@article{oai:u-ryukyu.repo.nii.ac.jp:02007187, author = {平敷, 兼貴 and 糸村, 昌祐 and Heshiki, Kenki and Itomura, Shosuke}, issue = {6}, journal = {琉球大学理工学部紀要. 工学篇, Bulletin of Science & Engineering Division, University of the Ryukyus. Engineering}, month = {Mar}, note = {This paper is a report of study on the casting defects occurable to cement-bonded and molasses-added mold, concerning to the permeability of mold and the pressure of gas from core in pouring process of cast iron and aluminum alloy. Results are obtained as follows:1) Permeability of the testing sand after 24 hours' drying at room temperature shows 210-290. This figure means that the cement-bonded molds have good permeability. 2) The pressure of gas from core changes under influence of water and molasses. Higher gas pressure caused by higher water content tends to produce more gas-originated defects. 3) Improper decrease of water content tends to cause other type of casting defects, such as rough surface, sand hole, sand inclusion. So, a proper mixing ratio of additions should be selected to produce sound castings; for example, weight ratio of sand 100, cement 10, water 5 ~6, and molasses 3~4, for our experimental conditions, can be recommended., 紀要論文}, pages = {1--5}, title = {糖蜜を添加したセメント鋳型による鋳造欠陥について}, year = {1973} }