100 



SwKlvTl'.NED CoNDIiNSKD MlLK SEALING 



can. Tliis seal is very simple, but is not \-er3' strc)ng- and not 

 hermetically ti,i;ht. In the case of the Gebec seal, a rim projects 

 around the openin<j 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 str(ing but not hermetically tight. The Sanitarj^ 

 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. The principal reason for which some of them are not 

 used more generally by milk condensing companies, lies in the 

 fact that these solderless seals are all patented. In most cases 

 the in\entors or patent holders are condensed milk manu- 

 facturers. They refuse to sell their pa- 

 tents at a reasonable price to other 

 condenseries and they charge exor- 

 bitant royalties for the use of their 

 patents by their com])etitors. AA'ith the 

 possible exception of the "Sanitary 

 can," solderless seals are not as re- 

 liable as solder seals. 



'■.- .. ....i. ....,:•--;.■-' . / 



Fig. 36, Soldering stove 



Courtesy of Arthur Harris & Co. 



Soldering Devices and Machinery. 



The sealing of all solderless seals is 

 done by specially constructed sealing 

 machines. 



For seals with solder there are se\'- 

 eral machines on the market but much 



Fig. 35. A convenient de- 

 vice for soldering by hand 



