Plastic Extrusion Research Articles

Modern Biodegradable Plastics-Processing and Properties: Part I.

This paper presents a characterization of a plastic extrusion process and the selected properties of three biodegradable plastic types, in comparison with LDPE (low-density polyethylene). The four plastics include: LDPE, commercial name Malen E FABS 23-D022; potato starch based plastic (TPS-P), BIOPLAST GF 106/02; corn starch based plastic (TPS-C), BioComp®BF 01HP; and a polylactic acid (polylactide) plastic (PLA), BioComp®BF 7210. Plastic films with determined geometric parameters (thickness of the foil layer and width of the flattened foil sleeve) were produced from these materials (at individually defined processing temperatures), using blown film extrusion, by applying different extrusion screw speeds. The produced plastic films were tested to determine the geometrical features, MFR (melt flow rate), blow-up ratio, draw down ratio, mass flow rate, and exit velocity. The tests were complemented by thermogravimetry, differential scanning calorimetry, and chemical structure analysis. It was found that the biodegradable films were extruded at higher rate and mass flow rate than LDPE; the lowest thermal stability was ascertained for the film samples extruded from TPS-C and TPS-P, and that all tested biodegradable plastics contained polyethylene.

Modeling and Implementation of a Proportional Hydraulic System to Control the Position and Pressure of a Plastic Extruder

Model and implement a hydraulic system with fuzzy position control of a double acting cylinder and PID pressure control of a hydraulic motor on a plastic extruder. The control system will be implemented with the Festo TP 702 by means of a controller, display, graphical interface and link to Fuzzy control and MATLABTM PID_Tuner to obtain graphs. Modeling provides the process transfer function, proportional control constants and position and pressure control graphs, which are then validated between the WinCC Advanced interface graphs of the physical process implementation with the Festo S7-1200 PLC, generating a graphical comparison of the control of position and pressure variables. This results in an accuracy error of 1% between the result of the modeling and the physical implementation, which is acceptable in an industrial process. The HMI, as well as the SCADA system was performed in WinCC Basic and WinCC Advanced respectively, generating a graphical interface both local and remote in approximately real time. The mathematical modeling of an industrial process guarantees the reliability and optimal behavior of the plastic extrusion process, minimizing production costs and raw material waste.

Design and Evaluation of General Purpose, Barrier, and Multichannel Plasticating Extrusion Screws

Extrusion screw designs and validation are presented for three multiple channel, fractal screws for comparison with common general purpose, and barrier screws using an instrumented single screw extruder with high impact polystyrene (HIPS) and low density polyethylene (LDPE) at varying screw speeds. The fractal screws are designed with multiple channels and pressure–volume–temperature relations to control shear heating with cooling by adiabatic decompression. The general‐purpose design had the highest throughput but did not provide sufficient mixing and so resulted in excessive variation in the melt temperature and pressure at screw speeds above 40 RPM. The barrier screw was a capable design with good performance for LDPE and HIPS with screw speeds from 20 to 60 RPM. However, it tended to provide excessive shear heating at higher screw speeds due to the large surface area of the barrier and mixing sections. The first fractal screw design was a multichannel variant of the general‐purpose design and exhibited good consistency but excessive heating due to the large bearing area between the flights and barrel. The second fractal screw design provided decompression in the feed zone and metering zone to improve throughput but was limited by a poor transition section design. The third fractal screw design remedied these deficiencies with an improved transition section and intermittent clearances for dispersive mixing. Its performance rivaled that of the barrier screw with respect to volumetric output and energy efficiency but provided better melt pressure consistency. Cold screw freezing experiments were performed for all five screws with 5% black, blue, and violet colorants serially added to neat HIPS. The cold screw pulls showed that the general purpose and barrier screws exhibited significant racing of the materials within their screw channels and, thus, broad residence time distributions. Examination of the material cross sections indicated persistent coiled sheet morphologies, which were best dispersed with the third fractal screw. POLYM. ENG. SCI., 60:752–764, 2020. © 2020 The Authors. Polymer Engineering & Science published by Wiley Periodicals, Inc. on behalf of Society of Plastics Engineers.

