scholarly journals Investigation of Press Forming Process for CF/PEEK and GF/PP Thermoplastic Composite Materials

2021 ◽  
Vol 2 (3) ◽  

Aerospace industry requires engineering materials with significant mechanical strength, low cost, easy to recycle, easy to process, and high chemical resistance. Thermoplastic composites are considered as new generation aerospace structural materials due to their superior characteristics. In this study, one of the most common methods used in manufacturing of thermoplastic composite parts from unidirectional (UD) pre-consolidated prepreg (blank), press forming process is investigated and crack behavior of the samples is examined. The forming process is utilized, and consolidated blanks of UD CF/PEEK and GF/PP composite materials are shaped by pressing, and mechanical tests are performed. Micro defects on the samples are monitored by microscopic examination and scanning electron microscopy (SEM) analysis. Results show that when the temperatures of CF/PEEK and GF/PP blank are increased by preheating, the formability of both composites are enhanced. Final outcomes reveal that both CF/PEEK and GF/PP composite materials can easily be used for possible aircraft structures. Additionally, CF/PEEK is found to be appropriate not only secondary structures but also for primary structures.

2021 ◽  
Vol 36 (1) ◽  
pp. 35-43
Author(s):  
M. Längauer ◽  
G. Zitzenbacher ◽  
C. Burgstaller ◽  
C. Hochenauer

Abstract Thermoforming of thermoplastic composites attracts increasing attention in the community due to the mechanical performance of these materials and their recyclability. Yet there are still difficulties concerning the uniformity of the heating and overheating of parts prior to forming. The need for higher energy efficiencies opens new opportunities for research in this field. This is why this study presents a novel experimental method to classify the efficiency of infrared heaters in combination with different thermoplastic composite materials. In order to evaluate this, different organic sheets are heated in a laboratory scale heating station until a steady state condition is reached. This station mimics the heating stage of an industrial composite thermoforming device and allows sheets to slide on top of the pre-heated radiator at a known distance. By applying thermodynamic balances, the efficiency of chosen parameters and setups is tested. The tests show that long heating times are required and the efficiency of the heating is low. Furthermore, the efficiency is strongly dependent on the distance of the heater to the sheet, the heater temperature and also the number of heating elements. Yet, using a full reflector system proves to have a huge effect and the heating time can be decreased by almost 50%.


2014 ◽  
Vol 618 ◽  
pp. 140-145
Author(s):  
Yang Liu ◽  
Ren Zhang ◽  
En Quan Liang ◽  
Dong Li ◽  
Ying Chen ◽  
...  

The history of GLARE laminate was introduced. Through comparison with conventional aluminum alloy sheets, the excellent performance of GLARE as a new generation aeronautic material is discussed. The properties and application of GLARE in large civil aircraft indicates that new composite materials such as GLARE will replace bulk aluminum alloy in future aircraft structure. With the continuous development of material technologies, a trend of developing high strength and low cost composite materials will lead aviation industry to a new stage.


2011 ◽  
Vol 217-218 ◽  
pp. 1683-1688 ◽  
Author(s):  
Wei Tian ◽  
Yan Qing Li ◽  
Zhao Hang Feng ◽  
Cheng Yan Zhu

The preforms were woven by the co-yarns which were consisted of GF, PP and PET. Then the co-yarns were manufactured into hybrid thermoplastic composites. The parameters of the forming process were studied by analyzing the tensile properties of the composites. The results show that the composite holds the best tensile properties when the pressure is 5MPa, the packing temperature is 190°C, and the holding time is 30 min. The existing of a second pressure of 10 MPa at 150°C for 3 min will help to improve the capacity of the load supporting for the GF/PET thermoplastic composites


2021 ◽  
pp. 095400832110515
Author(s):  
Guangming Dai ◽  
Lihua Zhan ◽  
Chenglong Guan ◽  
Minghui Huang

The forming process is the core factor to control the quality of thermoplastic composite components. In this paper, the common I-stiffened structures in the aerospace field were taken as the research object, and the forming process scheme was designed. Based on the prefabrication of C-shaped parts, the I-stiffened structures were prepared by the compression molding process. The influence law of molding temperature on the quality of the prefabricated C-shaped parts was explored. The time dependence of the PEEK melt viscosity was tested to provide the basis for the optimization of forming process parameters of I-stiffened structures. The influencing mechanism of thermoplastic composites repeatedly forming to the bonding strength of remelting interface was studied. The results show that repeated forming would lead to polymer aging and result in low bonding strength at the remelting interface of the I-stiffened structures. Optimizing the forming process could effectively reduce the aging of materials and improve the bonding strength of the remelting interface and overall mechanical properties of components. The research provides technical guidance for the manufacturing of complex thermoplastic composite components, especially the influence mechanism of the forming process on the bonding strength of remelting interface.


