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Fabrication and Properties of Polylactic Acid/Hydroxyapatite Biocomposites for Human Bone Substitute Materials
Published in S. M. Sapuan, Y. Nukman, N. A. Abu Osman, R. A. Ilyas, Composites in Biomedical Applications, 2020
N. Bano, S. S. Jikan, H. Basri, S. Adzila, N. A. Badarulzaman, Z. M. Yunus, S. Asman
The last topic for discussion of important PLA/HAP properties in this chapter is melt flow property measured by PLA/HAP biocomposites' index values. MFI is a quantity of the mass of polymer that is extruded via a capillary die at a definite temperature and force. Takayama et al. (2013) reported the effects of particle size distribution on physical properties of injection-molded HAP/PLA composites. They found that the properties of HAP as fillers that allow these effects are particle size distribution, high aspect ratio, and rod-like particle shape. Altogether, these factors are assumed to affect the flow rates and increase the MFI value of the composite. At this stage, a higher amount of filler loading leads to higher filler attraction. This is the main reason responsible for the increase in the MFI value.
Metal Matrix Composite from Thermoplastic Waste
Published in Rupinder Singh, J. Paulo Davim, Additive Manufacturing, 2018
Narinder Singh, Rupinder Singh, I. P. S. Ahuja
Melt flow index is an analytical method used for determination of quality of polymer and flow properties. Various research studies showed the relationship between the MFI and different physical and chemical properties, such as viscosity, shear strength, molecular weight distribution and shear rate. The MFI method is a measure of ability of a polymer or plastic into flow under certain conditions like pressure and fixed-size orifice. Dimensions of orifice, temperature and load pressure are specified by ASTM standards, and then value is measured in grams per 10 min, which is heated by the surrounding heater. The heater is covered by insulating material so that the heat loss can be minimized, and this heater is processed by automatic machine controls. This system consists of standard weights that pressurise the melted material from upper side and forces the material to flow out of die at standard condition. After selection of polymer waste as the matrix material the MFI of HDPE was tested with reinforcement of SiC and Al2O3 powder (Table 5.1).
Polymer Processing Techniques Used in Photovoltaic Packaging and Balance of Systems (BOS) Component Fabrication
Published in Michelle Poliskie, Solar Module Packaging, 2016
MFI, not viscosity, is typically reported on technical data sheets. There is an inverse relationship between MFI and viscosity, with a high MFI indicating a low viscosity and a low MFI indicating a high viscosity. Polymers used for adhesives and lamination have the highest MFI and can easily flow with limited pressure. Injection molding is typically performed on thermoplastics with a low MFI, requiring high packing pressure and high temperatures to mold the polymer into the desired shape.
Low density polyethylene tubular reactor control using state space model predictive control
Published in Chemical Engineering Communications, 2021
D. Muhammad, Z. Ahmad, N. Aziz
Based on Muhammad and Aziz (2017) review, most of the control objective in LDPE tubular reactor study reported are focusing on product quality variables (i.e.Melt Flow Index or Gloss Index) and reactor temperature. In practice, temperature control is utilized by manipulating either initiator or jacket feed flow rates to maintain the reactor’s temperature and prevent temperature runaway. The product quality is usually controlled using CTA by inhibiting the production of large polymer molecules and thus reducing the polymer final molecular weight. The polymer molecular weight corresponds to certain polymer end-use quality, such as Melt flow index (MFI).
Metal injection moulding (MIM) as an alternative fabrication process for the production of TWIP steel
Published in Powder Metallurgy, 2019
Karen-Adriana García-Aguirre, Juan-Luis Felguera-Jiménez, Gemma Herranz, Jessica Calvo-Muñoz, José-Antonio Benito-Páramo, José-María Cabrera-Marrero
The prealloyed TWIP powder and a multicomponent binder system based on high-density polyethylene (HDPE) and paraffin wax (PW) developed in previous research [9] were used for feedstock formulation. Stearic acid was included to improve the metallic powder’s wettability. Feedstocks with 60%, 62% and 64% vol. of metallic loading were prepared. The components were pre-mixed in a Turbula mixer for 30 min to homogenise the material for the subsequent step. Mixing processes were carried out in a rotors mixer which measures mixing torque in real time (Thermo Scientific Haake PolyLab QC) at 170°C and 70 min−1 for 90, 118 and 151 min, for 60%, 62% and 64% metal loading feedstock, respectively. Elaborated feedstocks were evaluated via MFI measurements performed in a laboratory melt flow indexer (Dynisco LMI 5000) under 2 and 5 kg loads at 150°C and 170°C as an additional means of evaluating whether their flow was appropriate for injection moulding. MFI measurements were also useful for Sa’ude et al. [11] in determining proper metallic loading. Moreover, Thavanayagam et al. [12,13] found that the results of the MFI tests had the same trend as the fluidity test performed by capillary rheometry. MFI can be evaluated as melt mass flow rate (MFR), or as melt volume flow rate (MVR). MFR is the mass in grams of feedstock that is forced to pass through a cylindrical die under a weight and temperature prescribed during a 10-min period. MVR corresponds to the volume in cm3 of the feedstock extruded for 10 min [14]. A higher value of MVR indicates an easier flow, and therefore, a lower viscosity [11]. The optimal feedstock was injected in a low-pressure plastic injector (A.B. Machinery AB-400M) at 190°C, using a compressed air pressure of 0.48 MPa and a mould temperature of 80°C. Rectangular bars were obtained.
An approach toward augmenting materials, additives, processability and parameterization in rotational molding: a review
Published in Materials and Manufacturing Processes, 2020
Nikita Gupta, PL. Ramkumar, Vrushang Sangani
Fluidity properties play an exceptional role to determine the compatible processibility in rotational molding process. The major parameters determining the flow property are quantified by melt flow index (MFI) and density. The value of MFI should lie in the range of 2 grams/10 minutes to 8 grams/10 minutes for rotational molding process.[47] If the value is less than 2 grams/10 minutes, then it is difficult to obtain a proper fusion of powder.[59,60]