148 INSPECTION OF CANS 



rapidly. In large factories an automatic stamping- outfit is at- 

 tached to the filling, sealing or labeling machine and the cans 

 are stamped automatically while they are being filled, sealed, 

 or labeled. 



INSPECTING 



The sealed and stamped cans are placed, with caps down, in 

 wooden trays holding twenty-four medium-sized cans. All trays 

 of one batch are stacked together. A card indicating number 

 and date of batch and number of cans in the batch is attached 

 to the stack and a copy of the same is filed in the office. The cans 

 are placed with their caps down in order to detect " leakers" 

 (cans with defective seals). Before labeling, the trays should 

 be taken down, the cans turned over and examined for leaky 

 seals. Unless the factory is behind in filling orders the cans will 

 have been in stock at least twenty-four hours or usually longer. 

 In the case of sweeetened condensed milk, if any seals are de- 

 fective, a little condensed milk will have oozed out by that time. 

 Inexperienced sealers are prone to cause a high percentage of 

 leaky cans. A careful sealer may reduce the number of leakers 

 to .1 per cent. 



Checking the Work of the Sealers. In order to regulate and 

 improve the Avork of the sealers and to locate those doing poor 

 work, it is advisable to number the sealers and supply each with 

 small tin tag's bearing his or her respective number. Each sealer 

 drops one tag into each tray of cans sealed by him. The inspectors 

 record the number of leakers found in each tray. Thus each 

 sealer is charged up with the leakers he made. 



Disposition of Leaky Cans. Small leaks, in the case of 

 sweetened condensed milk, can usually be soldered over success- 

 fully and the mended cans are returned to their respective 

 batches. In the case of very defective seals, attempts at mending 

 generally cause the milk in the can to burn, forming a brown 

 crust on the cap, which spoils the can for the market. The con- 

 tents have a burnt taste and smell, and upon stirring, brown and 

 black specks of burnt milk appear. It is best to cut bad leakers 

 open and pour the contents into the succeeding batch of milk. 



