Project-Based Teaching of a Manufacturing Class During the COVID-19 Pandemic

Author(s):  
Davide Masato ◽  
Stephen Johnston

Abstract The Plastics Engineering program at the University of Massachusetts Lowell has taught mold design and engineering to undergraduate students for over 60 years. In 2020, the unexpected arrival of the COVID-19 pandemic in March forced the instructors to revisit the class program and objectives. Similar to other academic courses, the class became virtual. This meant redesigning an intensive hands-on manufacturing class into one that could be taught and taken from our home offices while maintaining academic rigor and continuing to meet critical student learning objectives. The timing of the pandemic meant that students, who were completing tooling split designs and starting CNC programming, could not move forward with machining, assembly, and molding. Instead, their projects became virtual learning experiences. This paper provides the analysis and discussion of how new ideas in teaching were implemented to virtually introduce engineering students to the world of plastic manufacturing. The students' work was carried out on plastic part designs of their choice, some of which included thin walls (<2 mm) and micro-scale features (~ 800 ?m) typical of a micro injection molding process.

2017 ◽  
Author(s):  
Saeed Beheshtian Mesgaran ◽  
Farzad Elhami Nik ◽  
Seyyed Emad Seyyed Mousavi

Injection Molding is among the most popular processes in plastic parts production. Through this process, burn marks and shrinkage play the most significant role in decreasing surface quality as well as increasing costs, especially when manufacturers use this method in order to produce thin-walled plastic parts. In this paper, a new strategy to remove the defects caused by shrinkage and burn marks has been proposed for the injection molding process of a specific plastic part which is used to keep the doors of an automobiles open during the painting process. Burn marks caused by the trapped air inside thin walls of the part were first simulated in MOLDFLOW 2010 software. Next step is to compare the simulation results to results that are obtained from experimental analysis. Then, Burn marks and shrinkage effects were eliminated by optimization of the process which includes mold design revision by means of SOLIDWORKS software, modification of the simulation in MOLDFLOW and the mold modification in workshop environment by improvising some ejector pins in certain points. Furthermore, shrinkage amount of the part after cooling process was calculated by applying Finite Element Method (FEM) and obtained results were used to optimize the design of the mold. Results demonstrate that mold design optimization would be possible through designing flawless molds that contain certain points for trapped air discharge and calculating shrinkage amount by FEM for optimization of design procedure. Results consequently decrease costs as well as providing surface quality improvement.


2013 ◽  
Vol 133 (4) ◽  
pp. 105-111
Author(s):  
Chisato Yoshimura ◽  
Hiroyuki Hosokawa ◽  
Koji Shimojima ◽  
Fumihiro Itoigawa

2015 ◽  
Vol 10 (2) ◽  
pp. 66
Author(s):  
Junaidi - ◽  
Ichlas Nur ◽  
Nofriadi - ◽  
Rusmardi -

Waste plastic mounting, but can be recycled into other products in the form of granules before further processed into pellets and seed injection molding process produces products such as buckets, plates, bottles and other beverages. To be processed into the required form of granules of plastic thrasher. Though so small plastic recycling industry is still constrained in plastic enumeration process because the machine used was not optimal ability. The purpose of this research is the development of the system thrasher plastic crusher and cutter cylinder-type reel and technical evaluation. This study was conducted over two years, the first year the design and manufacture of machinery, the second year is a technical evaluation of the engine, engine performance improvements and economic analysis of granular plastic products.From the results obtained engine design capacity of the machine ± 350 kg / h, the engine size is 50 cm x 120 cm x 30 cm, power motor of 10 HP at 1450 RPM rotation with 3 phase. Some of the major components of the engine that is, counter crusher unit consists of two counter rotating cylinders opposite, counter shaft size Ø 4 cm x 58 cm, blade chopper Ø 17 cm x 2 cm with the number of teeth / blades 7 pieces and the number of blades along shaft 7 pieces, buses retaining Ø 10 cm x 2 cm. Counter-cylinder unit consists of a reel-type cutter counter shaft size Ø 4 cm x 90 cm, the middle shaft mounted cylinder with Ø 17 cm x 40 cm as the holder of the chopper blades. Chopper blade consists of 4 pieces with a size of 40 cm x 2 cm x 4 cm with ASSAB materials. Furthermore, as the blade retaining bedknife shear force of the blade chopper, upper frame, lower frame, strainer, funnel entry, exit funnel, and the drive unit consists of an electric motor, reducer, belts, pulleys and 2 pieces of gear transmission. The results of performance testing machine crusher round cylinder 75 RPM and 1450 RPM reel-type cutting machine capacity ± 300 kg / h on the filter hole Ø 1.5 cm, with a 80% grain uniformity.


