Identification of Surface Quality of Plastic Electrodes after Blasting

2013 ◽  
Vol 334-335 ◽  
pp. 71-76
Author(s):  
B. Haluzíková ◽  
Jan Valíček ◽  
P. Škubala ◽  
Marta Harničárová ◽  
D. Bražina ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Surface Roughness ◽  
Surface Characteristics ◽  
Injection Molding Process ◽  
Maximum Height ◽  
Molding Process ◽  
Arithmetic Average ◽  
Average Maximum ◽  
Wide Range

Nowadays, plastics have become one of the most demanded materials, replacing the traditional ones such as metals. Therefore, many companies are concerned with the production of plastics, with their distribution and innovation development. Plastics have found utility in a wide range of applications, we use them every day. Measurement of surface roughness of plastic moldings produced by the injection molding process was carried out by a contact profilometer Mitutoyo Surftest SJ401. A reason for this measurement is to obtain information about surface roughness. For further technical adjustment is required to have higher surface roughness what helps to increase electrical conductivity of plastic moldings. This involves determination of a ratio between Ra/Rz (the ratio between the arithmetic average of the roughness profile Ra and the average maximum height of the profile Rz) in order to satisfy customer demand for achieving better surface characteristics leading to an increase in electrical conductivity.

Polypropylene Based Piezo Ceramic Compounds for Micro Injection Molded Sensors

2017 ◽  
Vol 742 ◽  
pp. 807-814 ◽  
Author(s):  
Christoph Doerffel ◽  
Ricardo Decker ◽  
Michael Heinrich ◽  
Jürgen Tröltzsch ◽  
Mirko Spieler ◽  
...  
Keyword(s):  
Injection Molding ◽  
Ceramic Powder ◽  
Three Dimensional ◽  
Conductive Filler ◽  
High Sensitivity ◽  
Injection Molding Process ◽  
Molding Process ◽  
Ceramic Particles ◽  
Wide Range ◽  
Ceramic Compounds

Polymer matrix compounds based on piezo ceramic and electrically conducting particles within a thermoplastic matrix show distinctive piezoelectric and dielectric effects which can used for sensor applications. The electrical and mechanical properties can be adjusted in a wide range by varying the ratio of active filling particles and the matrix materials. The sensor effect of the compound is generated by the ceramic particles. A large ratio of piezo ceramic powder facilitates a high sensitivity. The electrical permittivity of the otherwise insulating matrix polymer can be adjusted by the amount of conductive filler. An aligned permittivity leads to a stronger electrical field in the ceramic particles. In contrast, too many conductive particles create a conductive network in the compound which short-circuits the sensors. The piezo ceramic compounds can be processed via micro injection molding for application as ceramic sensors. This offers a wide range of new sensor design variants, notably three-dimensional and highly complex geometries. However, there are two main demands for a highly sensitive sensor, which are conflicting. On the one hand the filler content of piezo ceramic particles in combination with electrical conductive carbon nanotubes must be very high, on the other hand the wall thickness should be as thin as possible. For filling cavities with a high aspect-ratio in an injection molding process, low viscosity polymer melts are necessary. These process characteristics conflict with the increasing viscosity by filling the melt with the particles. The sensor measuring area has to be designed as thin walled as possible. In order to overcome this obstacle a dynamically tempered mold design is applied to avoid solidification of the melt, before the mold is completely filled. The mold can be tempered by Peltier elements. The fully electric tempering is cleaner, more precise and more reliable than conventional water or oil tempering.

scholarly journals Disposable Injection Molded Conductive Electrodes Modified with Antimony Film for the Electrochemical Determination of Trace Pb(II) and Cd(II)

Sensors ◽  
2019 ◽  
Vol 19 (21) ◽  
pp. 4809 ◽  
Author(s):  
Savvina Christidi ◽  
Alexia Chrysostomou ◽  
Anastasios Economou ◽  
Christos Kokkinos ◽  
Peter R. Fielden ◽  
...  
Keyword(s):  
Anodic Stripping Voltammetry ◽  
Conductive Polymer ◽  
Stripping Voltammetry ◽  
Injection Molding Process ◽  
Molding Process ◽  
Film Sensor ◽  
Lake Water Sample ◽  
Relative Standard ◽  
Antimony Film

This work describes a novel electrochemical sensor fabricated by an injection molding process. This device features a conductive polymer electrode encased in a plastic holder and electroplated in situ with a thin antimony film. The antimony film sensor was applied to the determination of Pb(II) and Cd(II) by anodic stripping voltammetry (ASV). The deposition of Sb on the sensor was studied by cyclic voltammetry (CV) and microscopy. The experimental variables (concentration of the antimony plating solution, deposition potential and time, stripping waveform) were investigated, and the potential interferences were studied and addressed. The limits of detection were 0.95 μg L−1 for Pb(II) and 1.3 for Cd(II) (at 240 s of preconcentration) and the within-sensor percentage relative standard deviations were 4.2% and 4.9%, respectively, at the 25 μg L−1 level (n = 8). Finally, the sensor was applied to the determination of Pb(II) and Cd(II) in a phosphorite sample and a lake water sample.

