The Journal of Industrial Technology

ปกวารสาร (cover) - JIT volume 21, issue 2, 2025

2025-08-26T10:15:01+07:00

The journal of Industrial Technology, 21(2), 2025.

2025-08-26T10:23:07+07:00

Application of Geographic Information System for Benzene Impact Analysis and Spatial Measure Development in Bangkok Metropolitan Area

2025-08-19T14:27:00+07:00

This research aims to apply Geographic Information Systems (GIS) to analyze the impacts of benzene dispersion in Bangkok. The study collected benzene concentration data from four air quality monitoring stations under the Pollution Control Department between 2019 and 2023. The data were analyzed using spatial interpolation and overlay analysis techniques. The results revealed that high-risk areas for benzene exposure were concentrated in industrial zones and high-traffic areas, particularly in Bang Na, Lat Krabang, and Khlong Toei districts. Based on the findings, the study proposed three-tiered spatial mitigation measures: urgent actions in high-risk zones, preventive measures in moderate-risk areas, and monitoring protocols in low-risk zones. The research provides a preliminary framework for developing air quality management policies in Bangkok, emphasizing spatially targeted interventions based on benzene dispersion risks. However, further field implementation and efficacy assessments are required to ensure the proposed measures align with real-world operational contexts.

The Production Process Improvement to Reduce Defect in Hamburger Buns by Applying DMAIC Technique: A Case Study of President Bakery Public Company Limited

2025-08-19T17:11:59+07:00

Producing hamburger buns that meet high-quality standards and are free from defects remains a critical challenge in the food production industry. This research aims to apply the DMAIC technique to systematically investigate and improve hamburger bun production processes, with the goal of reducing manufacturing variability and enhancing product quality. An initial defect analysis identified warpage (21%) as the most frequent defect, attributed to mold deterioration and resolved through mold replacement. Therefore, efforts focused on reducing color variation (20%), the second most prevalent defect, linked to process instability. Root cause analysis using a cause and effect diagram identified that the volume of cooling water in the sponge process and the mixing velocity during the dough process significantly influenced the occurrence of discoloration (p<0.05). Following process improvements, the defect rate of hamburger buns with discoloration decreased by 77.29%. This study proposes a structured framework to enhance operational efficiency, reduce product variability, and ensure quality compliance, thereby offering a strategic approach for improving hamburger bun production and extend its applicability to other food manufacturing processes.

Physical and Mechanical Properties of Mortar Containing Marine Waste for Product Development

2025-08-21T09:41:48+07:00

This paper presents the physical and mechanical properties of mortar mixed with marine waste for product development. Marine debris was collected from coastal areas, and only plastic bottles were selected and crushed using a grinding machine. The cement-to-stone dust ratio was fixed at 1:4 by weight, with crushed plastic waste added at 3%, 6%, and 9% by total weight. The water-to-cement ratio was maintained at 0.4. The unit weight, water absorption, porosity, compressive strength, and microstructural analysis using a Scanning Electron Microscope (SEM) were tested. The most suitable mixture ratio was then used to form a prototype product. The study found that the unit weight of cement mortar decreased as the replacement level of crushed plastic waste increased. The incorporation of crushed plastic waste also led to higher water absorption and porosity with increasing plastic content. Using 6% crushed plastic waste by total weight in the cement mortar and stone dust mixture proved suitable for producing plant pots. This utilization of marine plastic waste to develop sustainable products promotes a circular economy and helps mitigate environmental impacts.

Classification of COVID-19 from Chest CT Images Using Ensemble Techniques

2025-08-20T09:03:12+07:00

The COVID-19 pandemic has emphasized the critical need for effective diagnostic tools that can assist medical personnel in evaluating patients more rapidly and accurately. This research presents the development of a model for classifying COVID-19 from chest computed tomography (CT) scans using ensemble learning methods. The study utilized the COVID-19 Radiography dataset containing 7,232 images, evenly divided between 3,616 COVID-19 positive images and 3,616 COVID-19 negative images. The dataset was split data to a training set (70%, 2,531 images), validation set (20%, 723 images), and test set (10%, 362 images), with 5-fold cross-validation (K=5). The experimental methodology was divided into three groups: Group 1 involved testing 38 popular deep learning models and selecting the three highest-accuracy models for further experimentation. Group 2 combined these models using bagging techniques across the five cross-validation data folds in three different experimental configurations. Group 3 utilized bagging to combine the highest-performing versions of each selected model in two experimental configurations. The results show that the experiment group 3 using MobileNet and DenseNet121 together achieved an accuracy of 99.30%, compared to the baseline model in group 1 with an accuracy of 97.23%, which is 2.07% higher.

