extrusion process
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2022 ◽  
Vol 5 (1) ◽  
pp. 27-34
Author(s):  
Fatma DEMİRCAN KESKİN ◽  
Ural ÇİÇEKLİ ◽  
Doğukan İÇLİ

LWT ◽  
2022 ◽  
Vol 155 ◽  
pp. 112926
Author(s):  
Elizabet Janić Hajnal ◽  
Janja Babič ◽  
Lato Pezo ◽  
Vojislav Banjac ◽  
Radmilo Čolović ◽  
...  

2022 ◽  
pp. 136943322110572
Author(s):  
Shao Lian ◽  
Ou Jinping ◽  
Zhou Zhi

Carbon fiber–reinforced polymer (CFRP) rods have been considered as a candidate material for prestressed concrete applications because of their superior properties. For current applications, successful use of CFRP rods is linked to an efficient anchorage system design. This paper presents a newly developed anchorage system for CFRP rods and the design concept that the extrusion process is used to generate gripping force. The proposed anchorage system consists of a steel barrel and an aluminum sleeve, and an extrusion region is designed on the outside of barrel to generate a suitable contact pressure distribution on the CFRP rod. A mathematical model was proposed to estimate the contact pressure on the CFRP rod and the capacity of anchorage system. The simulation of extrusion and loading process was conducted with a three-dimensional (3D) finite-element (FE) model. The key design parameters of anchorage system were analyzed to obtain an optimized parameter combination. The experimental validation showed that the new anchorage system is capable of allowing the CFRP rod to attain the ultimate tensile strength.


Polymers ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 240
Author(s):  
Andrzej Nastaj ◽  
Krzysztof Wilczyński

A novel scaling-up computer system for single screw extrusion of polymers has been developed. This system makes it possible to scale-up extrusion process with both starve feeding and flood feeding. Each of the scale-up criteria can be an objective function to be minimized, represented by single values or functional dependencies over the screw length. The basis of scaling-up is process simulation made with the use of the GSEM program (Global Screw Extrusion Model). Scaling-up is performed using the GASES program (Genetic Algorithms Screw Extrusion Scaling) based on Genetic Algorithms. Scaling-up the extrusion process has been performed to increase extrusion output according to the scaling-up criteria defined by the single parameters of unit energy consumption, polymer plasticating rate and polymer temperature, as well as by the process parameters profiles of the temperature and plasticating. The global objective function reached the lowest value for the selected process parameters, and extrusion throughput was significantly increased.


Author(s):  
Dhanvanth J.S. Talluri ◽  
HuanTan Nguyen ◽  
Reza Avazmohammadi ◽  
Amir K. Miri

Abstract Extrusion three-dimensional (3D) bioprinting typically requires an ad-hoc trial-and-error optimization of the bioink composition towards enhanced resolution. The bioink solutions are solidified after leaving cone-shaped or cylindrical nozzles. The presence of bioink instability not only hampers the extrusion resolution but also affects the behavior of embedded cellular components. This is a key factor in selecting bioinks and bioprinting design parameters for well-established desktop and handheld bioprinters. In this work, we developed an analytical solution for the process of bioink deposition and compared its predictions against numerical simulations of the deposition. We estimated the onset of bioink instability as a function of bioink rheological properties and nozzle geometry. Both analytical and simulation results demonstrated that enhancing shear-thinning behavior of the bioink stabilizes the printing process whereas bioink shear-thickening behavior induces an opposite effect through extending the toe region of the deposition. The present study serves as a benchmark for detailed simulations of the extrusion process for optimal bioprinting.


Sensors ◽  
2022 ◽  
Vol 22 (1) ◽  
pp. 379
Author(s):  
Grzegorz Piecuch ◽  
Rafał Żyła

The article presents an extensive analysis of the literature related to the diagnosis of the extrusion process and proposes a new, unique method. This method is based on the observation of the punch displacement signal in relation to the die, and then approximation of this signal using a polynomial. It is difficult to find in the literature even an attempt to solve the problem of diagnosing the extrusion process by means of a simple distance measurement. The dominant feature is the use of strain gauges, force sensors or even accelerometers. However, the authors managed to use the displacement signal, and it was considered a key element of the method presented in the article. The aim of the authors was to propose an effective method, simple to implement and not requiring high computing power, with the possibility of acting and making decisions in real time. At the input of the classifier, authors provided the determined polynomial coefficients and the SSE (Sum of Squared Errors) value. Based on the SSE values only, the decision tree algorithm performed anomaly detection with an accuracy of 98.36%. With regard to the duration of the experiment (single extrusion process), the decision was made after 0.44 s, which is on average 26.7% of the extrusion experiment duration. The article describes in detail the method and the results achieved.


