scholarly journals An Investigation of the Effect of Processing Conditions on the Interface of Flax/Polypropylene Composites

2001 ◽  
Vol 10 (6) ◽  
pp. 096369350101000 ◽  
Author(s):  
N. E. Zafeiropoulos ◽  
C. A. Baillie ◽  
F. L. Matthews
Keyword(s):  
Surface Modification ◽  
Composite Materials ◽  
Flax Fibre ◽  
Natural Fibres ◽  
Processing Conditions ◽  
Cooling Rates ◽  
Polypropylene Composites ◽  
Flax Fibres ◽  
The Matrix ◽  
The Cost

In recent years there has been an increasing interest in using natural fibres as potential reinforcements for polymers. It is well known that the properties of composite materials are controlled by the properties of the matrix and the fibre, as well as of the interface. The most usual methods of strengthening the interface involve the application of surface modification methods on the fibres, or the application of compatibilisers in the matrix. However, it may be possible that one may achieve similar results just by simply controlling the processing conditions, and thus avoiding the application of chemicals that tend to increase the cost. In the present study the effect of cooling rates upon the interface in flax fibre/iPP composites was investigated by means of fragmentation tests. It was found that slower cooling leads to a stronger interface for two different grades of flax fibres; dew retted and green flax.

scholarly journals Critical Fibre Length and Apparent Interfacial Shear Strength of Single Flax Fibre Polypropylene Composites

1998 ◽  
Vol 7 (3) ◽  
pp. 096369359800700 ◽  
Author(s):  
M.J.A. Van Den Oever ◽  
H.L. Bos
Keyword(s):  
Shear Strength ◽  
Interfacial Shear Strength ◽  
Fibre Length ◽  
Stress Transfer ◽  
Interfacial Shear ◽  
Flax Fibre ◽  
Polypropylene Composites ◽  
Flax Fibres ◽  
Shear Yield ◽  
The Matrix

The stress transfer in, both elementary and technical, single flax fibre polypropylene composites is studied by determining the critical fibre length and the apparent interfacial shear strength. The influence of improved fibre-matrix interaction is reported and the results are compared with data from literature. The study indicates that the critical fibre length for elementary flax fibres is equal to or even higher than the flax fibre lengths found after extrusion and injection moulding processes. Furthermore, addition of maleic anhydridy modified polypropylene to the matrix results in an apparent interfacial shear strength for elementary flax fibres close to the shear yield strength of the matrix, for technical fibres the interfacial shear strength is somewhat lower.

scholarly journals Influence of Flax Fibre Hybridization on Mechanical Behaviour of Sisal Fibre-Polypropylene Composites Prepared with an Injection Moulding Machine

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
J. Allen Jeffrey ◽  
A. Sivakumar ◽  
R. Naveen Kumar ◽  
A. Anbazhagan ◽  
G. Manojkumar ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Flax Fibre ◽  
Physical Parameters ◽  
Sisal Fibre ◽  
Polypropylene Composites ◽  
Specific Strength ◽  
Flax Fibres ◽  
Low Weight ◽  
Moulding Machine ◽  
Low Modulus

Due to their low weight, high specific strength, and low environmental impact, sisal fibre-polypropylene composites have gained popularity. However, the material has a low modulus and poor moisture resistance, among other shortcomings. This study investigated how flax fibre hybridization affects the physical parameters of sisal fibre-polypropylene composites. We used maleic anhydride-grafted polypropylene to improve compatibility between fibres and polypropylene. Adding flax fibres to polypropylene-silica composites resulted in increased tensile strength, flexibility, and impact strength, according to researchers. Water resistance was further improved by adding flax fibres. Tensile strength values of polypropylene-sisal fibre composites filled with 0, 5, 10, 15, and 20 wt% of flax fibres were 29.46, 30.56, 31.57, 33.12, and 34.64 MPa, respectively.

