CONDENSED MILK SEALING 



113 



the can. This seal is very simple, but is not very strong and 

 not hermetically tight. In the case of the Gebee seal, a rim pro- 

 jects around, the opening of the can. After the cap is inserted, 

 it is crimped over this rim by means of a series of revolving dies. 

 This seal is reasonably strong but not hermetically tight. The 

 Sanitary can is entirely open at one end when filled. The cover 

 or end is crimped around the periphery of the body of the can 

 by means of revolving dies. This seal is reasonably strong 

 and usually hermetically tight. The chief advantages of the 

 seals without solder lie in the saving of labor and the reduction 

 of the cost due. to the omission of solder. 



Soldering Devices and Machinery. 

 The sealing of all solderless seals is 

 done by specially constructed sealing 

 machines. 



Fig*. 44. Soldering- stove 

 Courtesy of Arthur Harris & Co. 



For seals with solder there are sev- 

 eral machines on the market but much 

 of this work is as yet done by hand. 

 For this, different types of soldering 

 coppers are in use and the copper tips 

 are heated in soldering stoves or pots. 

 Some soldering coppers have hollow 

 circular tips with a diameter equal to 

 that of the cap used. The hollow tip 

 is telescoped by a rod which holds the, 

 cap in place and the periphery of the tip fits into the groove 

 of the opening of the can, where it melts the solder. A rapid, 

 neat and leakless seal can be made with this instrument. 



Ordinary soldering coppers with a blunt point, such as are in 



Pig-. 45. A convenient de- 

 vice for soldering by hand 