Author(s):  
Cleiton André Comelli ◽  
Richard Davies ◽  
HenkJan van der Pol ◽  
Oana Ghita

AbstractThe heating and extrusion process in fused filament fabrication (FFF) is significantly shorter than the conventional extrusion process where longer heating times and significant pressure are applied. For this reason, it is important to understand whether the crystal history of the feedstock is fully erased through the FFF process and whether the FFF process can be tailored further by engineering the crystallization of the feedstock filaments. In this context, a methodology for evaluating the influence of morphology and mechanical properties on different feedstock and extruded filaments is proposed. Filaments with three different PEEK 450G crystalline structures (standard crystallinity, drawn filament and amorphous filament) were selected and evaluated, before and after free extrusion. The resulting morphology, crystallinity and mechanical properties of the extruded filaments were compared against the feedstock properties. X-ray diffraction (XRD), transmission electron microscopy (TEM), differential and fast scanning calorimetry (DSC/FDSC) and tensile test were the techniques used to evaluate the materials. The results showed clear differences in the properties of the feedstock materials, while the analysis of the extruded filaments points to a homogenization of the resulting material producing mostly similar mechanical properties. However, the use of the drawn filament highlighted a statistically significant improvement in crystallinity and mechanical performance, especially in strain values. This conclusion suggests the innovative possibility of improving the quality of manufactured parts by tailoring the microstructure of the feedstock material used in the FFF process. Graphical abstract


2022 ◽  
Vol 5 (1) ◽  
pp. 44
Author(s):  
Pranabendu Mitra ◽  
Sagar Khanvilkar ◽  
Sai Kumar Samudrala ◽  
Kaushal Sunil Shroff

The main objective of this study was to convert the cranberry pomace into value-added extruded cereals/snacks blending with rice flour using a single screw extruder based on the physicochemical properties of extrudates because utilization of the byproduct cranberry pomace would be necessary for the growth of cranberry juice processing industries and the extruded snacks/cereals with higher fiber and antioxidant and less carbohydrate would be required to fulfill the consumers’ demand. The six different formulations by blending 0, 5, 10, 15, 20 and 25% cranberry pomace with 100, 95, 90, 85, 80 and 75% of rice flour, respectively, were extruded using a single screw extruder. The temperature (150℃), screw speed (270 rpm), feed rate (20 Kg/hr) and feed moisture content (35%) were constant during extrusion. The physicochemical properties of the extrudates were characterized to determine the desirable formulations. The results indicated that radial expansion ratio (1.11-1.67), the solid density (0.71-0.76 g/mL), piece density (0.20-0.63 g/mL), porosity (14.49-72.38%), hardness (23-157.73 N), crispness (4.17-13.5), moisture content (3.22-4.39%), water activity (0.14-0.36) and the water solubility (7.07-30.80%) of rice flour and cranberry pomace blend extrudates were varied depending on the combinations of the rice flour and cranberry pomace. The results revealed that up to 20% cranberry pomace could be added with 75-80% rice flour to develop high fiber and antioxidant with less carbohydrate cereal/snack products. The utilization of cranberry pomace combining with rice flour through extrusion process can provide a unique opportunity to generate healthier snacks and cereals that have higher fiber and antioxidant and low carbohydrate.


2022 ◽  
pp. 194-209
Author(s):  
Sachin Salunkhe ◽  
G. Kanagachidambaresan ◽  
C. Rajkumar ◽  
K. Jayanthi

Fused deposition modelling (FDM) is a technology used for filament deposition of heated plastic filaments by a given pattern by the melted extrusion process. Delamination is a critical issue of FDM's incredibly complex parts. In this chapter, the artificial intelligence (machine learning) model is used for online detections and prediction of FDM parts. The proposed machine learning and convolutional neural network model is capable of online detect delamination of FDM parts. The proposed model can also be applied for different types of additive manufacturing materials with less human interaction.


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