scholarly journals Evaluating Orientation Effects on the Fire Reaction Properties of Flax-Polypropylene Composites

Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2586
Author(s):  
Swagata Dutta ◽  
Nam Kyeun Kim ◽  
Raj Das ◽  
Debes Bhattacharyya
Keyword(s):  
Heat Flux ◽  
Cone Calorimeter ◽  
Ignition Time ◽  
Natural Fibre ◽  
Heating Process ◽  
Fire Dynamics ◽  
Polypropylene Composites ◽  
Combustion Properties ◽  
Wide Range ◽  
Sample Orientation

In this work, the fire reaction properties of flax-polypropylene (PP) composites were investigated at multiple sample angles both experimentally and numerically under two different heat flux conditions (35 and 50 kW/m2) in the cone calorimeter environment. An innovative testing setup which can accommodate a wide range of angles between 0° and 90° for the sample angle frame was developed to perform cone calorimeter tests at different sample angles. An advanced numerical predictive model based on the finite volume method was developed using the fire dynamics simulator (FDS) to quantify the dependency of ignition and combustion properties with sample angles. The numerical model was validated against experimental data from the cone calorimeter tests. The experimental and numerical analyses were conducted to quantify the effects of sample orientation on the different fire reaction properties i.e., ignition time, ignition temperature, burn time, heat release rate (HRR), critical heat flux, etc. The numerical method was utilised to analyse the mechanisms controlling the effect of heat convection and radiation blockage on the heating process. The study establishes that the sample orientation (with respect to the heat flux normal) has a significant influence on the fire reaction properties of natural fibre composites.

Experimental study on fire behaviors of flexible photovoltaic panels using a cone calorimeter

2017 ◽  
Vol 36 (1) ◽  
pp. 63-77 ◽  
Author(s):  
Xiaoyu Ju ◽  
Xiaodong Zhou ◽  
Kun Zhao ◽  
Fei Peng ◽  
Lizhong Yang
Keyword(s):  
Heat Flux ◽  
Differential Scanning Calorimetry ◽  
Polyethylene Terephthalate ◽  
Cone Calorimeter ◽  
Mass Loss Rate ◽  
Ignition Time ◽  
Scanning Calorimetry ◽  
Photovoltaic Panel ◽  
Photovoltaic Panels ◽  
Fire Properties

Photovoltaic arrays are mounted on the surfaces of modern buildings to harness renewable energy. When a building catches fire, burning photovoltaic panels could worsen an already very hazardous environment. This work deals with the effect of building flame radiation on the fire behaviors of flexible photovoltaic panel installed in building-integrated photovoltaic systems. Cone calorimeter tests were conducted in air with a piloted ignition. The influence of heat flux on photovoltaic fire properties was studied. Several characteristic parameters are systematically determined or calculated, including ignition time, critical heat flux, mass loss rate, gasification heat, heat release rate, and effective heat of combustion. Thermogravimetry and differential scanning calorimetry test was conducted to identify the decomposition mechanism. The comparison of fire properties of photovoltaic and polyethylene terephthalate + tedlar-polyester-tedlar and thermogravimetry and differential scanning calorimetry analysis reveal that polyethylene terephthalate is the main component responsible for decomposition and burning of flexible photovoltaic panel.

Flammability of Bamboo Fabric Reinforced Polypropylene Composites and their Hybrids

2016 ◽  
Vol 851 ◽  
pp. 155-162 ◽  
Author(s):  
Nurul Zuhairah Mahmud Zuhudi ◽  
Krishnan Jayaraman ◽  
Richard Lin
Keyword(s):  
Release Rate ◽  
Glass Fibre ◽  
Cone Calorimeter ◽  
Hybrid Composites ◽  
Natural Fibre ◽  
Reinforced Composites ◽  
Polypropylene Composites ◽  
Peak Heat Release Rate ◽  
Positive Effect ◽  
Fibre Reinforced Composites

Hybridisation is introduced as one way to use bamboo fabric as natural fibre reinforced composites (NFRCs). The research intends to determine the extent to which bamboo fabric can replace glass fibre in glass polypropylene (GPP) composites and whether the proposed hybrids are capable of competing, particularly in comparison to the flammability of GPP composites. This study evaluates the effect of hybridization on the flammability properties of bamboo fabric reinforced polypropylene composites and their hybrids. Flammability tests using cone calorimeter show that the peak Heat Release Rate (HRR) was reduced up to 39% for BPP50%, at 511.8 kW/m2, in comparison with that of neat PP, based on maximum peak values of 842 kW/m2. Interestingly, in the hybrid composites, the peak HRR reduced as glass fibre was replaced with bamboo fibre. These composites demonstrate a significant decrease in peak HRR, over 30% less than the neat PP and GPP composites respectively. These results indicate that a significant portion of the glass in GPP may be replaced with bamboo fabric, with a positive effect on fire resistance. This reduction in flammability and the improved properties obtained demonstrate promise for these hybrid materials in future applications.

scholarly journals A Review of the Flammability Factors of Kenaf and Allied Fibre Reinforced Polymer Composites

