Failure mechanisms in composites reinforced with unidirectional Phormium leaf fibre

Newman, Roger H.; Guen, Marie-Joo Le; Battley, Mark; Carpenter, James

doi:10.1016/j.compositesa.2009.11.001

Cited by 32 publications

(17 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Mounted fibres were observed using an Olympus BX60F5 microscope to make sure they were single. Harakeke single fibre has polygonal cross section [6], but, for simplicity, it was assumed perfectly circular. Diameters of selected fibres were measured at 3 points along the fibre length under the same microscope with a magnification of 200 and the average diameter was calculated and used for calculation of tensile properties.…”

Section: Single Fibre Tensile Testingmentioning

confidence: 99%

“…In harakeke leaves, fibre bundles have different cross sectional shapes including "key-holes" and "horseshoes" or "molar teeth" [6,[8][9][10][11]. The "key-hole" bundles which have larger cross section are located in the upper part of the leaf while the "horseshoe" bundles are in the lower part and between these bundles, in the centre of the leaf are helical fibril cells with a thin wall called vascular bundles which are considered to be the pathways of fluids in the leaf [9,10].…”

Section: Fibre Morphologymentioning

confidence: 99%

“…The "key-hole" bundles which have larger cross section are located in the upper part of the leaf while the "horseshoe" bundles are in the lower part and between these bundles, in the centre of the leaf are helical fibril cells with a thin wall called vascular bundles which are considered to be the pathways of fluids in the leaf [9,10]. The fibre bundles are usually surrounded by thin walled cells known as sheath cells and cuticles or epidermis still adhere to the fibre bundles at the side close to the leaf surface [6,10]. When fibre bundles are extracted from the leaves, some of them are longitudinally split into smaller bundles [10].…”

Section: Fibre Morphologymentioning

confidence: 99%

See 2 more Smart Citations

The potential of harakeke fibre as reinforcement in polymer matrix composites including modelling of long harakeke fibre composite strength

Pickering

2015

Composites Part A: Applied Science and Manufacturing

View full text Add to dashboard Cite

Hypertension presenting with metabolic alkalosis with hypokalemia is not uncommon. In this analysis, we present the management of such a scenario in white and black patients. Six patients (white¼4 [1 females, 2 males, age¼24-62]; blacks¼2 [1male, 1 female, age¼32, 40]) with hypokalemia (2.9-3.3 mEq/L), metabolic alkalosis (28-32 mm Eq/L) and hypertension (155-180/90-105 mmHg) were seen in hypertension clinic. All had a BMI of >32 and metabolic syndrome. None had clinical evidence of sleep apnea. All had been on adequate dosage of at least three BP meds (calcium channel blocker, ACE-I/ARB, metoprolol/carvedilol). All had a negative Doppler ultrasound for renal artery stenosis. Their serum aldosterone to renin ratio was 15-18 (normal¼less than 20). Urinary aldosterone in the six patients ranged from 10-12 ng/l (reference abnormal¼>14 ng/dl). Because of normal aldosterone to renin ration, CT scan was not obtained in these patients. Nonetheless, considering obesity and aldosterone production by adipocytes (high normal urinary aldosterone), treatment with spironolactone/eplerenone was initiated with normalization of blood pressure in 3/4 whites (<140/90 mmHg). The non-responder (white female age 62) was treated with amiloride with subsequent control of BP to <140/90 mmHg. Two black patients also responded better to amiloride compared to spironolactone/eplerenone bring them to the goal (<140/90 mmHg). While aldosterone is an important mediator of hypertension in obese individuals, over-activity of sodium channel in the distal tubule (ENaC) must be considered in the management uncontrolled hypertension with hypokalemic metabolic alkalosis, particularly in blacks. It has been suggested before that amiloride provides better BP control in resistance hypertension in blacks compared to white patients providing validity to ENaC over-activity. Genetic testing was not performed in our cohort to investigate the presence of Liddle's syndrome.

show abstract

Section: Single Fibre Tensile Testingmentioning

confidence: 99%

Section: Fibre Morphologymentioning

confidence: 99%

Section: Fibre Morphologymentioning

confidence: 99%

See 1 more Smart Citation

The potential of harakeke fibre as reinforcement in polymer matrix composites including modelling of long harakeke fibre composite strength

Pickering

2015

Composites Part A: Applied Science and Manufacturing

View full text Add to dashboard Cite

show abstract

“…The real difficulties emerge owing to the wide diversity of shapes and compositions in Phormium technical fibers, which range from coarse fibers to finely‐split fragments. This may also affect the quality of fiber impregnation with polymer resin, resulting in its wide variability, and more generally in a broad scattering of mechanical and structural properties [25]. To address this issue, a number of solutions have been proposed, which range from optimizing chemical treatment of fiber surface for increasing its compatibility with the polymer matrix [26] to cultivar selection or improved fiber selection after extraction [25].…”

Section: Introductionmentioning

confidence: 99%

Poly(lactic acid)/Phormium tenax composites: Morphology and thermo‐mechanical behavior

et al. 2011

View full text Add to dashboard Cite

Composites of Phormium tenax fibers in a poly(lactic acid) matrix with fiber content of up to 40 wt%, produced by injection molding and twin screw compounding, were characterized by scanning electron microscopy, differential scanning calorimetry, thermogravimetric analysis, and mechanical tests (static and dynamic). Thermal analysis showed that cold-crystallization peak shifted to lower temperatures with increasing fiber content, confirming that the addition of Phormium fiber has the effect of promoting crystallinity. Dynamic mechanical analysis (DMA) results showed that the addition of Phormium fiber did not affect significantly the T(g) of the polymer and the area under the tan delta decreased with the addition of Phormium fiber. Tensile modulus has been consistently increased by reinforcing the composite with growing amounts of fibers, whilst the effect on tensile strength is less evident. SEM micrographs of fracture surfaces allowed highlighting failure modes of the composites, which included a diffuse presence of fiber pull-out and debonding. POLYM. COMPOS., 32: 1362-1368, 2011. (C) 2011 Society of Plastics Engineer

show abstract

“…Long natural fibre can be easily aligned by hand combing [2,3] or hand carding machines [4,5]. Alternatively, intermediate processing can also be conducted such as that carried out for textile fibre including spinning to produce continuous material that can then be directionally controlled during composite manufacture, although this requires substantial infrastructure.…”

Section: Introductionmentioning

confidence: 99%

High performance aligned short natural fibre – Epoxy composites

Pickering

2016

Composites Part B: Engineering

View full text Add to dashboard Cite

Aligned short harakeke fibre (New Zealand flax) mats were produced using dynamic sheet forming, impregnated with epoxy resin, then pressed and cured on a compression moulder to manufacture composite materials. These composites were found to have significantly higher tensile properties than planar random oriented short fibre composites; the tensile strength (136 MPa) obtained for the composites is higher than any seen in the literature to date for short natural fibre composites. Fibre orientation was not affected by fibre content despite the higher processing pressure required and fibre orientation factors obtained from Modified Rule of Mixtures equations for Young's modulus and tensile strength were found to be similar.

show abstract

Failure mechanisms in composites reinforced with unidirectional Phormium leaf fibre

Cited by 32 publications

References 30 publications

The potential of harakeke fibre as reinforcement in polymer matrix composites including modelling of long harakeke fibre composite strength

The potential of harakeke fibre as reinforcement in polymer matrix composites including modelling of long harakeke fibre composite strength

Poly(lactic acid)/Phormium tenax composites: Morphology and thermo‐mechanical behavior

High performance aligned short natural fibre – Epoxy composites

Contact Info

Product

Resources

About