Influence of the polarity of the matrix on the breakage mechanisms of lignocellulosic fibers during twin‐screw extrusion

2019 ◽  
Vol 41 (3) ◽  
pp. 1106-1117 ◽  
Author(s):  
Françoise Berzin ◽  
Loubna Lemkhanter ◽  
Carlos Marcuello ◽  
Brigitte Chabbert ◽  
Véronique Aguié‐Béghin ◽  
...  
Keyword(s):  
Twin Screw Extrusion ◽  
Lignocellulosic Fibers ◽  
Screw Extrusion ◽  
The Matrix ◽  
Twin Screw

Research on Processing Technology Product Design and the Application of Nano-Wood-Plastic Composite Materials

2020 ◽  
Vol 20 (12) ◽  
pp. 7787-7792
Author(s):  
Xin Fang ◽  
Jinjin Rong ◽  
Yilin Deng ◽  
Moon-Hwan Jee
Keyword(s):  
Mechanical Properties ◽  
Wood Plastic Composite ◽  
Twin Screw Extrusion ◽  
Cross Sectional ◽  
Plastic Composite ◽  
Screw Extrusion ◽  
Different Types ◽  
The Matrix ◽  
Twin Screw ◽  
Treatment Agent

This study focused on the design of wood-plastic composite (WPC) products. In this study, recycled high-density polyethylene plastic was used as the matrix, wood powder was used as the filler, different types of nanofillers and self-synthesized nanofiller treatment agents were added, and the twin-screw extrusion granulation method was used to prepare nano-WPC materials. The effects of different types of nanofillers on the mechanical properties of nano-WPC materials were investigated, and the cross-sectional structures of the materials were analyzed by scanning electron microscopy. The results showed that nanofiller treatment agents improved the interface compatibility of the materials. When the treatment agent content reached 2.5% and the nano-montmorillonite content reached 10%, the mechanical properties of the material reach their maximum values.

Correlation of Rheological and Electrical Percolation in PVDF-MWNT Nanocomposites

2013 ◽  
Author(s):  
Reza Rizvi ◽  
Hani Naguib
Keyword(s):  
Electrical Conductivity ◽  
Filler Particle ◽  
Multiwall Carbon Nanotubes ◽  
Twin Screw Extrusion ◽  
Electrical Percolation ◽  
Percolation Behavior ◽  
Screw Extrusion ◽  
The Matrix ◽  
Twin Screw ◽  
And Storage

This study investigates the evolution of filler particle networks using electrical and rheological property measurements. Polyvinylediene Flouride (PVDF) was used as the matrix thermoplastic polymer which was reinforced with multiwall carbon nanotubes (MWNT) as the filler phase using high shear twin screw extrusion mixing. Electrical conductivity and dielectric constant measurements were done using impedance spectroscopy. Viscosity and storage modulus measurements were performed using a dynamic rheometer. Morphologies of the composites were observed using scanning electron microscopy. The percolation behavior in electrical conductivity was determined to be 1.3 wt% MWNT content in PVDF. This is in contrast to the nanocomposite viscosity percolation threshold which occurred at 1.9 wt%.

Thermal Conductivity Measurements of Nylon 11-Carbon Nanofiber Nanocomposites

2009 ◽  
Vol 131 (9) ◽  
Author(s):  
Arden L. Moore ◽  
Antonette T. Cummings ◽  
Justin M. Jensen ◽  
Li Shi ◽  
Joseph H. Koo
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanofiber ◽  
Effective Medium Theory ◽  
Twin Screw Extrusion ◽  
Medium Theory ◽  
Interface Thermal Resistance ◽  
Screw Extrusion ◽  
The Matrix ◽  
Twin Screw ◽  
Nylon 11

Carbon nanofibers (CNFs) were incorporated into nylon 11 to form nylon 11-carbon nanofiber nanocomposites via twin screw extrusion. Injection molding has been employed to fabricate specimens that possess enhanced mechanical strength and fire retardancy. The thermal conductivity of these polymer nanocomposites was measured using a guarded hot plate method. The measurement results show that the room temperature thermal conductivity increases with the CNF loading from 0.24±0.01 W/m K for pure Nylon 11 to 0.30±0.02 W/m K at 7.5 wt % CNF loading. The effective medium theory has been used to determine the interface thermal resistance between the CNFs and the matrix to be in the range of 2.5–5.0×10−6 m2 K/W from the measured thermal conductivity of the nanocomposite.

scholarly journals In-Line Rheo-Optical Investigation of the Dispersion of Organoclay in a Polymer Matrix during Twin-Screw Compounding

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2128
Author(s):  
Paulo F. Teixeira ◽  
José A. Covas ◽  
Loïc Hilliou
Keyword(s):  
Local Heating ◽  
Polymer Nanocomposite ◽  
Structural Rearrangement ◽  
Particle Dispersion ◽  
Optical Investigation ◽  
Twin Screw Extrusion ◽  
Clay Particles ◽  
Clay Dispersion ◽  
Screw Extrusion ◽  
Twin Screw

The dispersion mechanisms in a clay-based polymer nanocomposite (CPNC) during twin-screw extrusion are studied by in-situ rheo-optical techniques, which relate the CPNC morphology with its viscosity. This methodology avoids the problems associated with post extrusion structural rearrangement. The polydimethylsiloxane (PDMS) matrix, which can be processed at ambient and low temperatures, is used to bypass any issues associated with thermal degradation. Local heating in the first part of the extruder allows testing of the usefulness of low matrix viscosity to enhance polymer intercalation before applying larger stresses for clay dispersion. The comparison of clay particle sizes measured in line with models for the kinetics of particle dispersion indicates that larger screw speeds promote the break-up of clay particles, whereas smaller screw speeds favor the erosion of the clay tactoids. Thus, different levels of clay dispersion are generated, which do not simply relate to a progressively better PDMS intercalation and higher clay exfoliation as screw speed is increased. Reducing the PDMS viscosity in the first mixing zone of the screw facilitates dispersion at lower screw speeds, but a complex interplay between stresses and residence times at larger screw speeds is observed. More importantly, the results underline that the use of larger stresses is inefficient per se in dispersing clay if sufficient time is not given for PDMS to intercalate the clay galleries and thus facilitate tactoid disruption or erosion.

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.

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