene (ABS) tensile specimens produced by 3D printing in two different orientations, injection molding, and subtractive machining were fractured by tensile overload in accordance with ASTM D638. In this study, the tensile properties and fracture surfaces of the different manufacturing methods are compared and contrasted using optical microscopy, computed tomography (CT) and scanning electron microscopy (SEM). CT reconstructions of the pre-failed tensile bars and images (optical and SEM) of the fracture surfaces are provided and discussed.
Compounds of soy flour, biochar and a polymer matrix, such as PLA, have proven to be effective fertilizers comparable to commercial products. Prototype composites achieved NPK values of 2.85, 0.20, 0.49 and 3.08, 0.21, 0.48 %, respectively for PLA- and PHA-based composites. These composites only leached a fraction of nitrogen compared to a commercially available synthetic fertilizer. Low leachate values, as compared to commercial fertilizers, may be associated to the absorption and releasing of nutrients by biochar. The nitrogen within the soy is also not readily water soluble and is released over time by microbial action.
The relationship between the degree of crystallinity and the ultrasonic velocity was analyzed in this study for injection molded poly(lactic acid) (PLA) parts undergoing an annealing process. An annealing process was first employed to produce PLA parts with different degrees of crystallinity. Next, a novel ultrasonic water immersion method was presented for calculating the ultrasonic velo?cities of these annealed PLA parts. Then, the ultrasonic velocity results were plotted with the crystallization re?sults from differential scanning calorimeter (DSC) mea?sure?ments for analysis. Experimental results show that the inverse effective ultrasonic velocity versus the degree of crystallinity over the whole crystallinity range for three different annealing temperatures show good linearity, with a correlation coefficient of around 99%. The linear rela?tionship observed in this study might provide a novel method for investigating the degree of crystallinity of semi-crystalline polymers in practical production.
In this work, we have studied the electrochemical behavior of non-porous and porous nano-graphene/polyimide composite films fabricated by the thermal degradation of grafted flexible acrylic acid on polyamic acid backbone. It is observed that pore size distribution has a significant effect on specific capacitance and bulk resistance of the composite material. BET and Electrochemical impedance spectroscopy (EIS) data reveal a complex pore distribution for the materials. As the porosity of the composite material increased, its bulk resistance decreased by up to 400% and the specific capacitance increased by up to 200%. Ionic diffusion resistance associated with the pore structure for the porous composite decreased due to easy access of electrolyte ions through the pore length of the material. Specific capacitance of up to 34,240mF/g was obtained for the composite system at a scan rate of 50mV/s which remained fairly stable through the 50 cycle runs. Potassium hexaflorophosphate (KPF6) dissolved in propylene carbonate was used as electrolyte for all the electrochemical techniques.
In order to design and manufacture natural fiber-polymer composites as structural components in existing and novel technological applications, the long term viscoelastic behavior of the materials must be understood. In order to do that, the time?temperature superposition principle (TTSP), is used to predict long-term viscoelastic behavior from short-term experimental data. Dynamic?mechanical analysis (DMA), was used to study the viscoelastic properties of composites made from fique mats and low-density polyethylene?aluminium (LDPE?Al) obtained from recycled long-life Tetra Pak packages. This paper reviews the effect in using Chemical treatments such as alkalinization with NaOH, silanization, and polyethylene impregnation treatments for composites, understanding the interaction mechanisms between natural fibers and the LDPE-Al; and presents the effects of treatments on the viscoelastic behavior. Fractographic evaluations in the scanning electron microscope (SEM) confirm the quantitative characterization obtained from DMA.
Polymer based thermoelectric materials were usually fabricated using solvent casting methods in the past. However, such processes may involve the usage of highly toxic solvents and solutions. In this paper, we present the results of thermoelectric performance of poly(vinylidene fluoride) (PVDF) based thermoelectric material with graphene nano-platelets (GNP) and multiwall carbon nanotube (MWCNT) as fillers. The samples were fabricated though melt blending method, which is a cheaper, simpler process and can be easily scaled up to industrial level for mass production. Our results indicated that melt blending process can produce either similar or superior results compare to the traditional solvent casting methods. For GNP/PVDF samples, we have found a superior Seebeck coefficient approximately 200% higher compared to the value reported from previous studies, while the electrical and thermal conductivity show similar values. In addition, our melt blended MWCNT/PVDF samples showed a similar trend comparing to solvent casted samples that were reported in literature.
Heat Treatment is defined as the controlled heating and cooling, of metals, in order to alter their physical and mechanical properties.
First, before the mold is designed, the Engineering department reviews the quote then employs proven methods of design, material selection, and heat treatment.
This understanding is the key to selecting the best material, for a particular component. Additionally, the ability to specify this, to your outside services, will provide the end result you desire.
All Engineers do not have metallurgy knowledge, therefore, the heat treatment processes defined below will include some of the language used by a Metallurgist. This will help when specifying treatments, on mold design components, and to better relate to the processes used.
When designing injection molds, many decisions are made while quoting. Parts are examined for entrapment or details that cause them. Solving entrapment issues requires creative undercut solutions. There are many undercut solutions offered today. The designer needs to know how to quickly select the correct option for the most efficient molding and tool building.