2020 ◽  
Vol 8 (2) ◽  
pp. 68-129
Author(s):  
J. Müssig ◽  
N. Graupner

Due to the increasing discussion about sustainable and CO2-reduced materials, the demand for cellulose-based fibres as a reinforcing component in thermoplastic composites has increased considerably. Knowledge about the possibilities of modifying fibres for improved adhesion to the plastic matrix is essential in this context. The fibre/matrix adhesion in cellulose fibre-reinforced polymers is of considerable importance for the design of composite materials. Unfortunately, there are no standards for many essential methods to determine fibre/matrix adhesion. In this review article, various methods for measuring the interfacial shear strength between fibres and matrix, as an indirect characterisation of adhesion, are presented. Additionally, a brief overview of different methods for surface modification of cellulose fibres to improve the adhesion to a thermoplastic matrix is given. This review focuses on the fact that the parameters for the production of test specimens as well as the test method itself can vary considerably from study to study. Because of this, the comparison of data from different publications is not always possible. Therefore, in this article, the main influencing factors and differences in the methods are presented and discussed. Based on a systematic review and a clear description and discussion of the methods, the reader is given a broad basis for a better understanding of characteristic values for fibre/matrix adhesion.


2009 ◽  
Vol 620-622 ◽  
pp. 241-246 ◽  
Author(s):  
Xue Gang Luo ◽  
Xiao Yan Lin ◽  
Feng Liu

New technique has been used to extract of lignin by adding carboxylic acid derivates and organic solvent to precipitate and extract lignin from black liquor (pulp wastewater). Through this new treatment process, new carboxylate which is decomposed to carbondioxide, water and metal oxide at the high temperature was formed. The process of using organic carboxylic acid and organic solvent to precipitate and extract lignin is low-cost and can not cause second pollution. The lignin obtained through this new process is water insoluble and thermoplastic. Its weigh average molecular weight, purity, and glass transition temperature are higher than 2000, 90% and 150°C, respectively. Through the methods of thermoplastic modification, the thermoplastic properties for high purity lignin-based composite materials are improved significantly. Its melt flow ratio, tensile strength and elongation at break are 0.73 g/10 min, 11.8 MPa, and 21%, respectively. Thermoplastic lignin-based composite materials have good processing properties as well as synthetic polymers for extruding, injection molding, and blowing processes. Lignin, as a kind of natural thermoplastic polymers with good processing properties, can be carried out to process for film, foam, and thermoplastic composite.


2012 ◽  
Vol 504-506 ◽  
pp. 243-248 ◽  
Author(s):  
Peng Wang ◽  
Nahiene Hamila ◽  
Philippe Boisse

The Continuous Fibre Reinforcements and Thermoplastic resin (CFRTP) are widely employed in the prepreg processes. Currently, the most used thermoplastic resins in aeronautics are PPS (polyphenylene sulfide) and PEEK (Polyetheretherketone). They present many advantages on their mechanical properties. However, these mechanical properties depend strongly upon the thermoforming conditions, especially the intraply shearing. In order to improve and complete the understanding about the in-plane shear behavior of thermoplastic composite materials in their forming processes, the thermo-mechanical analysis of PPS/carbon and PEEK/carbon commingled fabrics at different forming temperatures are performed by using the bias-extension tests. The experimental data leads to significant difference on the in-plane shear behavior under different temperature, as well as the wrinkles can be noted in certain thermoforming conditions. Therefore, in order to predict the feasible forming conditions and optimize the important forming parameters of the thermoplastic composites, the in-plan shear behaviors in function of temperature will be integrated into our numerical model to carry out the numerical simulations of thermoforming processes.


