An Experimental Investigation on Surface Quality Extruded Wood-Polypropylene Composite

2012 ◽  
Vol 428 ◽  
pp. 89-93 ◽  
Author(s):  
Ehsan Soury ◽  
Amir Hossein Behravesh ◽  
Nathan Jafarian Jam ◽  
Ali Haghtalab
Keyword(s):  
Surface Quality ◽  
Polymeric Materials ◽  
Melt Flow Index ◽  
Extrusion Process ◽  
Diameter Ratio ◽  
Flow Index ◽  
Screw Speed ◽  
Melt Temperature ◽  
Wood Content ◽  
Length To Diameter Ratio

This paper presents an experimental study on surface quality (roughness) for extruded wood plastic composites (WPC) in an extrusion process. A problem that usually occurs in production of extruded parts of polymeric materials, and in special case of WPC, is flow instabilities at the extrusion die exit. The instabilities lead to production of profiles with unacceptable surface quality. In this paper, the influences of the important material and process parameters on the surface quality are investigated. The variable parameters were selected as wood content, polymer melt flow index (MFI), screw speed, melt temperature, die diameter and finally length-to-diameter ratio of the die land. The experiments specified that increasing die land length-to-diameter ratio (L/D), die temperature and wood content and decreasing screw speed and polymer MFI lead to improve the surface quality.

scholarly journals Effect of Hard Plastic Waste on the Quality of Recycled Polypropylene Blends

Recycling ◽  
2021 ◽  
Vol 6 (3) ◽  
pp. 58
Author(s):  
Patrizio Tratzi ◽  
Chiara Giuliani ◽  
Marco Torre ◽  
Laura Tomassetti ◽  
Roberto Petrucci ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Polymeric Materials ◽  
Melt Flow Index ◽  
Plastic Waste ◽  
Flow Index ◽  
Yield Strain ◽  
Melt Index ◽  
Polypropylene Blends ◽  
Post Industrial ◽  
Plastic Containers

The recycling of plastic waste is undergoing fast growth due to environmental, health and economic issues, and several blends of post-consumer and post-industrial polymeric materials have been characterized in recent years. However, most of these researches have focused on plastic containers and packaging, neglecting hard plastic waste. This study provides the first experimental characterization of different blends of hard plastic waste and virgin polypropylene in terms of melt index, differential scan calorimetry (DSC), thermogravimetric analysis (TGA), mechanical properties (tensile, impact and Shore hardness) and Vicat softening test. Compared to blends based on packaging plastic waste, significant differences were observed in terms of melt flow index (about 10 points higher for hard plastic waste). Mechanical properties, in particular yield strain, were instead quite similar (between 5 and 9%), despite a higher standard deviation being observed, up to 10%, probably due to incomplete homogenization. Results demonstrate that these worse performances could be mainly attributed to the presence of different additives, as well as to the presence of impurities or traces of other polymers, other than incomplete homogenization. On the other hand, acceptable results were obtained for selected blends; the optimal blending ratio was identified as 78% post-consumer waste and 22% post-industrial waste, meeting the requirement for injection molding and thermoforming.

Thermomechanical investigations of PEKK-HAp-CS composites

2019 ◽  
Vol 233 (11) ◽  
pp. 1196-1203
Author(s):  
Rupinder Singh ◽  
Gurchetan Singh ◽  
Jaskaran Singh ◽  
Ranvijay Kumar ◽  
Md Mustafizur Rahman ◽  
...  
Keyword(s):  
Melt Flow Index ◽  
Extrusion Process ◽  
Flow Index ◽  
Fused Deposition Modelling ◽  
Index Test ◽  
Melt Flow ◽  
Scanning Calorimetry ◽  
Fused Deposition ◽  
Ether Ketone ◽  
Input Variables