Abrasive wear behavior of WC-10Co-4Cr cladding deposited by TIG welding process

The aim of the present study is to fabricate a highly wear resistant WC-10Co-4Cr cladding on AISI 304 stainless steel using TIG welding process. The effect of current and speed on the microstructure, hardness, and abrasive wear of the cladding was investigated. Tribological behaviour of the claddings slided against SiC emery paper was examined using pin-on-disc tribometer. FESEM, XRD and EDS spectrums were used to analyse the microstructure of cladding. Different parametric combination of current and speed has been used to produce the variation in heat input during the cladding. Process parameters, such as current and speed influence the solidification time which results in different kind of microstructure. The results revealed that the TIG cladding deposited at low heat input produces a hard and wear resistance cladding. Increase in hardness and wear resistance was attributed to the partially melted WC grains reinforced in CoCr matrix. SEM images showed the formation of wear tracks on the surface of worn out cladding. The wear tracks was formed due to the plastic deformation and extrusion of CoCr matrix. However, the cladding developed at low heat input shows relatively smooth surface with lesser depth of wear tracks.

CO2 and steam electrolysis using a microtubular solid oxide cell

Nickel-yttria stabilized zirconia (Ni-YSZ) supported tubes were fabricated by plastic extrusion molding (PEM). YSZ was used as the electrolyte and LSM-YSZ (lanthanum-strontium doped manganite) as the oxygen electrode. Both layers were deposited by dip coating and were then sintered at 1500 °C and 1150 °C, respectively. Coelectrolysis experiments were performed in these cells at 850 °C, using different fuel gas conditions varying the amount of steam, carbon dioxide, nitrogen and hydrogen. Area specific resistance (ASR) values ranged from 0.47 Ωcm2, when rich steam and CO2 flows are used, to 1.74 Ωcm2, when a diluted composition is used. Gas chromatography was used to examine the amount of H2 and CO in the output gas. The obtained results are consistent with the equilibrium of the water gas shift reaction. For all the different analysed conditions, faradaic efficiency was found to be close to 100%. This experiment confirmed that there is no electronic conduction taking place through the YSZ electrolyte. The threshold for electronic conduction in the diluted feeding conditions (Poor H2O and CO2) for these particular YSZ-based cell was found at voltages of about 1.65 V.

Profile Cross Rolling of High‐Interstitial Austenitic Stainless Steels for Application in Plastics Extrusion

FeCrMnCN stainless austenitic high‐interstitial steels (HIS) combine the properties of conventional FeCrNi austenites (superior ductility and surface corrosion resistance) with the potential of significant strengthening. This combination of properties makes them promising candidates for environments that require resistance to both wear and corrosion, e.g., processing of plastics. The aim herein is to make use of the high work‐hardening ability of HIS. Thus, machined preforms with an application‐related design are formed by profile cross rolling. The preform design enables a hardness increase in component regions that are most subjected to wear. Rolling of the specimens results in a very high surface quality with a roughness Rz in the range of 1 μm. Hardness measurements in rolled specimens confirm a significant hardness increase in the subsurface up to a depth of ≈2.5 mm. Hardness values of about 600 HV1 are yielded within a surface distance of ≈0.3 mm. Furthermore, tests on a modified pin‐on‐disc tribometer suggest that the wear behavior of the work‐hardened HIS is comparable with nitriding steel. Thus, the results of this study support the development of a forming technology for screws in corrosive environments.

Influence of Combined Severe Plastic Deformation and Sheet Extrusion Process on the Superplastic Formability of AA 5083 Aluminum Alloy Assessed by Free Bulge Test

A combination of two forming operations is considered for producing metal sheets with improved mechanical properties. As the first operation, a newly introduced severe plastic deformation method called dual equal channel lateral extrusion (DECLE) was performed at 300 °C for different passes on the AA 5083 aluminum blocks. Following the DECLE operation, sheet extrusion was conducted to convert the bulk samples, severely deformed through various passes, into 1.8-mm-thick sheets. Mechanical properties of the processed specimens, after each step of deformation, were examined using tensile and shear punch tests. It was found that the material after three passes of DECLE and also the corresponding forwardly extruded sheet presented the greatest strength. In order to evaluate the biaxial formability of the sheets, gas bulge forming tests were conducted using a PLC-controlled gas circuit. It was shown that the material processed via three passes of DECLE operation and extrusion demonstrated the maximum biaxial superplastic formability with an effective strain associated with 400% uniaxial elongation. This sheet specimen also required the minimum forming time, coinciding with a strain rate of 4 × 10−4 s−1, which is higher than strain rate for the sheet extruded from the annealed sample.

