Application of Fuzzy Control to Improve Flow Balance of Multi-Cavity Hot Runner System

In this study, we propose a new temperature compensation control strategy for a multi-cavity hot runner injection molding system, At first, the melt filling time of each cavity can be measured by installing temperature sensors on the position around end filling area, and filling time difference between the various cavities can be calculated. Then the melt temperature of each hot nozzle can be adjusted automatically by a control strategy established based on the Fuzzy Theory and a program compiled with LABVIEW software. Temperature changes the melt mobility, so the adjustment of temperature can equalize the filling time of the melt in each cavity, which can reduced the mass deviation between each cavity and make product properties of each cavity consistent. The conclusion of the experiment is as follows： For this contact lens box of a four-cavity Hot Runner mold, by applying hot runner temperature compensation control system, time difference can be reduced from 0.05 s to 0.01 s at each cavity, and the mass Standard deviation of the four cavity can be improved from 0.006 to 0.002. The ratio of imbalance can be reduced from 20% to 4%. Hence, the hot runner temperature compensation control system has significant feasibility and high potential in improving melt flow balance of multi-cavity molding application.

Molding of polyether ether ketone(PEEK)and its composites:a review

Over the last half-century,polyether ether ketone(PEEK)has emerged as a widely adopted thermoplastic polymer,primarily due to its lower density,exceptional mechanical properties,high-temperature and chemical resistance,and biocompatibility.PEEK and its composites have found extensive applications across various fields,including machinery,aerospace,military equipment,electronics,and biomedicine,positioning themselves as promising substitutes for traditional metal structures.Nevertheless,achieving optimal performance and functional molding of PEEK and its composites presents a formidable challenge,given their inherent characteristics,such as semi-crystallinity,high melting temperature,heightened viscosity,low dielectric coefficient,and hydrophobic properties.In this paper,we present a comprehensive review of the molding methods and processes of PEEK and its composites,including extrusion molding,hot compression molding,injection molding,and 3D printing.We also introduce typical innovative applications within the fields of mechanics,electricity,and biomedicine while elucidating methodologies that leverage the distinctive advantages of PEEK and its composites.Additionally,we summarize research findings related to manipulating the properties of PEEK and its composites through the optimization of machine parameters,process variables,and material structural adjustments.Finally,we contemplate the prevailing development trends and outline prospective avenues for further research in the advancement and molding of PEEK and its composites.

A Study of Fabrication Technique, Structural and Morphological Behavior of Polypropylene Reinforced with Short Natural Fiber Banana

Fiber reinforced polypropylene has been widely accepted as material for structural and engineering applications in recent years.Jute,Banana fibers etc.are the most common low cost,versatile,renewable and abundantly available natural fibers which have biodegradable properties.All these fibers are versatile,renewable and most common agro based fibers that have enormous aspect due to their potentiality in composite manufacture.In comparison to other artificial fibers there are many advantages of natural fibers due to everyday applications such as,paperweight,suitcases,lampshades,helmets,and shower and bath units.Untreated and alkali treated banana fiber reinforced with Polypropylene matrix composite were fabricated with 10-25%loading of fiber by weight and were fabricated as Polypropylene Banana Composite(PPBC).Using melt mixing hot press molding technique these biodegradable composites were prepared.Different characteristics like morphologies and micro structural analysis of the composites were studied by Scanning electron microscope(SEM)and infrared spectroscopy instrument(IR).Due to the concept of group vibration infrared spectroscopy has the extensive application.Any kind of structural change such as addition or substitution of groups or atoms in a molecule may affect the relative mode of vibration of the group.This causes change in IR spectral band position,change in relative intensities and appearance of new bands and disappearance of any band and splitting of a single band into two or more bands.To increase the utility of fiber infrared spectroscopy can also be used.It deals with the interaction of infrared light with matter.The former can indicate the presence of functional groups qualitatively and the latter can provide a semi quantitative measure of their concentrations.On the other hand Electron Microscopy is most widely used to obtain information regarding the morphology of fiber surfaces,especially SEM(Scanning Electron Microscopy).Using SEM,it is easy to determine the differences of fiber surface topography after and before treatment,and hence the formation of fiber polymer composites.Fiber deboning was also observed for untreated and treated fiber pp matrix composite.The SEM can have a magnification range from a few times to several hundred thousand times.

Fabrication and Characterization on Physico-Mechanical and Structural Properties of Sawdust Reinforced Acrylonitrile Butadiene Styrene (ABS) Composites

The sawdust reinforced Acrylonitrile Butadiene Styrene (ABS) composites were prepared by using hot press molding machine for five different wt% (0%, 5%, 10%, 15% and 20%) at 180°C temperature and 50 KN load. Sawdust was collected from local saw mill of Savar, Dhaka, Bangladesh and ABS polymer was collected from local market of Dhaka, Bangladesh. In this study, different properties of composites like physical (bulk density and water absorption), mechanical (tensile properties and hardness) and structural (Fourier Transform Infrared Spectroscopy) properties were studied. The bulk density of composites was not altered consistently and it gave greater value for 5% and 20% composites. The water absorption enhanced for all composites with the accumulation of fiber content and soaking time. The reduction of tensile strength and Leeb’s rebound hardness of the composites were observed with the increase of the fiber content in all compositions. Maximum (%) of elongation was found for 5% composite, and then it gradually decreased;however, elastic modulus increased with the increased of fiber content in composites. Fourier Transform Infrared (FTIR) spectroscopy study was done for structural characterization. It was found that there was a new bond (C≡C) stretching formed for 20% composite;moreover, C-H rocking for 0% composite was broken for all other composites after the addition of sawdust in ABS polymer matrix.

Microstructure and mechanical property of MIM 418 superalloy

In this study, the influence of hot isostatic pressing（HIP） process on the 418 alloy produced by metal injection molding（MIM） technique（named as MIM 418）was investigated based on the characteristic analysis of 418 alloy powder. And comparison analysis of the microstructure and mechanical property between the MIM 418 and as-cast 418 alloys was performed by scanning electron microscopy（SEM）, energy-dispersive spectroscopy（EDS）,and X-ray diffraction（XRD）. The results show that MIM418 alloy exhibits fine grain（~30 μm） and uniform microstructure. The defects existing in MIM 418 alloy formed during sintering process can be eliminated through HIP treatment, and the relative density increases from97.0 % to 99.5 %. The mechanical property can be improved significantly because of the elimination of defects, and the tensile strength and elongation are1,271 MPa and 16.8 %, respectively, which are increased by 34.5 % and 180 % compared with K418 alloy after solution heat treatment.