Bacterial Cellulose Reinforced Flax Fibre Composites: Effect of Nanocellulose Loading on Composite Properties

2015 ◽  
Vol 825-826 ◽  
pp. 1063-1067
Author(s):  
Marta Fortea-Verdejo ◽  
Elias Bumbaris ◽  
Koon Yang Lee ◽  
Alexander Bismarck
Keyword(s):  
Tensile Strength ◽  
Bacterial Cellulose ◽  
Flax Fibre ◽  
The Other ◽  
Cellulose Content ◽  
Polypropylene Composites ◽  
Flax Fibres ◽  
Paper Making ◽  
Fibre Composites ◽  
Composite Properties

Loose hierarchical flax fibres/polypropylene composites were manufactured in a simple way based on a paper-making process in order to include nanocellulose and allow the hornification of the nanofibres in a controlled manner. The effect of flax fibre content on the flax/polypropylene composites and the influence of nanocellulose on the properties of these composites are discussed. By increasing the flax content a slight decrease of the tensile strength and an increase of the Young´s modulus were observed. On the other hand, no significant effect was noticed when increasing the bacterial cellulose content in the composites.

Interfacial properties of all-polypropylene composites

e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Shadi Houshyar ◽  
Robert A. Shanks
Keyword(s):  
Optical Microscope ◽  
Processing Conditions ◽  
Polypropylene Composites ◽  
Melting Temperatures ◽  
Pull Out ◽  
Physico Chemical ◽  
Microbond Test ◽  
The Matrix ◽  
The Difference ◽  
Poly Propylene

AbstractPreparation and characterization of novel composites, consisting of polypropylene (PP) fibres in a random poly(propylene-co-ethylene) (PPE) matrix, were investigated. These composites possess unique properties, due to chemical compatibility of the two polymers allowing creation of strong physico-chemical interactions and strong interfacial bonds. The difference between the melting temperatures of PP fibre and PPE was exploited in order to establish processing conditions for the composites. Suitable conditions were chosen so that the matrix was a liquid, to ensure good wetting and impregnation of the fibres, though the temperature must not be high enough to melt the fibres. The morphology of the composites was investigated using optical and scanning electron microscopy. Optical microscope images showed that transcrystallization of the matrix was observed on PP fibre surfaces. SEM photographs displayed a thin layer of matrix on the reinforcement, attributed to good impregnation and wetting of the fibres. Adhesion between PPE matrix and PP fibres was characterized using a microbond test inspired by a fibre pull-out technique. The results showed that adhesion was appreciably increased when PP fibres were used instead of glass fibres in the matrix. Nevertheless, thermal processing conditions of the composites caused reduction in mechanical behaviour of the reinforcement.

Rheological Study of Composite Materials Based on Thermosetting Matrix and Fillers Mineral

2013 ◽  
Vol 550 ◽  
pp. 79-84
Author(s):  
Amar Irekti ◽  
B. Bezzazi
Keyword(s):  
Shear Stress ◽  
Composite Materials ◽  
Rheological Behavior ◽  
Rheological Parameters ◽  
Mineral Filler ◽  
Composites Materials ◽  
Matrix Properties ◽  
The Matrix ◽  
The Cost ◽  
Mineral Fillers

In the development of composites materials, the matrix acts as a binder of different reinforcements can distribute the stress, provide good resistance to chemical structure and the desired shape to the final product. But there are still some drawbacks that arise in the physicochemical and mechanical properties of thermosetting matrices. Our job is to synthesize composite materials with news formulations of thermosetting matrices (Granitex products) by the incorporation of 40% of local mineral fillers. The latter give the matrix properties which it does not have, first, to reduce the cost of composite materials, and secondly, to improve implementation by increasing the viscosity and reducing the withdrawal to its minimum value. Rheological testing of mixtures prepared is made on the cone-plate viscometer, or the sample undergoes a shear in the conical space between the plane and the cone. The geometry of the cone - package ensures constant velocity gradient throughout the volume. The rheograms obtained, represents the evolution of the shear stress as a function of shear rate of resin mixtures containing 35% of mineral filler (pozzolan). The mineral filler increases significantly in rheological parameters, whatever the nature of the mineral filler. Compared to the control without charges, an increase of 60% of the shear stress and that of plastic viscosity were recorded for the epoxy resin. The software Rheowine viscometer, enabled us to model and identified the rheological behavior of these mixed with resin. The results obtained in this modeling, confirmed that the resin mixtures have shear-thinning rheological behavior and their behavior follows the model of the Ostwald of Waele.

