scholarly journals Dynamic Modeling of the Reactive Twin-Screw Corotating Extrusion Process: Experimental Validation by Using Inlet Glass Fibers Injection Response and Application to Polymers Degassing

2012 ◽  
Vol 51 (35) ◽  
pp. 11381-11388 ◽  
Author(s):  
T. Goma-Bilongo ◽  
F. Couenne ◽  
C. Jallut ◽  
Y. Le Gorrec ◽  
A. Di Martino
Keyword(s):  
Dynamic Modeling ◽  
Experimental Validation ◽  
Glass Fibers ◽  
Extrusion Process ◽  
Twin Screw

Definition of a JA-2 Equivalent Propellant to be Produced by Continuous Solventless Extrusion

2013 ◽  
Vol 80 (3) ◽  
Author(s):  
Thelma G. Manning ◽  
Joseph Leone ◽  
Martijn Zebregs ◽  
Dinesh R. Ramlal ◽  
Chris A. van Driel
Keyword(s):  
Extrusion Process ◽  
Continuous Manufacturing ◽  
Twin Screw Extrusion ◽  
Extrusion Processing ◽  
Roll Mill ◽  
Screw Extrusion ◽  
Twin Screw ◽  
Ballistic Properties ◽  
Definition Of ◽  
Double Base

In order to eliminate residual solvents in ammunition and to reduce the emissions of volatile organic compounds to the atmosphere, the U.S. Army ARDEC has teamed with TNO in developing a new process for the production of solventless propellant for tank ammunition. To reduce the costs of solventless propellants production, shear roll mill and continuous extrusion processing was investigated. As described in this paper JA-2 a double base propellant cannot be processed without solvent by the extrusion process. An alternative JA-2 equivalent propellant was defined. The aim of this work is to demonstrate the manufacturing of this propellant by solventless continuous twin screw extrusion processing while maintaining gun performance characteristics of conventional JA-2 propellant. This is elucidated by explicitly researching the relationship between interior ballistic properties of the gun propellant and utilizing a continuous manufacturing process. Processing conditions were established, and the propellant was manufactured accordingly. The extruded propellant has the desired properties, which resulted in a comparable gun performance as the conventional JA-2 propellant.

Effect of different extrusion methods on physicochemical properties and qualities of noodles based on rice flour

2021 ◽  
pp. 108201322110692
Author(s):  
Nispa Seetapan ◽  
Bootsrapa Leelawat ◽  
Nattawut Limparyoon ◽  
Rattana Yooberg
Keyword(s):  
Moisture Content ◽  
Rice Flour ◽  
Extrusion Process ◽  
Scanning Electron Micrographs ◽  
Twin Screw Extruder ◽  
Capillary Rheometer ◽  
Screw Extruder ◽  
Scanning Calorimetry ◽  
Twin Screw ◽  
Thermomechanical Processes

Rice noodles have been manufactured in the food industry using different extrusion methods, such as traditional and modern extrusions, which affect the noodle structure and qualities. Therefore, the effects of the extrusion process on qualities of rice noodles using the same blend of rice flour and crosslinked starch were evaluated. In this study, a capillary rheometer was used as an alternative approach to simulate the traditional extrusion method in which the noodles are obtained by continuously pressing the pregelatinized noodle dough through a die. For modern extrusion, a twin-screw extruder was employed to obtain the noodles in a one-step process. The optimal range of moisture content used in the formulation was studied. Upon cooking, the noodles showed a decrease in cooking time and cooking loss with increasing moisture content in the formulation. All cooked noodles showed comparable tensile strength, but those extruded by a twin-screw extruder had substantially greater elongation. Scanning electron micrographs revealed that the noodles prepared using the extruder had a denser starch matrix, while those obtained from a capillary rheometer showed the aggregation of starch fragments relevant to the existence of starch gelatinization endotherm from differential scanning calorimetry. This indicated that the extrusion process using the twin-screw extruder provided a more uniform starch transformation, i.e., more starch granule disruption and gelatinization, thus giving the noodles a more coherent structure and better extensibility after cooking. The obtained results suggested that different thermomechanical processes used in the noodle industry gave the extruded rice noodles different qualities respective to their different microstructures.

The Effect of the Compounding Procedure on the Morphology and Mechanical Properties of PLA/PBAT-Based Nanocomposites

2021 ◽  
Vol 36 (2) ◽  
pp. 219-227
Author(s):  
P. Saiprasit ◽  
A. K. Schlarb
Keyword(s):  
Mechanical Properties ◽  
Residence Time ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Extrusion Process ◽  
Poly Lactic Acid ◽  
Silicon Dioxide Nanoparticles ◽  
Twin Screw ◽  
One Step ◽  
Thermodynamic Driving Force

Abstract Poly(lactic acid) (PLA)/poly(butylene adipate-co-terephthalate) (PBAT)-based nanocomposites filled with 1 vol.% silicon dioxide nanoparticles (nano-SiO2) were prepared using a co-rotating twin-screw extruder and injection molding. The nanocomposites with various blending sequences were investigated using PLA-based and PBAT-based nanocomposite masterbatches. Morphology of the PLA/PBAT/SiO2 nanocomposites was examined using a scanning electron microscope (SEM) and a focused ion beam (FIB) SEM. It is found that the nano-SiO2 locates in the original polymer phase, in which it is firstly incorporated in the masterbatch process, as well as at the interface between the two polymers. However, as the residence time in the extrusion process increases, the nanoparticles migrate from the original phase to the interface, governed by the thermodynamic driving force. The best optimization of mechanical properties is achieved by using the PBAT-based masterbatches with a one-step process or short residence time. The processing history, therefore, has a tremendous impact on the final properties of the resulting materials.

