Development and application of a mold clamping mechanism for improving dimensional accuracy of vacuum casting parts and reducing mold production cost

Author(s):  
Chil-Chyuan Kuo ◽  
Hsueh-An Liu ◽  
Hong-Yi Lu ◽  
Pi-Rong Shi
2012 ◽  
Author(s):  
H. Y. Heo ◽  
D. H. Youn ◽  
H. Chung

Since ship hull blocks are constructed by assembling numerous intermediate parts, negligible dimensional variations in the parts can easily accumulate to cause serious misalignment in block erection stage. Considering the welding – the primary joining process in ship production which inherently causes distortions, the quality of block’s dimensional variations during the assembly would deteriorate even faster. Thinking that the intermediate products with low dimensional quality in the ship production are not scrapped but reworked, the productivity of each workstation greatly depends on the dimensional quality of these dimensionally critical intermediate products. Reworks such as recutting, mechanical and/or thermal correction against misalignment, excessive welding for wide gap and thermal straightening are commonly subsequently increases the total production cost. One of the major dimensional accuracy control activities is the shrinkage margin design. The optimal length of excess edge is assigned to plates in order to compensate welding shrinkage. In the past, the welding shrinkage is predicted based mostly on the empirical formula or just designer's experience, so the accuracy of the assigned was relatively poor and could not effectively help reducing non-value-added rework activities. The simplified margin calculation procedure could not consider the welding sequence as well as process variations such as welding heat input. This work aims to develop the optimal shrinkage margin calculation system for dimensional quality improvement. The proposed system calculates the optimal shrinkage margin using computer-aided engineering toolsets based on finite element analysis as well as design point searching procedure adopting the quality loss function and statistical values considering shrinkage variation values during welding. The developed scheme improves the accuracy control procedure in the ship production process thus enhance competitiveness of shipbuilders in dimensional accuracy technology by minimizing the accuracy impact on productivity.


Author(s):  
Z Shan ◽  
Y Yan ◽  
R Zhang ◽  
J Liang

The technique of precision rapid mould by transferred coating forming is an innovative rapid tooling (RT) process. It combines many techniques such as transferred coating and rapid prototyping. The main advantages of this process compared with other RT processes are low investment and production cost, shorter production cycles and many kinds of scale tool. The manufacturing process and the coating materials have been researched. The results of application show that net shape production may be fabricated in 2–7 days. The surface roughness of tools, Ra, can reach 1.6–6.3 äm, and dimensional accuracy may attain CT4-CT6.


2020 ◽  
Vol 14 (1) ◽  
pp. 6417-6429 ◽  
Author(s):  
Nur Nabilah Mohd Mustafa ◽  
Aini Zuhra Abdul Kadir ◽  
N. H. Akhmal Ngadiman ◽  
A. Ma'aram ◽  
K. Zakaria

Rapid vacuum casting has been proven to be a successful method in producing high-quality parts in small series. However, a challenge lies in the selection of proper Additive Manufacturing (AM) technologies for the development of a master pattern for the vacuum casting process. Each AM technologies differ from one another in terms of dimensional accuracy, surface finish, cost and lead times. The aim of this study is to investigate the performance of casting mating parts based on different additive manufacturing patterns for small batch. Three types of AM-based patterns: Fused Deposition Modeling (FDM), Stereolithography (SLA) and Multi-Jet Fusion (MJF) were compared. The Taguchi method, Signal to Noise ratio (S/N), Analysis of Variance (ANOVA) and T-test were conducted in determining the optimized parameters. From the findings, curing time is shown to be a significant parameter for dimensional accuracy and surface finish. Dimensional deviation varies in different directions of parts. For surface finish, there was only a slight change from the master pattern whereas the surface roughness of casting parts decreased within the range 0.23% to 2.85%. Tolerance grades for the selected dimensions of the parts were in the permissible range, based on ISO286-1:2010. When using distinct kinds of AM patterns to create replacement components, design tolerance is needed. It was suggested to select AM technology similar to that had been used for the original components.  Battery cover was selected as a case study to represent the mating application parts.


2011 ◽  
Vol 464 ◽  
pp. 698-702
Author(s):  
Y.C. Dai ◽  
Jian Zhong Zhou ◽  
Shu Huang ◽  
J. Guo ◽  
L. Xiao

A silicone mould fabrication technique based on vacuum casting was developed and its reproducibility was demonstrated. Orthogonal DOE method was adopted to analyze the effects of vacuum casting process parameters, and the process parameters that had an influence on the quality of the micro-mould cavities were identified and optimized. Micro-casting experiments were carried out using the optimized process parameters and the replicated micro-gears were obtained, these silicone copies were subjected to thorough analysis for dimensional accuracy against the master pattern. The results showed that the fabricated micro-mould was capable of producing functional micro-parts that were able to replicate micro-features, and micro-gears were successfully transferred from the silicone rubber moulds into PU resin pieces under vacuum conditions.


