CNC machining is an umbrella term that covers several manufacturing processes, including bead blasting. It’s a mechanical procedure used to refine surfaces for better finish or prepare them for coating or painting. Before diving into the intricate details of how bead blasting contributes to the production process within CNC machining, let’s quickly define what these terms mean.
CNC stands for Computer Numerical Control, and it refers to a method in modern machining where pre-programmed computer software dictates the movement of factory machinery and tools. This process enables the control of multiple axes simultaneously, resulting in precise and high-quality outputs.
On the other hand, bead blasting is considered as a surface preparation technique, which involves forcibly propelling a stream of abrasive material against a surface under high pressure using specialized equipment. The primary purpose of bead blasting is to smooth, clean, or shape the targeted areas.
Production Process Involved in Bead Blasting
To carry out bead blasting, components are placed in a chamber where small glass beads are directed towards the surface at varying speeds depending on the application. For removing rust and paint, high-speed bead blasting is employed whereas lower speed bead blasting suffices when cleaning delicate parts without causing any damage. Usually, aluminum oxide, glass beads, plastic particles, walnut shells, etc., act as abrasives in blasting media.
After blasting, the remaining bead blasting media gets filtered, segregating reusable beads from waste debris, while air dust collectors eliminate airborne particles, making the whole process environmentally friendly.
Role of Bead Blasting in CNC Machining
1. Preparing Surface for Coatings: One of the main reasons CNC machined components undergo bead blasting is to ensure optimal adhesion of coatings. The process creates a rougher surface texture that provides excellent grip for paints and coatings. If CNC machined parts are straightaway coated or painted without bead blasting, they may chip or deteriorate quickly.
2. Enhancing Aesthetic Appearance: Bead blasting can also significantly improve the aesthetic appeal of a CNC machined part. It gives materials a visually appealing satin finish — thoroughly removing surface defects like machining lines, scratches, extrusion marks, and more.
3. Removing Corrosion and Contaminants: If metal parts are subjected to oxidation over time, bead blasting can scrape away these impurities precisely without affecting the base material. This step is crucial in restoring old components or preparing them for remanufacturing.
4. Stress Relieving: Bead Blasting not only cleans but also strengthens the surfaces by inducing beneficial compressive stresses that help elongate material fatigue life.
5. Augmenting Dimensional Accuracy: The minute glass beads used in this process do not disrupt the dimensions of the component being treated. Therefore, complicated shapes obtained through CNC machining continue to retain their detail post-blasting.
Conclusion
Without a doubt, bead blasting plays a paramount role in ensuring high quality of CNC machined products—making them durable, aesthetically pleasing, rust-free, and ready for effective coating application. However, thorough knowledge and extreme caution are required during bead blasting processes as mishandling could lead to unwanted outcomes such as erosion or deformation of parts. Remember, every manufacturing operation contributes to the final product’s performance, making each procedure as important as the next in producing superior CNC machined outputs.