Evaluation of Process Wear of Selected Tool Steels for Injection Molds

2013 ◽  
Vol 739 ◽  
pp. 171-176 ◽  
Author(s):  
František Greškovič ◽  
Ľudmila Dulebová ◽  
Branislav Duleba ◽  
Janusz W. Sikora
Keyword(s):  
Adhesive Wear ◽  
Glass Fibers ◽  
Polymeric Materials ◽  
Tool Steels ◽  
Screw Extruder ◽  
Laboratory Equipment ◽  
Before And After ◽  
Twin Screw ◽  
Weight Decrease ◽  
Short Glass

The aim of this contribution is to test the suitability of selected types of tool steels used for manufacturing of injection molds. Experiments were realized by the simulation of adhesive wear using laboratory equipment Amsler, which allows the testing of grinding pairs. Evaluated grinding pairs consisted of tool steel and two types of roundels. Tested polymeric materials were based on pure PA6 and PBT filled with short glass fibers, prepared by mixing process in twin screw extruder. The wear of five types of tool steels were evaluated by weight decrease before and after the experiment, while changing the friction coefficient of grinding pairs, material of grinding pairs and sensing the roughness of steel before and after wear.

scholarly journals The structure, composition and preparation of injection-molded composite materials based on glass-filled polysulfone

2019 ◽  
Vol 14 (4) ◽  
pp. 39-44
Author(s):  
A. B. Baranov ◽  
T. I. Andreeva ◽  
I. D. Simonov-Emelʼyanov ◽  
O. E. Peksimov
Keyword(s):  
Composite Materials ◽  
Glass Fiber ◽  
Glass Fibers ◽  
Critical Length ◽  
Fiber Concentration ◽  
Extrusion Head ◽  
Short Glass Fiber ◽  
Twin Screw ◽  
Time Optimal ◽  
Short Glass

In the course of this study, compositions and designed structures for the polysulfone (PSF) and short glass fibers systems were calculated. Additionally, disperse-filled polymer composite materials (DFPCM) based on PSF-190 were classified in accordance with their respective structures, and the optimal amount of glass fiber (13.5–18.5 vol %) was determined. This article describes the production of DFPCM using PSF and a short glass fiber with a twin-screw extruder (Labtech Engineering Company LTD, model Scientific FIC 20-40). Furthermore, optimal mixing parameters for the creation of composites wherein the glass fiber length exceeds the critical length (lcr) were established. The critical length was calculated, and the curves for fiber size distribution of polysulfone composites were depicted, and a difference in fiber concentration between the dispenser and the extrusion head (up to ~10–15%) was found when the fiber content was at 18–25 vol %. For the first time, optimal parameters (which pertain to medium-filled dispersions) for the structure of DFPCM based on PSF and short glass fiber are able to be demonstrated. 

Dynamic modeling of 1–3 piezoelectric composite hydrophone and its experimental validation

2016 ◽  
Vol 150 ◽  
pp. 246-254 ◽  
Author(s):  
Zengtao Yang ◽  
Hua Wang ◽  
Deping Zeng ◽  
Chunliang Zhao ◽  
Ziguang Chen
Keyword(s):  
Dynamic Modeling ◽  
Experimental Validation ◽  
Piezoelectric Composite

Optimization of nutrient retention in whole flours extruded from cowpea biofortified grain

2021 ◽  
Vol 24 ◽  
Author(s):  
Jorge Minoru Hashimoto ◽  
Jéssica Pinheiro Mendes Sampaio ◽  
Luís José Duarte Franco ◽  
Elizabeth Harumi Nabeshima ◽  
Kaesel Jackson Damasceno e Silva
Keyword(s):  
Moisture Content ◽  
Rotation Speed ◽  
Nutrient Retention ◽  
Magnesium Content ◽  
Extrusion Process ◽  
Screw Extruder ◽  
Twin Screw ◽  
Iron And Zinc ◽  
Copper Zinc ◽  
Extruded Products

Abstract Whole flour of cowpea grains of the cultivar BRS Tumucumaque biofortified in iron and zinc were processed in a co-rotating twin-screw extruder Clextral HT 25. A central rotational composite design 23, combining temperature (from 86.4 to 153.6 °C), screw rotation speed (from 163.6 to 836.4 rpm) and moisture content (from 16.6% to 23.4%), was used to assess the effects on flour constituents. The three variables significantly affected (p < 0.05) the levels of protein and copper in the extrudates. The reactions of the extrusion process caused a decrease in the levels of proteins and an increase in the levels of copper, zinc and potassium, and these amounts were accentuated as the values of the process variables approached those of the central point region. Extreme conditions at high rotational screw speeds combined with low moisture content reduced the magnesium content, at the opposite end of the values for these two variables, the intensity of the reduction was lower. In the analysis of global desirability, it was found that the extrusion condition at 112.6 °C, 587.4 rpm and 23.4% moisture provided the highest nutrient retention. The levels of iron and zinc remained above 60 and 40 mg kg-1, respectively, in extruded products.

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