The following points highlight the six main tests done to determine the essential qualities of sand. The tests are: 1. Grain Fineness Test 2. Permeability Test 3. Sand Mould Strength Test 4. Moisture Content Test 5. Clay Content Test 6. Hardness Test. 1. Grain Fineness Test: Granular particles of various sizes and shapes provide variable interstices (space between grains) and [...]
Small or medium-sized castings are made in flask— a box shaped container without top and bottom, which confines the sand moulds (Refer Fig. 3.28). It is made in two parts, held in alignment by dowel pins. The top part is called the cope and the lower part is called the drag. If the flask is made in three parts, the [...]
The following points highlight the three main types of sand moulding machines used in industries. The types are: 1. Jolt Machine 2. Squeezing Machine 3. Sand Slinging Machine. Type # 1. Jolt Machine: This machine is equipped with adjustable flask lifting pins to permit the use of flasks of various sizes within the capacity of the machine. The flask is [...]
In this article we will discuss about:- 1. Meaning of Shell Moulding 2. Patterns and Materials for Making Shell Mould 3. Process 4. Merits 5. Demerits. Meaning of Shell Moulding: Shell moulding is a recent invention in casting techniques for mass production and smooth finish. It was originated in Germany during Second World War. For some time, it was called [...]
In this article we will discuss about:- 1. Meaning of Core Moulding 2. Material Used for Cores 3. Reinforcement 4. Types 5. Making 6. Baking 7. Dressing 8. Core Chaplet 9. Method of Supporting Cores 10. Characteristics 11. Uses. Meaning of Core Moulding: A core is a pre-determined shaped mass of dry sand, which is made separately from mould. It [...]
In this article we will discuss about:- 1. Meaning of Machine Moulding 2. Operations for Machine Moulding 3. Advantages 4. Limitations. Meaning of Machine Moulding: Moulding by hand is a slow and laborious process and also does not yield good results as it does not impart uniform hardness to the rammed mould. In machine moulding, the production become faster, labour [...]