Design of 3D filament extruder for Fused Deposition Modeling (FDM) additive manufacturing

Filament extruder produces plastic filaments with specified diameter by using corresponding dies. Input materials (thermoplastics) are used in the form of granules and pellets and waste plastic materials can be used. Rod heaters are used to melt the input materials and Screw is used to feed the input raw materials longitudinally along the barrel. Screw is consisted of three zones namely feed, melt, and transition zone. Input raw material is melted by using rod heater. Two temperature zone with six rod heaters are used to acquire maximum efficiency. Analog temperature controller is used to control the temperature of the two heaters zone. This article describes a filament extruder, which is a plastic extruder capable of making commercial quality 3D printing filament. Specifically, this paper describes the design, fabrication and operation of a filament extruder. A 2.5 mm die was used to extrude the filament at the diameter of 1.75mm. Diameter of the filament can be further reduced by using DC-motor to draw the filament coming out of the die. Production can be further increased by increasing the barrel diameter above 45mm and screw diameter above 16 mm. Mechanical and thermal properties were improved by adding different fillers to the input raw material

The Design of a Small-scale Plastic Extruder Machine

Abstract This paper discusses the design steps, working principle and structure of a small-scale thermo-plastic extrusion machine that will be used in a laboratory at the Sapientia University. The aim of the laboratory is to present the polymer processing technologies by student-built machines and to stress the importance of plastic recycling. In order to recycle plastic parts a grinding process is necessary, followed by extrusion. During the process the machine melts the polymer and extrudes a filament that can be converted into granulates or used as it is. The structure of the extrusion machine is rather similar to that of a commercial one, however it focuses on presenting the manufacturing principles and cost effectiveness.

Effects of AlN and BCN Thin Film Multilayer Design on the Reaction Time of Ni/Ni-20Cr Thin Film Thermocouples on Thermally Sprayed Al2O3.

Thin film thermocouples are widely used for local temperature determinations of surfaces. However, depending on the environment in which they are used, thin film thermocouples need to be covered by a wear or oxidation resistant top layer. With regard to the utilization in wide-slit nozzles for plastic extrusion, Ni/Ni-20Cr thin film thermocouples were manufactured using direct-current (DC) magnetron sputtering combined with Aluminiumnitride (AlN) and Boron-Carbonitride (BCN) thin films. On the one hand, the deposition parameters of the nitride layers were varied to affect the chemical composition and morphology of the AlN and BCN thin films. On the other hand, the position of the nitride layers (below the thermocouple, above the thermocouple, around the thermocouple) was changed. Both factors were investigated concerning the influence on the Seebeck coefficient and the reaction behaviour of the thermocouples. Therefore, the impact of the nitride thin films on the morphology, physical structure, crystallite size, electrical resistance and hardness of the Ni and Ni-20Cr thin films is analysed. The investigations reveal that the Seebeck coefficient is not affected by the different architectures of the thermocouples. Nevertheless, the reaction time of the thermocouples can be significantly improved by adding a thermal conductive top coat over the thin films, whereas the top coat should have a coarse structure and low nitrogen content.

