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 Properties of core-half wrapped shell structure wood-polymer composites containing glass fiber-reinforced shells

BioResources ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 9088-9102
Author(s):  
Runzhou Huang ◽  
Xian Zhang ◽  
Zhuangzhuang Teng ◽  
Fei Yao
Keyword(s):  
Thermal Expansion ◽  
Glass Fiber ◽  
Polymer Composites ◽  
Mechanical Performance ◽  
Impact Resistance ◽  
Shell Layer ◽  
Flame Resistance ◽  
Wood Polymer ◽  
Wood Polymer Composites ◽  
The Impact

Glass fiber (GF) is commonly applied as a filler in the preparation of polymer composites. Due to the presence of GF, composite mechanical performance, flame resistance, and thermal performance could be greatly improved. The influence of a GF-filled polymer shell layer was investigated relative to the morphology, mechanical, thermal, and fire flammability performance of the core-half wrapped shell structured wood high-density polyethylene (HDPE) composites prepared via co-extrusion. The use of the relatively less-stiff pure HDPE with high linear coefficients of thermal expansion (LCTEs) lowered the general thermal stability and modulus of the wood polymer composites (WPCs). Flexural and thermal expansion properties were improved for the GF-filled HDPE shells in comparison to the unmodified material, enabling a well-balanced performance of this novel core–shell material. Implementation of GF-modified HDPE or unmodified HDPE layers as a shell for WPC core remarkably improved the impact resistance of the co-extruded WPCs. In comparison with composites possessing unmodified HDPE shell, the flame resistance performance of the shell layer was slightly improved in case that the GF content was below 25 wt%. A slight decrease in composite general heat release and rate was discovered in case that the GF content was greater than 25 wt%.

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.

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.

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