Plastic Injection Moulding Research Articles

Development of a Smart Plastic Injection Mold with Conformal Cooling Channels

Injection molding is a popular method that is used to make plastic product due to high productivity, efficiency and manufacturability. This paper presents the development of a smart plastic injection mold with conformal cooling channels for making a complex automotive part with variable thickness at some positions. To cool the positions with thicker walls, we proposed local conformal cooling channels in which the cooling lines are in the spiral form. The mold was designed with special inserts. Selective laser melting (SLM) 3D printing has been used to make the inserts with conformal cooling channels inside. In the first phase of the development process, the research results show that conformal cooling channels reduce the cycle time approximately 30% compared to conventional cooling channels. To make the mold to be smart, the temperature of the mold will be monitored by sensor system. In addition, a quality control system is applied on this smart mold in order to ensure the quality of molded part.

Green density optimization of stainless steel powder via metal injection molding by Taguchi method

Metal injection moulding (MIM) has gains much attention due to its ability in producing large amount of small part with complex geometry and intricate shape. In order to obtain better shape retention, optimum density of green part is required. This paper deals with the application of Taguchi method in optimising the green density of moulded components base on parameters setting in plastic injection moulding machine. For this purposes only 7 process parameters were considered here are injection pressure, injection temperature, cooling time, injection speed, injection time, packing time and mould temperature. An orthogonal array of L27 experimental base design was conducted. Base on the experimental results, cooling time plays significant contribution to density followed by injection pressure, time, speed, mould temperature, packing time and injection temperature. Confirmation test was done base on optimization level for each factors and shows good results in green density of the injected moulded samples.

Applications’ Integration and Operation Platform to Support Smart Manufacturing by Small and Medium-sized Enterprises

Many developed countries are making various efforts to innovate their own manufacturing industries, through initiatives such as Manufacturing innovation 3.0, Industry 4.0, and Manufacturing 2025. Innovation in the manufacturing industry, represented by the so-called “smart factories,” is being developed through the latest technologies such as Internet of things (IoT), cloud, and big data. However, as the application of these technologies requires a lot of cost and time, small and medium-sized enterprises (SMEs) are often hampered in their efforts to take full advantage of them. For an enterprise that operates a manufacturing information system, the integrated management of information between systems is essential to the application of a new technology. If the enterprise lacks the relevant experts, it will have difficulty applying a new technology in the field. This study suggests the application of a cloud-based applications’ integration and operation platform (AIOP) in order to resolve those problems. The AIOP must accept a large volume of data at IoT-based manufacturing fields, interconnect between manufacturing fields and AIOP, and provide application contents in the form of service. The suggested study contents are applied to a company that produces electric components using plastic injection molds to verify their effects. It is expected that this study can be used as a reference model for applying smart factory technologies to other SMEs in the future.

A Brief Review on injection moulding manufacturing process

The term quality has become a “catch all” term used in describing the various characteristics of an object. It is nearly impossible to define the term consistency. The quality is any particular or specific characteristics of a product development design object that contains or relates information about the object. This is primarily a chunk of geometry distinguished by its ability to perform a function with one or more other. In this primary processing conditions are studied from concept development to manufacturing of the product. Effect of different factors studied on the basis of processing parameters. Since quality and productivity are the two important contradictory objectives in any machining process. Some extent of quality has to be compromised while assurance giving for high productivity. Similarly productivity will be decreased while the efforts are channelized to enhance quality. To ensure high quality and productivity, it is necessary to optimize machining parameters. Various responses of quality of injection moulding process has been studied on the basis of performance parameters and methods. This paper aims to present plastic injection moulding process conditions. The processing conditions satisfied quality based product manufacturing.