Prediction and Optimization of Production Quantities in Innoson Manufacturing Extraction Plastic Product

In this research, it focused on the prediction and optimization of the production quantity in Innoson Plastic Manufacturing Company, Nnewi, Anambra State, Nigeria. The research method used is the application of factorial design methods to model, to evaluate the best optimal solutions for the production quantity of extrusion plastic pipes in the aforementioned company. The analysis shows that the parameters used to model the production quantity are significant and the model produced is also significant with its coefficient of determination to be 0.9968 and the adjusted R-Squared is 0.9823. Adequate Precision measures the signal to noise ratio. A ratio greater than 4 is desirable. The ratio of 29.271 indicates an adequate signal. This model can be used to navigate the design space. The Model F-value of 68.99 implies the model is significant. There is only a 1.44% chance that an F-value this large could occur due to noise. Values of "Prob > F" less than 0.0500 indicate model terms are significant. The 3D surface plot shows the effect of the variables in production system. It describes the variations of the input and output parameters in production of plastic extrusion products. The factorial design method applied shows the optimal solution which revealed that the best quantity of the product that is necessary to produce in any given month is 14414.112 units of a 25mm diameter plastic pipes with the optimal desirability of 100%. The tool also shows that the pigment is almost not important in the optimization of the product production quantity due to its insignificant quantity. However, the results further revealed that the industry should be conscious of highly influence input variable during production.

Avaliação e caracterização de insalubridade pro exposição á ruído em uma empresa de reciclagem de plástico

As condições de trabalho em muitas empresas e indústrias possibilitam situações de risco à qualidade de vida dos seus colaboradores, dentre essas situações está à exposição aos altos níveis de ruído. Portanto, o presente trabalho tem como objetivo avaliar a higiene ocupacional de um colaborador no processo de extrusão de plástico em uma empresa de reciclagem, através da análise da emissão de ruído, com a perspectiva do cálculo de insalubridade. O trabalho foi realizado em uma empresa de recuperação de plástico do município de Caçador/SC, para os cálculos de insalubridade seguiu a partir da dose e exposição ao ruído conforme a NR-15 e NHO-01. Através do estudo pode-se observar que o colaborador da empresa está sob uma situação de exposição inaceitável, obtendo a consideração técnica como critica e nível de atuação recomendada para ações de controle urgente, conformes as diretrizes de cálculos da NR-15 e NHO-01, visto que o nível do ruído Leq é de 87,18 dB(A), buscando atenuar esse questão o colaborador recebe Equipamento de Proteção Individual (EPI) que atenua o ruído. Assim, é preciso de um monitoramento continuo da segurança do trabalhador em questão, visto que se o mesmo não realizar a utilização do EPI o mesmo pode sofrer consequências no seu processo de audição.
 Palavras-chave: Monitoramento do Ruído. Ruído Ocupacional. Ruído.

Effect of hydrophilic and hydrophobic cyclodextrins on the release of encapsulated allyl isothiocyanate (AITC) and their potential application for plastic film extrusion

ABSTRACTAllyl isothiocyanate (AITC), a natural pungent flavor from wasabi and horseradish, is well‐known antimicrobial agents against foodborne pathogens. However, its highly volatile nature and low thermal stability restrict its application in the food packaging industry. Also, its strong organoleptic characteristics hinder its application at a higher dosage. We encapsulated AITC in β‐cyclodextrin (β‐CD) and triacetyl‐β‐CD (TA‐β‐CD) and evaluated the performance as slow releasing active compounds through low‐density polyethylene (LDPE)–cyclodextrins (CDs) matrix. Also, the thermal, optical, mechanical, and barrier properties of two ternary blends, LDPE/β‐CD/AITC(L‐CDs) and LDPE/TA‐β‐CD/AITC(L‐TACDs), were investigated to compare their compatibility under the plastic extrusion process. During the 15 days of the storage period, L‐TACDs maintained more consistent AITC release and a higher concentration than L‐CDs. Also, the blending of LDPE and TA‐β‐CD was more compatible with that of LDPE and β‐CD. No significant optical, mechanical, and barrier property changes were observed in LDPE with less than 3% of TA‐β‐CD while L‐CDs showed substantial agglomeration on the ternary blend films and the lower mechanical and barrier properties than pure LDPE. The results indicate that the LDPE films containing TA‐β‐CD/AITC can be applied as an effective antimicrobial packaging material for food and nonfood applications. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 48137.