In this experimental study, a composite of poly-ether-ketone-ketone by reinforcement of hydroxyapatite and chitosan has been prepared for possible applications as orthopaedic scaffolds. Initially, different weight percentages of hydroxyapatite and chitosan were reinforced in the poly-ether-ketone-ketone matrix and tested for melt flow index in order to check the flowability of different compositions/proportions. Suitable compositions revealed by the melt flow index test were then taken forward for the extrusion of filament required for fused deposition modelling. For thermomechanical investigations, Taguchi-based design of experiments has been used with input variables in the extrusion process as follows: temperature, load applied and different composition/proportions. The specimens in the form of feedstock filament produced by the extrusion process were made to undergo tensile testing. The specimens were also inspected by differential scanning calorimetry and photomicrographs. Finally, the specimen showing the best performance from the thermomechanical viewpoint has been selected to extrude the filament for the fused deposition modelling process.

scholarly journals Effect of the Compounding Conditions of Polyamide 6, Carbon Fiber, and Al2O3 on the Mechanical and Thermal Properties of the Composite Polymer

Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3047 ◽  
Author(s):  
Young Shin Kim ◽  
Jae Kyung Kim ◽  
Euy Sik Jeon
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Injection Molding ◽  
Mechanical Strength ◽  
Melt Flow Index ◽  
Polyamide 6 ◽  
Extrusion Process ◽  
Flow Index ◽  
Process Conditions ◽  
Mechanical And Thermal Properties

Among the composite manufacturing methods, injection molding has higher time efficiency and improved processability. The production of composites via injection molding requires a pre-process to mix and pelletize the matrix polymer and reinforcement material. Herein, we studied the effect of extrusion process conditions for making pellets on the mechanical and thermal properties provided by injection molding. Polyamide 6 (PA6) was used as the base, and composites were produced by blending carbon fibers and Al2O3 as the filler. To determine the optimum blending ratio, the mechanical properties, thermal conductivity, and melt flow index (MI) were measured at various blending ratios. With this optimum blending ratio, pellets were produced by changing the temperature and RPM conditions, which are major process variables during compounding. Samples were fabricated by applying the same injection conditions, and the mechanical strength, MI values, and thermal properties were measured. The mechanical strength increased slightly as the temperature and RPM increased, and the MI and thermal conductivity also increased. The results of this study can be used as a basis for specifying the conditions of the mixing and compounding process such that the desired mechanical and thermal properties are obtained.

PREDICTING THE FLOW PROPERTIES OF POLYAMIDE NANOCOMPOSITES BY USING VINOGRADOV-MALKIN MODEL

2015 ◽  
Vol 9 (3) ◽  
pp. 2446-2452
Author(s):  
Tomasz Mariusz Majka ◽  
Marcin Majka ◽  
Muhammad Kamrul Hasan
Keyword(s):  
Shear Rate ◽  
Flow Direction ◽  
Polymeric Materials ◽  
Melt Flow Index ◽  
Polyamide 6 ◽  
Flow Index ◽  
Melt Flow ◽  
Melt Flow Rate ◽  
Shear Rates ◽  
Different Temperatures

This article reports the prediction of the theoretical flow curves of polyamide composites by using Vinogradov-Malkin model. Determination of the melt flow index of polymeric materials is the first step to study viscosity-shear rate relationship. The viscosity of the composites at different temperatures were calculated by using the Williams, Landel'a and Ferry (WLF) equation. Other important rheological characteristics were calculated by using appropriate equations. One point method is employed to correlate the changes in viscosity with temperatures. As expected, it is found that incorporation of nanoclay to polyamide 6 (PA6) significantly decreases the Melt Flow Rate of the composites and hence, increases density. Addition of stabilizer further increases density of the PA6/nanoclay composites. The simulations of viscosity curves for PA6 composites were carried out at measurement temperature, 240°C and in the range of 180°C - 350°C with shear rate of 10-1 – 103 1/s. It is found that addition of nanoclay and stabilizer to PA6 decreases viscosity of the composites in the order of PA6/OMMT > PA6 > PA6/I1098 > PA6/OMMT/I1098 > PA6/MMT/I1098 > PA6/MMT. At higher shear rates, viscosity decreases in the same sequence as low shear rates. At further higher shear rates (> 1000 1/s), filler particles are arranged in the flow direction thus exerting no significant effect on viscosity of composites both with and without the stabilizer. During injection moulding in the shear rate ranging from 101 – 104 1/s at 240°C temperature, it is evident that viscosity decreases drastically with increase in shear rate.

