Vacuum Hold Down

Vacuum hold down is an important component in any process utilizing a CNC router. The woodworking industry is a major industry that uses CNC routers. CNC routers usually use one or more vacuum pumps to “hold down” the process material (wood, composite, plastics, etc.) to the router table. The vacuum can hold the material against the table without damaging or distorting the material. This eliminates the need for fixtures like clamps.

The material to be machined is placed on top of rubber pots connected to a vacuum pump. The vacuum creates a low pressure underneath the materials. Barometric pressure will be much greater than the pressure underneath the materials. As a result, the material pushes down on the table. However, the level of CNC vacuum hold down that can be achieved in this process is determined by the amount of non-condensable leakage through the materials and into the vacuum system. Too high an air flow rate will limit the minimum operating pressure allowed.

Generally, Wintek would recommend using an oil-sealed liquid ring vacuum system for vacuum hold-down applications due to its high reliability and low utility cost. Additionally, Wintek offers inlet filtration vessels used to prevent the liquid ring vacuum system from seeing process carryover. We also recommend frequent oil changes to ensure the sealant is not damaging the inside of the vacuum pump. Wintek has provided oil-sealed liquid ring vacuum systems to numerous woodworking companies.