Thermal and Vapor Smoothing of Thermoplastic for Reduced Surface Roughness of Additive Manufactured RF Electronics

Additive manufacturing (AM) of electronics provides a route for creating customized systems with novel geometries that are not feasible with traditional methods. Standard AM processes such as extrusion can produce substrates on which electrical traces can be deposited. However, the surface roughness of plastic extrusion reduces the effective electrical conductivity and can introduce anisotropy, especially in radio frequency (RF) devices. The roughness can be reduced using vapor smoothing (VS), but solvent absorption changes the surface composition slightly, can be environmentally hazardous, and is not feasible with all thermoplastics. A new method introduced here—coined thermal smoothing (TS)—utilizes a heat source to locally reflow the material, thus minimizing the roughness of the undulating surfaces without the drawbacks of VS. This research work compares the surface roughness impacts of both smoothing processes with profilometry and scanning electron microscope (SEM) images. Both smoothing processes significantly reduce the surface roughness of extruded components by 80% and 90% for TS and VS, respectively. This paper also examines the influence of surface smoothing on high-frequency conductivity of microdispensed conductors (CB028 paste) deposited on the substrates. The measured loss on coplanar waveguides shows an improvement of up to 40% at 7 GHz.

Design of an extrusion machine for the manufacture of plastic tubes

Currently in Colombia in the northern region of Santander, exist a large number of farmers who grow different agricultural products and require more appropriate irrigation systems hoses, but due to the high demand, local manufacturers do not meet the requirements and in many cases the hoses are brought from other parts of the country bringing higher costs. In the present work, the design of a prototype plastic extrusion machine for hose producers in the province of Ocaña was carried out. The development of the research was carried out through the execution of mathematical calculations with the support of specialized bibliographic material and a Finite Element Analysis with help of SolidWorks Simulation Software, where the geometric model of the machine in order to identify the elements subjected to maximum of efforts. The results obtained show that the prototype will be in charge of producing 1/2, 3/4 and 1 inch. In conclusion the prototype works in adequate conditions always ensuring high levels of safety and operation; Moreover, the machine will be low cost to promote growth and competitive capacity of hose producers, as a solution to the problems based on competitiveness, working conditions and resources economic.

Heat and mass transfer analysis of 3D Maxwell nanofluid over an exponentially stretching surface

The flow of nanofluid over a bi-directional stretching sheet is quite popular among recent researchers because of its industrial and engineering applications. Specifically, such a mechanism appears in plastic sheet extrusion, wire drawing, hot rolling, plastic film drawing, paper production, fiber glass, cooling of a metallic plate in a cooling bath, etc. In this paper, we have studied the effects of nanofluid on the flow over a bi-directional stretching sheet for non-Newtonian fluid. Similarity transformations are used to transform the governing partial differential equations into a system of coupled non-linear ordinary differential equations. An optimal homotopy analysis method (OHAM) is employed by defining the average squatted residual errors and the concept of minimization. The effects of different involved physical parameters on the flow field are discussed graphically.

Investigation of Abrasive Wear Behavior of Industrial Wastes on Al 6061 Material Using Rubber Wheel Abrasion Test (RWAT) Method

In this study, the abrading characteristics of the slags, generated in the form of industrial waste during raw iron, steel and ferrochromium ore production, are investigated. Granulated blast furnace slag (GBFS), basic oxygen furnace slag (BOF) ferrochromium slag (FCS) and commercial Al2O3 powder were used during the tests. Abrasion tests were conducted using Rubber Wheel Abrasion Wear (RWAT) method. Al 6061 was chosen as the counter body material. The tests were conducted under 25, 50, 75 and 100 N loads with 100 r/min rubber wheel rotational speed. The highest rate of abrasion was obtained from GBFS under all loads as a result of the conducted tests. Under high loads, the abrading performance of FCS reached that of the commercial Al2O3 powder. BOF was found to have no abrading capability. Surface morphology and SPQ (spike parameter-quadratic fit) value were as effective as the particle hardness in the evaluation of abrading performance. As dominant wear mechanisms, spalling, ploughing and micro-scratch formation were observed on the specimens abraded with GBFS and Al2O3, whereas severe plastic deformation-induced extrusion was observed on the specimen abraded with FCS.

