MATTER: International Journal of Science and Technology

LOSS ANALYSIS IN BREAD PRODUCTION PROCESS USING MATERIAL FLOW COST ACCOUNTING TECHNIQUE

Bunyaporn Yoddee, Rungchat Chompu-inwai — Wed, 15 Nov 2023 00:00:00 +0000

The case study factory manufactures a range of bread and bakery products for distribution in the North of Thailand. Losses from the production process were recently discovered, which besides being lost costs, also impacted the environment. This research is conducted under the concept of Material Flow Cost Accounting (MFCA) to analyze the losses from each process of the case study bread factory. This is to pinpoint where most of the losses occur and suggest methods for future improvement. This research is conducted with the principle of Plan Do Check Action (PDCA). The “Plan” was to determine a target product, which in this case was raisin bread, as it accounted for the largest proportion of production. Subsequently, a study was conducted of the production process, and a scope under the “Do” stage of the procedure was determined. Input and output factors were identified for each Quantity Center (QC) in both physical units and financial units. Subsequently at the “Check” stage, an analysis of costs was conducted for each QC with the MFCA technique. This was divided into positive product, meaning costs generating revenue, and which were manifest in the product, and negative product, which were costs not generating revenue and were losses from each production stage. Finally, at the “Action” stage, negative products were ranked using Pareto diagram to identify and evaluate opportunities for improvement. The research found that the total costs to produce one production lot of raisin bread were 2,935.55 THB, which were divided into materials costs of 2,270.79 THB (77.35%), system costs of 500.30 THB (17.04%) and energy costs of 164.46 THB (5.60%). Overall, negative product was 25.19%, of which negative product in material costs was 19.41%. This negative product was wastage and losses from dough and fillings being deposited in the machinery, and the failure of packaging films when they were being installed in the packing machine. It was also found that negative materials costs arose maximum in the QC of packing. The conclusions from this research are that it has informed about losses arising in the production process and evaluated them in the form of costs, which should help in proposing methods to reduce this wastage in the future.

MECHANICAL ACTIVATION OF LIZARDITE BY DRY GRINDING FOR ENHANCED MINERAL CARBONATION

Hakan Çiftçi — Wed, 15 Nov 2023 00:00:00 +0000

Mechanical activation of Ca/Mg silicates by grinding is a pre-treatment of some mineral carbonization processes. In this study, the mechanical activation of lizardite ore from a chromite beneficiation plant waste by grinding in a stirred media mill was studied. For grinding studies, grinding times of 10-20-30 min and stirring speeds of 600-800-1000-1200 rpm were the parameters investigated, while the ball charge rate was 60% and the ore charge rate was kept constant at 40%. This way, the effects of grinding time and stirring speed on particle size distribution and energy consumption were investigated. At the end of the grinding studies, the stirring speed was determined as 1200 rpm, and the grinding time was 10 min for the finer particle size distribution (d₁₀: 2,7 µm, d₅₀: 13,6 µm, d₉₀: 57.6 µm) with less energy consumption (130.4 kWh/ton). FT-IR analyses proved that the samples were dehydroxylated by the milling process. As a result, according to the analysis performed after grinding, it can be said that the finer product obtained can be used in mineral carbonation processes.

EFFECT OF CRYOGENIC AND NATURAL AGING PROCESS APPLIED TO Al-Zn-Mg-Cu ALLOYS ON LIFE TIME CALCULATION

Gözde Altuntaş, Onur Altuntaş, Bülent Bostan — Wed, 15 Nov 2023 00:00:00 +0000

In this study, life time calculation of aluminum 7075 alloy with cryogenic and natural aging processes was performed by thermal analysis. The aluminum alloy was quenched after solid solution treatment at 480°C and naturally aged for 10-100 days at room temperature (25°C). Other samples were cryogenically treated at -40°C and -80°C for 2 hours after solid solution treatment at 480°C. After the cryogenic treatment, natural aging was done at room temperature for 10-100 days. At the end of each period determined for the samples, the hardness values were measured. It was observed that there was no significant change in hardness values at the end of 10 and 100 days at -80 °C. Thus, it was determined that the natural aging process does not start after cryogenic treatment at -80 °C. It was observed that the hardness value of naturally aged samples after cryogenic treatment at -40 °C increased more than the natural aged samples only. This showed that -40 °C improved the mechanism by creating a driving force in the material. Life time calculations between 30 °C and 320 °C also showed that -40 °C cryogenic treatment + natural aging increased life time by approximately 20% compared to natural aging alone.