A Data-Driven Holistic Approach to Fault Prognostics in a Cyclic Manufacturing Process

The complexity of manufacturing systems is increasing due to the increased requirements related to the variety and quality of the products, their complexity, and due to the general technological developments. In turn, the data related to the manufacturing processes is growing in size and in complexity. This presents new challenges for real-time monitoring, diagnostics, and prognostics of the processes. The challenges are addressed by new tools, methodologies, and concepts, collectively referred to as Big Data. The paper deals with the use of advanced methods for prognostics of infrequent faults on available but highly dimensional manufacturing process data. A holistic approach, which includes data generation, acquisition, storage, processing, and prognostics, is shown in a case of a plastic injection moulding process. Real industrial data acquired from five injection moulding machines and the Manufacturing Execution System within a period of six months is used. It is shown how the approach is able to tackle the high dimensionality and the large size of the data to create and evaluate prediction models for prognostics of the unplanned machine stops.

Performance Stability of Silicone Oxide-Coated Plastic Parenteral Vials.

A new packaging system was developed for parenteral pharmaceuticals that combines the best attributes of plastic and glass without their respective drawbacks. This technological advancement is based on the synergy between high-precision injection-molded plastics and plasma coating technology. The result is a shatter-resistant, optically clear, low-particulate, and chemically durable packaging system. The demand for this product is driven by the expanding market, regulatory constraints, and product recalls for injectable drugs and biologics packaged in traditional glass materials. It is shown that this new packaging system meets or exceeds the important performance characteristics of glass, especially in eliminating the glass delamination and breakage that has been observed in many products. The new packaging system is an engineered, multilayer, glass-coated plastic composite that provides a chemically stable contact surface and oxygen barrier performance that exceeds a 2 year shelf life requirement. Evaluation of the coating system characteristics and performance stability to chemical, temperature, and mechanical extremes are reported herein.LAY ABSTRACT: A new packaging system for parenteral pharmaceuticals was developed that combines the best attributes of plastic and glass without their respective drawbacks. This technological advancement is based on the synergy between high-precision injection-molded plastics and plasma coating technology. The result is a shatter-resistant, optically clear, low-particulate, and chemically durable packaging system. It is shown that this new packaging system meets or exceeds the important performance characteristics of glass, especially in eliminating the glass delamination and breakage that has been observed in many products. The new packaging system is an engineered, multilayer, glass-coated plastic composite that provides a chemically stable contact surface and oxygen barrier performance that exceeds a 2 year shelf life requirement. Evaluation of the coating system characteristics and performance stability to chemical, temperature, and mechanical extremes are reported herein.

Polymer Injection Molding: Advanced Simulations or Tablet Computations

Simulation of injection molding of polymeric materials is a common way of solving issues in plastic part and injection mold design. CAE software is getting more available and user-friendly, which sometimes leads to unreasonable use cases of these programs. The original, relatively simple tool has been introduced to validate runner systems in injection molds. It allows a fast identification of the most important design parameters of runner system. This tool does not require any support of FEM simulations, but results obtained from it have been successfully compared with injection molding simulations.

A cost-effective approach for rapid manufacturing wax injection molds with complex geometrical shapes of cooling channels

Rapid tooling techniques can reduce the time to market compared to conventional machining approaches. The aluminum-filled epoxy resin mold is a promising choice for short production runs because it can be a useful alternative of conventional steel mold and employed in wax injection mold or plastic injection mold. However, the cycle time is significantly longer because of the poorer thermal conductivity of the material compared to conventional mold steels. In this study, a new technique to produce wax injection molds with complex geometrical shapes of cooling channels was presented. The main advantages of this technique include low production cost, simple manufacturing processes, and short processing time.

Application of carbon reinforced composites and rapid prototyping in low volume automotive production

Abstract In this publication, a method was developed for the production of plastic parts for the use in low volume automotive production. The hollow parts having a complex geometry were produced in blown plastic injection molds. The part production method employed a combination of carbon fiber reinforced composites and rapid prototyping technology. Surface operations were applied on the core model and the effects of the surface quality were researched as a case study. The fused deposition modeling method was used to build the core from soluble material. This technique affected the inside surface roughness and quality of the final parts. As these types of components require smooth surfaces for good air flow and low resistance, the surface area of the physical model of the soluble core was unfortunately too rough to be used directly in the carbon fabric application process and consequently, required preliminary surface treatment in order to improve the surface quality of the manifold part. Specimens were fabricated using different surface treatments in order to determine the smoothest surface quality. The best result was obtained using the acetone-gelcoat post-processing method.