This paper addresses methods of releasing threads, snaps, hooks, holes and anything that has a mechanical action that must take place before a part can be ejected and the mold opened. Often a certain method is used for a mold that is traditional, but with a fresh look at the part and current solutions, the design can be simplified. This can result in lowering molding time, manufacturing time and ultimately cost.
This informative guide addresses the most common undercut conditions with simple and long-lasting solutions. It compares traditional methods to non-traditional methods and explains the advantages and disadvantages.
Using gas-assist in conjunction with foam injection molding has the potential of creating a highly synergistic production technique. By combining two supplementary processing strategies, weight savings with higher quality cell morphologies can be achieved. In this study, the effects of gas-assist processing parameters were systematically examined on the cell morphology of TPU. These gas-assist parameters include the holding time, holding pressure and start delay. The cavity pressure for different gas-assist pressure profiles was also examined.
Cellulose nanofiber (CeNF) is generally provided by micronizing a plant fiber to a nanometer-size in diameter. A CeNF reinforced thermoplastic composite is recently expected to indicate integrated high performance concerning light weight, thermal resistance and mechanical strength. It is important to disperse and defibrate CeNF uniformly in a resin in the extrusion process. In this study, various compounds of microcrystalline cellulose (MCC), CeNF, PLA, and PP were made using additives by the extrusion process. The mechanical properties were also evaluated.
Modern inorganic pigments are no longer just colorants for visual appeal; rather, they are functional colored materials exhibiting a wide range of properties. This distinction is important as pigments now provide specific physical and chemical advantages in addition to bright colors. It is therefor important to understand the fundamental correlations between crystal structure and physical properties when designing new pigments. New research pushes the boundaries of traditional metal oxide pigments by utilizing unusual host lattices, new elemental combinations, and unique synthetic methods. This paper will establish the basic considerations of modern pigment design and discuss the recent advancements in blue pigments, namely in the YIn1-xMnxO3 family.
In Japan, eggs are widely used in many food products on the market, and 200,000 tons of eggshells are annually discharged and most of them get discarded.
Re-use of discarded eggshells into food trays is one of the efficient ways to realize a recycling-oriented society.
Many food trays consist of polypropylene or polystyrene, and sometimes recycled products. Thus, it is possible to use biomass materials such as eggshells as a bulking agent. Eggshells need to be compounded into resin when used in food trays, but the egg?s unique sulfur smell is emitted when applying heat in the manufacturing process.
In order to solve this odor problem, we compounded under different conditions with polypropylene and eggshell to research ways to reduce odor.
The results suggested that molding temperatures exert significant influence on odor generation.
By molding at the lowest temperature that enables resin to mold, a possible countermeasure for odor reduction is created.
Fiber-reinforced composites assume a key function in lightweight design. Due to high material and manufacturing costs, the objective is the near net shape manufacture of composite components via the forming processes. Subsequent cutting processes such as deburring are, however, still necessary. This post-processing leads to a reduction in the mechanical properties, not only through the cutting of the continuous fibres but also through potential production-related damage. The excellent durability properties of fiber-reinforced composites are thus lost. In this paper it is assumed that the production-related reduction in the mechanical properties of composites with thermoplastic matrix is not only caused and influenced by the design of the machining process but also through the method of clamping the parts which is necessary during the process. The qualitative evaluation is done through microscopical determination of the surface damage and the inter-laminar damage through ultrasonic inspection. Following an accelerated ageing process under the influence of bending loads, the determination of the flexural strength is carried out.
Current lightweight composite solutions demonstrate their technological feasibility by using lightweight material. The whole lightweight potential of composite parts, however, can only be used in combination with lightweight design principles. There is a limitation in creating lightweight optimized applications. The manufacturing technology must achieve both, economic process with low cycle times and high process integration.
The article gives an overview of material lightweight and structural lightweight design of continuous fibre reinforced thermoplastic composite applications. Furthermore new process technologies for present automotive applications are shown (bumper systems, seat structures) which integrate structural and material design in a One-Shot-Process. The key benefit of the Technologies, beside the lightweight potential of the used materials and design, is a short cycle time (less a minute) that can only be realized due to using thermoplastic composites and a process integration/combination. Therefore these processes are ready for implementation in mass production.
Selective laser sintering (SLS) of polymer powder is readily used for the additive manufacturing of plastic parts. During SLS processing a laser is used to fuse powders together to form whole parts. The build direction, which corresponds to the axis on which the longest dimension of the part is oriented, can greatly influence the morphology and material performance of the final product. In this study we evaluate the microstructure and mechanical behavior of SLS processed polyamide 12 (PA-12) as a function of build direction.
LORD offers adhesive solutions that effectively bond plastics to substrates directly in an injection molding process. A specially designed injection mold was created to evaluate adhesive technologies and their effectiveness in bonding various thermoplastics, such as nylon, polycarbonate, PC/ABS, and TPU?s, to substrates such as aluminum and glass. This paper focuses on in-mold bonding of PC, PC/ABS, and nylon 66 to aluminum. Molded assemblies were tested for adhesion directly after molding and after environmental exposures (thermal cycling, heat and humidity, and anodizing). This process and product technology offers a number of design and cost benefits, such as light weighting, design freedoms, and manufacturing efficiencies.
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.
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