Rotational molding of self-hybrid composites based on linear low-density polyethylene and maple fibers

2017 ◽  
Vol 39 (11) ◽  
pp. 4094-4103 ◽  
Author(s):  
Fatima Ezzahra Hanana ◽  
Denis Rodrigue
Keyword(s):  
Hybrid Composites ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Linear Low Density Polyethylene ◽  
Rotational Molding

Experimental investigation of linear low density polyethylene composites based on coir for rotational molding process

2020 ◽  
pp. 096739112095324
Author(s):  
Nikita Gupta ◽  
PL. Ramkumar
Keyword(s):  
Thermal Analysis ◽  
Weight Ratio ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Coir Fiber ◽  
Linear Low Density Polyethylene ◽  
Rotational Molding ◽  
Molding Process ◽  
Weight Percentage ◽  
Heat Parameter

Rotational Molding is a plastic manufacturing process mainly implemented to produce stress free hollow products. Linear Low Density Polyethylene (LLDPE) is widely preferred as base resin for molding roto molded product, but it displays moderate value in some critical applications where strength is the major criteria. Additives can fill the gap in sustaining the necessary strength needed. In the present work, an attempt has been made to analyze the optimum percentage of coir reinforced with LLDPE for rotational molding technique to provide requisite processability for rotational molding process. Coir in its powder form is mixed at concentrations varying in the range of 3% to 20% with respect to LLDPE. In order to justify the prerequisite of processability for rotational molding, various experiments namely FTIR, MFI, rheology and thermal analysis were conducted. FTIR suggested the range of 5% to 15% wherein the significance of LLDPE and coir peaks can be observed. MFI test supported FTIR result which ended in considering 3% to 12% by weight ratio suitable in terms of flow ability. Rheological and thermal analysis subjecting to shear and heat parameter respectively, confirmed the range of 10 weight percentage of coir or below is suitable in terms of material processability. From the experimental results, it is concluded that 10% or less concentration of coir fiber in LLDPE as an optimum range of blend yielding better processability for rotational molding process.

Dynamic Viscoelastic Properties of Organic / Inorganic Fibres Reinforced lldpe Composites in Molten State

2001 ◽  
Vol 11 (5) ◽  
pp. 258-263 ◽  
Author(s):  
Takeschi Kitano ◽  
S.A.R. Hashmi ◽  
Navin Chand
Keyword(s):  
Viscoelastic Properties ◽  
Parallel Plate ◽  
Hybrid Composites ◽  
Loss Modulus ◽  
Angular Frequency ◽  
Low Density Polyethylene ◽  
Rheological Parameters ◽  
Low Density ◽  
Linear Low Density Polyethylene ◽  
Glass Fibres

Abstract Dynamic rheological parameters such as storage modulus, G’, loss modulus, G”, and dynamic viscosity, h’, at 200°C were studied for Kevlar fibres, glass fibres and their hybrids reinforced linear low density polyethylene (LLDPE). Parallel plate rheometer was employed for these tests. G’, G” and h’ increased with the increased reinforcement and angular frequency, w. Two sets of reinforcement, 10 and 20 vol.% of fibres are used in LLDPE. The composition of fibres in hybrid composites was varied. The replacement of glass fibres with Kevlar increases the values of G’, G” and h’. The values of these rheological parameters also increased with the thickness of the composite. This increase was associated with the decreased average orientation of fibres present in the composite. The effects of the change in strain amplitude on G’ and G” is also studied and reported here.

scholarly journals Rotational Molding of Linear Low-Density Polyethylene Composites Filled with Wheat Bran

Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1004 ◽  
Author(s):  
Aleksander Hejna ◽  
Mateusz Barczewski ◽  
Jacek Andrzejewski ◽  
Paulina Kosmela ◽  
Adam Piasecki ◽  
...  
Keyword(s):  
Polymer Composites ◽  
Wheat Bran ◽  
Mechanical Performance ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Linear Low Density Polyethylene ◽  
Rotational Molding ◽  
Wood Polymer ◽  
Wood Polymer Composites ◽  
The Impact

Application of lignocellulosic fillers in the manufacturing of wood polymer composites (WPCs) is a very popular trend of research, however it is still rarely observed in the case of rotational molding. The present study aimed to analyze the impact of wheat bran content (from 2.5 wt.% to 20 wt.%) on the performance of rotationally-molded composites based on a linear low-density polyethylene (LLDPE) matrix. Microscopic structure (scanning electron microscopy), as well as physico-mechanical (density, porosity, tensile performance, hardness, rebound resilience, dynamic mechanical analysis), rheological (oscillatory rheometry) and thermo-mechanical (Vicat softening temperature) properties of composites were investigated. Incorporation of 2.5 wt.% and 5 wt.% of wheat bran did not cause significant deterioration of the mechanical performance of the material, despite the presence of ‘pin-holes’ at the surface. Values of tensile strength and rebound resilience were maintained at a very similar level, while hardness was slightly decreased, which was associated with the porosity of the structure. Higher loadings resulted in the deterioration of mechanical performance, which was also expressed by the noticeable rise of the adhesion factor. For lower loadings of filler did not affect the rheological properties. However, composites with 10wt.% and 20 wt.% also showed behavior suitable for rotational molding. The presented results indicate that the manufacturing of thin-walled products based on wood polymer composites via rotational molding should be considered a very interesting direction of research.

scholarly journals Identification of the LLDPE Constitutive Material Model for Energy Absorption in Impact Applications

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1537
Author(s):  
Luděk Hynčík ◽  
Petra Kochová ◽  
Jan Špička ◽  
Tomasz Bońkowski ◽  
Robert Cimrman ◽  
...  
Keyword(s):  
Strain Rate ◽  
Material Model ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Linear Low Density Polyethylene ◽  
Stress Strain ◽  
Rate Dependent ◽  
Constitutive Material Model ◽  
Principal Directions ◽  
Constitutive Material

Current industrial trends bring new challenges in energy absorbing systems. Polymer materials as the traditional packaging materials seem to be promising due to their low weight, structure, and production price. Based on the review, the linear low-density polyethylene (LLDPE) material was identified as the most promising material for absorbing impact energy. The current paper addresses the identification of the material parameters and the development of a constitutive material model to be used in future designs by virtual prototyping. The paper deals with the experimental measurement of the stress-strain relations of linear low-density polyethylene under static and dynamic loading. The quasi-static measurement was realized in two perpendicular principal directions and was supplemented by a test measurement in the 45° direction, i.e., exactly between the principal directions. The quasi-static stress-strain curves were analyzed as an initial step for dynamic strain rate-dependent material behavior. The dynamic response was tested in a drop tower using a spherical impactor hitting a flat material multi-layered specimen at two different energy levels. The strain rate-dependent material model was identified by optimizing the static material response obtained in the dynamic experiments. The material model was validated by the virtual reconstruction of the experiments and by comparing the numerical results to the experimental ones.

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