Coopers Ware

vessels such as barrels, containers, tanks, and vats intended for storage and transportation of liquid, semiliquid, and free-flowing dry products. There are stationary and transport types of coopers’ ware. Among the stationary types are containers for storage and aging of wine ingredients and wines and tanks for fermentation and sedimentation of must in winemaking and wort in brewing, with a volume of 250 to 2,000 decaliters. Barrels are a form of technological packaging that participate directly in the process of wine maturation (for example, in the production of cognac); they are manufactured from oak. Woods of coniferous trees or oak are used for vats. All types of barrels, tubs, and so on are included in the transport types of coopers’ ware.

Coopers’ ware may be classified as wooden, plywood, wood-fiber, wood-chip, and polymer. Most common are wooden barrels, including extra-dense, unenameled barrels for storage and transport of wine, juices, sweet drinks, kvass, and so on, with volumes from 50 to 600 liters; extra-dense enameled barrels that can withstand increased internal pressures, used for beer, with volumes of 50 to 150 liters; dense, wet-pack barrels for foodstuffs in marinades and brines (pickled fish, vegetables, fruits, berries, and so on), with volumes of 15 to 250 liters; and dry-pack barrels for frozen fish, solid fats, dry free-flowing products, and other types of products that contain no liquids, with volumes of 50 to 250 liters. Tubs, buckets, and other containers are used for transport and storage of produce and dairy products (cabbage, curds, sour cream, and other products).

Wooden coopers’ ware consists of an oval or conical body and one or two circular or oval bottoms inserted in special grooves placed around the interior circumference of the body of the barrel at a distance of 20–140 mm from its ends. Stock in the form of stave boards is mechanically processed (trimming of ends to desired length, contour planning of the seam, and contour jointing of edges) on general-purpose wood-shaping lathes with adapters (for barrels and tanks) and on coopers’ lathes. The processed staves of the barrel body are mounted on assembly forms. To give the wood flexibility, the barrel body is subjected to hydrothermal processing in a boiling bath or in a steamroom dome. The barrel shape is obtained by drawing together the free ends of the staves on a coupling machine (drum). In order to insert the bottoms, the end portions of the body are processed on a grooving lathe (shaping of edges, skinning places for grooves, and clearing the grooves for insertion of bottoms). The bottoms are cut by machine from panels previously assembled from separate staves. The bodies and bottoms are joined on a coupling drum, and then the permanent hoops are put on and set by a hoop-setting press. The barrels are enameled (if necessary), and openings are bored. Tubs, buckets, and tanks are assembled from contoured staves without hydrothermal processing.

Plywood (pressed plywood) barrels are used to replace dry-pack barrels, mainly for transport and storage of evaporated milk, solid fats, and powdered eggs. These barrels, with volumes of 50 liters, are produced from birch, alder, aspen, linden, and pine woods. The barrel is assembled from three pieces—a body and two bottoms, each piece consisting of three to five veneer laminations.

For wet-pack barrels with volumes of 50 liters, wood-fiber and wood-chip materials are used; for 15- to 50-liter barrels, polymer materials are used. Wood, straw, cane, rush, reed mace, flax refuse, and the like serve as raw material for barrels of wood-fiber materials. The barrels usually consist of four pressed body staves and two unit-pressed bottoms. Barrels of wood chips are manufactured by mixing chips with cementing tars and then forming the stock components by cold or hot pressing in the press forms of hydraulic presses. Barrels of polymer materials are obtained by inflation of a cylindrical sleeve (stock) issuing from an extruder. The removable covers are pressed. Most promising is production of coopers’ ware from plywood, wood-fiber, wood-chip, and polymer materials. Such production is accomplished with minimal expenditure of materials and a high level of mechanization.