Life Cycle Assessment of Natural Fibre Reinforced Cementitious Composites

2018 ◽  
Vol 761 ◽  
pp. 204-209 ◽  
Author(s):  
Ildiko Merta ◽  
Ana Mladenovič ◽  
Janez Turk ◽  
Aljoša Šajna ◽  
Alenka Mauko Pranjić
Keyword(s):  
Life Cycle Assessment ◽  
Life Cycle ◽  
Natural Fibre ◽  
Natural Fibres ◽  
Cementitious Composites ◽  
Aquatic Ecotoxicity ◽  
Flax Fibres ◽  
Sea Grass ◽  
The Matrix ◽  
Composite Mixture

Three cementitious composites containing different natural fibres (flax, hemp and sea-grass) were evaluated from an environmental perspective by means of Life Cycle Assessment (LCA) method applying the cradle-to-gate approach. The environmental impact of these composites was compared to that of cementitious composites reinforced with conventional synthetic polyacrilonitrile (PAN) fibres. The functional unit was the production of one cubic meter of cementitious composites ready-for-use. The results show that generally the environmental footprint of composite with synthetic fibres is bigger than the footprint of the composites with added natural fibres. Exceptions may only be the impacts on eutrophication and freshwater aquatic ecotoxicity, which are significantly affected by cultivation of crops. Flax and hemp cultivation is associated with emissions to soil and water. For this reason, the composite mixture with flax fibres has a significantly greater impact on eutrophication and freshwater aquatic ecotoxicity than the composite mixture with synthetic fibres. A cementitious composite mixture with sea-grass shows the lowest impacts in all impact categories. The entire life cycle of the studied composites was not included in this research since the life cycle of natural fibre composites is not straightforward and is highly dependent on the durability of the fibres within the matrix.

MANUFACTURING FLAX FIBRE-REINFORCED POLYPROPYLENE COMPOSITES BY HOT-PRESSING

2006 ◽  
Vol 20 (25n27) ◽  
pp. 4601-4606 ◽  
Author(s):  
MARC JOLLY ◽  
KRISHNAN JAYARAMAN
Keyword(s):  
Composite Materials ◽  
Hot Pressing ◽  
Mass Fraction ◽  
Fibre Length ◽  
Natural Fibre ◽  
Thermoplastic Composites ◽  
Processing Temperature ◽  
Polypropylene Composites ◽  
Flax Fibres ◽  
Fibre Degradation

The renewable characteristic of natural fibres, such as flax, and the recyclable nature of thermoplastic polymers, such as polypropylene, provide an attractive eco-friendly quality to the resulting composite materials. Common methods for manufacturing natural fibre-reinforced thermoplastic composites, injection moulding and extrusion, tend to degrade the fibres during processing. Development of a simple manufacturing technique for these composites, that minimises fibre degradation, is the main objective of this study. Flax fibres were conditioned, cut into lengths ranging from 1 mm to 30 mm with scissors and a pelletiser, and shaped into randomly oriented mats using a drop feed tower. Polypropylene in sheet form, was added to the fibres to furnish polypropylene/flax/polypropylene sandwiches with a fibre mass fraction of 25%, which were then consolidated by the hot pressing technique. Tensile, flexural and impact properties of these composite sheets were determined as functions of fibre length and processing temperature.