Priority-Aware Wireless Fieldbus Protocol for Mixed-Criticality Industrial Wireless Sensor Networks

Industrial wireless sensor networks are becoming popular for critical monitoring and control applications in industrial automation systems. For such type of applications, providing reliable real-time performance regarding data delivery is considered as a fundamental challenge. The problem becomes more prominent with mixed-criticality systems, where different data flow with different levels of criticality (importance) coexist and characterized by different requirements regarding delay and reliability. In this paper, we propose a wireless fieldbus protocol to enable real-time communication and service differentiation for cluster-based mixed-criticality networks. A process monitoring scenario of plastic extrusion is used to define the protocol requirements and elaborate the working principle of the proposed work. In our proposed protocol, each data flow is scheduled for channel access based on its criticality level using a distributed prioritized medium access mechanism that ensures a guaranteed channel access for the most critical traffic over other traffic types. The performance of the proposed protocol is analyzed analytically using a discrete-time Markov chain model to evaluate the performance in terms of delay and throughput. Moreover, the extensive simulations are conducted to prove the analytical claims and different performance assessments are provided, which also demonstrate the effectiveness of the proposed approach compared with the related existing work.

Biocompatibility of Poly(acrylonitrile-butadiene-styrene) Nanocomposites Modified with Silver Nanoparticles.

We evaluated the biological, mechanical, and surface properties of polymer nanocomposites manufactured via plastics processing, extrusion, and injection moulding. The aim of this study was to identify the interaction of fibroblasts and osteoblasts with materials intended for middle ear implants. We examined if silver nanoparticles (AgNPs) may change the mechanical parameters of the polymer nanocomposites. In our study, the biostable polymer of thermoplastic acrylonitrile-butadiene-styrene (ABS) copolymer was used. Silver nanoparticles were applied as a modifier. We discuss surface parameters of the materials, including wettability and roughness, and evaluated the microstructure. The mechanical parameters, such as the Young’s modulus and tensile strength, were measured. Cytotoxicity tests were conducted on two cell lines: Hs680.Tr human fibroblasts and Saos-2 human osteoblasts. Cell viability, proliferation, and morphology in direct contact with nanocomposites were tested. Based on the results, the incorporated modifier was found to affect neither the number of osteoblasts nor the fibroblast cells. However, the addition of AgNPs had a relatively small effect on the cytotoxicity of the materials. A slight increase in the cytotoxicity of the test materials was observed with respect to the control, with the cytotoxicity of the materials tending to decrease after seven days for osteoblast cells, whereas it remained steady for fibroblasts. Based on optical microscope observation, the shape and morphology of the adhered cells were evaluated. After seven days of culture, fibroblasts and osteoblasts were properly shaped and evenly settled on the surface of both the pure polymer and the silver nanoparticle-modified composite. Water droplet tests demonstrated increased hydrophilicity when adding the AgNPs to ABS matrices, whereas roughness tests did not show changes in the surface topography of the investigated samples. The 0.5% by weight incorporation of AgNPs into ABS matrices did not influence the mechanical properties.

The application of an extrusion slit die in the rheological measurements of polyethylene composites with calcium carbonate using an in‐line rheometer

This article has reported the results of rheological testing of low‐density polyethylene (LDPE) and its calcium carbonate composites containing 7, 14, 21, and 28 wt% filler, respectively. The polymer composites were produced in a twin‐screw extrusion process. The assessment of the rheological properties of the polymeric materials was made under extrusion process conditions, using an in‐line rheometer with an extrusion slit die (W = 20, H = 2, L = 150 mm), at temperatures of 170°C, 180°C, and 190°C, respectively. The rheological parameters were determined based on the Ostwald‐de‐Waele power law model. The employed testing stand enabled the assessment of the effect of filler addition and slit die temperature on the variations in viscosity, power law index (n), consistency index (K), maximum flow velocity (Vmax), and maximum flow profiles (Vz), under the conditions of technological processing (extrusion) of plastics. POLYM. ENG. SCI., 59:E16–E24, 2019. © 2018 Society of Plastics Engineers