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
C. H. Lee ◽  
Mohd Sapuan Salit ◽  
M. R. Hassan
Keyword(s):  
Ignition Time ◽  
Fire Behavior ◽  
Fire Retardant ◽  
Natural Fibre ◽  
Main Concern ◽  
Content Type ◽  
Reinforced Polymer ◽  
Kenaf Fibre ◽  
Wide Range ◽  
Fibre Reinforced Polymer

Natural fibre is a well-known reinforcement fibre in polymer-matrix Composites (PMC) lately. Natural fibre has fast growing and abundance properties which make it available at very low cost. For kenaf fibre there is long lists of research projects which have been done regarding its behaviour, and properties and modification made to it. In this paper, fire flammability is the main concern for natural fibre reinforced polymer (NFRP) composites especially kenaf fibre. To estimate its flammability, a wide range of factors can be considered such as fibre content, type of matrices, pH conditions, treatment, and fire retardant (FR) filler’s type. The most important criteria are the ignition time, rate of propagation, and fire behavior. thermogravimetric analysis (TGA), different scanning calorimetric (DSC), and dynamic mechanical analysis (DMA) are the three most famous methods used to investigate the fire behaviour of composites.

Mechanical Properties and Dislocation Structure of Single Crystal Cdte Deformed in Compression at 300°C

1976 ◽  
Vol 34 ◽  
pp. 592-593
Author(s):  
Ernest L. Hall ◽  
J. B. Vander Sande
Keyword(s):  
Mechanical Properties ◽  
Single Crystal ◽  
Dislocation Structure ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Strain Curve ◽  
Optical Devices ◽  
Semiconductor Compound ◽  
Wide Range ◽  
Sample Orientation

The present paper describes research on the mechanical properties and related dislocation structure of CdTe, a II-VI semiconductor compound with a wide range of uses in electrical and optical devices. At room temperature CdTe exhibits little plasticity and at the same time relatively low strength and hardness. The mechanical behavior of CdTe was examined at elevated temperatures with the goal of understanding plastic flow in this material and eventually improving the room temperature properties. Several samples of single crystal CdTe of identical size and crystallographic orientation were deformed in compression at 300°C to various levels of total strain. A resolved shear stress vs. compressive glide strain curve (Figure la) was derived from the results of the tests and the knowledge of the sample orientation.

scholarly journals Effects of Graphene Nanoplatelets on Mechanical and Fire Performance of Flax Polypropylene Composites with Intumescent Flame Retardant

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 4094
Author(s):  
Imran Ali ◽  
Nam Kyeun Kim ◽  
Debes Bhattacharyya
Keyword(s):  
Flame Retardant ◽  
Decomposition Rate ◽  
Natural Fiber ◽  
Fire Retardant ◽  
Graphene Nanoplatelets ◽  
Intumescent Flame Retardant ◽  
Fume Hood ◽  
Fire Dynamics ◽  
Polypropylene Composites ◽  
Set Up

The integration of intumescent flame-retardant (IFR) additives in natural fiber-based polymer composites enhances the fire-retardant properties, but it generally has a detrimental effect on the mechanical properties, such as tensile and flexural strengths. In this work, the feasibility of graphene as a reinforcement additive and as an effective synergist for IFR-based flax-polypropylene (PP) composites was investigated. Noticeable improvements in tensile and flexural properties were achieved with the addition of graphene nanoplatelets (GNP) in the composites. Furthermore, better char-forming ability of GNP in combination with IFR was observed, suppressing HRR curves and thus, lowering the total heat release (THR). Thermogravimetric analysis (TGA) detected a reduction in the decomposition rate due to strong interfacial bonding between GNP and PP, whereas the maximum decomposition rate was observed to occur at a higher temperature. The saturation point for the IFR additive along with GNP has also been highlighted in this study. A safe and effective method of graphene encapsulation within PP using the fume-hood set-up was achieved. Finally, the effect of flame retardant on the flax–PP composite has been simulated using Fire Dynamics Simulator.

Near-Wall Microlayer Evaporation Analysis and Experimental Study of Nucleate Pool Boiling on Inclined Surfaces

1998 ◽  
Vol 120 (3) ◽  
pp. 641-653 ◽  
Author(s):  
G. F. Naterer ◽  
W. Hendradjit ◽  
K. J. Ahn ◽  
J. E. S. Venart
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Heating Surface ◽  
Nucleate Boiling ◽  
Inclined Surfaces ◽  
Wide Range ◽  
Model Predictions ◽  
Microlayer Evaporation ◽  
Near Wall

Boiling heat transfer from inclined surfaces is examined and an analytical model of bubble growth and nucleate boiling is presented. The model predicts the average heat flux during nucleate boiling by considering alternating near-wall liquid and vapor periods. It expresses the heat flux in terms of the bubble departure diameter, frequency and duration of contact with the heating surface. Experiments were conducted over a wide range of upward and downward-facing surface orientations and the results were compared to model predictions. More active microlayer agitation and mixing along the surface as well as more frequent bubble sweeps along the heating surface provide the key reasons for more effective heat transfer with downward facing surfaces as compared to upward facing cases. Additional aspects of the role of surface inclination on boiling dynamics are quantified and discussed.

