This choice involves taking a 40- to 50-hp rotary screw vacuum generator and directing a high level of cfm flow through a porous substructure to hold-down flat panel products. This is the most expensive vacuum option and most misapplied. It is not a universal, cure-all system. A purchaser considers this design to avoid the need for machine setup and vacuum fixture boards. This zero set-up time feature makes high output vacuum ideal for custom panel processing. There are however, the following system limitations.
- Approximately 75 percent of the activated table area or zones need to be covered with work material for an overall effective seal.
- Parts need to be 8 inch by 8 inch or larger to be held down. Thus it is better for panel processing than machining solid wood.
- Once every shift, production must be stopped for the top of the porous (usually MDF) substrate board to be machined off to eliminate the “dust plug” as well as cutter tracks. This represents lost production time as well as the need to replace the MDF panels as often as every week at an annual cost of up to $5,000 per operating table. There is also the cutter cost to perform this needed step.
There are several necessary design steps required so as not to “starve” cfm flow from the pump to your panel on the machine table. Failure to recognize or provide what is required could result in a machine not being able to properly hold down material.
Accu-Router flow-thru vacuum systems incorporate a no-flow restriction plumbing design that includes:
- System on/off butterfly valve,
- 20’ of 4” ID Tigerflex type hose from the pump to the machine,
- 4” ID rear table mounted manifold into which four 2” ID incoming lines come from four different table top areas,
- Recessed table top providing for air clearance below the bleeder panel
- Table top access holes are screened to help keep debris out (inset photo).
The vacuum system is powered by a Travaini 40 HP / 500 CFM liquid ring vacuum pump with motor starter and inlet filter. The Travaini pump is amazingly quiet and can be placed near the machine cell without concern for excess noise. It includes an attractive two year warranty plan.