Design and Development of Standard Calibrator for Horizontal Sprit Level

2025-08-20T09:24:56+07:00

The objective of this research is to design and develop a standard calibrator for a horizontal spirit level that is efficient and can be used to obtain the laboratory accreditation ISO/IEC17025: 2017 in the scope of spirit level calibration. The research began with collecting needs for using the calibrator of 30 people in the calibration laboratory by face-to-face interviews and questionnaires. Quality Function Deployment (QFD) was then applied to translate these needs into technical requirements of the calibrator. The next step was to generate 3 design concepts of the calibrator, and the most prominent one was then selected using the concept scoring technique. Subsequently, the selected design concept was finally revised based on recommendations from calibration and engineering experts before developing the prototype, which was called the Precision Bar. A comparative test of performance between the previously used calibrator and the one developed in this study showed the following results; (1) Calibration time has been reduced from 120 minutes to 52 minutes, (2) Spirit levels can be calibrated according to the same JIS B 7510: 1993 standard, (3)The weight of the calibrator has been reduced from 25 kg to only 2 kg, (4) The floor slope of the calibrator can be adjusted as small as 0.02 mm/m per one scale, and (5) Profit from calibration service increased from 200 baht to 600 baht. Moreover, the new calibrator also has the same calibration capability as the standard calibrator imported from abroad, and its cost was 110,000 baht lower, or 73% price reduction.

Development of Heat Resistance Properties of Geopolymer Bricks from Fly Ash and Metakaolin by Bagasse Ash Addition

2025-08-20T09:36:10+07:00

This research aimed to develop geopolymer bricks using fly ash blended with metakaolin and bagasse ash to enhance thermal insulation properties. The study examined the effects of replacing fly ash with bagasse ash at proportions of 0%, 10%, 20%, and 30% by weight on the physical and mechanical properties, including compressive strength, density, porosity, water absorption, thermal conductivity coefficient, and high-temperature resistance. The results showed that increasing the bagasse ash content significantly reduced thermal conductivity, with the BA30 formulation achieving the greatest reduction of 41.1% (0.277 W/m·K). Meanwhile, compressive strength tended to decrease with increasing bagasse ash content. At 28 days, formulations BA0, BA10, BA20, and BA30 exhibited average compressive strengths of 14.23, 13.29, 8.53, and 9.18 MPa, respectively. Overall, the BA10 formulation was found to be optimal, with compressive strength exceeding the TIS 77-2565 standard by 32.9%, thermal conductivity reduced by 12.8%, and maximum heat resistance, retaining 18.7% of its strength at 1000°C. Cost analysis revealed that geopolymer bricks cost approximately 4 baht per unit. It also exhibited thermal conductivity values over 40% lower than those of conventional clay and concrete bricks, and withstood fire exposure for more than 4 hours, clearly demonstrating superior thermal insulation performance.

Thermal insulation hollow concrete blocks using palm oil clinker containing surgical face masks and KF94 masks as aggregate

2025-08-20T10:12:47+07:00

This study aimed to utilize waste materials to identify suitable compositions for developing thermally insulating hollow concrete blocks. The research incorporated palm oil clinker aggregates as the base material, partially replaced by surgical face masks and KF94 masks at substitution rates of 0%, 2%, 4%, and 6% by weight of the palm oil clinker. This study evaluated the compressive strength, density, water absorption, electrical resistivity, and microstructure of cement mortar specimens. Additionally, the thermal insulation performance was assessed using 70x190x390 millimeters hollow concrete blocks. The experimental results indicated that incorporating the surgical face and KF94 masks reduced the compressive strength and density. However, when tested in hollow concrete block form, palm oil clinker aggregate blocks demonstrated significantly superior thermal insulation compared to commercially available hollow concrete blocks. Furthermore, the inclusion of surgical face and KF94 masks slightly enhanced the thermal insulation performance. In conclusion, hollow concrete blocks composed of palm oil clinker aggregates blended with surgical face masks and KF94 masks present a viable approach for manufacturing nonloadbearing hollow concrete blocks with enhanced thermal insulation properties.

Improving Production Efficiency in Hot Coil Plate Production Process

2025-08-26T08:39:22+07:00

This research aimed to improve the production efficiency of hot coil plates. The main problems identified were production delays and deviation from the planned schedule. The study began with an analysis of the hot coil plate production process, followed by brainstorming and the use of a cause-and-effect diagram to identify the root causes. It was found that the deburring process caused significant delays. The ECRS principle was applied, specifically by eliminating the deburring step through the adjustment of die clearance to suit the thickness of the material type, in order to improve the edge folding process and reduce waste. After the improvement, burr formation at the workpiece edge was eliminated, leading to the removal of unnecessary steps and a reduction in processing time. The processing time for the fan frame component was reduced from 2,630.58 seconds to 1,363.81 seconds, a reduction of 48.16 percent. For the left and right plate components, the time was reduced from 3,769.96 seconds to 1,886.62 seconds, a reduction of 49.96 percent. Additionally, the average daily production of fan frame components increased from 170 to 295 units, an increase of 73.53 percent, and the left and right plate components increased from 213 to 427 units per day, an increase of 100.00 percent.