2018 ◽  
Vol 4 (2) ◽  
pp. 43-55
Author(s):  
Ika Yulianti ◽  
Endah Masrunik ◽  
Anam Miftakhul Huda ◽  
Diana Elvianita

This study aims to find a comparison of the calculation of the cost of goods manufactured in the CV. Mitra Setia Blitar uses the company's method and uses the Job Order Costing (JOC) method. The method used in this study is quantitative. The types of data used are quantitative and qualitative. Quantitative data is in the form of map production cost data while qualitative data is in the form of information about map production process. The result of calculating the cost of production of the map between the two methods results in a difference of Rp. 306. Calculation using the company method is more expensive than using the Job Order Costing method. Calculation of cost of goods manufactured using the company method is Rp. 2,205,000, - or Rp. 2,205, - each unit. While using the Job Order Costing (JOC) method is Rp. 1,899,000, - or Rp 1,899, - each unit. So that the right method used in calculating the cost of production is the Job Order Costing (JOC) method


2020 ◽  
Vol 14 (3) ◽  
pp. 7296-7308
Author(s):  
Siti Nur Humaira Mazlan ◽  
Aini Zuhra Abdul Kadir ◽  
N. H. A. Ngadiman ◽  
M.R. Alkahari

Fused deposition modelling (FDM) is a process of joining materials based on material entrusion technique to produce objects from 3D model using layer-by-layer technique as opposed to subtractive manufacturing. However, many challenges arise in the FDM-printed part such as warping, first layer problem and elephant food that was led to an error in dimensional accuracy of the printed parts especially for the overhanging parts. Hence, in order to investigate the manufacturability of the FDM printed part, various geometrical and manufacturing features were developed using the benchmarking artifacts. Therefore, in this study, new benchmarking artifacts containing multiple overhang lengths were proposed. After the benchmarking artifacts were developed, each of the features were inspected using 3D laser scanner to measure the dimensional accuracy and tolerances. Based on 3D scanned parts, 80% of the fabricated parts were fabricated within ±0.5 mm of dimensional accuracy as compared with the CAD data. In addition, the multiple overhang lengths were also successfully fabricated with a very significant of filament sagging observed.


2020 ◽  
Vol 8 (2) ◽  
pp. 128-149
Author(s):  
Dini Maulana Lestari

This paper will discuss about the immaterial costs and production yields at one of the refined sugar factory companies in Makassar, South Sulawesi. The theory is based on the fact that Immaterial is a cost that is almsgiving, meaning costs that are outside of the basic costs of the company in producing production, so this research aims to find out: (1) what is the production cost needed to produce this production, (2) the maximum level of production at company from 2013 to 2017. This type of research is a quantitative study because it uses a questionnaire in the form of values ​​that are processed using the marginal cost approach formula. The results of the analysis show that (1) the maximum level of production costs occurred in 2016 amounting to 6,912 with an Immaterial cost of Rp. 2,481,796,800 and the total production produced is 359,077.3 tons (2) The required workforce with the total production produced is 359,077.3 tones of 180 people including the maximum production point which means that the lowest value is achieved (optimal).    


2019 ◽  
Vol 5 (1) ◽  
pp. 63
Author(s):  
Elias Kamaruzzaman ◽  
Norzaidi Mohd Daud ◽  
Samsudin Wahab ◽  
Rozhan Abu Dardak

Technology changes will always be for the better, not only to the end users but also to the intellectual property owners of the technology and the implementers of the technology. The objective of this paper is to study the feasibility and viability for entrepreneurs to become service providers for the dispensation of fertilizers, pesticides, fungicides and supporting services such as aerial crop reconnaissance using Unmanned Aerial Vehicles (UAV) or drones. The methodology used for this study is SWOT Analysis. Both primary and secondary data is used for this analysis. This study finds that paddy farming employing drones is feasible. The beneficiaries of this study shall be the government, by way of lowering financial cost to subsidise the paddy planting, the farmers who no longer need the services of migrant workers, thus saving production cost, and finally the drone service providers and their downstream business associates who can engaged themselves in very lucrative businesses.


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