Numerical Model for Compression Molding Process of Hybridly Laminated Thermoplastic Composites based on Anisotropic Rheology

Sandwich composites are widely used in the manufacture of aircraft cabin interior panels for commercial aircraft, mainly due to the light weight of the composites and their high strength-to-weight ratio. Panels are used for floors, ceilings, kitchen walls, cabinets, seats, and cabin dividers. The honeycomb core of the panels is a very light structure that provides high rigidity, which is considerably increased with fiberglass face sheets. The panels are manufactured using the compression molding process, where the honeycomb core is crushed up to the desired thickness. The crushed core breaks fiberglass face sheets and causes other damage, so the panel must be reworked. Some damage is associated with excessive build-up of resin in localized areas, incomplete curing of the pre-impregnated fiberglass during the manufacturing process, and excessive temperature or residence time during the compression molding. This work evaluates the feasibility of using rigid polyurethane foams as a substitute for the honeycomb core. The thermal and viscoelastic behavior of the cured prepreg fiberglass under different manufacturing conditions is studied. The first part of this work presents the influence of the manufacturing parameters and the feasibility of using rigid foams in manufacturing flat panels oriented to non-structural applications. The conclusion of the article describes the focus of future research.

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Estimation of Maximum Flow Length for CF-PEEK Overmolded Grid Structures Using the Finite Element Method

Volume 2: Manufacturing Processes; Manufacturing Systems; Nano/Micro/Meso Manufacturing; Quality and Reliability ◽

10.1115/msec2021-62311 ◽

2021 ◽

Author(s):

Carlos Rodríguez-Mondéjar ◽

Álvaro Rodríguez-Prieto ◽

Ana María Camacho

Keyword(s):

Aspect Ratio ◽

Injection Molding ◽

Cross Section ◽

Maximum Flow ◽

Thermoplastic Composites ◽

Injection Molding Process ◽

Geometrical Parameters ◽

Molding Process ◽

Support Tool ◽

Flow Length

Abstract Injection overmolding process is a high versatile process that permits, when used in combination with fiber reinforced thermoplastic composites, the obtaining of high mechanical properties structures with complex geometries in short time cycles. The maximum flow length is a parameter that reflects the success of filling in a polymer injection molding process. Geometry of the part, rheological properties of the polymer and process parameters, such as injection pressure and temperature, are involved on the value of this parameter and therefore on the viability of a certain configuration. For injection molding manufacturing, the understanding of the relation between maximum flow length and main geometrical parameters of the molded part is fundamental to approach the product design, which is conditioned severely by processing capabilities. In this work, the maximum flow length is obtained for different geometries of an overmolded rectangular stiffener grid of carbon fiber filled polyether eter ketone (CF-PEEK) using the software Moldflow© Adviser© for calculations. Value of maximum flow length is provided as a function of cross section aspect ratio for gate diameters between 0.8 mm and 1.4 mm and cross section areas from 10 to 50 mm2. An exponential decrement of maximum flow length has been observed with the increment of aspect ratio of the cross section as well as a linear increment with the increment of cross section area. Gate diameter variation is slightly related with maximum flow length for the simulated values. These results provide a support tool for geometry sizing in overmolded rectangular grid parts at preliminary design stages.

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Modeling and Numerical Simulation of Laminated Thermoplastic Composites Manufactured by Laser-Assisted Automatic Tape Placement

International Polymer Processing ◽

10.1515/ipp-2020-350509 ◽

2020 ◽

Vol 35 (5) ◽

pp. 471-480

Author(s):

G. Ausias ◽

G. Dolo ◽

D. Cartié ◽

F. Challois ◽

P. Joyot ◽

...

Keyword(s):

Temperature Distribution ◽

Numerical Model ◽

Pressure Field ◽

Processing Parameters ◽

Thermoplastic Composites ◽

Final Thickness ◽

Intimate Contact ◽

Polymer Flow ◽

Compaction Force ◽

Heat Transfer Simulation

Abstract A comprehensive numerical model is developed for the simulation of the laser-assisted automated tape placement process of carbon fiber/thermoplastic composites. After being heated with a laser, the thermoplastic is welded with the help of a consolidation roller onto a substrate made up of layers of tapes bonded onto one another. Under the pressure applied by the roller, the thermoplastic flows and the tape reaches its final thickness. The numerical model is developed in three sequential steps that can be used to identify the required pressure and temperature distribution to achieve a good bond. Firstly, a heat transfer simulation is performed to determine the temperature distribution into the incoming tape under the consolidation roller. Secondly, a rheological model is developed to examine the polymer flow under the roller and to obtain the pressure field. Finally, the consolidation level between the substrate and the tape is investigated through the degree of intimate contact, which is related to the processing parameters such as the roller velocity, the laser power density and the compaction force.