scholarly journals Electricity Consumption Estimation of the Polymer Material Injection-Molding Manufacturing Process: Empirical Model and Application

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1740 ◽  
Author(s):  
Ana Elduque ◽  
Daniel Elduque ◽  
Carmelo Pina ◽  
Isabel Clavería ◽  
Carlos Javierre
Keyword(s):  
Environmental Impact ◽  
Injection Molding ◽  
Empirical Model ◽  
Electricity Consumption ◽  
Injection Molding Process ◽  
Molding Process ◽  
Polymer Injection ◽  
Wide Range ◽  
Molded Parts ◽  
Polymer Injection Molding

Polymer injection-molding is one of the most used manufacturing processes for the production of plastic products. Its electricity consumption highly influences its cost as well as its environmental impact. Reducing these factors is one of the challenges that material science and production engineering face today. However, there is currently a lack of data regarding electricity consumption values for injection-molding, which leads to significant errors due to the inherent high variability of injection-molding and its configurations. In this paper, an empirical model is proposed to better estimate the electricity consumption and the environmental impact of the injection-molding process. This empirical model was created after measuring the electricity consumption of a wide range of parts. It provides a method to estimate both electricity consumption and environmental impact, taking into account characteristics of both the molded parts and the molding machine. A case study of an induction cooktop housing is presented, showing adequate accuracy of the empirical model and the importance of proper machine selection to reduce cost, electricity consumption, and environmental impact.

Evaluation of a Piezoelectric Energy Extraction Device for Cavity Pressure Sensing in Injection Molding

2003 ◽  
Author(s):  
Charles B. Theurer ◽  
Li Zhang ◽  
David Kazmer ◽  
Robert X. Gao
Keyword(s):  
Injection Molding ◽  
Mechanical Strain ◽  
Piezoelectric Element ◽  
Polymer Melt ◽  
High Energy ◽  
Injection Molding Process ◽  
Molding Process ◽  
Transient Model ◽  
Piezoelectric Energy ◽  
Wide Range

This paper presents the design, analysis, and validation of a self-energized piezoelectric pressure sensor that extracts energy from the pressure differential of the polymer melt during the injection molding process. To enable a self-energized sensor design, an analytical study has been conducted to establish a quantitative relationship between the polymer melt pressure and the energy that can be extracted through a piezoelectric converter. Temperature and pressure are monitored during an injection molding cycle and the performance of the piezoelectric element is evaluated with respect to a mechanically static, electrically transient model. In addition to corroboration of the proposed model, valuable statistical information about the working temperature in the prototype sensor will prove very useful in the package design of molding cavity sensors. A linear model examining the energy conversion mechanism due to interactions between the mechanical strain and the electric field developed within the piezoelectric device is established. This model is compared to the functional prototype design to evaluate the relevance of the assumptions and accuracy. The presented design enables a new generation of self-energized sensors that can be employed for the condition monitoring of a wide range of high-energy manufacturing processes.

Investigation of ultrasonic vibration on thrust force, surface integrity, and geometrical tolerances during drilling of natural filler reinforced composites

2020 ◽  
Vol 234 (20) ◽  
pp. 4041-4055
Author(s):  
Farzad Pashmforoush ◽  
Reza Farshbaf Zinati ◽  
Davoud Maleki
Keyword(s):  
Surface Roughness ◽  
Ultrasonic Vibration ◽  
Thrust Force ◽  
Walnut Shell ◽  
Injection Molding Process ◽  
Reinforced Composites ◽  
Performance Parameters ◽  
Molding Process ◽  
Impact Action ◽  
Natural Filler

Growing global environmental threats have attracted researchers and engineers toward design and manufacture of green materials. In this regard, natural filler reinforced composites are environmentally friendly, cost-effective materials with a lot of advantages over conventional carbon/glass fiber reinforced composites. Hence, in this study, the drilling performance of walnut shell powder reinforced composite material was experimentally investigated. For this purpose, the composite specimens were first fabricated by injection molding process, followed by further drilling tests, which were performed with and without ultrasonic vibration. The effect of drilling parameters and ultrasonic vibration was investigated on surface roughness, thrust force and geometrical tolerances (circularity and cylindricity), as the process performance parameters. The obtained results demonstrated that by increase of the spindle rotational speed and decrease of feed rate, the thrust force, surface roughness and geometrical tolerances were reduced. Also, it was seen that ultrasonic vibration could effectively enhance the performance parameters, which was attributed to the intermittent cutting process and impact action of ultrasonic vibration, leading to reduced friction, improved material removal, reduced cutting forces, and better surface quality.

