Metal materials for catering equipment.
Introductory news. Construction materials are divided into metal, to which they belong: iron and iron alloys, non-ferrous metals, and non-metallic, to which they belong: ceramic materials, plastics, wood, papier, skin, glass and auxiliary materials (varnishes, adhesives etc.).
Metals have good electrical and thermal conductivity. They also show great plasticity. Moreover, metals are opaque and reflect light (metallic shine). Pure metals are rarely used in the manufacture of utility items. Usually they are mixed and melted together in different proportions, creating alloys with different properties.
Cast iron. In the blast furnace process, as a result of fusing iron ore with appropriate fluxes and coke, a product called pig iron is obtained. Pig iron is not used as a construction material. The salad is melted with additives and cleaned in furnaces called cupolas. As a result of this process, cast iron is obtained. Cast iron has good casting properties and is used to make many machine parts. The carbon in cast iron may be in the form of graphite or cementite. Cast iron, in which the carbon has separated as graphite, is called gray cast iron, and cast iron, in which the carbon was released in the form of cementite - white cast iron. Gray cast iron is characterized by high strength, abrasion resistance and good machinability. White cast iron is not suitable for structural parts, because it's tough, brittle and unworkable. Malleable cast iron is obtained by long-term annealing of white cast iron.
For the construction of boilers, furnace parts, elements of water and sewage systems, stove and kitchen fittings, cast iron cookware and cast iron cookware are cast or wrought iron. Hot plates are also made of cast iron, pans and grills. The advantages of this cast iron are: even heat conduction, high load resistance, non-toxicity. The disadvantages are the tendency to rust, the occurrence of discoloration in contact with food, as well as dark color and high density. Maintenance consists of washing with diluted detergents and lubrication, during longer storage, a thin layer of oil.
For encasing gas and electric stove tops, as well as refrigerators and freezers, and for the manufacture of food containers, patelni, enameled cast iron is used for roasting pans and pots. The advantage of this cast iron is resistance to acids, the disadvantage is the chipping and cracking of the enamel due to heating.
Drawing. Enameled dishes: a) cooking pot in a water bath, b) frying pan with grained bottom, c) roasting pan with self-humidifying lid.
For making pots and other utensils and small kitchen utensils (spoons, rosy, cochle, mixers) tinned cast iron is used. The advantages of this cast iron are: low price, good endurance, non-toxicity, bright color and good thermal conductivity. Disadvantages - the need for re-tinning in the event of damage to the coating and high density.
Drawing. Tinned whisks and stirrers used for dough beaters: a) right, b) flat agitator, c) dense rod, d) a sparse rod.
Preserving consists of washing with detergents, rinsing and drying thoroughly. Harsh powders should not be used for scrubbing tinplate dishes.
Zinc-plated cast iron is used for covering walls and for making sinks. It's cheap, it is characterized by high durability, however, it has serious drawbacks: it is toxic, the zinc coating wears off quickly, it is not resistant to the effects of even weak acids and bases, It rusts easily. Galvanized surfaces should be washed with soap and water and lubricated with a thin layer of oil.