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Influence of ethylene-propylene-diene terpolymer addition on processing parameters, phase structure and thermal behaviour of polypropylene/low-density polyethylene blends

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JOURNAL OF ELASTOMERS AND PLASTICS 2015年第6期47卷 502-514页

作者： Penava, Nina Vranjes Rek, Vesna Slouf, Miroslav Jelcic, Zelimir Univ Zagreb Fac Chem Engn & Technol Zagreb 10000 Croatia Acad Sci Czech Republ Inst Macromol Chem Prague Czech Republic PLIVA Croatia Ltd TAPI R&D Zagreb Croatia

The influence of blend composition and ethylene-propylene-diene terpolymer (EPDM) content on the processing parameters, phase structure and thermal behaviour of polypropylene (PP) and low-density polyethylene (LDPE) blends was studied. processing parameters of blends in twin-screw extruder were followed by output (Q), torque (TQ) and back pressure (p), and apparent viscosity as given by TQ/Q and p/Q ratios, while the thermal behaviour was measured using differential scanning calorimetry. Phase structure was investigated using scanning transmission electron microscopy (STEM). The degree of crystallinity ((c)) of PP phase decreased and (c) of LDPE phase increased with higher LDPE content in blends with and without EPDM. STEM micrographs of EPDM compatibilized PP/LDPE blends of compositions 80/20 and 20/80 showed particulate morphology, whereas in the blends of compositions 60/40 and 40/60 the morphology was co-continuous. The EPDM compatibilizer was localized on the interface.

关键词： PP LDPE blends compatibilization processing parameters morphology thermal behaviour

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Flow-induced β-crystal of iPP in microinjection molding: effects of addition of UHMWPE and the processing parameters

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JOURNAL OF POLYMER RESEARCH 2016年第2期23卷 1-11页

作者： Chen, Qianying Xiang, Zhang Yang, Qi Kong, Miqiu Huang, Yajiang Liao, Xia Niu, Yanhua Zhao, Zhongguo Sichuan Univ Coll Polymer Sci & Engn State Key Lab Polymer Mat Engn Chengdu 610065 Peoples R China

The flow-induced beta-crystal of isotactic polypropylene (iPP) with addition of ultrahigh molecular weight polyethylene (UHMWPE) molded by microinjection and influences of processing parameters on the formation of beta-crystal in iPP/UHMWPE microparts were investigated by differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WAXD) and scanning electron microscopy (SEM). It was found that the contents and the dispersion of UHMWE affect the formation of beta-crystal in iPP/UHMWPE blend. With the addition of UHMWPE, K-beta values of the blends increased significantly compared with that of the pure iPP and reached the maximum at the content of 2 wt% UHMWPE. In addition, a better dispersion of UHMWPE can facilitate the formation of the beta-crystal in the iPP/UHMWPE. The results showed that the thermal stability of the beta-crystal was enhanced with increasing the mold temperature. When the mold temperature was increased from 60 to 120 degrees C, the beta-crystal become more perfect. High injection speeds can promote the formation of the beta-crystal, but the value of the injection speed must be within a certain range.

关键词： Isotactic polypropylene Ultrahigh molecular weight polyethylene Microinjection molding beta-crystal processing parameters

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THE USE OF TWIN-SCREW EXTRUSION IN processing OF WOOD: THE EFFECT OF processing parameters AND PRETREATMENT

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BIORESOURCES 2011年第4期6卷 4615-4625页

作者： Hietala, Maiju Niinimaki, Jouko Oksman, Kristiina Lulea Univ Technol Dept Engn Sci & Math SE-97187 Lulea Sweden Univ Oulu Dept Proc & Environm Engn FI-90014 Oulu Finland

In this study the effect of processing parameters on different types of wood raw material in extrusion was examined. The study consisted of two parts: the first part was to break and separate individual fibers from wood chips during the extrusion process;in the second part the effect of chemical pre-treatment and screw elements on wood raw material was evaluated. Statistical analysis was performed to evaluate the most important factors affecting wood particle size in extrusion. The statistical analysis showed that the screw speed is the main factor affecting wood fiber length in twin-screw extrusion of wood chips. This study showed that a twin-screw extruder can be used to separate individual fibers from wood chips, and the separated fibers have higher aspect ratios than the wood flour particles typically used in wood-polymer composites. When more fibrous and chemically softened wood raw material was used, fibers with even higher aspect ratios were obtained.