Author(s):  
André Hürkamp ◽  
Sebastian Gellrich ◽  
Antal Dér ◽  
Christoph Herrmann ◽  
Klaus Dröder ◽  
...  

AbstractIn this contribution, a concept is presented that combines different simulation paradigms during the engineering phase. These methods are transferred into the operation phase by the use of data-based surrogates. As an virtual production scenario, the process combination of thermoforming continuous fiber-reinforced thermoplastic sheets and injection overmolding of thermoplastic polymers is investigated. Since this process is very sensitive regarding the temperature, the volatile transfer time is considered in a dynamic process chain control. Based on numerical analyses of the injection molding process, a surrogate model is developed. It enables a fast prediction of the product quality based on the temperature history. The physical model is transferred to an agent-based process chain simulation identifying lead time, bottle necks and quality rates taking into account the whole process chain. In the second step of surrogate modeling, a feasible soft sensor model is derived for quality control over the process chain during the operation stage. For this specific uses case, the production rejection can be reduced by 12% compared to conventional static approaches.


Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 965 ◽  
Author(s):  
Nguyen Truong Giang ◽  
Pham Son Minh ◽  
Tran Anh Son ◽  
Tran Minh The Uyen ◽  
Thanh-Hai Nguyen ◽  
...  

In the injection molding field, the flow of plastic material is one of the most important issues, especially regarding the ability of melted plastic to fill the thin walls of products. To improve the melt flow length, a high mold temperature was applied with pre-heating of the cavity surface. In this paper, we present our research on the injection molding process with pre-heating by external gas-assisted mold temperature control. After this, we observed an improvement in the melt flow length into thin-walled products due to the high mold temperature during the filling step. In addition, to develop the heating efficiency, a flow focusing device (FFD) was applied and verified. The simulations and experiments were carried out within an air temperature of 400 °C and heating time of 20 s to investigate a flow focusing device to assist with external gas-assisted mold temperature control (Ex-GMTC), with the application of various FFD types for the temperature distribution of the insert plate. The heating process was applied for a simple insert model with dimensions of 50 mm × 50 mm × 2 mm, in order to verify the influence of the FFD geometry on the heating result. After that, Ex-GMTC with the assistance of FFD was carried out for a mold-reading process, and the FFD influence was estimated by the mold heating result and the improvement of the melt flow length using acrylonitrile butadiene styrene (ABS). The results show that the air sprue gap (h) significantly affects the temperature of the insert and an air sprue gap of 3 mm gives the best heating rate, with the highest temperature being 321.2 °C. Likewise, the actual results show that the height of the flow focusing device (V) also influences the temperature of the insert plate and that a 5 mm high FFD gives the best results with a maximum temperature of 332.3 °C. Moreover, the heating efficiency when using FFD is always higher than without FFD. After examining the effect of FFD, its application was considered, in order to improve the melt flow length in injection molding, which increased from 38.6 to 170 mm, while the balance of the melt filling was also clearly improved.


2006 ◽  
Vol 326-328 ◽  
pp. 187-190
Author(s):  
Jong Sun Kim ◽  
Chul Jin Hwang ◽  
Kyung Hwan Yoon

Recently, injection molded plastic optical products are widely used in many fields, because injection molding process has advantages of low cost and high productivity. However, there remains residual birefringence and residual stresses originated from flow history and differential cooling. The present study focused on developing a technique to measure the birefringence in transparent injection-molded optical plastic parts using two methods as follows: (i) the two colored laser method, (ii) the R-G-B separation method of white light. The main idea of both methods came from the fact that more information can be obtained from the distribution of retardation caused by different wavelengths. The comparison between two methods is demonstrated for the same sample of which retardation is up to 850 nm.


Sign in / Sign up

Export Citation Format

Share Document