Optimization of Coliform Bacteria Removal in Surface Water using a Hydrodynamic Cavitation Reactor with the Response Surface Methodology

2025-08-20T13:53:34+07:00

This research aims to determine the optimal conditions for eliminating coliform bacteria in surface water using a hydrodynamic cavitation reactor. The response surface methodology was employed to analyze the influence of variables on the amount of total coliform bacteria. The studied variables included the duration of coliform bacteria removal, the number of holes, and the diameter of the holes on the orifice plate. The experimental results showed that the cavitation occurring within the reactor effectively reduced the amount of total coliform bacteria. The key variables significantly affecting the reduction of total coliform bacteria were the duration of removal, the number of holes, and the diameter of the holes on the orifice plate. The developed mathematical model was found to predict the amount of total coliform bacteria with high accuracy, with a coefficient of determination (R²) of 0.9462. The optimal conditions for eliminating coliform bacteria were determined to be a removal duration of 89.33 minutes, an orifice plate with 5 holes, and a hole diameter of 3 mm. Under these conditions, the amount of total coliform bacteria in surface water was reduced from 200 CFU/100 ml to 0 CFU/100 ml.

Metasurface Rectenna Array for Wireless Energy Harvesting from 5G Communications

2025-08-20T14:21:44+07:00

This article introduces a novel approach to wireless energy harvesting using a metasurface antenna array and rectifier circuits, designed in a 4×4 array configuration consisting of 16 antennas and 32 rectifier circuits. The system is aimed at harvesting wireless energy from 5G base stations operating at a frequency of 2.6 GHz. The antennas are designed with a suspended structure and circular radiating plate, featuring dual-linear polarization to enhance signal reception and ensure compatibility with 5G systems. For the superstate layer, unit cells are arranged in a 3×3 hexagonal ring pattern, enabling unidirectional radiation and achieving a gain exceeding 9 dBi for both polarizations at the 2.6 GHz. The rectifier circuits utilize SMS736 Schottky diodes, offering a conversion efficiency of 26.7% and generating a maximum DC voltage of 1.53 V under an input power of 4 dBm with a load resistance of 3 kΩ. Experimental evaluation of the 4×4 metasurface antenna array revealed that series and parallel connections of the rectifier circuits produced maximum DC voltages of 9.78 V and 0.42 V, respectively, at a distance of 3.5 meters from the rear of the 5G antenna. This work demonstrates the potential of metasurface-based rectenna arrays for efficient wireless energy harvesting in 5G applications, highlighting their high gain performance and effective energy conversion capabilities.

Design of experiments to analyze factors for block digestion affecting the defect of nitrogen tubes

2025-08-20T14:43:43+07:00

This research aims to reduce the waste of nitrogen tubes generated from testing for the quantities of Nitrogen and crude protein in laboratory settings of a case study factory, using 2^k Full Factorial Design. The study to identify factors and their levels in adjusting the settings of the Block Digestion machine appropriately. The experimental design comprises three main factors: temperature, burning time, and cooling time. The experiments were repeated three times, totaling 24 trials. The experimental results indicated that temperature, burning time, and cooling time had a statistically significant effect on the occurrence of cracks in the test tubes at the 95% confidence level. Moreover, significant interaction effects were observed between temperature and burning time, as well as between temperature and cooling time and the appropriate factors and levels for adjusting the settings of the Block Digestion machine are: temperature at 400 degrees celsius, burning time of 120 minutes, and cooling time of 50 minutes. Subsequently, the appropriate factors and levels were used to collect data for comparison before and after adjustment. It was found that before adjustment, there were 359 instances of tube damage, whereas after adjustment, the instances reduced to 7, resulting in a reduction of waste by 98.05%. When comparing the expenses incurred, it was found that before adjustment, the cost of the 359 damaged tubes amounted to 502,600 baht, with a unit cost of 1,400 baht per tube. After adjustment, with only 7 damaged tubes, the cost amounted to 9,800 baht, resulting in a reduction in expenses by 492,800 baht.