关键词： Wood Twin-screw extrusion processing parameters Statistical analysis

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Synthesis of high surface area nanocrystalline anatase-TiO₂ powders derived from particulate sol-gel route by tailoring processing parameters

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JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY 2006年第1期40卷 15-23页

作者： Mohammadi, M. R. Cordero-Cabrera, M. C. Ghorbani, M. Fray, D. J. Univ Cambridge Dept Mat Sci & Met Cambridge CB2 3QZ England Sharif Univ Technol Dept Mat Sci & Engn Tehran Iran Sharif Univ Technol Inst Nanosci & Nanotechnol Tehran Iran

Stabilised titania sols were prepared using an additive free particulate sol-gel route, via electrostatic stabilisation mechanism, with various processing parameters. Peptisation temperature, 50 degrees C and 70 degrees C, and TiO2 concentration, 0.1, 0.2 and 0.4 molar, were chosen as processing parameters during sol preparation. Results from TiO2 particle size and zeta potential of sols revealed that the smallest titania hydrodynamic diameter (13 nm) and the highest zeta potential (47.7 mV) were obtained for the sol produced at the lower peptisation temperature of 50 degrees C and lower TiO2 concentration of 0.1 M. On the other hand, between the sols prepared at 70 degrees C, smaller titania particles (20 nm) and higher zeta potential (46.3 mV) were achieved with increasing TiO2 concentration up to 0.4 M. X-ray diffraction (XRD) and Brunauer-Emmett-Teller (BET) results of produced powders annealed at different temperatures showed that the 300 degrees C annealed powder made from 0.1 M sol prepared at 50 degrees C was a mixture of anatase and brookite, corresponding to a major phase of anatase (similar to 95% estimated), with the smallest average crystallite size of 1.3 nm and the highest specific surface area (SSA) of 193m(2)/g. Furthermore, increasing TiO2 concentration up to 0.4 molar for the sols prepared at 70 degrees C resulted in decreasing the average crystallite size (1.9 nm at 300 degrees C) and increasing SSA (116m(2)/g at 300 degrees C) of the powders annealed at different temperatures. Anatase-to-rutile phase transformation temperature was increased with decreasing peptisation temperature down to 50 degrees C, whereas TiO2 concentration had no effect on this transition. Anatase percentage increased with decreasing both peptisation temperature and TiO2 concentration. Such prepared powders can be used in many applications in areas from photo catalysts to gas sensors.

关键词： anatase-TiO2 sol-gel processing parameters characterisation

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The Unidirectional Glass Fiber Reinforced Furfuryl Alcohol for Pultrusion. II. Correlation of processing parameters for Optimizing the Process

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JOURNAL OF APPLIED POLYMER SCIENCE 2011年第3期119卷 1788-1796页

作者： Chen, Chin-Hsing Chen, I-Ken Chinese Culture Univ Dept Chem & Mat Engn Taipei Taiwan

