Moulding Machines: Moulding processes may be classified as hand moulding or machine moulding according to whether the mould is prepared by hand tools or with the aid of some moulding machine. Hand moulding is generally found to be economical when the castings are required in a small number. Advantages: · When the number of castings is substantial, the additional cost
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Furnaces in casting: Melting furnaces used in the foundry industry are of many diverse configuration The selection of the melting unit is one of the most important decisions foundries must make with due consideration to several important factors including: · The temperature required to melt the alloy · The melting rate and quantity of molten metal required · The economy
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Pattern: Pattern is the solid form that is used to make the mould. Even though a pattern generally resembles the casting being produced, it differs from the casting in terms of certain allowances that are required for producing the correct shape and dimensions and in eliminating some minor details which are too complicated or small to be produced by casting
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Pattern: Pattern is the solid form that is used to make the mould. Even though a pattern generally resembles the casting being produced, it differs from the casting in terms of certain allowances that are required for producing the correct shape and dimensions and in eliminating some minor details which are too complicated or small to be produced by casting
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Methods of Sand testing: The moulding sand after it is prepared should be properly tested to see that require properties are achieved. Tests conducted on a sample of the standard sand. The moulding sand should be prepared exactly as it is done in the shop on the standard equipment and then carefully enclosed in a container to safeguard its moisture
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Types of Moulding Sands: According to their use in the foundry, moulding sands are classified into following categories: 1. Foundry Green sand: It is a sand used in wet condition for making the mould. It is a mixture of silica sand with 15-25 per cent clay and 6-8 per cent water As explained earlier, green sand moulds are not dried, when
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Properties of moulding sands: The important properties are: 1. Strength: · The sand should have adequate strength in its green, dry and hot states · Green strength is the strength of sand in the wet state and is required for making possible to prepare and handle the mould. · If the metal is poured into a green mould the sand
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Moulding Sands: Most sand casting operations use Silica sand (SiO2). Usually sand used to manufacture a mould for the casting process is held together by a mixture of water and clay. A typical mixture by volume could be 89% sand, 4% water, 7% clay. Control of all aspects of the properties of sand is crucial when manufacturing parts by sand
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1. Rawhide mallet: It is a mallet to loosen the pattern in the mould by striking slightly, so that it can be withdrawn without damaging the mould. 2. Gate cutter: It is a metal piece to the gate the opening that connects tee sprue with the mould cavity. 3. Rapping plate (or) Lifting plate: It is used to facilitate shaking
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Moulding Tools: 1. Shovel: It is just like rectangular pan fitted with a handle. It is used for mixing the moulding sand and for moving it from one place to the other. 2. Riddle: It is used for removing foreign materials like nails, shot metal splinters of wood etc from the moulding sand. 3. Rammer: It is a wooden tool
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