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Compression Molding of All-Thermoplastic Composites by Using Fiber Wastes

Advances in Composite Materials and Structures - Key Engineering Materials ◽

10.4028/0-87849-427-8.81 ◽

2007 ◽

pp. 81-84

Author(s):

Tomoaki Kaneda ◽

Teruo Kimura

Keyword(s):

Compression Molding ◽

Thermoplastic Composites

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High flow compression molding for recycling discontinuous long fiber thermoplastic composites

Journal of Composite Materials ◽

10.1177/0021998320913625 ◽

2020 ◽

Vol 54 (23) ◽

pp. 3343-3350

Author(s):

Éric Léger ◽

Benoit Landry ◽

Gabriel LaPlante

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Compression Molding ◽

High Flow ◽

Low Flow ◽

Thermoplastic Composites ◽

Direction Parallel ◽

Significant Difference ◽

Long Fiber Thermoplastic ◽

Flow Compression

An investigation into high flow compression molding for recycling thermoplastic discontinuous long fiber composites is presented. High flow recycled panels and conventional low flow baseline panels were produced with a large rectangular (2:1 aspect ratio) mold. Flow was induced in the recycled panels by stacking cut sections of conventionally produced baseline panels in the center of the mold cavity, representing 25% initial coverage. High flow compression molded panels were found to exhibit significantly higher than baseline tensile strength (+50%) and modulus (+31%) when tested in the direction parallel to flow. When tested in the direction perpendicular to flow, the opposite effect was found, with reductions in tensile strength (−42%) and modulus (−37%). However, when the average results of both directions are compared to baseline, no significant difference was found between the recycled and baseline panels. This severe anisotropic redistribution of mechanical properties suggests chip orientation is affected by flow. Additionally, micrographic analysis revealed that high flow molding induces intra-ply chip shearing and a reduction in resin rich regions within panels. Baseline panels also exhibited in-plane anisotropy, despite initial random distribution of chips and no or near no flow induced during molding. In this case, mechanical properties favored the direction perpendicular to that of the recycled panels.

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BVID analysis of non-crimp fabric cross-ply laminate manufactured through wet compression molding process

AIAA Scitech 2020 Forum ◽

10.2514/6.2020-0727 ◽

2020 ◽

Author(s):

Sooyoung Lee ◽

Chaeyoung Hong ◽

Taeseong Choi ◽

Hye-gyu Kim ◽

Wooseok Ji

Keyword(s):

Compression Molding ◽

Molding Process ◽

Wet Compression

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Study on Processes and Properties of Continuous Woven Roving Reinforced Polyurethane Composites

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.306-307.879 ◽

2011 ◽

Vol 306-307 ◽

pp. 879-883 ◽

Cited By ~ 1

Author(s):

Xiao Li Dai ◽

Xiang Wang ◽

Jun Wang

Keyword(s):

Mass Fraction ◽

Interfacial Adhesion ◽

Bending Strength ◽

Compression Molding ◽

Micro Structure ◽

Molding Process ◽

Elongation At Break ◽

Vacuum Infusion ◽

Polyurethane Composites ◽

Sem Morphology

E-glass fiber woven roving reinforced polyurethane composites were manufactured by three different processes: hand lay-up, compression molding and vacuum infusion to assess the feasibility of all the processes. The results showed that all composites led to significant improvements in both flexural and tensile properties except elongation at break in comparison with the neat PU. Among the three processes, the best bending strength was exhibited by the hand lay-up process. This is attributed to higher PU mass fraction leads to a better fiber–matrix interfacial adhesion. Mechanical properties of the composite molded by vacuum infusion were superior to that produced by compression molding process. The SEM morphology revealed that vacuum infusion composite had more homogeneous micro- structure.

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