Design and Production of the Injection Mould with a Cax Assistance

Abstract This paper is focused on the process of designing the desired plastic component and injection mould by using the 3D CAD systems. The subsequent FEM analysis of the injection mould process was carried out in order to define shrinkage and deformation of the plastic material by CAE system. The dimensions of the mould were then modified to compensate the shrinkage effect. Machining process (milling and the laser texturing) of the mould was performed by using CAM systems. Finally, after the production of the plastic components by the injection mould technology, the inspection of the plastic component dimensions was carried out by CAQ in order to define the accuracy of the whole CAx chain. It was also demonstrated that CAx systems are an integral part of pre-production and production process.

Designing an Injection Mould Using Advance CAD-CAM Programs

This paper presents the design of plastic injection mould for producing a plastic product. The plastic part was designed into two different types of product, but in the same usage function. The mould was designed using the CAD program ProEngeneering Wildfire 3.0 and the DepoCam software was used to simulate the manufacturing time. The execution of the mould and the experiments were done at a private factory. Designing and simulating an injection mould before actually producing it is very useful in order to save time and cut manufacturing costs

Wavefront measurement of plastic lenses for mobile-phone applications

Abstract In camera lenses for mobile-phone applications, all lens elements have been designed with aspheric surfaces because of the requirements in minimal total track length of the lenses. Due to the diffraction-limited optics design with precision assembly procedures, element inspection and lens performance measurement have become cumbersome in the production of mobile-phone cameras. Recently, wavefront measurements based on Shack-Hartmann sensors have been successfully implemented on injection-molded plastic lens with aspheric surfaces. However, the applications of wavefront measurement on small-sized plastic lenses have yet to be studied both theoretically and experimentally. In this paper, both an in-house-built and a commercial wavefront measurement system configured on two optics structures have been investigated with measurement of wavefront aberrations on two lens elements from a mobile-phone camera. First, the wet-cell method has been employed for verifications of aberrations due to residual birefringence in an injection-molded lens. Then, two lens elements of a mobile-phone camera with large positive and negative power have been measured with aberrations expressed in Zernike polynomial to illustrate the effectiveness in wavefront measurement for troubleshooting defects in optical performance.

Application of RSM to Optimize Moulding Conditions for Minimizing Shrinkage in Thermoplastic Processing

This study focuses on the analysis of plastic injection moulding process simulation using Autodesk Moldflow Insight (AMI) software in order to minimize shrinkage by optimizing the process parameters. Two types of gates which is single and dual gates have been analysed. Nessei NEX 1000 injection moulding machine and P20 mould material details are incorporated in this study on top of Acrylonitrile Butadiene Styrene (ABS) as a moulded thermoplastic material. Coolant inlet temperature, melt temperature, packing pressure and cooling time are selected as a variable parameter. Design Expert software is obtained as a medium for analysis and optimisation to minimize the shrinkage. The polynomial models are obtained using Design of Experiment (DOE) integrated with RSM Center Composite Design (CCD) method in this study. The results show that packing pressure is a main factor that contributed to shrinkage followed by coolant inlet temperature, while melt temperature and cooling time has less significant for both single and dual gates. Meanwhile, single gate shows a better result of shrinkage compared to the dual gates.

Multi-objective optimization of injection molding process parameters in two stages for multiple quality characteristics and energy efficiency using Taguchi method and NSGA-II

In this paper, the parameters optimization of plastic injection molding (PIM) process was obtained in systematic optimization methodologies by two stages. In the first stage, the parameters, such as melt temperature, injection velocity, packing pressure, packing time, and cooling time, were selected by simulation method in widely range. The simulation experiment was performed under Taguchi method, and the quality characteristics (product length and warpage) of PIM process were obtained by the computer aided engineering (CAE) method. Then, the Taguchi method was utilized for the simulation experiments and data analysis, followed by the S/N ratio method and ANOVA, which were used to identify the most significant process parameters for the initial optimal combinations. Therefore, the range of these parameters can be narrowed for the second stage by this analysis. The Taguchi orthogonal array table was also arranged in the second stage. And, the Taguchi method was utilized for the experiments and data analysis. The experimental data formed the basis for the RSM analysis via the multi regression models and combined with NSGS-II to determine the optimal process parameter combinations in compliance with multi-objective product quality characteristics and energy efficiency. The confirmation results show that the proposed model not only enhances the stability in the injection molding process, including the quality in product length deviation, but also reduces the product weight and energy consuming in the PIM process. It is an emerging trend that the multi-objective optimization of product length deviation and warpage, product weight, and energy efficiency should be emphasized for green manufacturing.

