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.

Tribology study of hydroxyapatite (HAp) scaffold blended single based binder via rheology and mechanical properties

2017 ◽  
Vol 69 (3) ◽  
pp. 414-419
Author(s):  
Mimi Azlina Abu Bakar ◽  
Siti Norazlini Abd Aziz ◽  
Muhammad Hussain Ismail
Keyword(s):  
Mechanical Properties ◽  
Injection Molding ◽  
Palm Stearin ◽  
Polymeric Materials ◽  
High Energy ◽  
Single Step ◽  
Injection Molding Process ◽  
Plastic Behavior ◽  
Molding Process ◽  
Content Type

Purpose This paper aims to investigate the vital characteristic of an innovative ceramic injection molding (CIM) process for orthopedic application with controlled porosity and improved tribological and mechanical properties which were affected by complex tribological interactions, whether lubricated like hip implants and other artificial prostheses. The main objective is to maximize the usage of palm stearin as a single based binder as the function of flow properties during injection molding process. Design/methodology/approach The binder used in this present study consists of 100 per cent palm stearin manufactured by Kempas Oil Sdn Bhd and supplied by Vistec Technology Sdn Bhd. The feedstock was prepared by using a Z-blade mixer (Thermo Haake Rheomix OS) and Brabender mixer model R2400. The feedstock prepared was injection molded using a manually operated vertical benchtop machine with an average pressure of about 5-7 bars. The firing step included the temporary holds at intermediate temperatures to burn out organic binders. At this stage, the green molded specimen was de-bound using a single-step wick-debinding method. Findings The maximum content of ceramic material is applied to investigate the efficiencies of net formulation that can be achieved by ceramic materials. The longer the viscosity will change with shear rate, the higher the value of n obtained instead. From the slope of the curves obtained in Figure 3, the value of n for the feedstock was determined to be less than 1, which indicates a pseudoplastic behavior and suitability for the molding process. Moreover, high shear sensitivity is important in producing complex and intrinsic specimens which are leading products in the CIM industry. Originality/value The feedstock containing HAp powder and palm stearin binder was successfully prepared at very low temperature of 70°C, which promoting a required pseudo-plastic behavior during rheological test. The single binder palm stearin should be optimized in other research works carried out, as palm stearin is most preferred compared to other polymeric materials that provided high energy consumption when subjected to the sintering process. Besides the binder is widely available in Malaysia, low cost and harmless effect during debinding process.

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 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.

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.

scholarly journals Evaluation by nanoindentation of technological products manufactured by pulse injection molding process

2018 ◽  
Vol 145 ◽  
pp. 02006
Author(s):  
Margarita Natova ◽  
Ivan Ivanov ◽  
Sabina Cherneva ◽  
Maria Datcheva ◽  
Roumen Iankov
Keyword(s):  
Injection Molding ◽  
Polymer Melt ◽  
Injection Molding Process ◽  
Melt Flow ◽  
Molding Process ◽  
Polymer Injection ◽  
Pulse Injection ◽  
Molding Flow ◽  
Different Parts ◽  
Technological Products

During conventional polymer injection molding, flow- and weld lines can arise at the molded parts caused by disturbed polymer melt flow when it crosses different parts of the equipment. Such processed plastic goods have discrete zones of inhomogeneities of very small dimensions. In order to stabilize the melt flow and to equalize dimensions of such defective products, an approach for pulse injection molding is applied during production of polymer packagings. Testing methods used for evaluation of macromechanical performance of processed polymer products are not readily applicable to estimate the changes in visual surface obtained during pulse injecting. To overcome this testing inconvenience the performance of processed packagings is evaluated by nanoindentation. Using this method, a quantitative assessment of the polymer properties is obtained from different parts of technological products.

An Investigation into the Influencing Factors for Polymer Melt at the Filling Stage in Micro Injection Molding

2013 ◽  
Vol 562-565 ◽  
pp. 1380-1386
Author(s):  
Jian Zhuang ◽  
Da Ming Wu ◽  
Ya Jun Zhang ◽  
Lin Wang ◽  
Xiong Wei Wang ◽  
...  
Keyword(s):  
Injection Molding ◽  
Influencing Factors ◽  
Polymer Melt ◽  
Theoretical Models ◽  
Injection Molding Process ◽  
Melt Flow ◽  
Molding Process ◽  
Micro Injection Molding ◽  
Filling Stage ◽  
Conventional Injection Molding

The flow behaviors for polymer melt at the filling stage in micro injection molding are different from those in conventional injection molding due to the miniaturization of plastic parts. This paper focuses on the study of the effects of three main influencing factors, including the microscale viscosity and wall slip, on melt filling flow in microscale neglected those in conventional injection molding process. The theoretical models and the interrelation of these factors in microscale channels were constructed by means of the model correction method. Then, the micro melt flow behaviors were investigated with comparisons of the available experimental data. The results indicate that the dimensions affect the shear rates and viscous dissipation, which in turn affects the apparent viscosity. Finally, the conclusion is that the melt flow behaviors in microchannels are different from those in macrochannels owing to these significant influencing factors.

