Mold technology for mass production of continuous fiber-reinforced sandwich parts

2016 ◽  
Vol 36 (6) ◽  
pp. 589-596 ◽  
Author(s):  
Christian Hopmann ◽  
Philipp N. Wagner ◽  
Robert Bastian ◽  
Kai Fischer ◽  
Arne Böttcher
Keyword(s):  
Systems Engineering ◽  
Composite Structures ◽  
Large Scale ◽  
Functional Integration ◽  
High Surface ◽  
Fiber Reinforced ◽  
Continuous Fiber ◽  
Short Cycle ◽  
Impregnation Process ◽  
Cycle Times

Abstract In order to reduce cycle times, increase functional integration and automation further, the innovative gap impregnation process and mold technology was developed at the Institute of Plastics Processing at RWTH Aachen University (Germany) in collaboration with industry partners. The novel process enables an automated production of continuous fiber-reinforced sandwich composite structures in integral design with high surface quality in short cycle times, which is demonstrated by manufacturing a carbon fiber-reinforced plastic (CFRP) engine hood. For the first time, the gap impregnation and mold technology makes it possible to manufacture large-scale, three-dimensionally shaped sandwich components in one shot and in short cycle times at similar mechanical properties compared to the reference steel hood. Furthermore, a weight reduction of about 60% to only 5 kg was achieved for the CFRP engine hood. This paper focuses on the systems engineering of the RTM-related gap impregnation process. The focus is on the utilized mold concepts for the pressurized air-assisted ejector pins, vacuum-tight sealing, the motion concept of the mold halves, resin traps, sensors for process control and the specially treated mold surfaces for class A surface components. Additionally, the main procedures, capabilities and characteristics of this innovative process are discussed.

Reinforcement Elements Aligned with the Direction of Forces for Load Transfer Areas of Long-Fiber-Reinforced Thermoplastic Components

2015 ◽  
Vol 825-826 ◽  
pp. 779-786 ◽  
Author(s):  
Katharina Arnaut ◽  
Patrick Schiebel ◽  
Anna Lang ◽  
Axel S. Herrmann
Keyword(s):  
Large Scale ◽  
Load Transfer ◽  
Fiber Reinforcement ◽  
Scale Production ◽  
Fiber Reinforced ◽  
Continuous Fiber ◽  
Cycle Times ◽  
Reinforced Plastics ◽  
Construction Methods ◽  
New Construction

Large-scale production of carbon fiber reinforced plastics often fails due to the increased material and manufacturing costs. Using the lightweight potential for competitive costs of materials, new construction methods are necessary, which enables an intelligent use of continuous fiber reinforcement, a largely automated production process as well as short cycle times. [1] The combination of continuous fiber reinforcement in the areas of maximum loads and cheaper materials such as long-fiber reinforced thermoplastic offers an efficient material application. Thereby, a required ratio of mechanical properties and attractive cost profile can be achieved.

Feasibility and Characterization of Large-Scale Additive Manufacturing With Long Fiber Reinforced Composites

2020 ◽  
Author(s):  
Aditya R. Thakur ◽  
Ming C. Leu ◽  
Xiangyang Dong
Keyword(s):  
Additive Manufacturing ◽  
Carbon Fiber ◽  
Carbon Fibers ◽  
Large Scale ◽  
Flexural Modulus ◽  
High Deposition Rate ◽  
Reinforced Composites ◽  
Fiber Reinforced ◽  
Continuous Fiber ◽  
Long Carbon Fibers

Abstract A new additive manufacturing (AM) approach to fabricate long fiber reinforced composites (LFRC) was proposed in this study. A high deposition rate was achieved by the implementation of a single-screw extruder, which directly used thermoplastic pellets and continuous fiber tows as feedstock materials. Thus, the proposed method was also used as a large-scale additive manufacturing (LSAM) method for printing large-volume components. Using polylactic acid (PLA) pellets and continuous carbon fiber tows, the feasibility of the proposed AM method was investigated through printing LFRC samples and further demonstrated by fabricating large-volume components with complex geometries. The printed LFRC samples were compared with pure thermoplastic and continuous fiber reinforced composite (CFRC) counterparts via mechanical tests and microstructural analyses. With comparable flexural modulus, the flexural strength of the LFRC samples was slightly lower than that of the CFRC samples. An average improvement of 28% in flexural strength and 50% in flexural modulus were achieved compared to those of pure PLA parts, respectively. Discontinuous long carbon fibers, with an average fiber length of 20.1 mm, were successfully incorporated into the printed LFRC samples. The carbon fiber orientation, distribution of carbon fiber length, and dispersion of carbon fiber as well as porosity were further studied. The carbon fibers were highly oriented along the printing direction with a relatively uniformly distributed fiber reinforcement across the LFRC cross section. With high deposition rate (up to 0.8 kg/hr) and low material costs (< $10/kg), this study demonstrated the potentials of the proposed printing method in LSAM of high strength polymer composites reinforced with long carbon fibers.

