scholarly journals Thermal and Mechanical Analysis of Polyethylene Homo-Composites Processed by Rotational Molding

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 528 ◽  
Author(s):  
Antonio Greco ◽  
Francesca Ferrari ◽  
Maria Grazia Buccoliero ◽  
Greta Trono
Keyword(s):  
Mechanical Properties ◽  
Compression Molding ◽  
Mechanical Analysis ◽  
Rotational Molding ◽  
Reinforcing Bars ◽  
Molding Process ◽  
Bending Tests ◽  
Fiber Placement ◽  
A Value ◽  
Uhmwpe Fibers

This work is aimed at studying the suitability of ultra-high molecular weight polyethylene (UHMWPE) fibers for the production of polyethylene homo-composites processed by rotational molding. Initially pre-impregnated bars were produced by co-extrusion and compression molding of UHMWPE fibers and linear low-density polyethylene (LLDPE). A preliminary screening of different processing routes for the production of homo-composite reinforcing bars was performed, highlighting the relevance of fiber impregnation and crystalline structure on the mechanical properties. A combination of co-extrusion and compression molding was found to optimize the mechanical properties of the reinforcing bars, which were incorporated in the LLDPE matrix during a standard rotational molding process. Apart from fiber placement and an increase in processing time, processing of homo-composites did not require any modification of the existing production procedures. Plate bending tests performed on rotational molded homo-composites showed a modulus increase to a value three times higher than that of neat LLDPE. This increase was obtained by the addition of 4% of UHWMPE fibers and a negligible increase of the weight of the component. Dart impact tests also showed an increased toughness compared to neat LLPDE.

Synergistic effect of carbon nanotubes and nano-hydroxyapatite on mechanical properties of polyetheretherketone based hybrid nanocomposites

2020 ◽  
pp. 096739112096950
Author(s):  
Manjeet Kumar ◽  
Rajesh Kumar ◽  
Sandeep Kumar
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Elastic Modulus ◽  
Storage Modulus ◽  
Fracture Resistance ◽  
Compression Molding ◽  
Mechanical Analysis ◽  
Hybrid Nanocomposites ◽  
Hybrid Nanocomposite ◽  
And Storage

Hybrid nanocomposites utilize the benefits of properties of different fillers to enhance its desired properties. Polyetheretherketone (PEEK) based hybrid nanocomposites have immense potential applications in aerospace, automobile, high-temperature electrical applications, and medical and health care. The present work is an attempt to improve the elastic modulus, hardness, fracture resistance, and storage modulus simultaneously by reinforcing the PEEK matrix with multiwall carbon nanotubes (MWCNTs) filler and 30 wt.% nano hydroxyapatite (nHA)-MWCNT hybrid filler. The nanocomposites having 0,1,3,5 and 7 wt.% of MWCNTs were fabricated by the Ball Mixing and Compression Molding Method. Customized Die Heater setup was used to ensure uniform heating and cooling during compression molding. The morphology was examined by Field Emission Scanning Electron Microscopy (FESEM) and Energy-Dispersive X-ray Spectroscopy (EDS) and uniform distribution of nano-fillers was observed. The nanoindentation method was adopted to investigate the Static Mechanical Analysis (SMA) and Dynamic Mechanical Analysis (DMA) at varying frequencies of loading, of nanocomposites. At 5 wt.% of MWCNTs, the enhancements in elastic modulus, hardness, fracture resistance, and storage modulus were observed to be 80%, 36%, 32%, and 58% respectively in case of PEEK/(0–7%)MWCNT nanocomposite and 104%, 76%, 16%, and 80% respectively in case of PEEK/30%nHA-(0–7%)MWCNT hybrid nanocomposite. The decrements in loss factor indicated the improvement in elastic behavior of nanocomposites with increasing wt.% of MWCNTs. The elastic modulus of PEEK/30%nHA-5%MWCNT hybrid nanocomposite was observed to be 7.67 GPa, which falls within the range of elastic modulus of the human cortical bone. The results revealed that 5 wt.% of MWCNTs is optimum filler composition for improving the mechanical properties.

