Pultrusion is a technological process in which fibers impregnated with resin move through the heated die and solidify into a composite profile with a constant cross section, as in the metallic die. The effectiveness and productivity of conventional pultrusion processes, preserving the quality of pultruded profiles, could be improved by process optimization or by the application of new, effective heating sources instead of electrical resistances with high heat losses. Due to the large dimension of the numerical problem and multiple iterations applied for the solution of government equations, an optimization methodology was developed, using the method of experimental design and the response surface technique. To develop microwave-assisted pultrusion processes, as well as pultrusion tooling design and process control, new effective electromagnetic-thermo-chemical finite element models and algorithms were developed by using general-purpose finite element software that results in considerable savings in development time and costs and makes available various modeling features of the finite element packages. The effectiveness and productivity of the optimized conventional pultrusion processes and the developed microwave-assisted pultrusion processes are estimated in comparison with the real pultrusion processes used in laboratory and industrial shops.
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http://dx.doi.org/10.3390/polym14040841 | DOI Listing |
Nat Commun
November 2024
Department of Agriculture, Forestry and Bioresources, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, Republic of Korea.
Many studies try to comprehend and replicate the natural silk spinning process due to its energy-efficient and eco-friendly process. In contrast to spider silk, the mechanisms of how silkworm silk fibroin (SF) undergoes liquid-liquid phase separation (LLPS) concerning the various environmental factors in the silk glands or how the SF coacervates transform into fibers remain unexplored. Here, we show that calcium ions, among the most abundant metal ions inside the silk glands, induce LLPS of SF under macromolecular crowded conditions by increasing both hydrophobic and electrostatic interactions between SF.
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October 2024
Dipartimento di Ingegneria, Università degli Studi di Palermo, Viale delle Scienze, ed. 6, 90128 Palermo, Italy.
In order to limit the ever-increasing consumption of new resources for material formulations, regulations and legislation require us to move from a linear to a circular economy and to find efficient ways to recycle, reuse and recover materials. Taking into account the principles of material circularity and waste reuse, this research study aims to produce thermoplastic composites using two types of industrial waste from neighbouring companies, namely waste polypropylene (wPP) from household production and carbon-fibre-reinforced epoxy composite scrap from a pultrusion company. The industrial scrap of the carbon-fibre-reinforced epoxy composites was either machined/ground to powder (pCFRC) and used directly as a reinforcement agent or subjected to a chemical digestion process to recover the carbon fibres (rCFs).
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July 2024
Department of Civil Engineering, University of Texas, Arlington, TX 76006, USA.
Pultruded fiber reinforced polymer composites used in civil, power, and offshore/marine applications use fillers as resin extenders and for process efficiency. Although the primary use of fillers is in the form of an extender and processing aid, the appropriate selection of filler can result in enhancing mechanical performance characteristics, durability, and multifunctionality. This is of special interest in structural and high voltage applications where the previous use of specific fillers has been at levels that are too low to provide these enhancements.
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June 2024
Department of Industrial Engineering, University of Salerno, 84084 Fisciano, Italy.
Pultrusion is a highly efficient continuous process to manufacture advanced fiber-reinforced composites. The injection pultrusion variant permits a higher control of the resin flow, enabling the manufacturing of a high reinforcement volume fraction. Moreover, it reduces the emission of volatile compounds that are dangerous for the operators and for the working environment.
View Article and Find Full Text PDFMaterials (Basel)
May 2024
Beijing Spacecraft Manufacturing Co., Ltd., Beijing 100094, China.
A crimping and pultruding forming process for truss rods using Carbon Fiber (CF)/Polyether-Ether-Ketone (PEEK) prepreg tape as the raw material is proposed to address the problem of continuous manufacturing of space trusses on orbit. The proposed process provides material rods for continuous truss manufacturing. Through numerical simulation and experimental verification, the effects of relevant parameters on the forming process are determined, an efficient method of rod curl pultrusion, in-rail, equal material forming is proposed, and the structural configuration of the rod curl pultrusion forming mold is determined.
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