Unidirectional glass fiber reinforced furfuryl alcohol (FA) composites have been prepared by the pultrusion processes. The optimum processing parameters of the glass fiber reinforced FA composites by pultrusion has been studied. The effects of the optimum processing parameters on the properties (flexural strength, flexural modulus, notched Izod impact strength, glass transition temperature (T(g)), dynamic shear storage modulus (E'), shrinkage ratio, and roughness) investigated including die temperature, pulling rate, postcure temperature and time, and filler type and content. Results show that the pultruded composites possessed various optimum pulling rates at different die temperatures. On the basis of the DSC diagram, the swelling ratio and the mechanical properties of pultruded composites, the optimum die temperature can be determined. The mechanical properties and T(g) increase at a suitable postcure temperature and time. Furthermore, the properties which decrease due to the degradation of pultruded composites for a long postcure time will be discussed. The mechanical properties of pultruded composites reach a maximum value at various filler content corresponding to the talc and calcium carbonate, respectively, and then decreased. When the fillers are added to the pultruded glass fiber reinforced FA composites, the shrinkage ratio of composites become smaller, and the surface of composites became smooth. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 119: 1788-1796, 2011

关键词： pultrusion glass fiber furfuryl alcohol processing parameters composites

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Effects of processing parameters on the mechanical properties of polypropylene random copolymer

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POLYMER TESTING 2005年第8期24卷 1012-1021页

作者： Sahin, S Yayla, P Kocaeli Univ Dept Mech Engn Fac Engn TR-41040 Kocaeli Turkey

The mechanical properties of polypropylene random copolymer (PP-R) with different processing parameters were studied. Special attention is devoted to the investigation of the influence of masterbatch addition on the variation in the mechanical properties of injection moulded PP-R. Tensile, instrumented Charpy impact, Shore D hardness, differential scanning calorimeter (DSC) and Vicat softening temperature (VST) tests were conducted on the test samples containing different colour masterbatches varying from 0.5 to 10 wt%. The observed changes in the mechanical behaviour are explained by the type and level of masterbatch content. The natural UV weathering performance of the PP-R material was studied from the masterbatch type point of view. The effect of processing parameters on material performance was studied on samples which were directly obtained from extruded pipes and on injection moulded samples. Finally, the effects of storage time on the polymer properties were investigated. (c) 2005 Elsevier Ltd. All rights reserved.

关键词： polypropylene random copolymer processing parameters masterbatch types masterbatch contents ultraviolet degradation storage time

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Multi-Response Optimization of Injection Moulding processing parameters Using the Taguchi Method

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POLYMER-PLASTICS TECHNOLOGY AND ENGINEERING 2011年第15期50卷 1519-1526页

作者： Mehat, Nik Mizamzul Kamaruddin, Shahrul Univ Sains Malaysia Sch Mech Engn Nibong Tebal 14300 Pulau Pinang Malaysia Kolej Kemahiran Tinggi MARA Balik Pulau Genting Dept Mould Technol Balik Pulau Penang Malaysia

Determining the superlative optimal processing parameters on multi-responses is an intricate task. A new constitutive approach in solving multi-response problems using a combination of single responses through the Taguchi method is developed in this study. Mechanical properties improvement of the part made of recycled PP is highlighted to demonstrate the significance of the approach. From the results, the flexural modulus and strength of the part produced by the approach improved to 4.1% and 6.7%. Therefore, the solution from this approach can be used by engineers who are searching for a simple and straightforward optimal solution using the injection moulding process.

关键词： Multi-response Optimization processing parameters Recycled plastic Taguchi method

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Influence of processing parameters on dynamic recrystallization and the associated annealing twin boundary evolution in a nickel base superalloy

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MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND processing 2017年 700卷 49-58页

作者： Pradhan, S. K. Mandal, S. Athreya, C. N. Babu, K. Arun de Boer, B. Sarma, V. Subramanya Indian Inst Technol Khcragpur Dept Met & Mat Engn Kharagpur 721302 W Bengal India Indian Inst Technol Madras Dept Met & Mat Engn Madras 600036 Tamil Nadu India VDM Met GmbH Plettenberger Str D-258791 Werdohl Germany