Effect of Plastic Filament Type on Mechanical Properties of 3D-printed Parts

2025-08-20T14:55:33+07:00

The manufacturing process has been continuously improved in the industry. The 3D-printer has become one of the most widely used new techniques for manufacturing. This study aims to investigate how the mechanical characteristics of the test samples are affected by the 3D-printing parameters. Types of plastic (ABS, PLA, PETG), printing speed, infill density, shell thickness, and layer height are all printing parameters. In the test findings, the mechanical characteristics of samples made using 3D-printers are compared. It was found that the printing parameters, which are plastic type, shell thickness, layer height, printing speed, and Infill density, respectively had a significant effect on the mechanical properties. The mechanical strength increases when the printing parameters are increased. Furthermore, the findings indicate that the shell thickness 3 layers, printing speed 30 mm/s, Infill density 20%, and layer height 0.3 mm are the printing parameters that provide the best mechanical qualities for all kinds of plastics. PLA is the plastic that exhibits the best mechanical qualities in this study which the compressive, tensile, and bending strengths are 25.29, 20.84, and 63.44 MPa, respectively.

Development of the PLC Practical Set with the Arduino Embedded System for Electro-pneumatic Device Control

2025-08-21T09:19:57+07:00

This experimental research has the objective of developing and evaluating the effectiveness of the PLC practical set with the Arduino embedded system for electro-pneumatic device control. The steps for carrying out the research are as follows: (1) Creation of the tools used in the study, which is an Arduino embedded system practical set using a ladder for electro-pneumatic device control. (2) The sampling groups used in the research were students in the Higher Vocational Certificate program in Machine Tool Technology, Faculty of Technical Education, Rajamangala University of Technology Isan, Khon Kaen Campus, 2nd year, 30 students, using the Purposive Sampling method. (3) Data collection to determine the effectiveness of the practical set. Start by teaching the use of the practical set so that the learners can understand and learn to use the practical set according to each practice test topic and then test with the practice test again. Then, the scores obtained from the in-class practice test and the post-test practice were used to calculate the effectiveness of the practice practical set. The results of the research found that an Arduino-embedded system practical set using a ladder for electro-pneumatic device control was effective, accounting for 93 percent.

Enhancing Productivity and Reducing Handling Cost through Standard Time and Motion Study: A Case Study of a Warehouse Service Business

2025-08-21T13:14:56+07:00

This research aims to enhance productivity and reduce handling costs in a warehouse storing alcoholic beverages such as beer and spirits. The research applies Work Study concepts, including Standard Time Analysis and Motion Study, across seven subprocesses: unloading, inbound checking, put-away, picking, stamping, outbound checking, and loading. It also integrates ECRS principles (Eliminate, Combine, Rearrange, Simplify) and the concept of the seven types of waste to eliminate inefficiencies and improve labor productivity. The findings indicate that put-away and stamping were identified as bottleneck activities with noticeably higher time consumption than other tasks. After implementing improvements, the number of forklifts was reduced by four, and 17 personnel positions were eliminated, resulting in annual cost savings of over 4.97 million baht—without compromising the warehouse’s service capacity. These results demonstrate that effective standard time setting and resource allocation can significantly improve warehouse operations. The proposed approach is practical for warehouses facing budget constraints and seeking cost-effective, immediately applicable solutions without relying on high-cost automation systems or advanced technologies.

Fatigue Performance of Full-scale Crumb Rubber Concrete Slabs

2025-08-22T13:41:31+07:00

Cracking of concrete bridge decks is a significant issue that leads to premature maintenance and repair of bridges. The primary cause of this problem is the repeated loading applied to the bridge decks, which induces fatigue and eventually results in cracking and damage. The use of finely ground recycled rubber particles from waste tires as a concrete additive has been proven to be an effective method for reducing cracking. This research aims to address the problem of fatigue-induced cracking in concrete bridge decks. The experimental variables were designed to closely simulate real-life applications. The study compares the crack reduction performance of concrete bridge decks with dimensions of 2.00 x 8.00 x 0.20 meters, constructed using both conventional concrete and concrete incorporating finely ground recycled rubber particles, replacing 25% of the sand volume. A total of 8 specimens were tested under two-way slab loading conditions. The first specimens of each concrete type were subjected to static loading tests to determine the maximum load-bearing capacity (specimens 1 and 2). Subsequently, fatigue tests were conducted on specimens 3 through 8 by applying loads at 40% 55% and 70% of the maximum load capacity to evaluate the fatigue resistance provided by the rubberized concrete in reducing cracking. The fatigue performance was assessed by measuring the area of cracking equivalent to 40% of the total slab surface, comparing the number of load cycles and the load ratio relative to the ultimate load capacity of the slabs. The test results indicated that, in the range where the load ratio to the ultimate load capacity was less than 0.5, the CRC slabs exhibited 93.08% higher fatigue resistance compared to the NC slabs. In the range where the load ratio exceeded 0.5, the fatigue performance of CRC slabs was comparable to that of NC slabs.

กองบรรณาธิการ (Editorial Board) / วัตถุประสงค์ (Objectives) / บทบรรณาธิการ (Editorial Note) / สารบัญ (Table of Contents)

2025-08-26T11:06:46+07:00