Moulding Tools | Components Required for Moulding

Casting
Casting is a manufacturing process by which a liquid material is usually poured into a mold, which contains a hollow cavity of the desired shape, and then allowed to solidify. The solidified part is also known as a casting, which is ejected or broken out of the mold to complete the process. Casting materials are usually metals or various cold setting materials that cure after mixing two or more components together; examples are epoxy, concrete, plaster and clay. Casting is most often used for making complex shapes that would be otherwise difficult or uneconomical to make by other methods.

Types of Moulding Sand | Properties of Moulding Sand

Components Required for Moulding:
1. Moulding Sand (Green Sand)
2. Moulding Boxes
3. Pattern
4. Moulding Tools

1. Moulding Sand:
Green sand is an aggregate of sand, bentonite clay, pulverized coal and water. Its principal use is in making molds for metal casting. The largest portion of the aggregate is always sand, which can be either silica or olivine.
Green sand (and other casting sands) is usually housed in what casters refer to as flasks which are nothing other than boxes without a bottom or lid. The box is split into two halves which are stacked together in use. The halves are referred to as the top (cope) and bottom (drag) flask respectively. Green sand is not green in color, but “green” in the sense that it is used in a wet state (akin to green wood).

2. Moulding Box:
It is also called moulding flask. It is frame or box of wood or metal. Wood is cheaper and boxes can be made quickly. Wood wears out quickly. It is destroyed by contact with hot metal. A metal box is steel, cast iron and aluminum alloys are used in mass production. Moulding boxes are used for making sand moulds.

3. Pattern:
In casting, a pattern is a replica of the object to be cast, used to prepare the cavity into which molten material will be poured during the casting process. Patterns used in sand casting may be made of wood, metal, plastics or other materials The making of patterns, called pattern making (sometimes styled pattern-making or pattern making), is a skilled trade that is related to the trades of tool and die making and mold making, but also often incorporates elements of fine woodworking.

4. Moulding Tools:

a) Shovel:
It is one of the foundry tools which have a broad metal blade with a long wooden handle. It is used to carry moulding sand from the sand pit to the moulding box and is also used for mixing and tempering (adding sufficient water) the sand.

b) Riddle:
It is a metal sieve used for removing foreign materials such as stones, nails etc., from the moulding sand.

c) Rammer:
It is used for packing or ramming the moulding sand in the moulding box.

d) Trowels:
It is used for smoothening the surfaces of mould and also to repair the damaged portion of mould.

e) Slick:
It is used for repairing and finishing surfaces and to round corners of the mould.

f) Lifter:
It is used to remove the loose sand from the mould. It is also used to finish the bottom and sides of the mould.

g) Strike off bar:
It is used to remove excessive sand from the mould after tempering.

h) Sprue pin:
It is used to make sprue hole to pour the molten metal in the mould.

i) Vent rod:
It is used for making vent holes in the sand mould so that the molten gases released during casting process, can easily escape from mould.

j) Bellows:
It is used to blow off loose sand particles from the mould and pattern.

k) Gate cutter:
It is used for cutting gates and runners in the mould.