Assessment of Fire Dynamics Simulator for Heat Flux and Flame Heights Predictions from Fires in SBI Tests

2008 ◽  
Vol 46 (2) ◽  
pp. 291-306 ◽  
Author(s):  
Jianping Zhang ◽  
Michael Delichatsios ◽  
Matthieu Colobert
Keyword(s):  
Heat Flux ◽  
Fire Dynamics ◽  
Fire Dynamics Simulator

scholarly journals Physical Properties of Thermoplastic Starch Derived from Natural Resources and Its Blends: A Review

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1396
Author(s):  
Z. N. Diyana ◽  
R. Jumaidin ◽  
Mohd Zulkefli Selamat ◽  
Ihwan Ghazali ◽  
Norliza Julmohammad ◽  
...  
Keyword(s):  
Thermoplastic Starch ◽  
Natural Fibre ◽  
Polymer Materials ◽  
Secondary Pollution ◽  
Wide Range ◽  
Potential Applications ◽  
Long Time ◽  
To Come ◽  
Main Component ◽  
Significant Attention

Thermoplastic starch composites have attracted significant attention due to the rise of environmental pollutions induced by the use of synthetic petroleum-based polymer materials. The degradation of traditional plastics requires an unusually long time, which may lead to high cost and secondary pollution. To solve these difficulties, more petroleum-based plastics should be substituted with sustainable bio-based plastics. Renewable and natural materials that are abundant in nature are potential candidates for a wide range of polymers, which can be used to replace their synthetic counterparts. This paper focuses on some aspects of biopolymers and their classes, providing a description of starch as a main component of biopolymers, composites, and potential applications of thermoplastics starch-based in packaging application. Currently, biopolymer composites blended with other components have exhibited several enhanced qualities. The same behavior is also observed when natural fibre is incorporated with biopolymers. However, it should be noted that the degree of compatibility between starch and other biopolymers extensively varies depending on the specific biopolymer. Although their efficacy is yet to reach the level of their fossil fuel counterparts, biopolymers have made a distinguishing mark, which will continue to inspire the creation of novel substances for many years to come.

Evaporite Palynology: a case study on the Permian (Lopgingian) Zechstein Sea

2021 ◽  
pp. jgs2020-174
Author(s):  
Martha E. Gibson ◽  
David J. Bodman
Keyword(s):  
Thermal Conductivity ◽  
Heat Flux ◽  
Rapid Growth ◽  
Western Europe ◽  
Thermal Maturity ◽  
Near Surface ◽  
Wide Range ◽  
Terrestrial Environments ◽  
Insight Into

Evaporites characterize the Lopingian of Europe but present obstacles for biostratigraphic analysis. Here we present a case study for processing the Lopingian Zechstein Group evaporites of central-western Europe for the recovery of palynomorph assemblages. We demonstrate that full recovery is easily achieved with two main modes of palynomorph preservation observed; palynomorphs are either exceptionally well-preserved and orange-brown in colour, or poorly-preserved, brown-black, opaque and fragmented. The latter are reminiscent of palynomorphs of high thermal maturity. However, we propose that the intact nature of preservation is a result of the rapid growth of near-surface halite crystals, with their darkening a consequence of locally-enhanced heat flux due to the relatively high thermal conductivity of salt. This case study has enabled novel insight into an otherwise undescribed environment, and demonstrates the utility and possibility of extracting palynomorphs from a variety of rock salt types. This method should be applicable to a wide range of ancient evaporite and could also be applied to other Permian evaporite systems, which are used as analogues for extra-terrestrial environments.

Experimental Measurements and CFD Evaluation of the Onset Flow Boiling at Low Pressure and High Subcooling Flow of R-11 Within Vertical Annulus

2014 ◽  
Author(s):  
Y. Bouaichaoui ◽  
R. Kibboua ◽  
M. Matkovič
Keyword(s):  
Heat Flux ◽  
Liquid Velocity ◽  
Flow Boiling ◽  
Fluid Model ◽  
Computer Code ◽  
Computational Method ◽  
Subcooled Boiling ◽  
Two Phase ◽  
Local Flow ◽  
Wide Range

The knowledge of the onset of subcooled boiling in forced convective flow at high liquid velocity and subcooling is of importance in thermal hydraulic studies. Measurements were performed under various conditions of mass flux, heat flux, and inlet subcooling, which enabled to study the influence of different boundary conditions on the development of local flow parameters. Also, some measurements have been compared to the predictions by the three-dimensional two-fluid model of subcooled boiling flow carried out with the computer code ANSYS-CFX-13. A computational method based on theoretical studies of steady state two phase forced convection along a test section loop was released. The calculation model covers a wide range of two phase flow conditions. It predicts the heat transfer rates and transitions points such as the Onset of Critical Heat Flux.

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