Influence of Melt Temperature on Structure of Polyacrylonitrile in Ionic Liquids during Plasticized Melt Spinning Process

2012 ◽  
Vol 268-270 ◽  
pp. 483-486
Author(s):  
Yin Cai Tian ◽  
Ke Qing Han ◽  
Wen Hui Zhang ◽  
Jing Jie Zhang ◽  
Rui Zhang ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Melt Spinning ◽  
Extrusion Process ◽  
Heat Emission ◽  
Processing Efficiency ◽  
Melt Temperature ◽  
Stabilization Process ◽  
In Situ Modification ◽  
Spinning Process ◽  
Dehydrogenation Reactions

The carbon fiber has excellent properties; however, the high cost limited its wide application. Here we report a novel process to reduce the heat emission during stabilization by in situ modification of spinning melt. In this paper, the effect of extruding temperature on the structures of PAN in the PAN/ILs melt was investigated by twin-screw extruder. FTIR and UV-vis absorption spectra of modified samples showed the formation of C=C and C=N group, which indicated the occurrence of cyclization and dehydrogenation reactions of PAN during extrusion process. The degree of cyclization was calculated from DSC test and the degree of cyclization can be up to 24.5% with the residence time of 14 min at 210 oC, which could decrease the heat release in the subsequent stabilization process during carbon fiber production. Therefore, this method should be benefit to improve the processing efficiency during stabilization process.

Pitch Carbon Fiber Melt Spinning Diameter Stabilization Method Based on Radial Basis Function Neural Network

2012 ◽  
Vol 538-541 ◽  
pp. 1281-1285
Author(s):  
Ju Mei Yuan ◽  
Yu Xiao Shen ◽  
Bin Liu ◽  
Min Zhou ◽  
Jun Qing Liu
Keyword(s):  
Neural Network ◽  
Carbon Fiber ◽  
Radial Basis Function ◽  
Basis Function ◽  
Melt Spinning ◽  
Measured Data ◽  
Wire Diameter ◽  
Stabilization Method ◽  
Radial Basis ◽  
Spinning Process

In order to control the wire diameter stability for pitch carbon fiber melt-spinning effectively, this can affect the performance of carbon fiber. This paper presents an asphalt carbon fiber melt-spinning wire diameter stabilization method based on radial basis function neural network. Firstly, the relation model that pitch carbon fiber melt-spinning wire diameter, spinning temperature, spinning pressure and spinning roller speed was established through measured data based on radial basis function neural network. Then control the spinning temperature, pressure and spinning rollers speed coordination changes to ensure the stability of spinning wire diameter in spinning process. Finally, we apply this method to our laboratory measured data and compared with existing experience formula. The result shows that the method is feasible and effective

scholarly journals Rheology of Polyacrylonitrile/Lignin Blends in Ionic Liquids under Melt Spinning Conditions

Molecules ◽  
2019 ◽  
Vol 24 (14) ◽  
pp. 2650 ◽  
Author(s):  
Jinxue Jiang ◽  
Keerthi Srinivas ◽  
Alper Kiziltas ◽  
Andrew Geda ◽  
Birgitte K. Ahring
Keyword(s):  
Carbon Fiber ◽  
Carbon Fibers ◽  
Melt Spinning ◽  
Lower Cost ◽  
Biomass Pretreatment ◽  
Limited Success ◽  
Spinning Process ◽  
Physical Interactions ◽  
Butyric Anhydride ◽  
Newtonian Behavior

Lignin, while economically and environmentally beneficial, has had limited success in use in reinforcing carbon fibers due to harmful chemicals used in biomass pretreatment along with the limited physical interactions between lignin and polyacrylonitrile (PAN) during the spinning process. The focus of this study is to use lignin obtained from chemical-free oxidative biomass pretreatment (WEx) for blending with PAN at melt spinning conditions to produce carbon fiber precursors. In this study, the dynamic rheology of blending PAN with biorefinery lignin obtained from the WEx process is investigated with the addition of 1-butyl-3-methylimidazolium chloride as a plasticizer to address the current barriers of developing PAN/lignin carbon fiber precursors in the melt-spinning process. Lignin was esterified using butyric anhydride to reduce its hydrophilicity and to enhance its interactions with PAN. The studies indicate that butyration of the lignin (BL) increased non-Newtonian behavior and decreased thermo-reversibility of blends. The slope of the Han plot was found to be around 1.47 for PAN at 150 °C and decreased with increasing lignin concentrations as well as temperature. However, these blends were found to have higher elasticity and solution yield stress (47.6 Pa at 20%wt BL and 190 °C) when compared to pure PAN (5.8 Pa at 190 °C). The results from this study are significant for understanding lignin–PAN interactions during melt spinning for lower-cost carbon fibers.