Rotomolding and polyethylene composites with rotomolded lignocellulosic materials: A review

2020 ◽  
Vol 39 (11-12) ◽  
pp. 459-472
Author(s):  
Lumirca Del Valle Espinoza León ◽  
Viviane Alves Escocio ◽  
Leila Lea Yuan Visconte ◽  
Julio Cesar Jandorno Junior ◽  
Elen Beatriz Acordi Vasques Pacheco
Keyword(s):  
Maleic Anhydride ◽  
Polymer Matrix ◽  
Polymer Melt ◽  
Polymeric Materials ◽  
Melt Flow Index ◽  
Polymer Particle ◽  
Morphological Properties ◽  
Flow Index ◽  
Main Process ◽  
Wood Fibers

Rotomolding is a versatile process used in the manufacture of thermoplastic polymeric materials to produce large hollow plastic parts. The aim of this review article was to discuss the rotomolding process and show the properties of the polyethylene composite and rotomolded lignocellulosic fibers, which are processed for prolonged periods under temperature. The main process parameters studied are the shaft speed of the equipment, molding temperature, polymer particle size, polymer melt flow index, and amount of material, which must be well controlled to achieve a non-degraded product with homogeneous thickness and no porosity. Rotomolded composites containing sisal, pine, coir, banana, flax, and maple wood fibers, among others, have been evaluated primarily for their mechanical (impact, flexural, and tensile strength) and morphological properties. The type, content, and treatment of lignocellulosic fillers are the most widely studied variables in polyethylene-based rotomolded composites. Fiber content was the variable that most influenced mechanical properties, particularly impact strength and hardness due to the voids formed by the hydrodynamic volume between the polymer matrix and lignocellulosic filler. Chemical treatment of the fiber by mercerization with NaOH made it more hydrophobic and the addition of maleic anhydride-grafted polyethylene as a coupling agent improved the interfacial adhesion between the non-polar polymer matrix and polar filler. However, the best mechanical property results were obtained with the use of maleic anhydride-grafted polyethylene.

The Effect of Polyquinone and Phenol-Phosphite Stabilizer on the Resistance of Polypropylene to Ionizing Radiation

2019 ◽  
Vol 816 ◽  
pp. 328-332 ◽  
Author(s):  
M.S. Lisanevich ◽  
Elvina R. Rakhmatullina ◽  
Yu.N. Khakimullin ◽  
Rezeda Yu. Galimzyanova ◽  
R.M. Akhmadullin ◽  
...  
Keyword(s):  
Ionizing Radiation ◽  
Medical Devices ◽  
Polymeric Materials ◽  
Melt Flow Index ◽  
Flow Index ◽  
Radiation Sterilization ◽  
Melt Flow ◽  
Medical Products ◽  
Degradation Temperature

For polymeric materials intended for the manufacture of disposable sterile medical devices, resistance to sterilization methods is important. For the manufacture of disposable medical products is widely used polypropylene, destructive during radiation sterilization. It is established that the addition of polyquinone leads to a decrease in the destruction of polypropylene, which is manifested in a decrease in the values of the melt flow index and an increase in the degradation temperature of polypropylene of the irradiated compositions.

scholarly journals Influence of Finishing Operations and Melt Flow Index on Surface Quality of Injection Molded Parts

2016 ◽  
Vol 16 (2) ◽  
pp. 334-338 ◽  
Author(s):  
Jiří Čop ◽  
Ladislav Fojtl ◽  
Ondřej Bílek ◽  
Vladimír Pata
Keyword(s):  
Surface Quality ◽  
Melt Flow Index ◽  
Flow Index ◽  
Melt Flow ◽  
Molded Parts ◽  
Injection Molded

scholarly journals Evaluation of PE Films Having NIR-Reflective Additives for Greenhouse Applications in Arid Regions

