空心面 meaning in English

vermicelli

The results show that the heat preservation coating and its proper thickness are favorable to the enhancement of filling mold speed of aluminium alloy ; the higher the pouring temperature is and the larger the ratio of hollow areas of vertical pouring is , the faster the speed of filling mold of aluminium alloy is ; if the mold is too thick or too thin , it may decrease the speed of filling mold ; the proper length and the area of vertical pouring are favorable to the enhancement of the speed of filling mold ; although negatire - pressure may improve filling the speed , too high negatire - pressure may enlarge the flaw in casting
结果表明：保温涂料及一定的涂层厚度有利于提高铝液的充型速度；浇注温度越高、直浇道空心面积率越大，铝液充型速度越快；模样厚度太厚或太薄，均会使铝液充型速度降低；一定的直浇道长度及直浇道面积有利于提高铝液的充型速度；施加负压会使铝液的充型速度大大提高，但负压过大会增大铸造缺陷。