Smart PCBs for Smart Appliances - Embedding as IoT Enabler

2015 ◽  
Vol 2015 (1) ◽  
pp. 000025-000030
Author(s):  
Nick Renaud-Bezot ◽  
Christian Galler ◽  
Christian Vockenberger
Keyword(s):  
Functional Integration ◽  
Low Energy ◽  
The Other ◽  
Passive Components ◽  
Short Cycle ◽  
Cycle Times ◽  
Smart Appliances ◽  
Fine Pitch ◽  
Low Energy Consumption ◽  
The Eu

Be it the trillion-dollar economy dreamed up by Cisco Systems at one extreme, or the multitude of small crowdsourced projects at the other, there is no denying that IoT is capturing minds and making the news. Each company is vying for a piece of the pie, with semiconductor suppliers scrambling to call the latest releases “IoT-ready”. Not wanting to feel left out, the PCB industry is of course finding ways to support this nascent economy. As main concerns are small sizes, low energy consumption and short cycle times, one solution is embedding. By placing active and passive components within the PCB itself, the system can:- be more integrated, as components disappear from the surface, making space for additional functionality, larger battery or simply fit in a smaller housing,- have lower losses, as stacking SMT components on top of the embedded allows for short connections, thus lowering resistance and inductance,- be created faster, to enable dimensional and functional integration without relying on complex and costly SoC design. Starting with a backgrounder on common embedding technologies currently available from leading suppliers, the paper will present recent advances from AT&S's ECP® (Embedded-Component Packaging), including reliability data. Expanding from that field, the document will explore its future and extreme applications, such as high-power (multi-kW) and fine-pitch fields for industrial and automotive devices, showing the scalability of the technology and the evolutions supported by the EU-funded EmPower and UNSETH projects.

Experimental Investigations on Integrated Conductor Paths in Fiber-Reinforced Thermoplastic Composite Structures

2017 ◽  
Vol 742 ◽  
pp. 793-799
Author(s):  
Tony Weber ◽  
Anja Winkler ◽  
Maik Gude
Keyword(s):  
Composite Structures ◽  
Construction Material ◽  
Functional Integration ◽  
Thermoplastic Composite ◽  
Experimental Investigations ◽  
Film Material ◽  
Fiber Reinforced ◽  
Forming Process ◽  
Sensors And Actuators ◽  
Definition Of

By the benefit of functional integration the advantages of fiber reinforced plastics (FRP) as construction material can be increased due to the possibilities of integrating sensors and actuators. In Regard to the layer-by-layer definition of the wall thickness, this class of material offers a high potential for the integration of additional smart elements within the stacking and forming process. In addition to the actual integration methods of sensors or actuators, the electrical signal transmission and contacting is of great importance for smart structures. Various approaches can be followed. On the one hand, the conductor path can be defined by means of a wire and, on the other hand, the definition of conductor paths can be accomplished by functionalized films (by means of printing technology). Within this paper, experimental investigations are intended to demonstrate the suitability of screen-printed conductor paths for the press-technical transformation of FRP structures. In addition to the variation of the screen printing material and the film material, for a material-homogeneous integration, an evaluation of a corresponding selection of materials takes place with respect to the stresses derived from the deformation-technical boundary conditions.

scholarly journals Fabrication of Fiber Reinforced Plastics by Ultrasonic Welding

2018 ◽  
Vol 2 (3) ◽  
pp. 56
Author(s):  
Andreas Gomer ◽  
Wei Zou ◽  
Niels Grigat ◽  
Johannes Sackmann ◽  
Werner Schomburg
Keyword(s):  
Carbon Fiber ◽  
Large Scale ◽  
Raw Materials ◽  
Glass Fibers ◽  
Ultrasonic Welding ◽  
Scale Production ◽  
Fiber Reinforced ◽  
Cycle Times ◽  
Reinforced Plastics ◽  
Fiber Reinforced Plastics

Ultrasonic fabrication of fiber reinforced plastics made from thermoplastic polymer films and carbon or glass fibers enables cycle times of a few seconds and requires investment costs of only some 10,000 €. Besides this, the raw materials can be stored at room temperature. A fiber content of 33 vol % and a tensile strength of approximately 1.2 GPa have been achieved by ultrasonic welding of nine layers of foils from polyamide, each 100 µm in thickness, and eight layers of carbon fibers, each 100 µm in thickness, in between. Besides unidirectional carbon fiber reinforced polymer composite (CFRP) samples, multi-directional CFRP plates, 116 mm, 64 mm and 1.2 mm in length, width and thickness respectively, were fabricated by processing three layers of carbon fiber canvas, each 300 µm in thickness, and eight layers of polyamide foils, each 100 µm in thickness. Furthermore, both the discontinuous and the continuous ultrasonic fabrication processes are described and the results are presented in this paper. Large-scale production still needs to be demonstrated.