Dynamic recrystallization (DRX) kinetics and its association with annealing twins in alloy 617 has been studied in a range of strain rates (0.001 s(-1) to 10 s(-1)) and temperatures (1173-1473 K). In both low (< 0.1 s(-1)) and high (>= 1 s(-1)) strain rate domains, DRX fraction is high as compared to intermediate strain rate (similar to 0.1 s(-1)). The lower critical strain for DRX initiation with higher growth of DRX grains is responsible for large DRX fraction with coarse grains microstructure in the low strain rate domain. In contrast, DRX at higher strain rates is mainly controlled by the large stored energy along with adiabatic temperature rise which leads to higher DRX nucleation. It is also noticed that the evolution of twins is greatly influenced by deformation temperature at all imposed strain rates. Here, the evolution of twins is quantified by measuring twin boundary length fraction and length density. The twin-length density increases with increase in DRX fraction at low temperatures (< 1423 K) but decreases with increasing DRX fraction at high temperatures (>= 1423 K). An exponential rise in recrystallized grain size with DRX fraction is observed at a temperature >= 1423 K. This suggests that rapid migration of high-angle boundaries happened at >= 1423 K which may not be favorable for nucleation of twins during DRX.

关键词： Ni-base superalloy Dynamic recrystallization Hot deformation processing parameters Annealing twin

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Determination of CNC processing parameters for the best wood surface quality via artificial neural network

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WOOD MATERIAL SCIENCE & ENGINEERING 2022年第6期17卷 685-692页

作者： Demir, Aydin Cakiroglu, Evren Osman Aydin, Ismail Karadeniz Tech Univ Fac Forestry Dept Forest Ind Engn TR-61080 Trabzon Turkey Artvin Coruh Univ Artvin Vocat Sch Mat & Mat Proc Artvin Turkey

The optimum adjustment the CNC (Computer Numerical Control) processing parameters is extremely important, especially in finishing processes such as coating, painting, and varnishing where surface quality is required. This work aimed to determine the CNC processing parameters for the best wood surface quality by ANN (Artificial Neural Network). For this aim, the surface roughness values of intermediate values not used in experimental studies were also estimated and the effects of parameter variables for each wood species were revealed. Surface roughness measurements (Ra) were made according to the DIN 4768 to determine the surface quality of wood materials. The prediction model with the best performance was determined through statistical and graphical comparisons. It has been observed that ANN models achieve quite satisfactory results with acceptable deviations. As a result of ANN analysis, the optimum values of tool diameter, spindle speed and feed rate for spruce wood were determined as 2 mm, 10000 rpm and 5 m/min, respectively. These values for beech wood were determined as 4 mm, 12500 rpm, 5 m/min, respectively. The findings of this study can be effectively applied in the furniture industry to reduce time, energy, and cost for experimental research within the range of experimentation conducted.

关键词： Artificial neural network CNC machine surface quality processing parameters

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Effect of processing parameters on the microstructural and mechanical properties of aluminum-carbon nanotube composites produced by spark plasma sintering

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INTERNATIONAL JOURNAL OF MATERIALS RESEARCH 2018年第10期109卷 900-909页

作者： Sadeghi, B. Shamanian, M. Cavaliere, P. Ashrafizadeh, F. Isfahan Univ Technol Dept Mat Engn Esfahan Iran Univ Salento Dept Innovat Engn Via Arnesano I-73100 Lecce Italy

Spark plasma sintering (SPS) has been recognized, in the recent past, as a very useful method to produce metal matrix composites with enhanced mechanical and wear properties. Obviously, the material's final properties are strongly related to the reinforcement types and percentages as well as to the processing parameters employed during synthesis. The present paper analyses the effect of 0.5 and 1 % of carbon nanotubes addition on the mechanical and microstructural behavior of Al-based metal matrix composites produced via SPS. The microstructural and mechanical behavior is analyzed as a function of the SPS parameters: heating rate, sintering temperature and pressure.

关键词： Spark plasma sintering Nanocomposites Carbon nanotubes processing parameters

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