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Syed K. H. Gulrez ◽  
Ahmed M. Abdel-Ghany ◽  
Ibrahim M. Al-Helal ◽  
Saeed M. Al-Zaharani ◽  
Abdullah A. Alsadon
Keyword(s):  
Near Infrared ◽  
Mechanical Test ◽  
Control Sample ◽  
Viscoelastic Behavior ◽  
Melt Flow Index ◽  
Extrusion Process ◽  
Flow Index ◽  
Scanning Calorimetry ◽  
Blend Films ◽  
Blown Film Extrusion

Linear-low-density-polyethylene- (LLDPE-) based formulations with several near-infrared- (NIR-) reflective pigments were prepared by melt blending technique and their subsequent films were prepared by blown film extrusion process. Thermal properties of these films were evaluated using differential scanning calorimetry (DSC). The results showed that the melting and crystallization temperatures (TmandTc, resp.) of these formulations were almost similar to that of control resin. The melt viscosity was measured by stress-controlled rotational rheometer and melt flow index (MFI) instruments. Rheological measurements indicated that the blend formulations with NIR-reflective additive have similar melt viscoelastic behavior (storage modulus and dynamic viscosity) to the control resin. The mechanical test performed on NIR-reflective films showed similar values of tensile strength for blend samples as that of control resin. The spectral radiometric properties of the blend films were evaluated in the solar wavelength range of 200–1100 nm and found to be improved over the control sample without having NIR-reflective pigment.

scholarly journals New Evidences on the Process Sensitivity of Some Renewable Blends Based on Starch considering Their Melt Rheological Properties

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Doina Dimonie ◽  
Marius Petrache ◽  
Celina Damian ◽  
Liliana Anton ◽  
Miruna Musat ◽  
...  
Keyword(s):  
Rheological Properties ◽  
Corn Starch ◽  
Polymeric Materials ◽  
Melt Flow Index ◽  
Melt Processing ◽  
Chemical Degradation ◽  
Flow Index ◽  
Cross Linking ◽  
Temperature Sensitive ◽  
Renewable Materials

The degradability and processability of new renewable materials based on starch and PVOH were studied using the melt flow index (MFI) method by measuring the melt rheological properties which depend not only on the extrusion conditions and material formulation but also on the macromolecule characteristics which can be modified by chemical degradation. These results were correlated with other material properties like color and cross-linking degree. The obtained results show that flowing in the melted state of the studied materials is accompanied by a second process of chains chemical degradation. It was observed that, at the same level of additivation, under identical extrusion conditions, the melted blends with corn starch as main component are highly mechanically sensitive and degrade mostly by chains scission and those with PVOH as major component are highly temperature sensitive and degrade mainly by cross-linking. The obtained results show also that each PVOH-starch blend requires particular formulation and individual windows of melt processing conditions. These results are a good proof that the MFI method is a good path to study the degradability and moldability of process sensitive polymeric materials like those based on starch and PVOH.

scholarly journals Thermal degradation of polyethylene film materials due to successive recycling

2006 ◽  
Vol 220 (8) ◽  
pp. 1099-1108 ◽  
Author(s):  
R Marsh ◽  
A J Griffiths ◽  
K P Williams ◽  
S L Evans
Keyword(s):  
Physical Properties ◽  
Polymeric Materials ◽  
Melt Flow Index ◽  
Reliable Data ◽  
Flow Index ◽  
Plastic Film ◽  
Mechanical Recycling ◽  
Plastic Materials ◽  
The Uk ◽  
Processing Properties

Mechanical recycling of plastic film involves subjecting plastic materials to a series of heat cycles that can potentially degrade the material, causing brittleness and increased melt viscosity. Plastic film recycling in the UK is in its infancy, in need of an increased understanding of how the physical properties of polymeric materials change before and during the process. Reliable data are required to estimate the behaviour of such film products when recycled. Measurements were made as to the changes in physical properties of four different varieties of polyethylene (PE) film products when subjected to a series of successive simulated heat cycles and evaluated after each step. Results showed that although changes in tensile properties were fairly small, changes in processing properties such as melt-flow index for highly branched or low-density PE are substantial and could be a concern during recycling operations.

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