In-Mold Monitoring of Temperature and Cavity Pressure During the Injection Molding Process

2014 ◽  
Author(s):  
Catalin Fetecau ◽  
Felicia Stan ◽  
Laurentiu I. Sandu
Keyword(s):  
Injection Molding ◽  
Pressure Sensors ◽  
Temperature Sensors ◽  
Injection Molding Process ◽  
Cavity Pressure ◽  
Molding Process ◽  
Shear Rates ◽  
Wide Range ◽  
Simulation Results ◽  
Two Temperature

This paper focuses on the in-mold monitoring of temperature and cavity pressure. The melt contact temperature and the cavity pressure along the flow path were directly measured using two pressure sensors and two temperature sensors fitted into the cavity of a spiral mold. Three melt temperatures and dies of different heights (1.0, 1.5 and 2 mm) were used to achieve a wide range of practically relevant shear rates. In order to analyze the extent to which the numerical simulation can predict the behavior of the molten polymer during the injection molding process, molding experiments were simulated using the Moldflow software and the simulation results were compared with the experimental data under the same injection molding conditions.

Experimental determination of friction coefficients between thermoplastics and rapid tooled injection mold materials

2005 ◽  
Vol 11 (3) ◽  
pp. 167-173 ◽  
Author(s):  
Mary E. Kinsella ◽  
Blaine Lilly ◽  
Benjamin E. Gardner ◽  
Nick J. Jacobs
Keyword(s):  
Injection Molding ◽  
Accurate Determination ◽  
Rapid Tooling ◽  
Injection Molding Process ◽  
Process Conditions ◽  
Molding Process ◽  
Friction Coefficients ◽  
Content Type ◽  
Temperature Conditions

PurposeTo determine static friction coefficients between rapid tooled materials and thermoplastic materials to better understand ejection force requirements for the injection molding process using rapid‐tooled mold inserts.Design/methodology/approachStatic coefficients of friction were determined for semi‐crystalline high‐density polyethylene (HDPE) and amorphous high‐impact polystyrene (HIPS) against two rapid tooling materials, sintered steel with bronze (LaserForm ST‐100) and stereolithography resin (SL5170), and against P‐20 mold steel. Friction tests, using the ASTM D 1894 standard, were run for all material pairs at room temperature, at typical part ejection temperatures, and at ejection temperatures preceded by processing temperatures. The tests at high temperature were designed to simulate injection molding process conditions.FindingsThe friction coefficients for HDPE were similar on P‐20 Steel, LaserForm ST‐100, and SL5170 Resin at all temperature conditions. The HIPS coefficients, however, varied significantly among tooling materials in heated tests. Both polymers showed highest coefficients on SL5170 Resin at all temperature conditions. Friction coefficients were especially high for HIPS on the SL5170 Resin tooling material.Research limitations/implicationsApplications of these findings must consider that elevated temperature tests more closely simulated the injection‐molding environment, but did not exactly duplicate it.Practical implicationsThe data obtained from these tests allow for more accurate determination of friction conditions and ejection forces, which can improve future design of injection molds using rapid tooling technologies.Originality/valueThis work provides previously unavailable friction data for two common thermoplastics against two rapid tooling materials and one steel tooling material, and under conditions that more closely simulate the injection‐molding environment.

Debinding Rate Enhancement of 17-4 Precipitation Hardening Stainless Steel Solvent Debinding on Metal Injection Molding Process as the Material for Orthodontic Bracket

2018 ◽  
Vol 929 ◽  
pp. 200-208 ◽  
Author(s):  
Sugeng Supriadi ◽  
Deni Ferdian ◽  
Gerra Maulana ◽  
Rizki Hidayatullah ◽  
Bambang Suharno
Keyword(s):  
Surface Roughness ◽  
Injection Molding ◽  
Investment Casting ◽  
Removal Rate ◽  
Metal Injection Molding ◽  
Injection Molding Process ◽  
Vacuum Furnace ◽  
Molding Process ◽  
Orthodontic Bracket ◽  
Binder Removal

Brackets fabrication should be done by a suitable process to produce great result. Processes commonly used are investment casting, machining, and metal injection molding. Investment Casting has a drawback in which the surface roughness is quite high for the standard of brackets and require further processing. Machining is done by removing unwanted part to get desire shape, whereas bracket shape requires a high accuracy and is quite complicated. In Metal Injection Molding, feedstock is injected into a mold where complicated shapes can be achieved with a better surface roughness. The weakness is the stages within the process are quite long. One of the problem is the efficiency of debinding stage. We conducted an experiment to enhance binder removal rate through solvent debinding with stirring and under vacuum condition. Sample use for this experiment is a cubic shape of 0.5 x 0.5 x 0.5 cm3. Experiment is done on magnetic stirrer and in vacuum furnace. The temperature is hold at 50°C. Drying process afterward is done in the vacuum furnace for 1 hour with temperature around 50°C. Amount of binder left is confirmed by STA and the particle morphology is seen by SEM. Results showed that stirring treatment enhances binder removal rate due to stirring mechanism that causes possibility of collisions between particles increases. Binder removal rate on the vacuum treatment has a mechanism similar to stirring, but with the addition of the solvent to be done on a regular basis due to decrease of solvent boiling point under vacuum. There were no cracks found on the surface with an increased rate of debinding. Stirring is use for experiment with sample of actual bracketorthodontic form. Debinding rate of the bracket sample is faster than the cubic sample. This result is affected by the dissimilarity on the volume to surface area.

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