scholarly journals Effect of Die Head Temperature at Compounding Stage on the Degradation of Linear Low Density Polyethylene/Plastic Film Waste Blends after Accelerated Weathering

2016 ◽  
Vol 2016 ◽  
pp. 1-18 ◽  
Author(s):  
S. M. Al-Salem ◽  
N. M. Al-Dousari ◽  
G. Joseph Abraham ◽  
M. Aromin D’Souza ◽  
O. A. Al-Qabandi ◽  
...  
Keyword(s):  
Light Transmission ◽  
Rapid Change ◽  
Low Density Polyethylene ◽  
Accelerated Weathering ◽  
Low Density ◽  
Plastic Film ◽  
Linear Low Density Polyethylene ◽  
Total Change ◽  
The Impact ◽  
Head Temperature

Accelerated weathering test was performed on blends of linear low density polyethylene (LLDPE) and plastic film waste constituting the following percentages of polyolefin polymers (wt.%): LLDPE (46%), low density polyethylene (LDPE, 51%), high density polyethylene (HDPE, 1%), and polypropylene (PP, 2%). Compounded blends were evaluated for their mechanical and physical (optical) properties. The impact of photodegradation on the formulated blends was studied, and loss of mechanical integrity was apparent with respect to both the exposure duration to weathering and waste content. The effect of processing conditions, namely, the die head temperature (DHT) of the blown-film assembly used, was investigated in this work. It was witnessed that surpassing the melting point of the blends constituting polymers did not always result in a synergistic behaviour between polymers. This was suspected to be due to the loss of amorphous region that polyolefin polymers get subjected to with UV exposure under weathering conditions and the effect of the plastic waste constituents. The total change in colour (ΔE) did not change with respect to DHT or waste content due to rapid change degradation on the material’s surface. Haze (%) and light transmission (%) decreased with the increase in waste content which was attributed to lack of miscibility between constituting polymers.

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.

Stiff and Tough Conductive Composites Using Carbon Black-Filled Polyethylene

2006 ◽  
Vol 312 ◽  
pp. 139-142 ◽  
Author(s):  
Qiang Yuan ◽  
Stuart Bateman ◽  
Dong Yang Wu
Keyword(s):  
Carbon Black ◽  
High Density Polyethylene ◽  
Tensile Modulus ◽  
Threshold Value ◽  
High Density ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Linear Low Density Polyethylene ◽  
Conductive Composites ◽  
The Impact

Stiff and tough conductive composites were manufactured using carbon black compounded with high and low density polyethylene, as well as linear low density polyethylene. A low percolation threshold value for the composites was achieved at 2 wt% carbon black. The impact strengths of the composites incorporating low density and linear low density polyethylene were found to be almost 16 and 26 times greater, respectively, than that of high density polyethylene composites. On the other hand, the modulus of high density polyethylene filled with carbon black was 2 times as high as low and linear low density polyethylene-based composites. Tensile modulus increased with the content of carbon black, however the impact strength of the composites decreased.

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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