Resistive Heating of Carbon Fiber Aided Rapid Curing of Vacuum Assisted Resin Infusion Molding

2014 ◽  
Vol 1030-1032 ◽  
pp. 170-173 ◽  
Author(s):  
Kao Min Zhang ◽  
Yi Zhuo Gu ◽  
Min Li ◽  
Shao Kai Wang ◽  
Zuo Guang Zhang
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Carbon Fiber ◽  
Cycle Time ◽  
Rapid Heating ◽  
Water Cooling ◽  
Cooling Process ◽  
Resistive Heating ◽  
Processing Cycle

A kind of rapid heating method which takes advantage of carbon fiber conductivity to shorten the cycle time of VARIM was designed in present paper. The processing cycle time, curing degree, glass transition temperature and mechanical properties of the laminates fabricated by carbon fiber internal resistive heating aided VARIM (R-VARIM) were studied. The results revealed that the cyle time of R-VARIM with con-water cooling process is only 450s, it is about 52% lower than that of previous study. Lower cooling rate before glass transition temperature is useful to complete cure of resin and improve the properties of the composites.

Study of the effect of the reinforcement direction on the identification of relaxation transitions of moisture-saturated carbon fiber VKU-25

2021 ◽  
Vol 87 (9) ◽  
pp. 38-43
Author(s):  
O. G. Ospennikova ◽  
P. S. Marakhovsky ◽  
N. N. Vorobyov ◽  
E. V. Nikolaev ◽  
A. I. Gulyaev ◽  
...  
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Carbon Fiber ◽  
Polymer Matrix ◽  
Structural Parameters ◽  
Polymer Materials ◽  
Thermal Coefficient ◽  
Initial State ◽  
Relaxation Transitions

Thermodilatometric methods of analysis are used to study the structural parameters of polymer materials, however, when studying moisture-saturated compositions certain difficulties arise in their identification. The results of thermophysical tests of VKU-25 carbon fiber samples in the initial state and after moisture saturation are presented. It is shown that heat treatment of materials affects the recorded values of the glass transition temperature of the epoxy matrix. When the samples are exposed in water or above the water surface, the sorbate penetrates into the polymer at the same rate, which is confirmed by almost identical values of water absorption at the same exposure time. The estimates of the thermal coefficient of linear expansion (TCLE) of the samples in the range of 20 - 250°C are given. Moreover, it is shown that the glass transition temperature of the plasticized polymer matrix depends on the direction of fiber reinforcement. In the case of moisture-saturated carbon fiber (CF)heated to 210°C, the formation of main cracks occurs mainly at the fiber-matrix interface. The glass transition temperature (GTT) of the material in the dry state (176 - 177°C), appeared almost independent on the heating rate, whereas for water-saturated samples, GTT changes significantly and can be described by a polynomial of the 2nd order. After exposure of the carbon fiber under conditions of high temperature and humidity, two relaxation transitions corresponding to the systems occur in the polymer matrix: epoxidian oligomer— amine hardener and polyfunctional resin— amine hardener. The glass transition temperature is 132 and 159°C in the first and in the second, respectively. The results obtained can be used in the development of new polymer composite materials.

Evaluation of the glass transition temperature variability of carbon-fiber plastic produced by the autoclave molding method

2019 ◽  
Vol 9 ◽  
pp. 17-24
Author(s):  
P. S. Marahovskij ◽  
◽  
O. G. Ospennikova ◽  
D. Ya. Barinov ◽  
N. N. Vorobev ◽  
...  
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Carbon Fiber ◽  
Temperature Variability ◽  
Molding Method ◽  
Fiber Plastic ◽  
Carbon Fiber Plastic

Foaming of Polystyrene/Supercritical CO2 in Rapid Decompression and Cooling Process

2006 ◽  
Vol 11-12 ◽  
pp. 761-764
Author(s):  
Xiao Dan Wu ◽  
Yu Cheng Peng
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Diffusion Mechanism ◽  
Gravimetric Method ◽  
Batch Process ◽  
Expansion Ratio ◽  
Cooling Process ◽  
Co2 Diffusion ◽  
Rapid Decompression

Foaming of polystyrene (PS)/ supercritical dioxide system was studied in a batch process in order to achieve a better understanding of supercritical CO2 diffusion mechanism in polymer and foaming condition. In this study, PS sample was treated with CO2 at 5-30 MPa and 40-160°C, soaking times was about 30-120min.Using gravimetric method, the solubility of CO2 in PS was obtained. The study datum shows that the solubility of CO2 in PS increases with increment of pressures, but decreases with the increment of temperature. The sorbed amount of CO2 is from 0.02 % (7MPa,160°C) to 0.11%(30MPa,40°C).The relation of glass transition temperature, volume expansion ratio, cells density of foaming with pressure and temperature also was discussed individually. The glass transition temperature of PS swelled with CO2 is 80°C-95°C, which is lower than the glass transition temperature of pure PS by 10°C-25°C. The cell density increases as the pressure increase, and it decrease as the temperature increase.