2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
B. Senthil Kumar ◽  
Subramanian Balachandar

A thermoplastic composite is produced from polypropylene matrix with glass fibre reinforcement. These types of composite materials are ecofriendly nature due to their reusability after their lifetime. These polymer composites are alternative to heavy metals that are currently being used in many non-structural applications. In spite of being ecofriendly nature, the range of applications is limited due to poor mechanical properties as compared with thermoset matrix composite. Hence an attempt was made in this work to improve the mechanical property such as flexural property of Glass/PP hybrid woven composites by optimizing the parameters during compression moulding, such as mould pressure, mould temperature, and holding time using Box-Behnken experimental design. Each process variables were taken in 3 different levels. Second order polynomial model with quadratic effect was chosen. The optimum combination of process parameters was obtained by using contour diagram. The levels of importance of process parameters on flexural properties were determined by using analysis of variance (ANOVA). The variation of flexural property with cited process parameters was mathematically modelled using the regression analysis.


2010 ◽  
Vol 129-131 ◽  
pp. 1238-1243 ◽  
Author(s):  
Wei Gou Dong ◽  
Hai Ling Song

Two forms of perform were prepared by a Glass fiber/Polypropylene fiber commingled yarn. One was a three-dimensional woven fabric with an angle-interlock structure, and another was a two-dimensional plain woven fabric laminate. The three-dimensional woven fabric reinforced thermoplastic composites(3-DWRC) and two-dimensional woven fabric reinforced thermoplastic composites(2-DWRC) were fabricated by hot-press process. The Impact and tensile performances of both 3-DWRC and 2-DWRC were examined. Compared to the 2-DWRC, the 3-DWRC have better impact properties, the energy required to initiate cracks, the threshold force of the first oscillation and maximum load increased by 41.90%, 54.41%, 38.75% respectively under the low-energy impact conditions. The tensile tests shown that the 3-DWRC presented batter fracture toughness than the 2-DWRC. The use of thermoplastic composites is growing rapidly because of their excellent properties, a high toughness and damage tolerance, short processing cycles, and the ability to be reprocessed. But thermoplastic materials usually have a difficulty to impregnate between reinforcing fibers, due to high melt polymer viscosity. It is a technology innovation that the commingled yarns composed of reinforced fibers and thermoplastic fibers are used as prepreg for thermoplastic composite materials. Because thermoplastic fiber and reinforced fiber are closely combined, which reduces distances of resin’s infiltration, this can effectively overcome the difficulties of resin’s impregnation. The commingled yarns can be woven and knitted, and can facilitate the processing of complex structural composites. Three-dimensional fabrics reinforced composites are ideal materials with excellent integrity because it is linked with yarns between layers. Its shearing strength between layers, damage tolerance and reliability are better than the two-dimensional fabric laminated composites. At present, the researches of thermoplastic materials with two-dimensional fabric reinforced structure made from commingled yarns are much more, such as manufacturing technology, material properties ,effects of process conditions on properties, relationship between structures and properties, and so on [1-8]. However, only a few studies appear in literature on the structure-property relationships of three-dimensional fabric reinforced thermoplastic composite materials made of commingled yarns [9-10]. Byun, Hyung Joon et al. [9] undertook the impact test and the tensile test on 3-D woven thermoplastic composite materials and 2-D plain woven laminate which is made by CF/PEEK mixed yarn. Dong Weiguo and Huang Gu[10] studied the porosity, tensile and bending properties on 3-D woven thermoplastic composites which make from core-spun yarn containing glass fibers and polypropylene fibers. The aim of this study was to investigate the impact behavior of and tensile properties of 3-D woven fabric thermoplastic composites made by a GF/PP commingled yarns. Attempts was made to identify the damage mode of the 3-D woven fabric thermoplastic composites under the low energy impact and tensile conditions.


2021 ◽  
Author(s):  
Camille Vernejoux ◽  
Xavier Fischer ◽  
Simon Deseur ◽  
Emmanuel Duc

In recent years, advanced manufacturing processes have been developed to increase the speed of production in order to reduce production costs. At the scale of thermoplastic composites, the translation is the combination of advanced manufacturing processes. The focus in this study is more specifically on the coupling of automated lay-up (AFP) and stamp forming processes. To date, a consolidation process, such as press-consolidation of thermoplastic composites, obtained blanks. Several trials have begun using an automated fiber placement consolidation to reduce manufacturing time and use unidirectional material. However, the combination of AFP and stamp forming is useful if it optimizes this process without the blank’s full consolidation, which by resulting reduces the manufacturing time. This study estimates blank characteristics through thermal history imposed by a more rapid manufacturing process. A set of blanks with varying process parameters is produced to investigate the influence at the microscopic scale. The interface behaviour is observed with optical microscope and image processing. A statistical study applied to the process is carried out in order to relate the material observations to the input parameters. The results of this study are used for the study of the next process of the combination: the stamp forming.


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