Polypropylene/polyethylene two-layered by one-step rotational molding

2018 ◽  
Vol 38 (7) ◽  
pp. 685-694 ◽  
Author(s):  
Ektinai Jansri ◽  
Narongchai O-Charoen
Keyword(s):  
Particle Sizes ◽  
Linear Low Density Polyethylene ◽  
Rotational Molding ◽  
Molding Process ◽  
Special Equipment ◽  
Blending Method ◽  
Probability Of Success ◽  
One Step ◽  
Flow Apparatus ◽  
Particle Shapes

AbstractAt present, a two-layered product can be molded through various processes. The rotational molding process is a thermoplastics process that can produce products with a two-layered structure; however, it requires special equipment or additional steps in the processing, which make the processing more complex. However, previous research has shown that, through the use of materials with different particle sizes and melting points, two-layered products can also be molded. Thus, this research uses an axial powder flow apparatus to determine the possibility of a two-layered molding between polypropylene (PP) and linear low-density polyethylene (LLDPE). The differences in the particle shapes of a PP homopolymer and copolymer have been considered. The particle sizes of both PPs were determined to be larger than that of LLDPE, and were mixed in a ratio of 50:50 (%wt) using a dry blending method. The results of this experiment show that the two-layered molding of PP and LLDPE using an uncomplicated technique for rotational molding has a high probability of success.

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.

Simplified Version of Polymer Rotational Molding Manufacturing Method

2016 ◽  
Vol 699 ◽  
pp. 97-103 ◽  
Author(s):  
Laurenţiu Slătineanu ◽  
Oana Dodun ◽  
Margareta Coteaţă ◽  
Gheorghe Nagîţ ◽  
Irina Beşliu
Keyword(s):  
Liquid Phase ◽  
Rotation Speed ◽  
Rotational Molding ◽  
Slow Speed ◽  
Molding Process ◽  
Manufacturing Method ◽  
Polyurethane Resin ◽  
Liquid Material ◽  
Complex Equipment ◽  
Plastic Parts

Rotational molding is a manufacturing method which supposes the rotation of the mold, during the solidification of the liquid phase material, so that finally a part having a hollow could be obtained. The method could be applied in manufacturing of metallic and nonmetallic parts. Usually, the equipment for rotational molding ensures slow speed rotating of the mold around two axes placed perpendicularly each other and this fact led to relatively complex equipment for achieving rotational molding. The capacity of the liquid material to entirely cover the internal walls of the mold depends essentially on the liquid material viscosity, on the rotation speed and on the movements applied to the mold. Simplified equipment including a single rotation movement could be materialized. In order to test such a solution, a preliminary experiment was designed and materialized, by using a device adapted on universal lathe. Thus, the objective of the research presented in the paper was to study if it is possible to achieve plastic parts made by rotational molding using a single rotation movement. A polyurethane resin obtained from two liquid components was used in order to obtain the liquid material that could be introduced in the mold. The research results proved the possibility to use simplified equipment for achieving a rotational molding process, at least in certain cases and with some technological limits.

Influence of Moisture on Flax Fiber in Polyethylene Composite Product Manufactured by Rotational Molding Process

2002 ◽  
Author(s):  
S. Panigrahi ◽  
L. G. Tabil ◽  
W. J. Crerar ◽  
S. Sokansanj ◽  
T. Powell ◽  
...  
Keyword(s):  
Flax Fiber ◽  
Rotational Molding ◽  
Molding Process ◽  
Polyethylene Composite ◽  
Composite Product

Impact of hybrid nanosilica and nanoclay on the properties of palm rachis-reinforced recycled linear low-density polyethylene composites

2020 ◽  
pp. 089270572094421
Author(s):  
Wagih Abdel Alim Sadik ◽  
Abdel Ghaffar Maghraby El Demerdash ◽  
Rafik Abbas ◽  
Alaa Bedir
Keyword(s):  
Tensile Modulus ◽  
Stress Transfer ◽  
Microscopy Study ◽  
Hybrid Nanoparticles ◽  
Morphological Properties ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Linear Low Density Polyethylene ◽  
Plastic Composite ◽  
Blending Method