Evaluation of the Variability of Glass Transition Temperature of Carbon-Fiber-Reinforced Plastic Fabricated by Autoclave Molding

2020 ◽  
Vol 13 (1) ◽  
pp. 73-79
Author(s):  
P. S. Marakhovskii ◽  
O. G. Ospennikova ◽  
D. Ya. Barinov ◽  
N. N. Vorob’ev ◽  
S. Yu. Shorstov ◽  
...  
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Carbon Fiber ◽  
Carbon Fiber Reinforced Plastic ◽  
Fiber Reinforced ◽  
Fiber Reinforced Plastic ◽  
Reinforced Plastic ◽  
Carbon Fiber Reinforced

A Rapid Heating and Cooling Rate Dilatometer for Measuring Thermal Expansion in Dental Porcelain

1989 ◽  
Vol 68 (9) ◽  
pp. 1316-1318 ◽  
Author(s):  
S.W. Twiggs ◽  
J.R. Searle ◽  
R.D. Ringle ◽  
C.W. Fairhurst
Keyword(s):  
Thermal Expansion ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Rapid Heating ◽  
Optical Pyrometer ◽  
Thermal Expansion Data ◽  
Dental Porcelain ◽  
Temperature Range ◽  
Heating And Cooling

Herein we describe a dilatometer that consists of a low-mass infrared furnace for rapid heating or cooling, an optical pyrometer, and a laser interferometer. The dilatometer facilitates observations of thermal expansion at rates comparable with those in dental laboratory practice over the temperature range necessary for comparison of thermal expansion of dental porcelain and alloy. Examples of thermal expansion data obtained at a 600°Clmin heating rate on NIST SRM 710 glass and dental porcelain are reported. To a limited extent, thermal expansion data above the glass-transition temperature range of dental porcelain were obtained. A shift of the glass-transition temperature range to higher temperatures was observed for both materials, compared with data obtained at 20°Clmin.

scholarly journals Deformation Resistance Performance of Carbon Fiber-Reinforced Plastic Machined by Controlling Drilling Area Temperature below the Glass Transition Temperature

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1394
Author(s):  
Chenping Zhang ◽  
Xiaohui Zhang ◽  
Yugang Duan ◽  
Yu Xia ◽  
Yueke Ming ◽  
...  
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Carbon Fiber ◽  
Cryogenic Treatment ◽  
Deformation Resistance ◽  
Cryogenic Machining ◽  
Fiber Reinforced ◽  
Machining Performance ◽  
Carbon Fiber Reinforced

Drilling of carbon fiber-reinforced plastics (CFRPs) is a challenging task in aviation and aerospace field. Damages, which can reduce the strength of the structure, often occur during secondary machining operations due to the applied cutting force and generated heat. The main objective of this study was to investigate the drilling performance and the deformation resistance of CFRPs subjected to cryogenic treatment based on glass transition temperature (Tg). Therefore, a cryogenic machining approach was adopted by fixing the workpiece inside a cryogenic box to drill CFRPs. The machining performance was briefly evaluated. Moreover, a through-hole drilling method was promoted to analyze the mechanism of different deformation mechanical properties. The results showed that the cryogenic machining approach improved the machining performance of CFRPs. Nevertheless, the residual intensity of cryo-treated specimen decreased (about 7.14%) due to the Tg-based viscoelasticity. These results demonstrate the great potential of this approach in advanced industrial applications and further pave the way for efficient secondary machining operation of CFRP components.

Effect of locally deposited nanosilica particles on interlaminar fracture toughness of high glass-transition temperature epoxy carbon fiber-reinforced composites

2019 ◽  
Vol 53 (25) ◽  
pp. 3599-3614 ◽  
Author(s):  
Bryan M Louis ◽  
Florian Klunker ◽  
Paolo Ermanni
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Carbon Fiber ◽  
Fracture Energy ◽  
Composite Laminates ◽  
Particle Distribution ◽  
Fiber Reinforced ◽  
High Glass Transition Temperature ◽  
Nanosilica Particles

This study explores the toughening of fiber-reinforced composite laminates to prevent against mode 1 delamination by using a selective placement of nanosilica particles in only the out-of-tow interlaminar regions of the laminate. In place of a conventional homogenous particle distribution throughout the laminate, “selective toughening” through controlled particle deposition is examined with the objective to increase the nanosilica toughening efficiency. Using a laboratory-scale manufacturing route conceptually similar to a combined prepreg and resin-film process, uni-directional carbon fiber composite laminates containing high glass-transition temperature amine-cured Dow D.E.R. 330 epoxy are produced from both particle distribution configurations. Comparisons are made by double cantilever beam testing for mode 1 delamination fracture energy G1C and by examination of the fracture surfaces. The results show that further nanosilica toughening efficiency is possible with local deposition and toughening compared to the conventional homogenous particle distribution throughout the laminate. For the same total nanosilica particle content in the laminate, the delamination toughening effects are maintained or improved when locally toughened in only the out-of-tow interlaminar regions. For mode 1 delamination initiation and propagation, fracture energy increases in the range of 60% over the untoughened laminates are found for the laminates with a local particle distribution. By comparison, those laminates with a conventional homogeneous particle distribution saw increase of 20–35% over the untoughened laminates. The implications of the localized toughening approach are discussed to provide further guidance in optimizing the use of nanosilica particles and particle toughening in general in composite laminates.

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