Investigation of the recycling of continuous fiber-reinforced thermoplastics

2018 ◽  
Vol 32 (3) ◽  
pp. 342-356 ◽  
Author(s):  
Bing Liu ◽  
Peng Zhu ◽  
Anchang Xu ◽  
Limin Bao
Keyword(s):  
Large Scale ◽  
Small Scale ◽  
Specimen Thickness ◽  
Limited Information ◽  
Fiber Reinforced ◽  
Continuous Fiber ◽  
Recycling Technology ◽  
Reinforced Thermoplastics ◽  
Simple Technology ◽  
Fiber Reinforced Thermoplastics

There is limited information on the recycling of continuous fiber-reinforced thermoplastics (FRTPs). Furthermore, existing research has been conducted in laboratories on a very small scale. In this article, we propose an effective and simple technology for recycling of FRTPs, which can be conducted on a large scale. To accelerate the rate of resin dissolution, prepared FRTPs were cut into small pieces. The obtained pieces were used to manufacture recycled chopped fabric tape-reinforced thermoplastics (R-CTTs). The feasibility of the recycling technology was confirmed by comparing the mechanical properties of the composites made from virgin materials (virgin chopped fabric tape-reinforced thermoplastics (V-CTTs)) and recycled materials. There was a significant improvement of the tensile properties with the increase of the specimen thickness. The strength of the materials was more sensitive to the length of the chopped tape than the modulus. Fibers in both V-CTT and R-CTT were well connected with the resins, as confirmed by scanning electron microscopy.

Leichtbau-Produktion mit flexibler Anlagentechnik*/Lightweight production in a configurable system – Production of fiber-reinforced components with a multifunctional tape and fiber placement system

2015 ◽  
Vol 105 (09) ◽  
pp. 586-590
Author(s):  
C. Brecher ◽  
D. Werner ◽  
M. Emonts
Keyword(s):  
Composite Structures ◽  
Fiber Reinforced ◽  
Fiber Volume ◽  
Cycle Times ◽  
Fiber Placement ◽  
Reinforced Composite ◽  
System P ◽  
Robot Systems ◽  
Configurable System ◽  
Machine Utilization

Zur Fertigung belastungsoptimierter faserverstärkter Strukturbauteile mit Tape- oder Fiber-Placement-Verfahren kommen vermehrt robotergeführte Systeme zur Anwendung. Im Gegensatz zu den aus der Luftfahrtindustrie bekannten Portalsystemen werden so Anlagenkosten gesenkt und neue Anwendungsfelder erschlossen. Um die Maschinenauslastung zu steigern, müssen auch Tape- oder Fiber-Placement-Systeme die flexible Fertigung faserverstärkter Komponenten in verschiedenen Prozessketten ermöglichen.   Automated manufacturing of load optimized fiber-reinforced composite structures by using tape and fiber placement systems is highly desirable and advantageous with regard to reproducibility, cycle times and fiber volume content. The combination of standard robot systems with tape and fiber placement technology reduces system costs and increases flexibility. To increase machine utilization and to reduce machine effort, tape and fiber placement systems also have to be flexible.

scholarly journals Visco-thermo-elastic Simulation Approach For Prediction of Cure-induced Residual Stresses in Fiber Reinforced Composites

2021 ◽  
Author(s):  
Jonas Müller ◽  
Michael Müller-Pabel ◽  
Niklas Lorenz ◽  
Benjamin Gröger ◽  
Johannes Gerritzen ◽  
...  
Keyword(s):  
Residual Stresses ◽  
Composite Structures ◽  
Relaxation Modulus ◽  
Maxwell Model ◽  
Liquid Composite Molding ◽  
Simulation Approach ◽  
Fiber Reinforced ◽  
Cycle Times ◽  
Generalized Maxwell Model ◽  
Elastic Simulation

Liquid composite molding (LCM) has established as a high quality manufacturing process for fiber reinforced composite structures. In order to reduce cycle times significantly, novel fast curing matrix resins are being introduced into series production. These put high requirements on process control and part reproducibility. Problems that may be encountered in this context involve process-induced distortion and surface waviness resulting from anisotropic and cure-dependent material properties. Numerical simulations represent a powerful approach to avoid the use of costly trial-and-error methods. For this reason, a simulation approach is being developed which aims at the prediction of residual stresses and accompanying effects on different length scales. Based on a resin characterization comprising reaction kinetics, cure-dependent relaxation modulus as well as thermal expansion and pressure-dependent chemical shrinkage, a generalized MAXWELL model is selected to describe the process-related mechanical behavior of the thermoset. Taking into account the influence of the process parameters on the resin properties enables a detailed analysis of process-property-relationships. By this, the developed simulation approach offers the possibility of a comprehensive analysis of both local and global process-induced phenomena and hence prevention of flaws.

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