The main goal of this work was to assess the technical feasibility of palm rachis (PR) as a reinforcing agent in the production of wood–plastic composites. Recycled linear low-density polyethylene/PR fiber composites were prepared at constant content (3 phc (per hundred compounds)) of maleic anhydride-grafted polyethylene as compatibilizer by melt blending method utilizing a two-roll mill and compression molding. The effect of nanosilica (NS), nanoclay (NC), and hybrid nanoparticles (NSNC) at different concentrations (2, 4, and 6 phc) on mechanical, physical, thermal, and morphological properties was investigated. The results of mechanical properties measurements demonstrated that when 6 phc NS, 4 phc NC, and 4 phc NSNC were added, tensile, modulus strength, and hardness reached their optimum values. At a high level of NC loading (6 phc), the increased populace of NC layers led to agglomeration and stress transfer gets restricted. Elongation at break and Izod impact strength were decreased by the incorporation of different nanoparticles. Water absorption and thickness swelling of prepared composites were found to decrease on the incorporation of NS and NC. In addition, the thermal stability showed slightly improved by the addition of nanoparticles, but there are no perceptible changes in the values of melting temperature by increasing the content of NS and NC or NSNC. Scanning electron microscopy study approved the good interaction of the PR fibers with the polymer matrix as well as the effectiveness of NS and NC in the improvement of the interaction. The finding indicated that wood–plastic composite treated by NS had the highest properties than other composites.

Banana and Abaca Fiber-Reinforced Plastic Composites Obtained by Rotational Molding Process

2013 ◽  
pp. 130614085148001 ◽  
Author(s):  
Z. Ortega ◽  
M. D. Monzón ◽  
A. N. Benítez ◽  
M. Kearns ◽  
M. McCourt ◽  
...  
Keyword(s):  
Fiber Reinforced ◽  
Rotational Molding ◽  
Molding Process ◽  
Fiber Reinforced Plastic ◽  
Plastic Composites ◽  
Reinforced Plastic

The effect of pressure variations on the formation of gas inclusions in the rotational molding process

2015 ◽  
Vol 35 (5) ◽  
pp. 481-491 ◽  
Author(s):  
Martin Löhner ◽  
Dietmar Drummer
Keyword(s):  
Cycle Time ◽  
Polymer Melt ◽  
Low Pressure ◽  
Rotational Molding ◽  
Molding Process ◽  
Inclusion Removal ◽  
Heating And Cooling ◽  
Polymer Powder ◽  
Major Disadvantage ◽  
Plastic Processing

Abstract The major disadvantage of rotational molding is the cycle time, which is very long compared to other plastic processing methods. A major percentage of the cycle time besides heating and cooling results from the time necessary to remove gas inclusions from the polymer melt, which are trapped while sintering the polymer powder. In this work the formation of gas inclusions is investigated by conducting a cycle time variation on a uniaxial rotational molding machine. The influence of low pressure during melting on the formation of inclusions is investigated by examining sintering experiments with a pressure variation during the melting of the polymer. Sintering experiments are conducted with different melt residence times to investigate the mechanisms of gas inclusion removal. By comparing the time to reach a pore-free polymeric melt, the cycle time reduction potential under low-pressure application while melting the polymeric powder is estimated.

Fe3O4@L-arginine as a Reusable Catalyst for the Synthesis of Polysubstituted 2-Pyrrolidinones

2019 ◽  
Vol 6 (1) ◽  
pp. 61-68 ◽  
Author(s):  
Mohammad Ali Ghasemzadeh ◽  
Mohammad Hossein Abdollahi-Basir ◽  
Zahra Elyasi
Keyword(s):  
Heterocyclic Compounds ◽  
Structure Elucidation ◽  
Reaction Times ◽  
Biologically Active ◽  
Reusable Catalyst ◽  
Particle Sizes ◽  
Magnetic Nanocatalyst ◽  
Green Method ◽  
One Step ◽  
Good Agreement

Background: This research introduces an effective and green method for the synthesis of polysubstituted 2-pyrrolidinone derivatives as biologically-active heterocyclic compounds using multi- component reactions using Fe3O4@L-arginine as a reusable organocatalyst. Material and Method: The Fe3O4@L-arginine nanoparticles were prepared by a facile one-step approach and the structure elucidation of the magnetic nanocatalyst has been done using various spectroscopy techniques. Results: L-arginine-functionalized magnetite nanoparticles were obtained with particle sizes around 10 nm. Fe3O4@L-arginine exhibited strong catalytic activity to obtain some polysubstituted 2- pyrrolidinone. Conclusion: The considerable advantages of this research are short reaction times, excellent yields, simple workup procedure and reusability of the nanocatalyst which is in good agreement with green chemistry disciplines. The study on the reusability of the Fe3O4@L-arginine nanoparticles showed that the recovered catalyst could be reused six consecutive times.

Sign in / Sign up

Export Citation Format

Share Document