Analysis of Transient Hygrothermal Ageing Analysis of Hybrid Composite Materials in Asymmetric Environments

2013 ◽  
Vol 550 ◽  
pp. 49-56
Author(s):  
B. Boukert ◽  
A. Benkhedda ◽  
S. Bergheul
Keyword(s):  
Composite Materials ◽  
Structural Reliability ◽  
Aerospace Industry ◽  
High Strength ◽  
Hygrothermal Ageing ◽  
The Matrix ◽  
Structural Parts ◽  
Degradation Of Properties ◽  
The Cost ◽  
Cost Of Construction

In recent years composite materials are widely used in the aerospace industry. The advantages of these materials are derived from their high strength, rigidity and lightness. More importantly, they have the potential to reduce the cost of construction, while improving structural reliability and increasing safety. Aircraft structural parts made of composite materials with polymeric matrix, subject to variables conditions and severe environments, require a good knowledge of their behavior under humidity and temperature. The matrix is very sensitive to these parameters. A degradation of properties is then observed [1-1.

High Strength Sinter-Hardening Powder Metallurgy Alloys

2008 ◽  
Vol 51 ◽  
pp. 3-9 ◽  
Author(s):  
K.S. Hwang ◽  
M.W. Wu ◽  
Chia Cheng Tsai
Keyword(s):  
Tensile Strength ◽  
Powder Metallurgy ◽  
Cooling Rate ◽  
High Hardness ◽  
High Strength ◽  
Alloying Elements ◽  
Cooling Rates ◽  
The Matrix ◽  
Fast Cooling ◽  
The Cost

High strength and high hardness can be readily attained after sintering when sinter-hardening grade powder metallurgy alloys are used. However, fast cooling rates greater than 60°C/min are usually required. This increases the cost of the sintering equipment and maintenance. To lower the required minimum cooling rate, the homogeneity of the alloying elements in the matrix and the hardenability of the material must be improved. Among the various popular alloying elements, nickel and carbon are the two most non-uniformly distributed elements due to their repelling effect. It is found that to improve their homogenization, the addition of Cr and Mo can alleviate the repelling effect between Ni and C. As a result, weak Ni-rich/C-lean ferrite and austenite are eliminated and replaced by hard bainite and martensite. A tensile strength of 1323 MPa and a hardness of 39 HRC are attained in sinter-hardened Fe-3Cr-0.5Mo-4Ni-0.5C compacts without any quenching treatment.

Water Absorption and Modification of Kenaf and Flax Fibres

2012 ◽  
Vol 545 ◽  
pp. 342-347 ◽  
Author(s):  
Masitah Abu Kassim ◽  
A. Crosky ◽  
David Ruys
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Water Absorption ◽  
Flexural Modulus ◽  
Strength Properties ◽  
Natural Fibres ◽  
Fibre Types ◽  
Absorption Characteristic ◽  
Flax Fibres ◽  
The Matrix

The experimental work for this project involved several strands; to study the water absorption characteristic of kenaf and flax in composites, to investigate the influence of fibre types on water absorption, and finally to investigate the influence of chemical treatment on water absorption. Hydrophilic character of natural fibres is responsible for the water absorption in the composites. Water absorption of kenaf and flax reinforced polyester composites was occurred via fibres lumen. Mechanical properties are affected by water absorption. After water absorption test, the specimens present poor mechanical properties such as lower value of flexural strength and flexural modulus. The matrix structure was also affected by water absorption by processes such as chain orientation and shrinkage. It was found that the different fibre types had influenced the different percentage of water absorption in composite. It seems that the compatibilization between fibres and matrix has influenced the water absorption of fibres. Acetylation of kenaf and flax fibres has reduced the hygroscopic nature of natural fibres and increased the dimensional stability of composites. The flexural strength properties of acetylated fibres were higher than untreated fibres composites.

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