EVAPORATED MILK SEALING 



135 



oblong trough, filled with hot water and through which the cans 

 pass on an endless chain. In the case of leaky cans, the -heat of 

 the hot water bath expands the air in the cans and causes it to 

 escape through the leak in the seal and percolate upward in the 

 water in the form of air bubbles. The operator standing over 

 the test trough picks the cans which expel air bubbles out so 

 that the defective seals can be mended. 



Most condenseries manufacturing evaporated milk are now 

 using a hot water 

 bath for testing the 

 sealed cans. But ex- 

 perience has shown 

 that the hot water 

 baths built on the 

 continuous chain 

 principle often fail 

 to give the desired 

 efficiency. This is not 

 the fault of the ma- 

 chine, but it is due 

 to the fact that it 

 becomes very tiresome for the inspector to watch the moving 

 line, of cans in the water bath and he soon becomes careless and 

 his work inefficient. It has been found that baths constructed 

 and operated on the principle of submerging a whole tray full 

 of cans, (usually 24 cans) at a time, give more satisfactory re- 

 sults, relieving the monotony and preserving more successfully 

 the keenness of observation of the inspector. 



The venthole filler is simple in construction, economical in 

 operation and easily cleaned and kept in sanitary condition. The 

 milk, from the time it comes within the range of the filler, is no 

 longer exposed to contaminating influences, such as the hands 

 of employes, insects, etc. The cans are uniformly filled to within 

 one gram of the guaranteed weight and the vents or pin holes 

 are automatically sealed with the minimum amount of solder. 

 While the quantity of solder must necessarily vary with oper- 

 ating conditions, it is possible to limit the average amount of 

 solder, under proper conditions, to 5 ounces per 1000 cans. The 



Fig*. 57. Chapman automatic can tester 

 Courtesy of Schaefer Mfg. Co. 