Optimization of mechanical properties of silk fiber-reinforced polypropylene composite using Box–Behnken experimental design

2016 ◽  
Vol 47 (5) ◽  
pp. 602-621 ◽  
Author(s):  
Rajkumar Govindaraju ◽  
Srinivasan Jagannathan
Keyword(s):  
Mechanical Properties ◽  
Experimental Design ◽  
Process Parameters ◽  
Polypropylene Fiber ◽  
Compression Molding ◽  
Silk Fiber ◽  
Fiber Reinforced ◽  
Polypropylene Composite ◽  
Molding Process ◽  
Polypropylene Composites

In this study, the compression molding process parameters for the development of silk fiber-reinforced polypropylene composites was optimized using Box–Behnken experimental Design with response surface methodology. The trimmed silk fibers from shuttleless loom silk selvedge waste were used as reinforcement in polypropylene fiber matrix. The process parameters of compression molding such as temperature (165–185℃), time (7–15 min) and pressure (35–45 bar) were optimized with respect to the mechanical properties of the silk fiber-reinforced polypropylene composite. The optimum parameters for better mechanical properties were found to be temperature, 180℃; time, 7 min, and pressure, 35 bar in compression molding. The optimised level of parameters has shown good response to the predicted model.

The Processing Characteristics and Mechanical Properties of Semi-Prepreg RTM Composites

2013 ◽  
Vol 721 ◽  
pp. 153-158 ◽  
Author(s):  
Wei Dong Li ◽  
Gang Liu ◽  
Xiao Lan Hu ◽  
Xue Feng An ◽  
Xiang Yu Zhong ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compression Molding ◽  
Internal Quality ◽  
Molding Process ◽  
Bismaleimide Resin ◽  
Transfer Molding ◽  
Rtm Process ◽  
Superior Mechanical Properties ◽  
Wet Winding ◽  
Properties Of Composites

A novel semi-prepreg resin transfer molding (RTM) process was developed to address difficulties associated with RTM process and to improve the mechanical properties of the resulting composites. Unidirectional semi-prepregs exhibiting relatively good overlay characteristics were prepared via prepolymerization of bismaleimide resin followed by wet winding. The processing characteristics and mechanical properties of composites fabricated via semi-prepreg RTM technology were compared with those of composites produced using a normal-prepreg compression molding process. Experimental results showed that the laminates fabricated by the semi-prepreg RTM process were of better internal quality and had superior mechanical properties as compared with laminates fabricated by the normal-prepreg compression molding process.

The Usage of Recycled Material in Rotational Molding Process for Production of Septic Tank

2018 ◽  
Vol 936 ◽  
pp. 151-158 ◽  
Author(s):  
Suradej Chaisrichawla ◽  
Rapeephun Dangtungee
Keyword(s):  
Mechanical Properties ◽  
Process Condition ◽  
Septic Tank ◽  
Rotational Molding ◽  
Forming Process ◽  
Molding Process ◽  
Melt Flow Rate ◽  
Large Product ◽  
Recycled Material ◽  
Recycled Hdpe

Rotational molding is the forming process that use in produce large product, complexity product and hollow product with the limitation of process ability and material. Most of the rotational molding is a large product with a longer useful life compare to other technique, so to reused the material from other process can help to increase the competition of rotational molding in the market. This paper chooses recycled HDPE from blowing process due to it generally used by the market and not difficult to find. So in this paper choose to studies the blend of virgin LLDPE (linear low density polyethylene) and recycled HDPE (high density polyethylene) for application in septic tank by rotational molding process. Various ratio of blending were investigated to find the morphology, mechanical properties and the relation of melt flow rate and rheology. Mechanical properties are generally referred to tensile test, hardness test, impact strength and Morphology by Scanning Electron Microscope. Many studies have carried out to investigate about rotational molding forming process control, mold and process condition, some on material ability and new material to used in rotational molding to improve the mechanical properties and various technique in forming by rotational molding. But this article will investigated more about the use of recycled material from other forming technique process (which refer to blowing process in this article) to use in rotational molding process for produce septic tank compare to the commercial quality.

