Answer:

Introduction:
The process of improving the cutting action of the grinding wheel is called dressing. Dressing is a necessary process in grinding operations to restore the required cutting properties of the grinding wheel. It involves removing the dull or worn-out abrasive grains from the surface of the wheel to expose fresh and sharp cutting edges. This helps in maintaining the accuracy of the grinding operation and achieving the desired surface finish.

Explanation:
Dressing is an essential process in grinding operations because over time, the abrasive grains on the surface of the grinding wheel become dull and lose their cutting efficiency. This can result in poor grinding performance, increased heat generation, and reduced productivity. Dressing the grinding wheel helps to restore its original shape and sharpness, ensuring optimal cutting action.

Truing vs Dressing:
- Truing: Truing is the process of restoring the shape of the grinding wheel. It involves removing the high spots on the wheel surface to make it run true and reduce vibration during grinding. Truing is typically done with a diamond tool.
- Dressing: Dressing, on the other hand, is focused on improving the cutting action of the wheel. It involves removing the dull abrasive grains and exposing fresh cutting edges. Dressing can be done using various methods, including using a single-point diamond tool, a dressing stick, or a rotating diamond wheel.

Importance of Dressing:
- Restores sharpness: Dressing removes the worn-out abrasive grains from the grinding wheel, exposing fresh and sharp cutting edges. This improves the wheel's cutting efficiency and ensures a consistent and accurate grinding operation.
- Improves surface finish: A properly dressed grinding wheel produces a smoother surface finish on the workpiece. This is important for applications where surface roughness and dimensional accuracy are critical.
- Reduces heat generation: Dull abrasive grains tend to generate more heat during grinding, which can lead to thermal damage to the workpiece and the grinding wheel itself. Dressing helps to maintain cooler cutting temperatures, reducing the risk of thermal damage.
- Extends wheel life: By removing the dull grains, dressing increases the lifespan of the grinding wheel. This results in lower overall abrasive costs and reduced downtime for wheel replacement.

Conclusion:
In conclusion, dressing is a crucial process in grinding operations to improve the cutting action of the grinding wheel. By removing dull abrasive grains and exposing fresh cutting edges, dressing helps to maintain accuracy, achieve the desired surface finish, reduce heat generation, and extend the life of the grinding wheel.