Towards Controllability of Injection Molding

1999 ◽  
Author(s):  
David Kazmer ◽  
David Hatch
Keyword(s):  
Injection Molding ◽  
System Design ◽  
Polymer Melt ◽  
Thermal Control ◽  
Polymer Processing ◽  
Injection Molding Process ◽  
Molding Process ◽  
Thermal Dynamics ◽  
Design Changes ◽  
Novel Processing

Abstract Process control has been recognized as an important means of improving the performance and consistency of thermoplastic parts. However, no single control strategy or system design has been universally accepted, and molding systems continue to produce defective components during production. The capability of the injection molding process is limited by the thermal and flow dynamics of the heated polymer melt. This paper discusses some of the difficulties posed by complex and distributed nature of the injection molding process. The flow and thermal dynamics of the process are analyzed with respect to transport and rheology. Then, two novel processing methods are described to enable in-cycle flow, pressure, and thermal control. Simulation and experimental results demonstrate effectiveness of these innovations to increase the consistency and flexibility in polymer processing. Such system design changes simplify the requisite control structures while improving the process robustness and productivity.

Viscosity Measurement in Injection Molding Using a Multivariate Sensor

2012 ◽  
Author(s):  
N. Asadizanjani ◽  
R. X. Gao ◽  
Z. Fan ◽  
D. O. Kazmer
Keyword(s):  
Injection Molding ◽  
Polymer Melt ◽  
Experimental Tests ◽  
Injection Molding Process ◽  
Online Measurement ◽  
Cavity Pressure ◽  
Molding Process ◽  
Ir Detector ◽  
Melt Temperature

Online measurement of polymer melt properties during an injection molding process is a key to provide a high quality plastic product. In-situ cavity pressure and temperature sensors are used to observe the polymer states in the mold cavity during an injecting molding process. A new multivariate sensor is introduced to measure pressure, temperature, velocity, and viscosity of polymer melt as the key parameters of the melt to improve the controlling process. This paper presents the viscosity calculating method based on melt velocity and the slope of melt pressure. The velocity is inferred using the melt temperature ramping rate; the new multivariate sensor detects melt temperature through the installed IR detector in the sensor, and the pressure is measured via the mounted piezoelectric rings. Injecting molding process of polymer melt is simulated under a range of melt velocity and temperature and the related viscosity values are inferred from simulation results and also from a set of experimental tests for a real injection molding process. Results are well matched with the expected rheological behavior of polymer.

The Effect of Nanoparticles on the Processing and Properties of Aluminum Nitride by Powder Injection Molding

2011 ◽  
Author(s):  
Valmikanathan P. Onbattuvelli ◽  
Sundar V. Atre ◽  
Timothy McCabe ◽  
Sachin Laddha
Keyword(s):  
Injection Molding ◽  
Aluminum Nitride ◽  
Powder Processing ◽  
Powder Injection Molding ◽  
Powder Injection ◽  
Injection Molding Process ◽  
Polymer Mixtures ◽  
Molding Process ◽  
Dimensional Precision ◽  
Wide Range

Aluminum nitride (AlN) exhibits many functional properties that are relevant to applications in electronics, aerospace, defense and automotive industries. However, the successful translation of these properties into final applications lies in the net-shaping of ceramics into fully dense microstructures. Increasing the packing density of the starting powders is one effective route to achieve high sintered density and dimensional precision. The present paper presents an in-depth study on the effects of nanoparticle addition on the powder injection molding process (PIM) of AlN powder-polymer mixtures. In particular, bimodal mixtures of nanoscale and sub-micrometer particles were found to have significantly increased powder packing characteristics (solids loading) in the powder-polymer mixtures. The influence of nanoparticle addition on the multi-step PIM process was examined. The above results provide new perspectives which could impact a wide range of materials, powder processing techniques and applications.

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