The drawing manufacturing process is a complex method of shaping parts by pulling or stretching the material through a die. The process starts with a cylindrical billet, which is reduced in size and then shaped into the desired product.
How Does the Drawing Process Work?
All drawing processes work on the same principle. Its working can be summarised as follow:
1. Heating
The first step in the drawing process is to heat the metal to a high temperature. This temperature range is the "drawing temperature" and is critical for achieving the necessary plastic deformation.
2. Loading into the Drawbench
Next, the heated metal is loaded into a drawbench, which consists of a series of dies and a pulling mechanism. The metal is positioned so that one end is in contact with the first die and the other is attached to the pulling mechanism.
3. Cleaning through an Acid Agent
Next, the heated metal is cleaned through an acid agent called acid pickling. This process ensures the metal is free from dust, collusion and other impurities.
4. Prepared with Lubricant Solutions
The metal is then coated with a lubricant solution, typically sulling, phosphating, and liming. Sulling involves coating with ferrous hydroxide. Likewise, Phosphate collating is applied to the metal under phosphating. Oil and grease are used for wire drawing, and soap for dry drawing.
5. Drawing Through the Dies
The pulling mechanism is activated, applying a tensile force to the metal. As the metal is pulled through the first die, it is reduced in cross-sectional area and elongated. The metal is then drawn through subsequent dies, each of which has a smaller diameter than the previous die. The number of dies and their specific dimensions will depend on the final product.
6. Cooling
After being drawn through the final die, the metal is rapidly cooled by air, water, or oil, depending on the material and desired final product. The cooling step stabilises the product's dimensions and prevents
Advantages of Drawing Manufacturing Process
The drawing Manufacturing Process can have several advantages. Here are a few of them:
1. Precision
Drawing provides high precision and accurate shapes. Products made through drawing have tight tolerances and uniform dimensions essential for industry use. The process can also produce parts with complex shapes, such as those with multi-lobes.
2. Cost-effective
Drawing is more cost-effective than other manufacturing processes for small to medium-sized parts. The overall deep drawing process can be automated, making it easy to produce quantities in the thousands and even millions. Thus, the cost per part is meagre.
3. Increased Productivity
The drawing process can be automated, increasing productivity and reducing production time. Automated drawing presses can produce parts much faster than manual processes.
4. Improved Surface Finish
The process can produce smooth, polished surfaces ideal for parts requiring a high level of finish or surface quality.
5. Improved Strength
The drawing process can increase the material's strength and hardness, making it more durable and corrosion-free. This is because drawing involves stretching the material, which aligns the molecules and causes them to harden, resulting in a stronger material.