Multi-objective optimization of injection molding process parameters for short cycle time and warpage reduction using conformal cooling channel

In this paper, cooling performance of conformal cooling channel in plastic injection molding (PIM) is numerically and experimentally examined. To examine the cooling performance, cycle time and warpage are considered. Melt temperature, injection time, packing pressure, packing time, cooling time, and cooling temperature are taken as the design variables. A multi-objective optimization of the process parameters is then performed. First, the process parameters of conformal cooling channel are optimized. Numerical simulation in the PIM is so intensive that a sequential approximate optimization using a radial basis function network is used to identify a pareto-frontier. It is found from the numerical result that the cooling performance of conformal cooling channel is much improved, compared to the conventional cooling channel. Based on the numerical result, the conformal cooling channel is developed by using additive manufacturing technology. The experiment is then carried out to examine the validity of the conformal cooling channel. Through numerical and experimental result, it is confirmed that the conformal cooling channel is effective to the short cycle time and the warpage reduction.

Optimization of Plastic Moulding by Reducing Warpage With the Application of Taguchi Optimization Technique & Addition of Ribs in Washing Machine Wash Lid Component

This paper deals with the optimization of plastic moulding by reducing warpage with the application of Taguchi optimization technique & part design modifications. Taguchi optimization technique is used for determining the optimum plastic injection moulding process parameters. In part design modifications, ribs are added to the wash lid component to provide additional strength to the washing machine. Analysis of the process parameters are initially carried out by utilizing the combination of process parameters based on three-level of L27 Taguchi orthogonal design. Further, signal-to-noise (S/N) ratio is applied to find the optimum process parameters for warpage defect in the wash lid component. The design modifications and analysis for warpage using optimum parameters obtained from S/N ratio using Pro-E design software and Solid Edge Plastic analysis software. The results obtained reveals that improvement in total warpage is 22.0% & in X-direction it is 37% and stress distribution is by 28% which proves that the strength of the wash lid has increased.

Screening for kidney malfunction using injection moulded plastic urinalysis cartridge

We have designed and fabricated an injection moulded plastic urinalysis cartridge and its reader to measure the concentrations of albumin and creatinine in the same sample and calculate the ACR (albumin/creatinine ratio) value for detecting kidney failure. A COC (Cyclic Olefin Copolymer) cartridge with a sample gathering pipette, pneumatic inlet, a needle to transfer pneumatic pressure to the sample gathering pipette, and two measurement modules to measure the albumin and creatinine levels in a urine sample were fabricated. A cartridge reader with LEDPD optics, pneumatic pump, and solution mixing motors was also fabricated. This system also has a sample solution-measurement / reagent-mixing mechanism using iron balls and permanent magnet with attached DC motors. We perform CV (coefficient of variation) testing for creatinine and albumin, with resulting CV values of less than 11%, which makes this process potentially suitable for commercial applications.

Determining the Optimum Parting Direction in Plastic Injection Molds Based on Minimizing Rough Machining Time during Mold Manufacturing

ABSTRACTThe versatility of plastic materials allows engineering components of very complex geometries and functionalities to be injection molded from them. Because the manufacturing cost of a mold increases with the complexity of the cavity, it is important to optimize the design of component and mold concurrently. In this study, a methodology for determining the optimum parting direction (PD) considering mold‐manufacturing factors such as tool accessibility and the amount of material to be removed is presented. The methodology starts with an accessibility analysis in which a three‐dimensional part is discretized, and candidate PDs are selected based on maximizing the accessible area, that is, the area that can be machined with a single workpiece orientation or setup. Then, the rough machining process is considered, and an optimum PD that minimizes the rough machining time for both the cavity and core plates is selected. The methodology is applied to four different automotive components: a mirror cover, an interior panel, a pillar, and a fender splash shield.