Study on the mechanism of inhomogeneous microdamage in short-pulse laser processing of carbon fiber reinforced plastic

2021 ◽  
pp. 073168442098359
Author(s):  
Luyao Xu ◽  
Jiuru Lu ◽  
Kangmei Li ◽  
Jun Hu
Keyword(s):  
Carbon Fiber ◽  
Pulse Energy ◽  
Short Pulse ◽  
Heterogeneous Material ◽  
Carbon Fiber Reinforced Plastic ◽  
Fiber Reinforced ◽  
Processing Efficiency ◽  
Fiber Reinforced Plastic ◽  
Reinforced Plastic ◽  
Carbon Fiber Reinforced

In this article, a micro-heterogeneous material simulation model with carbon fiber and resin phase about laser ablation on carbon fiber reinforced plastic (CFRP) is established by Ansys. The ablation process of CFRP by nanosecond ultraviolet laser is simulated, and the mechanism of pulse energy and spot spacing on the heat-affected zone (HAZ) is studied, then the process parameters are optimized with the goal of HAZ size and processing efficiency, and finally the validity of the model is verified by experiments. It is found that the residual gradient and the width of the radial HAZ increase with the increase of the spot spacing, and the width of the axial HAZ decreases slightly with the increase of the spot spacing, which indicates the existence of the optimal spot spacing. Second, the ablation depth increases with the increase of the pulse energy, and the carbon fiber retains a relatively complete degree of exposure when the pulse energy is low, which has a certain guiding significance for the cleaning and bonding of CFRP.

Effect of Crucible Parameters on Planar Flow Melt Spinning Process

2015 ◽  
Vol 68 (6) ◽  
pp. 1125-1129 ◽  
Author(s):  
M. Swaroopa ◽  
L. Venu Gopal ◽  
T. Kishen Kumar Reddy ◽  
B. Majumdar
Keyword(s):  
Melt Spinning ◽  
Planar Flow ◽  
Spinning Process

scholarly journals Friction-Induced Recycling Process for User-Specific Semi-Finished Product Production

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 663
Author(s):  
Thomas Borgert ◽  
Werner Homberg
Keyword(s):  
High Efficiency ◽  
Research Work ◽  
Hot Extrusion ◽  
Extrusion Process ◽  
Efficient Production ◽  
Secondary Aluminum ◽  
Shape Accuracy ◽  
Aluminum Chips ◽  
Spinning Process ◽  
Complex Parts

Modern forming processes often allow today the efficient production of complex parts. In order to increase the sustainability of forming processes it would be favorable if the forming of workpieces becomes possible using production waste. At the Chair of Forming and Machining Technology of the Paderborn University (LUF) research is presently conducted with the overall goal to produce workpieces directly from secondary aluminum (e.g., powder and chips). Therefore, friction-based forming processes like friction spinning (or cognate processes) are used due to their high efficiency. As a pre-step, the production of semi-finished parts was the subject of accorded research work at the LUF. Therefore, a friction-based hot extrusion process was used for the full recycling or rework of aluminum chips into profiles. Investigations of the recycled semi-finished products show that they are comparable to conventionally produced semi-finished products in terms of dimensional stability and shape accuracy. An analysis of the mechanical properties of hardness and tensile strength shows that a final product with good and homogeneously distributed properties can be produced. Furthermore, significant correlations to the friction spinning process could be found that are useful for the above-mentioned direct part production from secondary aluminum.

PLA/Carbon Nanotubes Multifilament Yarns for Relative Humidity Textile Sensor

2011 ◽  
Vol 6 (3) ◽  
pp. 155892501100600 ◽  
Author(s):  
Eric Devaux ◽  
Carole Aubry ◽  
Christine Campagne ◽  
Maryline Rochery
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Relative Humidity ◽  
Melt Spinning ◽  
Flexible Sensor ◽  
Spinning Process ◽  
Textile Sensor ◽  
Multifilament Yarns

Polylactide (PLA) was mixed with 4 wt.% of carbon nanotubes (CNTs) to produce electrical conductive multifilament yarns by melt spinning process for humidity detection. Thanks to a variation of electrical conductivity, this flexible sensor could detect the moisture presence. The introduction of plasticizer was necessary to ensure higher fluidity and drawability of the blend during the spinning process. The plasticizer modifies the crystallinity and the mechanical properties of the yarns. The effectiveness of this sensor (PLA/4 wt.% CNTs fibres) sensitive to humidity, is optimal when the spinning conditions are adapted. In this way, the temperature and the rate of the drawing roll were reduced. The influence of these parameters on the crystallinity, the mechanical properties and the sensitivity of the yarns were studied. Once the appropriate spinning conditions found, one humidity sensitive yarn was processed and the repeatability and efficient reversibility of its sensitivity were highlighted.

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