a machine used for the hermetic sealing of tin cans and glass jars. On tin cans the lid is rolled onto a flange on the body by a double-beaded seam, and on glass jars a tin top with a rubber collar hermetically seals the neck of the jar. A distinction is made between vacuum and non-vacuum, single-spindle and multispindle, and automatic and semiautomatic beading machines. Depending on the sealing method, beading machines for glass jars may be of the rolling, clamping, or pressing type.
The main element of a beading machine is the beading mechanism, which turns the beading rollers around the jar (stationary jars), moves them radially in the direction of the jar, and then returns them to their initial position. Modern automatic beading machines for tin cans have capacities of 300–500 cans per minute and higher for cans 39–123 mm in height and 50–100 mm in diameter; automatic beading machines for glass jars have rates of 80–200 jars per minute and higher, depending on the sealing method. Vacuum beading machines using vacuum pumps or devices for creating a thermal vacuum make possible the creation of a controlled rarefaction in the beading-mechanism chamber of 4.7–6.6 kilonewtons per sq m (kN/m2), or 350–500 mm of mercury (mm Hg), for tin cans and 2.4–3.3 kN/m2 , or 180–250 mm Hg, for glass jars.
D. S. GLUZ