scholarly journals Carbon Fabric Reinforced Addition-Cure Phenolic Resins Based on Propargyl and Allyl Ether Functional Novolac Produced

2020 ◽  
Vol 22 (2) ◽  
pp. 99
Author(s):  
S. Nechausov ◽  
B. Bulgakov ◽  
D. Kalugin ◽  
A. Babkin ◽  
A. Kepman ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Cost Effective ◽  
Mechanical Analysis ◽  
Interlaminar Shear Strength ◽  
Allyl Ether ◽  
Carbon Fabric ◽  
Molding Process ◽  
Plane Shear ◽  
Interlaminar Shear

Composites consisting of propargyl- and allyl/propargyl- modified novolac resins and carbon fabric were obtained by the vacuum infusion molding process. It was established that the presence of potassium cations remaining after the synthesis increase the resin melt viscosity, and acid washing is needed to obtain resins suitable for cost-effective injection techniques of composite fabrication. The mechanical properties of all composites such as compressive strength, tensile strength, in plane shear strength, and interlaminar shear strength were determined at 25, 200 and 230 °С. The carbon fiber reinforced plastics (CFRPs) retained their mechanical properties at temperatures up to 200 °C. It was shown that the use of the obtained allyl-containing polymer matrices improved mechanical properties and increased the thermal stability of the CFRPs in comparison with the propargylated novolac matrices. The composite material with novolac matrices modified by 18% propargyl and 23% allyl groups retains only up to 70% of the initial interlaminar shear strength values at 230 °C which corresponds to the data of the dynamic mechanical analysis of neat cured resins.

Degradation of Mechanical Properties of Conventional and Nanophased Carbon/Epoxy Composites in Seawater

2011 ◽  
Vol 133 (4) ◽  
Author(s):  
M. K. Hossain ◽  
K. A. Imran ◽  
M. V. Hosur ◽  
S. Jeelani
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Flexural Modulus ◽  
Microscopy Study ◽  
Epoxy Composites ◽  
Molding Process ◽  
Bending Tests ◽  
Three Point Bending ◽  
Degradation Of Mechanical Properties ◽  
Marine Applications

Composites used for marine applications are subjected to various environmental effects, such as moisture, temperature, UV radiation, and seawater. In this study, effect of seawater on the degradation of mechanical properties of conventional and nanophased carbon/epoxy composites was investigated. Epoxy resin was modified using 1 wt. %, 2 wt. %, and 3 wt. % nanoclay. Carbon/epoxy composites were fabricated by vacuum assisted resin transfer molding process and compared with neat samples with and without exposure to seawater. Nanoclay was dispersed into matrix by using magnetic stirring. Mechanical characterization performed through three point bending tests showed that 2 wt. % nanoclay loading was optimum. Flexural strength and modulus were increased by 25% and 12.51%, respectively, compared to neat system for samples not exposed to seawater. Flexure samples exposed to the seawater for 30-, 60-, and 180-day periods revealed that samples with nanoclay retained better mechanical properties compared to neat samples. After 30-day exposure to seawater, there was no significant reduction in the strength and modulus. However, flexural strength was reduced by 10.24%, 7.08%, 5.28%, and 7.13% for neat, 1 wt. %, 2 wt. %, and 3 wt. % nanoclay-infused samples, respectively, after the samples were exposed to seawater for 180-day. At the same time flexural modulus was reduced by 12.61%, 7.16%, 4.59%, and 6.11%, respectively. From scanning electron microscopy (SEM) studies, it was found that failure occurred due to delimitation and initiated from the compression side. Nanophased composites exhibited better bonding between fiber and matrix. SEM micrographs also revealed that both unconditioned and conditioned nanophased epoxy, which produce relatively rougher fracture surfaces compared to neat samples. Optical microscopy study revealed no significant physical change in outer surfaces of the samples conditioned up to a 90-day period.

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