Design and Fabrication of a Cost Effective Four Cavity Plastic Injection Mould for Bottled Water Handle

Design and Fabrication of a Cost Effective Four Cavity Plastic Injection Mould for Bottled Water Handle

Standardized evaluations of mechanical properties of biodegradable Mg strengthened poly-lactic acid composite through interfacial Properties

Event Abstract Back to Event Standardized evaluations of mechanical properties of biodegradable Mg strengthened poly-lactic acid composite through interfacial Properties Muhammadshoaib Butt1, Jing Bai1, Feng Xue1 and Cheng Chu1 1 southeast university, School of Material Science and engineering, China Introductions: Mg alloys, as prospective biodegradable orthopedic implants, are attracting wide attention. However, their high corrosion rate and hydrogen release during degradation leads to a potential limitation of application in future. Mg strengthened poly-lactic acid composite is a good attempt to integrate both their advantages and to avoid their weakness. Since there are many methods to prepare composite, it is necessary to develop a standardized system to evaluate the mechanical properties, especially the interfacial bonding strength during degradation. Materials and Methods: AZ31 alloy (96%Mg, 3%Al and 1%Zn) rod with diameter of 2.44mm, height 60mm and plate with dimension were 60mm×10mm×1.7mm (length ×width × height), were first prepared by smelting ,casting ,hot extrusion, wet drawing and annealing. Three surface treatment methods were performed for both Mg rod and plate, anodic oxidation (AO), micro-arc oxidation(MAO) and chemical conversion.These Mg rods and plates with and without surface coating were used to fabricate PLA/AO/Mg composite, rod with diameter of 4mm and height of 60mm, and plate with dimension of 60mm ×12.3mm ×3mm(length × width ×height), respectively (Fig. 1), by plastic injection molding (PIM) process. To evaluate the degradation performance of different composite, tensile tests, bending tests, degradation rate measurements, and interfacial morphology observations were carried out for these samples immersed in simulated body fluid (SBF) for different time. Results and Discussions: The mechanical testing results show the composites have significant higher bending and tensile strength than pure PLA[1]. For example, the average bending strength of rod samples improves from ~100MPa of pure PLA to ~175MPa of PLA/naked Mg composite, and further improve to ~190MPa of PLA/Mg with AO coating composite. The average tensile ultimate strength of rod samples improves from ~52MPa of pure PLA to ~95MPa of PLA/Mg with AO coating. Moreover, Mg with MAO coating can further improve strength[2] of composite than AO coating. From the samples after tensile test, it can be found that only outer PLA is broken during pulled out, while the Mg still can maintain structure integrity, indicating the interface of Mg and PLA is mechanical bonded and frictional force is an major factor to impact the interfacial bonding strength of Mg and PLA[3]. Additional, since there are two interface in these composites with surface treated Mg, namely Mg - coating interface and coating – PLA interface, both interfaces play important roles in influencing the mechanical properties of composite[4]. The present composites show good corrosion resistance during degradation, and there is no noticeable change after immersion for 1 month. Meanwhile, these composites also show good mechanical stability during degradation, and the average strengths are still more than half of their original strengths after 1-2 month immersion.[5] The decrease of strength is mainly attributed to the hydrolysis of PLA and the morphological changes of interfaces resulting from the corrosion. Conclusions: Biodegradable PLA/Mg composite were prepared by plastic injection molding(PIM). These composites show significant better mechanical properties than pure PLA, and with surface treatment of Mg the mechanical properties are further improved. Two interfaces between Mg and PLA play critical roles in influencing the mechanical properties of original composites as well as during degradation. Standardization to analysis the morphology and bonding strength was proposed and this is helpful to evaluate the mechanical properties of PLA/Mg composites during degradation. Programs Foundation of Ministry of Education of China (No. 20120092120048); The National Natural Science Foundation of China (No. 31570961)