Large workpieces clamped by vacuum

There are a huge number of solutions for clamping and machining large workpieces. The choice depends on the type of machine that is used. It is also important to know what type of machining will take place on products. Only machining operations on the surface of the workpiece (surface milling and groove milling for example), or machining operations fully through the workpiece (holes and slots for example).

Portal milling machines

Most portal milling machines have a vacuum chuck and machining table where, using a sealing cord, a vacuum sealed zone is created, which is a similar size to the workpiece. This is a suitable solution for workpieces that do not have to be fully cut through. However, if workpieces do have to be fully cut through, this vacuum type is unsuitable. A medium would have to be placed between the vacuum chuck and the workpiece. MDF is often chosen for this purpose. However, there are disadvantages of MDF:

  • A lot of dust is caused by milling MDF.
  • Significant leakage: the smaller the workpieces, the worse the clamping.
  • Due to vacuum leakage, significant vacuum volume is required, resulting in a large (expensive) vacuum pump which uses a lot of energy.
  • Extensive use of MDF is also expensive, plus it generates a lot of waste.
  • Height (Z axis) is inconsistent. Exposure to moisture in the air can cause MDF to shrink or expand.

Tepas has developed Perfo+ adapter plates specifically for cutting through workpieces. Micro holes are made in these adapter plates that significantly reduce vacuum leakage. These vacuum adapter plates can only  be used with the Tepas VacuMat or PerfoMat mats. Micro holes have been made in the clamping surface of these vacuum chucks. The very small micro holes limit the leakage of the vacuum with smaller workpieces or when workpieces are cut through. The Tepas PerfoMat mats have larger holes that enlarge the vacuum sealed zone.    

Connection of vacuum chucks

Vacuum pods

Workpieces that require numerous cutting through operations, such as frames, panels for engineering, doors, etc., can be placed using vacuum pods on a flat surface, precisely where support of this workpiece is required. The pods are attached by vacuum on the underside to the surface. The workpiece is clamped by vacuum activated at the top of the pods. Workpieces clamped with the Tepas vacuum pods can be fully cut through, even through drilling, tapping and thread milling. GridPods offer the highest clamping force with a sealing cord. PerfoPods allow cut through operations of the workpiece to also be performed above the pod. The PerfoPods therefore only work in combination with a PerfoMat.  

Customer-specific vacuum chucks

If standard products do not suffice, Tepas designs and supplies customer-specific vacuum chucks. The distinct advantage is that all requirements can be included in the design and anything superfluous to requirements can be omitted. This allows an ideal solution to be designed. Because of Tepas' long track record in designing and producing large vacuum chucks, these vacuum chucks can be supplied at reasonable prices.